
ABSTRACT
The main extracellular matrix components of the lung, type I and III
collagens, were studied in chronic allograft rejection developing in
a porcine heterotopic bronchial transplantation model. Specific
porcine complementary DNA probes were constructed for detection of
the expression of type I and III procollagen messenger RNAs in the
bronchial wall structures and in the obliterative plug by in situ
hybridization. In autografts, and in allografts immunosuppressed
with 40-O-(2-hydroxyethyl)-rapamycin, cyclosporine A, and
methylprednisolone, no histological changes of obliterative
bronchiolitis (OB) developed, and the number of fibroblast-like
cells expressing type I and III procollagen mRNA remained low. In
nontreated allografts obliterating within 21 d, a preponderance of
fibroblast-like cells showing positivity for type III procollagen
mRNA existed in the obliterative plug and bronchial wall. This study
shows for the first time the temporal and spatial activation of type
I and III procollagen genes during the course of obliterative
bronchiolitis. The number of cells expressing procollagen III mRNA
increased parallel to developing obliteration and fibrosis in
nontreated allografts, whereas autografts and immunosuppressed
allografts exhibited no such trend. This finding suggests a positive
association between type III collagen mRNA expression in
fibroblast-like cells and development of obliterative bronchiolitis.
INTRODUCTION
A Frenchman who was named the Pa article(Papin) spoke of in a report
that cooked procedure in 1682, he tried to refine gum form material
from the bone.
The collagen first time is admitted to is a kind of food that has
value to is in Napoleon's times, at that time is blockaded a British
period, it was used to supply to need very much protein of France.
The first English patent was recognized in 1754 issuable.
In 1870 the wave was a collagen especially----Protein.
Since 1950's, the collagen is industrial a is strengthened
Now, the high standard health production and product quality.
In the human body can natural formation, account for 25%-30% of the
healthy human body protein total amount about
Be located the leather layer in, fiber the female cell manufacturing
come out of the fiber form protein, have to prop up power goodly,
its role is like to support reinforcing bar structure of rising the
skin organization, can let the skin look plentiful smooth
More than 25 years old, the collagen runs off speed high in born
speed, the skin starts appearing the evidence of the decrepitude
The collagen enriches to contain
1. Glycine 25~30%,
2. proline12%
3. alanine 11%
4. hydroxyproline10%
5. hydroxylysine 0.5%
All is an essential An Ji is sour not
Chronic rejection in the form of obliterative bronchiolitis (OB) is
the major cause of long-term morbidity and mortality after lung
transplantation . The exact pathogenesis of OB is unknown, but the
respiratory epithelium is considered to be a potential allogeneic
target for immunological effector mechanisms . Progressive damage
and loss of airway epithelium are accompanied by increased
production of cytokines and fibrogenic growth factors indicated as
having a role in inducing the fibroproliferative events leading to
OB . Histologically, OB is characterized by inflammation of the
small airways and gradually progressing occlusion of the airway
lumen by fibrous tissue, permanently obliterating the bronchioli .
The main constituents of lung extracellular matrix are collagens I
and III . Fibroblasts are the major producers of type I and III
collagens in the lung, but endothelial, epithelial, alveolar type
II, and smooth muscle cells also synthesize these collagens . Both
collagen types occur in bronchial mucosa and subintima . Changes in
the distribution and increase in the production of interstitial
collagens I and III exist in fibrotic pulmonary diseases . The
presence of collagens I and III in subepithelial fibrotic lesions
has been a consistent finding in immunohistochemical studies of the
airways of patients with OB . In transbronchial biopsies from lung
transplant patients, increased amounts of type III collagen
deposition appear in clinically manifest OB.
Investigations of the mechanisms of OB have used several
experimental animal models with either ortho- or heterotopic
transplantation of lung, bronchial, or tracheal structures (15- 17).
Our group has developed a porcine heterotopic bronchial
transplantation model exhibiting histological changes similar to
those of human OB following lung transplantation. Total epithelial
destruction and permanent luminal obliteration occur rapidly in
allografts without immunosuppression . In lung allografts,
prevention of the obliterative process is achieved with combination
therapy of cyclosporine A (CsA), methylprednisolone (MP), and RAD,
that is, 40-O- (2-hydroxyethyl)-rapamycin .
Although collagen types I and III are found in OB lesions, their
transcriptional activity and the tissue distribution of cells
expressing these procollagen messenger RNAs (mRNAs) have not been
characterized. For further understanding of the deposition of these
extracellular matrix proteins in the obliterative process, we
investigated the changes in the temporal and spatial expression of
procollagen I and III mRNA in our pig heterotopic bronchial
allograft model. We also compared the activation of these
procollagen genes during the rapid and prevented obliteration.

The Role of Collagen in the Body
Collagen is not scattered as individual molecules throughout the
body, but is directed to form parts of higher-ordered structures.
These structures differ according to their location in the body,
however it is believed that each is composed in the same manner from
several stages of increasing complexity, as shown in the following
figure.
For example, the cornea is composed of collagen, and its
transparency is sustained by its unique higher-order structure.
In addition, intermolecular cross-linking occurs between collagen
molecules in such higher-ordered structures, and these links serve
to increase the strength of tissue and to ensure temperature
stability.

Extraction of Collagen
Collagen is widely used in the medical, cosmetic, and research
fields. Currently, collagen is obtained from animal tissues, but it
is difficult to do so because collagen in the body is completely
bound up due to its intermolecular cross-linking. The solution to
this problem lies in cleaving these crosslinks, or solubilizing the
collagen. One method of collagen solubilization utilizes proteases,
enzymes that break the crosslinks between collagen molecules, as
indicated in the following figure. Collagen obtained through
solubilization is called Atelocollagen.
METHODS
Experimental Model
Nonrelated domestic pigs served as donors and recipients. The
animals received humane care in compliance with the Guide for the
Care and Use of Laboratory Animals, NIH Publication No. 86-23,
revised 1985. Heterotopic bronchial transplantations were performed
as described. Briefly, for anesthesia, intramuscular ketamine
sulfate (10-15 mg/kg), azaperone (10-15 mg/kg), atropine sulfate
(0.05 mg/kg), and intravenous sodium pentobarbital (6-12 mg/kg),
diazepam (0.25 mg/kg), and pancuronium bromide (2-4 mg), plus
inhaled enflurane were used. In the operative procedure, bronchial
implants were transplanted subcutaneously into the ventral side of
the recipient. Three groups, with four pigs in each, were formed:
autografts, nontreated allografts, and allografts treated with a
daily oral dose of CsA 10 mg/kg, RAD 1.5 mg/kg, and MP 20 mg to
prevent obliteration. The grafts were removed on postoperative Days
3, 7, 10, 14, 21, 30, and 60. Postoperative pain was controlled with
intramuscular diclophenic acid (37.5 mg). At the end of the
follow-up, the animals were euthanized with intravenous sodium
pentobarbital.
Histological Evaluation
Epithelial destruction, luminal obliteration, fibrosis (defined as a
pathological increase of connective tissue composed of fibroblasts
and extracellular matrix) in the bronchial wall (considered as the
area beneath the epithelium to the cartilage), total fibrosis
(bronchial wall fibrosis and fibrosis in the pericartilaginous area
surrounding the cartilaginous structures), bronchial wall
inflammation (defined as the numbers of infiltrating inflammatory
cells in the tissue), and cartilage destruction and new cartilage
formation were graded on a semiquantitative scale of 0 to 3 in
hematoxylin-eosin-stained sections. In fibrotic areas, the relation
between cellular and extracellular matrix components was scored as
equal, < 1, or > 1.
Determination of Total Tissue Collagen
The hydroxyproline content of total tissue samples was analyzed by
high-pressure liquid chromatography. Total collagen content was
estimated, assuming that hydroxyproline comprises 13.7% collagen by
weight.
Construction of cDNA Clones for Porcine pro 1(I) Collagen and pro
1(III) Collagen mRNAs
For detection of porcine-specific mRNAs, complementary DNA (cDNA)
clones were constructed for porcine pro (I) and pro 1(III) collagen
mRNAs. Briefly, total RNA was extracted from experimental
granulation tissue by the method of Chomczynski and Sacchi, and
synthesized into cDNA by reverse transcription. Aliquots of cDNA
were amplified by polymerase chain reaction with primers based on
existing human, mouse, and rat sequences .
Northern Hybridization
Total RNA was extracted from the bronchial samples by an established
method. Northern hybridization was performed as previously described
by use of constructed cDNA clones as hybridization probes. The bound
probe was detected by autoradiography, and the relative intensity of
the bands analyzed by a computer-linked densitometer. Results were
corrected for minor variations in the amount of
glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA in the
respective samples.
In Situ Hybridization
Digoxigenin-labeled antisense and sense cRNA probes were created
from the above-described cDNA clones. Paraffin-embedded bronchial
samples were cut into sections and used for in situ hybridization
performed as described previously. Staining seen only with the
antisense probe was considered positive. The distribution and number
of positive cells for pro 1(I) and pro 1(III) collagen mRNA were
analyzed separately in the obliterative plug, in the bronchial wall,
and in the pericartilaginous area. Positive cells were counted in
five randomly chosen microscopic fields from each area at ×100
objective magnification. The number of positive cells was related to
the area of negative, pale staining microscopic field.
Statistical Analysis
All data are expressed as mean + SEM. Variation between the groups
was analyzed with the nonparametric Kruskal-Wallis one-way analysis
by ranks. The rank sums were then used for Dunn's test at a
significance level of 5%. Values of p < 0.05 were considered
significant.
RESULTS
Histopathology
The histopathological findings are shown in detail in Table E1 in
the online data supplement.
Epithelium. In nontreated allografts, the respiratory epithelium was
completely destroyed by Day 10. In autografts and in
immunosuppressed allografts, after initial ischemic damage, normal
ciliated epithelium was maintained throughout follow-up.
Significance (p < 0.05) in epithelial destruction was reached
between nontreated and immunosuppressed allografts at early
assessment points and between autografts and nontreated allografts
at later points.
Obliteration. No luminal obliteration was evident in autografts and
in allografts receiving immunosuppressive therapy and in allografts
receiving immunosuppressive therapy In nontreated allografts,
fibroproliferative tissue protruding into the bronchial lumen was
first seen on Day 7. Luminal obliteration was complete by Day 21 (p
< 0.05 when compared with autografts and immunosuppressed allografts);
whereafter, in the luminal fibrous tissue, the extracellular matrix
component gradually increased. In the course of the follow-up, the
degree of lymphocytic inflammation in the obliterative plug
decreased to nonexistent levels.

Figure 1. Photomicrographs of an autograft, a nontreated allograft,
and an allograft immunosuppressed with RAD, CsA, and MP on Day 21
(HE staining; original magnification: ×10). (A) Normal epithelium
and bronchial structures in autograft. (B ) Nontreated allograft
exhibiting total luminal obliteration by fibroproliferative tissue
(arrows), bronchial wall inflammation, and fibrosis (arrowhead ) and
destruction of cartilaginous structures (double
Bronchial wall. Bronchial wall fibrosis in autografts and in
nontreated allografts consisted of fibroblasts and extracellular
matrix components in equal proportions. In autografts, fibrosis
remained generally mild. In nontreated allografts, fibrosis
increased from mild to moderate by Day 10, persisting thereafter. In
immunosuppressed allografts, fibrosis remained mild, and on Days 14,
21, and 30 only sparse areas of fibrosis (p < 0.05 when compared
with nontreated allografts), consisting mainly of cellular
components were present in the bronchial wall. In all groups, a
highly fibrous capsule had formed around the implants, contributing
to total fibrosis.
The bronchial wall in autografts showed only slight lymphocytic
inflammation. In nontreated allografts, by Day 7, infiltration of
inflammatory cells was moderate, and remained moderate to severe,
with a significant (p < 0.05) difference from that of autografts. In
immunosuppressed allografts, inflammation was milder than in
nontreated allografts.
Cartilaginous structures. In autografts and in immunosuppressed
allografts, bronchial cartilage remained viable. In nontreated
allografts, nearly all cartilaginous structures were destroyed by
Day 14, with a significant (p < 0.05) difference from autografts on
Day 14 and thereafter. Formation of new cartilage was apparent in
autografts and in immunosuppressed allografts.
Total Collagen Content
Data on total bronchial collagen content are presented in Table 1.
In nontreated allografts, total collagen content decreased below the
level of total collagen in native bronchial tissue. An increased
total collagen content was evident in autografts and in
immunosuppressed allografts at all assessment points. The difference
between autografts and nontreated allografts reached significance (p
< 0.05) on Days 7, 21, and 60, with total collagen content higher in
autografts.
|
TABLE 1
TOTAL COLLAGEN CONTENT IN NATIVE BRONCHIAL TISSUE AND IN BRONCHIAL
AUTO- AND ALLOGRAFTS*
|
|
|
Groups (n = 4) |
|
D0 |
|
D3 |
|
D7 |
|
D10 |
|
D14 |
|
D21 |
|
D30 |
|
D60 |
|
Native bronchial tissue |
|
22.0 + 4.2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Autografts |
|
|
|
19.8 + 1.5 |
|
48.1 + 2.4 |
|
29.8 + 3.6 |
|
26.9 + 1.3 |
|
36.6 + 7.8 |
|
50.3 + 19.4 |
|
67.7 + 13.9 |
|
Allografts |
|
|
|
8.6 + 1.9 |
|
10.4 + 2.0 |
|
12.5 + 1.5 |
|
10.0 + 2.0 |
|
9.1 + 1.0 |
|
8.1 + 2.2 |
|
10.6 + 2.3 |
|
Immuno- suppressed allografts |
|
|
|
13.9 + 4.6 |
|
21.4 + 4.1 |
|
16.9 + 4.2 |
|
19.1 + 6.3 |
|
27.7 + 4.0 |
|
29.8 + 14.4 |
|
34.0 + 7.6 |
|
*All
data expressed as microgram of total
collagen/milligram of sample wet weight (mean + SEM).
D = days following transplantation.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Quantification of Procollagen I and III mRNA Expression
Clone pPCol1a1-1 detected two mRNAs of approximately 5.0 and 5.9 kb,
and clone pPCol3a1-1 one mRNA of approximately 5.1 kb in size in
Northern hybridization. Under the stringent washing conditions used,
no cross-hybridization to pro 1(I) and pro 1(III) collagen mRNAs was
observed. The transcriptional activity of procollagen I increased in
all groups by Day 7 . On Days 14 and 21, type I collagen mRNA
expression was induced in immunosuppressed allografts with no
obliteration. Quantification of procollagen III mRNA showed no
significant differences between groups. In immunosuppressed
allografts, induction of type III mRNA expression was seen on the
same days as of type I collagen mRNA.
Figure 2. Northern hybridization of total RNAs extracted from
bronchial autografts, nontreated allografts, and allografts
immunosuppressed with RAD, CsA, and MP for pro 1(I) collagen, pro
1(III) collagen, and GAPDH mRNAs on Days 7 and 21.

Figure 3. Summary of Northern analyses of bronchial autografts,
nontreated allografts, and allografts immunosuppressed with RAD, CsA,
and MP (n = 4 in each group) for mRNA levels of pro 1(I) collagen
(A) and pro 1(III) collagen (B). The mRNA levels expressed as
densitometric units (mean + SEM) corrected for GAPDH mRNA levels in
the same samples. *No data.
Localization of Procollagen I and III mRNA Expression
In situ hybridization for procollagen I and III mRNA revealed a
positive signal with antisense probes but not with sense probes. In
native tissue, only sparse positivity for procollagen III was
visible in blood vessels in the bronchial wall. Almost no positivity
for procollagen I mRNA was detectable. In auto- and allografts, the
expression of type I and III mRNA was detected nearly exclusively in
fibroblast-like cells and in occasional smooth muscle cells.
Obliterative plug. In nontreated allografts obliterating within 21
d, a positive label for procollagen I and III mRNA appeared in
fibroblast-like cells in the connective tissue plugs invading the
bronchial lumen. In early obliterative lesions on Day 7, cells
positive for procollagen I and III mRNA existed in equal numbers .
On Day 14, the majority of the positive cells were expressing type
III mRNA, which was the case also at subsequent assessment points.
Figure 4. Number of positive cells per microscopic field for type I
and III procollagen mRNA detected by in situ hybridization.
Nontreated allografts show a preponderance of and increase in
fibroblast-like cells expressing type III mRNA in the obliterative
plug and in the bronchial wall. In autografts and in
immunosuppressed allografts, no similar trend occurs between the
numbers of type III and type I procollagen mRNA-positive cells in
the bronchial wall. Cells were counted at ×100 objective
magnification in five microscopic fields. All data expressed as mean
+ SEM, n = 4 in each group.
Bronchial wall. In autografts, the number of cells expressing type I
and III mRNA transcripts decreased by Day 14 and remained low
thereafter. In nontreated allografts, only a few cells positive for
type I and III mRNA appeared on Days 3, 7, and 10. Fibroblast-like
cells expressing procollagen III mRNA started to increase on Day 14
and were significantly (p < 0.05) augmented on Days 21 and 30
compared with numbers of autografts. A slight decrease in the number
of positive cells followed thereafter. In nontreated allografts with
rapid obliteration, dominance of fibroblast-like cells showing a
positive signal for type III collagen mRNA was evident at all
assessment points, being most prominent from Day 14 onward. In
immunosuppressed allografts, no similar increase appeared in the
number of procollagen III mRNA-positive cells compared with
procollagen I mRNA-positive cells. The pattern of fibroblast-like
cell numbers expressing type I and III collagen mRNAs resembled that
of autografts.
Pericartilaginous area. The number of positive cells for procollagen
I and III mRNA in pericartilaginous areas is expressed in Table 2 as
a percentage of total cell count. In all groups, the majority of
positive cells were detected in this area at nearly all assessment
points. Comparison of absolute cell numbers in autografts and in
immunosuppressed allografts gave a preponderance of procollagen I
mRNA to type III mRNA expression in fibroblast-like cells, whereas
nontreated allografts showed the opposite finding.
|
TABLE 2
PROCOLLAGEN TYPE I AND III mRNA POSITIVE CELLS DETECTED BY IN SITU HYBRIDIZATION IN THE
PERICARTILAGINOUS AREA EXPRESSED AS A PERCENTAGE OF
TOTAL CELL COUNT OBSERVED IN ALL AREAS*
|
|
Procollagen Type mRNA |
|
D3 |
|
D7 |
|
D10 |
|
D14 |
|
D21 |
|
D30 |
|
D60 |
|
|
I |
|
59 |
|
71 |
|
74 |
|
100 |
|
82 |
|
 |
|
76 |
|
|
III |
|
35 |
|
48 |
|
62 |
|
45 |
|
81 |
|
100 |
|
55 |
|
|
I |
|
71 |
|
80 |
|
94 |
|
48 |
|
39 |
|
46 |
|
52 |
|
|
III |
|
72 |
|
78 |
|
65 |
|
34 |
|
34 |
|
34 |
|
26 |
|
|
I |
|
96 |
|
81 |
|
73 |
|
68 |
|
68 |
|
95 |
|
48 |
|
|
III |
|
55 |
|
66 |
|
95 |
|
57 |
|
38 |
|
72 |
|
35 |
|
|
*
Obliterative plug, bronchial wall, and pericartilaginous
area. D = days following transplantation.
|
|
DISCUSSION
Development of irreversible fibrotic changes in OB is a complex
process. To date, only a few studies have explored extracellular
matrix deposition in OB, and none has focused on collagen gene
expression in this disorder. In our large animal model of OB,
pathological changes in walls and lumina of small bronchi are
presumably triggered by epithelial injury. Our model provides an
opportunity to study chronic rejection in repeated adequate-size
samples in tissue areas where OB is known to occur in human lung
transplant recipients.
In studies of human OB, extracellular matrix deposition has been
analyzed in endobronchial biopsy specimens, which represent only a
small fraction of bronchial wall or in postmortem samples, in which
no development of the process can be followed. In this study, we
assessed the cells expressing procollagen I and III genes during the
development of OB in bronchial samples consisting of the full
circumference of the bronchus. We demonstrated that development of
OB was associated with an increase in fibroblast-like cells
expressing procollagen III mRNA. The predominance of cells
expressing procollagen III mRNA increased parallel to progressing
luminal obliteration, together with a histologically identified
increment in the amount of fibroblasts and extracellular matrix in
the bronchial wall.
In previous studies of bleomycin-induced pulmonary fibrosis, the
cells in fibrotic lesions expressing procollagen I and III mRNA were
primarily derived from cells resembling fibroblasts and were located
in the tissue underlying the airway epithelium. Increases in the
numbers of cells expressing procollagen I and III genes and enhanced
mRNA expression by individual cells were both suggested to
contribute to the development of pulmonary fibrosis. However, these
studies did not compare the expression of the procollagen genes. In
fibrotic processes, an increase in type III collagen synthesis is
suggested to occur in proliferating fibroblasts as a response to
various stimuli including inflammation.
Increased amounts of aminoterminal propeptide of type III
procollagen have been detected in bronchoalveolar lavage fluid of
patients with fibrosing alveolitis, adult respiratory distress
syndrome, and pulmonary edema, predicting poor prognosis. In OB
following lung transplantation, an increased deposition of type III
collagen in the bronchial submucosa correlates with poor lung
function. In silica-induced pulmonary fibrosis, an increased ratio
of type III:type I collagen has also occurred. Similarly, in our
study, the dominance of type III collagen expression in
fibroblast-like cells in the obliterative plug and in the bronchial
wall of rapidly obliterating allografts supports the hypothesis of a
positive association between increased synthesis and deposition of
procollagen III and severity of the disorder.
In our autografts, minor fibrotic changes with fibroblast-like cells
expressing procollagen I and III mRNA in the bronchial wall indicate
that the nonimmunological injury caused by our heterotopic method
activates procollagen gene expression. In immunosuppressed
allografts in which obliteration was prevented, histological
findings and cell numbers producing type I and III procollagen mRNA
resembled those of autografts. Although in both groups
fibroblast-like cells expressing I and III procollagen mRNAs were
detectable, only insignificant pathological alterations were
evident. In the bronchial wall, an important finding in autografts
and immunosuppressed allografts was the unaltered number of cells
expressing procollagen III mRNA.
The quantitation of total collagen and procollagen I and III mRNA
did not directly correlate with the increase in positive cells
detected by in situ hybridization. The changes in the collagen type
II derived from cartilage probably affected more the total collagen
content than the relatively small fibrous areas in the bronchial
wall or lumina. Quantification of mRNAs by Northern hybridization
does not identify the tissue origin of mRNA. At some assessment
points, cells positive for procollagen I and III mRNA were abundant
in the pericartilaginous area, even in the total absence of
positivity in the bronchial wall. This finding may explain the high
expression of procollagen genes in immunosuppressed allografts at
some assessment points when only a few positive cells were evident
in the bronchial wall.
In conclusion, mechanisms leading to extracellular matrix deposition
in OB are still in part unknown. This study shows for the first time
that expression of procollagen I and III mRNA in fibroblast-like
cells is found in OB lesions, along with a preponderance of and
increase in cells expressing type III mRNA. In autografts and in
allografts with immunosuppression adequate to prevent obliterative
airway disease, only a minor degree of procollagen gene activation
occurred, and no changes in the genetic activity between type I and
III collagen similar to those in rapidly obliterating allografts.
This observation indicates that one of the mechanisms in the
fibrotic process of OB is an increase in fibroblast-like cells
expressing procollagen III mRNA.
Collagen-Integrin Complex
Structural basis of collagen recognition by integrin alpha2beta1.
We have determined the crystal structure of a complex between the I
domain of integrin alpha2beta1 and a triple helical collagen peptide
containing a critical GFOGER motif. Three loops on the upper surface
of the I domain that coordinate a metal ion also engage the
collagen, with a collagen glutamate completing the coordination
sphere of the metal. Comparison with the unliganded I domain reveals
a change in metal coordination linked to a reorganization of the
upper surface that together create a complementary surface for
binding collagen. Conformational changes propagate from the upper
surface to the opposite pole of the domain, suggesting both a basis
for affinity regulation and a pathway for signal transduction. The
structural features observed here may represent a general mechanism
for integrin-ligand recognition.

Figure: Structure of the I Domain:Collagen Complex (A) Stereo
diagram of the alpha2-I domain in complex with the collagen peptide.
The I domain helices are shown as cylinders, beta-strands as arrows.
The three strands of the collagen triple helix are shown as colored
ribbons: leading strand in green, middle strand in yellow, and
trailing strand in blue.(B) Close-up of A, showing details of the I
domain collagen interface. Selected side chains are shown as
ball-and-stick, with H bonds as dotted lines. The metal ion is shown
as a blue ball labeled "M." The principal interactions with the
middle strand GFOGER motif (yellow) are: phenylalanine makes van der
Waals contacts with side chains of N154 and Q215; the hydroxyproline
carbonyl hydrogen bonds to N154; the glutamate bonds to the metal
and H-bonds to T221; the arginine side chain salt bridges to D215,
while its carbonyl H-bonds to H258. The principal interactions with
the trailing strand GFOGER motif (blue) are: the main chain carbonyl
preceding the GFOGER motif H-bonds to Y157; the phenylalanine makes
van der Waals contacts with L286 and Y157; the hydroxyproline
H-bonds to N154 main chain; the arginine makes weak ionic
interactions with E256. The leading strand (green) makes no contacts
with the I domain.(C) Stereo diagram of the MIDAS motif. The metal
ion is shown as a blue ball. Coordinating side chains are shown as
ball-and-stick, with oxygen atoms in red, carbon in black. Water
molecules are labeled "omega"; the collagen glutamate is in gold.
The three loops (L1, L2, and L3) coordinating the metal are shown
schematically as gray ribbons. E256 from L3, which forms an indirect
bond via the equatorial water, has been removed for clarity. The
figure is rotated about a vertical axis by 180° relative to B.
Exist in the knot Di organization of the vertebrates, is a body to
contain the most abundant structure of quantity fiber protein, have
a body about inside 25~ of the protein total amount is 30%.The
collagen organizes in the body in of role mainly is combine
organization and give knot Di to organize have to of the structure
and the machine mechanics property, as tensile strength, pull power
and stick to elasticity etc. with reach support and protect of
purpose, also be responsible for of the control numerator deeply and
promote the wound Yu match to repair with organization and adjust
physiology function of controling the cell and organization.
The organization that the collagen content enriches includes parts,
such as skeleton, muscle Jian, skin, Jin and ligaments...etc..Have a
great deal of collagen in the skin and the knot Di organization of
the human body, it and each organ of human body, organize and the
cell have the relation that can't box off, having 75% in the normal
skin, and having in the whole body 1/3, include hair, skeleton,
muscle and knot Di organization, internal organs, tooth, so, it is a
skeleton, cartilage, muscle Jian, ligaments, blood vessel, skin
necessary composing material.
Health the good collagen have to enrich of flexibility and
flexibility, can take rise the cell and the cell prop up, with
provide cell outside structure of stability.Young hour, the collagen
is very smooth, letting us look like very bright, the age becomes
big, the collagen will disappear gradually, letting of the cell prop
up decrease, appearing the crease of the loose loose Kua to our
skin.Add a collagen in good time, will recover the skin brilliance,
keep youth beautiful looks.
The structure of the collagen
The collagen enriches ductility, is by is dissolved in the aqueous
parallel lines type a form chain(the parallel linear boundles) not
easily, constitute, because the sweet An of the high content is
sour, the Pu An is sour and the Qian Pu An is sour, past α -spiral
of the structure all doesn't take place, each glimmer of type the
chain has three Xuans with left distortion it gather 肽Chain(the
polypeptide chain), this threes gathers ※the chain the hydrogen key
is close to combine and become one very strong and right Xuan three
heavy helixes(triple-helix).
Say simply, real can develop the collagen of the human body
physiology function have to by three tie up to round of keep a chain
constitute, become spiral structure, seem to be fried dough twist,
if three helixes keep stereoscopic structure of chain to encounter
to manufacturing or be subjected to high hot and break, then become
to be so called generally of clear gum.
The collagen is been smaller by the innumerable of of gum the
original fiber(the collagen fiber) constitute, and gum original
fiber again by many diameters 1-5 nms, grow several hundred go to
several thousand gum of the nms original the tiny fiber(the collagen
fibril) constitute.While being observed with electronic microscope,
gum original fiber the at interval of 67 nms presents namely a clear
and dark of horizontal Wen period.
The collagen numerator unit by three polypeptideses constitute of
three spiral structure(the Triple-helical structure).The
polypeptide(also call the a chain) of the collagen numerator of
different source constitutes a some differences(but likeness), past
the combination of the different chain can constitute the collagen
numerator unit of different form(Type).
The collagen numerator that so far have already been found and
categorize contain 21 kinds of forms, and is distributed in
different organization inside the body respectively in.In regard to
the constituting of collagen numerator of different form, some by
two homologies, and a different chain constitute, as the Type I, V
and the IV;Some by three chains of homologies constitute, as the
Type II, III, V, XII, X and the VII;And some by three not same
chains constitute, as Type VI, IX, and XI.
The molecular weight of the collagen numerator about 283,000
daltonses, grow about the 300 nms, diameter about 1.5 nms, both ends
the part of the not- spiral structure call telopeptide.The
telopeptide participates the collagen numerator formation that sets
up knot, have its meaning on the physiology activity, but then will
cause an allergy on the application of the biomedical science
material.
The collagen numerator is between cell in the body quality in will
not exist alone, but come together the fiber form, after being the
fiber formation, polypeptides the Hydroxyproline and Lysine will be
subjected to enzyme function and produce numerator inside or the
numerator hand over Lian(crosslink), so strengthen it to prop up
function.
The collagen fiber also meeting along with the growth of the age,
will add thick(the diameter can reach to 50~300 nms) and increase
its resilience, have to consider to the age factor of using the
animal in getting a choice of curing the material raw material.
The source of the collagen
Although at above-mentioned there is all collagen in many places,
industrial currently up produce to mainly come from cattle, pig,
bird
And the skin, skeleton and muscle etc. of the fish.
And in recent years of the living creature technique learn a house
to also try to reorganize DNA(also Is a genetic engineering)of
method, will produce a collagen relevant of the gene shear to
receive feedlot cells, such as cattle and sheep...etc.,
By the secreting of the milk or the sheep milk, can extract to the
collagen from it, and reach mass production of purpose.
These raw material after separating and turning and processing a
processing purely can reorganize the collagen numerator of[with]
various type, as fiber form(fibrillar), many hole sponge form(the
porous sponge), tube form(tubular), powder(powder), the film
slice(membrane) and the gum body(gel) etc., and the collagen of[with]
various type, apply scope differently.But fish or the plant collagen
of hot-resistant low in 20 °C, the collagen of the cattle, sheep,
pig also only the ability is 37 degrees, the former may put the
refrigerator heat preservation, the conservancy of the latter also
needs to notice particularly, otherwise may change sex or reduce an
activity.
The safety and the applicability of the collagen raw material source
|
Raw material source |
Safety |
Applicability |
|
Pig |
The foot-and-mouth disease(not person Xu is common to infect
disease) worry in uncertainty |
Change sex temperature:37
℃ |
|
Cattle |
The SPF(have no particular cause) pig, the safety is the
best |
Be applicable to the human body biomedical science material
and cosmetics |
|
Bird |
The mad cow disease(person Xu is common to infect disease)
worry in uncertainty, can cause mankind Creutzfeldt-Jacob
Disease, incubation period can long 20 years are above,
having a potential danger |
Change sex temperature:37 ℃ |
|
Fish |
The bird's flu virus(person Xu is common to infect disease)
worry in uncertainty and other viruses bring at first a
complicated variety |
Be applicable to the human body biomedical science material
and cosmetics |
|
Plant |
Have no collagen, claim to mislead consumer |
Extremely good cosmetics material, its advantage has:
1.Repair and maintenance function:Promote the epidermis cell grow,
repair and maintenance break the skin wound match with cracked Yu of
the skin.
2.Hydrate a function:Enhancing the epidermis layer absorbs water and
protects the function of the water, making skin lustrous and smooth
to have flexibility.
3.Diaphragm function:The formation protects a film, keeping the
epidermis humidity from running off, insulating bad material
incursion a skin.
4.Long effect function:Extension the valid composition is in skin
function time.
5.Stable function:Maintain the bio-chemical property of the valid
composition inside the formulation in the best appearance.
6.The help delivers a function:Provide the formulation composition
function good environment, insure valid composition to enter a skin
deep.
The collagen also is a very nice biomedical science material, its
advantage has:
1.Stop bleeding function good.
2.Low immunity.
3.Good living creature compatibility.
4.Resolve velocity appropraitely.
5.Supply the repair and maintenance raw material.
6.Adjust to control the growth factor and medicine to release.
The collagen is a very widely accepted manufacture technology
product in recent years, having very high popularity, the future
development potential in the application on the cosmetics very big,
anticipating will become important industry of the Taiwanese living
creature technique realm.
The applied realm of the collagen has:
Cosmetics-protect skin frost, the smooth hair...etc..
The food industry-health food, beverage, food additive etc..
Get to cure a material-wound dressing, stop bleeding cotton and
organize repair product etc..
The medicine article and the other medical science use-medicine
deliver system, the rheumatism arthritis to use a medicine and
decline a blood pressure, the urine bladder incontinence to use
medicine etc. with the medicine and cancer, the liver disease
diagnosis.
Chemical engineering raw material-coating, plastics, printing ink
etc..
(5)Studying the use-cell development, living creature sensor, the
bioreactor load body film and the blood platelets Ning gathers to
use a medicine.
(6)Other-the collagen and resin combine the cigarette Lyu mouth and
filter the material of.
The application of the medical science
General surgery: Stop bleeding a , artificial skin, wound dressing
Skin section: The skin facial plastic surgery and repair
Orthopedics: Bone, the cartilage( Cartilage) and the ligaments
repair and rebirth
Mouth cavity surgery: The mouth cavity organization repair and
rebirth
Heart afferent surgery: The blood vessel and heart valve repair
Orthopedic surgery: The organ organization orthopedics and repair
1. Raise immunity power
2. The Yu that helps wound matches
3. Raise the metabolism of the cell, contribute to reducing weight.
4. Provide the collagen in the skeleton, prevent the rheumatism
arthritis and the bone soft disease
5. Contribute to the treatment of the burn.
6. Can raise the skin hydration function, adjust skin surface grease
balance.
7. Promote the deep fiber of skin organize of the tension and the
flexibility.
Because the collagen has good of biology characteristic, can make
the collagen make use of extensively on the medical science(use
ratio by the collagen of Type I among them the most high, have 90%
about above), become important and ideal high mark son to get to
cure material.The collagen is to get an advantage of curing the
material and cans induce as follows:
a.The content is abundant-the source organize(the vertebrates body
inside protein about 30% is a collagen) for the animal, and obtains
easily.
b.The low antigen-collagen numerator cleans immunity after carrying
the telopeptide then become the material of the low antigen.
c.Directly by body inside resolve, absorb-have living creature and
can resolve sex, compatibility, so cure behind can directly by body
inside resolve, absorb, don't need to move follow-uply in addition
to working, .
d.Not poisonous-will not cause to develop a fever, dissolve the
blood, allergy, cancer-causing etc. get a bad function of body.
e.Can disinfect sex-can make use of to heat the method(direct heat,
fume heat, boil a method), air disinfection(wreath oxygen ethylene,
formaldehyde), radio disinfection method and have no germ filter
method etc. method disinfect with reduce the probability of the germ
infection.
f.Increasing the wound Yu matches speed-have already promoted the
cell adhere to the function of[with] growth, can increase the wound
Yu to match speed.
g.Stop bleeding sex-promote the blood platelets Ning gather, have
sex of stop bleeding.
h.Living creature plastic property-the high anti- pull sex and low
extension, having a plastic property of living creature.
i.In harmony with mechanics property-have appropriate machine
strength.
j.Can control it to resolve speed through processing a
processing-different body inside resolve speed to apply the
different need and purpose.
k.Can make use of different organic functions Ji to polish the
collagen numerator to change its thing to turn a property, and with
synthesize the high mark son to make compound material, make its
application is more extensive.
Because the collagen has good of biology characteristic, can make
the collagen make use of extensively on the medical science(use
ratio by the collagen of Type I among them the most high, have 90%
about above), become important and ideal high mark son to get to
cure material.The collagen is to get an advantage of curing the
material and cans induce as follows:
a.The content is abundant-the source organize(the vertebrates body
inside protein about 30% is a collagen) for the animal, and obtains
easily.
b.The low antigen-collagen numerator cleans immunity after carrying
the telopeptide then become the material of the low antigen.
c.Directly by body inside resolve, absorb-have living creature and
can resolve sex, compatibility, so cure behind can directly by body
inside resolve, absorb, don't need to move follow-uply in addition
to working, .
d.Not poisonous-will not cause to develop a fever, dissolve the
blood, allergy, cancer-causing etc. get a bad function of body.
e.Can disinfect sex-can make use of to heat the method(direct heat,
fume heat, boil a method), air disinfection(wreath oxygen ethylene,
formaldehyde), radio disinfection method and have no germ filter
method etc. method disinfect with reduce the probability of the germ
infection.
f.Increasing the wound Yu matches speed-have already promoted the
cell adhere to the function of[with] growth, can increase the wound
Yu to match speed.
g.Stop bleeding sex-promote the blood platelets Ning gather, have
sex of stop bleeding.
The artificial skin has to be used in to burn the burn wound
directly, so its safety is count for much, first is can't have any
possible infectious disease, can't have antibiotic and other
medicine to remain secondly, these considerations expel to use the
in common use collagen source-cattle, sheep, pig of the land, ?, So
choose a fish collagen at the beginning, but the farming fish still
has antibiotics and medicine to remain of possibility, so the
researcher of the Taiwanese animal science and technology, institute
decide to use the most safe and best deep sea fish collagen finally
to do the artificial skin.
The deep sea fish collagen is different from to extract in the
animal body of other lands of collagen, know nothing about common
infectious disease of someone Xu of worry in uncertainty, can't even
have the linger effect that the antibiotics and the He Er receive to
remain.And want to get in touch with wound directly, so its pure
degree the request reach 99% above, can't have any miscellaneous
quality, with the raw material of this kind of medical treatment
grade use in the hairdressing skin care products is a great evangel
to consumer.In addition to special collagen structure, the deep sea
fish collagen also has the human body cell repair and grows various
rare elements needed, especially among them little zinc, magnesium,
copper, chrome, selenium ……etc. element. The An Ji sour proline and
hydroxyproline that the deep sea fish collagen contains compare land
the collagen of the animal is few, so deep the sea fish collagen of
To compare with the land animal collagen, the constringency
temperature is low, also therefore the land animal is under the low
temperature skin easy constringency rise crease, but deep the sea
fish skin rises crease not easily more under the low temperature
because of constringency.Currently the series product inside use of
the collagen contain two kinds of types, big numerator three spiral
collagens(grow 300 Nanos, diameter 1.5 Nanos) of the integrity has
the hydration function that the skin surface humidity of prevent
from steams to spread, and after enzyme incising of the small
numerator collagen(the length is less than 10 Nanos, diameter 0.5
Nanos) have to permeate the skin surface layer quickly, then
repairing and adding a skin run off because of years of collagen.