SEARCH · PubMed Health

Results for “Type VII secretion”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

PubMed1997

Cell cycle and post-transcriptional regulation of annexin expression in IMR-90 human fibroblasts.

Based on the finding that the expression of some annexins varies dramatically as a function of cellular proliferation state [Schlaepfer and Haigler (1990) J. Cell Biol. 111, 229-238], it has been proposed that the cellular level of the annexins might be critical for the regulation of cell growth. To further test this hypothesis, we have studied the expression of various annexins in normal human IMR-90 fibroblasts synchronized by serum deprivation. Using immunoblotting, the cellular content of annexins (Anxs) II, V and VI was found to vary by less than 10% during the cell cycle. However, Anx IV expression increased by 50% during S-phase and the levels of Anxs I and VII were reduced by 40% in early G2/M. However, using RNase protection assays, the mRNAs of Anxs I and VII were found to be uniformly expressed throughout the cell cycle, suggesting that down-regulation of both proteins in G2/M occurred through a post-transcriptional process. In addition, cells transfected with Anx VII cDNA were shown to contain an amount of Anx VII similar to wild-type cells, despite the elevation of Anx VII mRNA content in transfected cells by approx. 2 orders of magnitude. Vector misconstruction or possible secretion of the overexpressed protein were ruled out using appropriate controls. Therefore, as with cell-cycle regulation, Anx VII expression in transfected cells is also controlled by post-transcriptional mechanisms. Furthermore, using pulse-chase analysis, we have determined that annexin VII, and other Anxs, have a slow turnover rate, consistent with the limited changes of expression throughout the cell cycle. Taken together, these results question the hypothesis that cellular expression of Anxs plays a general role in cell growth and support the concept that post-transcriptional mechanisms may control levels of Anxs I and VII.

3T3 Cells↗

PubMed1966

Pneumococcal neuraminidase.

Lee, L. T. (Columbia University, New York, N.Y.), and C. Howe. Pneumoccal neuraminidase. J. Bacteriol. 91:1418-1426. 1966.-The elaboration of neuraminidase by pneumococci grown under optimal conditions in liquid medium was studied in relation to the bacterial growth cycle. The enzyme was found free in the culture medium in increasing concentration throughout most of the logarithmic phase of growth, at the end of which enzyme concentration had reached a maximum. Only a small fraction of the total neuraminidase was cell-associated at any time. It appears, therefore, that pneumococcal neuraminidase is actively secreted by dividing cells and does not accumulate solely as a result of cellular autolysis. Neuraminidase in cell-free extracts (types I, III, VII, and XIV) was neutralized both by homotypic and by heterotypic antibody, thus demonstrating it to be a group antigen. The enzyme was separable in agar gel electrophoresis from other protein and polysaccharide pneumococcal antigens. Limited immunochemical data suggest that pneumococcal neuraminidase may be of relatively low molecular weight.

Antibodies↗

PubMed1992

Differential recognition of secretory vesicles by annexins. European Molecular Biology Organization Course "Advanced Techniques for Studying Secretion".

The interactions of synexin, calpactin, and p68 (annexins VII, II, and VI) with zymogen granules and adrenal medullary chromaffin granules were compared. Synexin promoted the aggregation and fusion of both types of organelles. Calpactin inhibited the action of synexin on zymogen granules but would aggregate only chromaffin granules. p68 inhibited aggregation of chromaffin granules by calpactin and fusion of zymogen granules by synexin. The results demonstrate that these annexins, all of which bind acidic phospholipids, interact differently with different biological membranes and therefore may play specific and non-overlapping roles in cells where they are co-expressed.

Adrenal Medulla↗

PubMed1997

The sequence of palF, an environmental pH response gene in Aspergillus nidulans.

To molecularly characterize the influence of external pH in the secretion of enzymes by filamentous fungi, we have cloned and sequenced the palF gene of Aspergillus nidulans (An). An An wild-type (wt) chromosome VII-specific cosmid library was used to transform a palF15 mutant strain. Selection for complementation was done on medium containing beta-glycerolphosphate as the sole Pi source. Two cosmids were identified (W2G08 and W4G12) and further subcloning of one cosmid (W2G08) defined a 5-kb PstI genomic fragment, which fully complements the palF15 mutation. An internal fragment from the genomic clone recognized a single message of approx. 3.5 kb on Northern blot. cDNA clones were obtained from a lambda gt10 cDNA library and sequenced, showing a nucleotide (nt) sequence of 3311 base pairs (bp), with a 828 bp long 5'-untranslated region (UTR). The major open reading frame (ORF) identified in the sequence codes for a putative 775 amino acid (aa) protein, which shares some similarity with two putative ORF products of Saccharomyces cerevisiae (Sc).

Amino Acid Sequence↗

PubMed1992

Ehlers Danlos syndrome type VIIB. Incomplete cleavage of abnormal type I procollagen by N-proteinase in vitro results in the formation of copolymers of collagen and partially cleaved pNcollagen that are near circular in cross-section.

We have shown that a child with Ehlers Danlos syndrome (EDS) type VII has a G to A transition at the first nucleotide of intron 6 in one of her COL1A2 alleles. Half of the cDNA clones prepared from the proband's pro alpha 2(I) mRNA lacked exon 6. The type I procollagen secreted by the proband's dermal fibroblasts in culture was purified, and collagen fibrils were generated in vitro by cleavage of the procollagen with the procollagen N- and C-proteinases. Incubation of the procollagen with N-proteinase resulted in a 1:1 mixture of pCcollagen and uncleaved procollagen. Incubation of this mixture with C-proteinase generated collagen and abnormal pNcollagen (pNcollagen-ex6) that readily copolymerized into fibrils. By electron microscopy these fibrils resembled the hieroglyphic fibrils seen in the N-proteinase-deficient skin of dermatosparactic animals and humans and were distinct from the near circular cross-section fibrils seen in the tissues of individuals with EDS type VII. Further incubation of the hieroglyphic fibrils with N-proteinase resulted in partial cleavage of the pNcollagen-ex6 in which the abnormal pN alpha 2(I) chains remained intact. These fibrils were not hieroglyphic but were near circular in cross-section. Fibrils formed from collagen and pNcollagen-ex6 that had been partially cleaved with elevated amounts of N-proteinase prior to fibril formation were also near circular in cross-section. The results are consistent with a model of collagen fibril formation in which the intact N-propeptides are located exclusively at the surface of the hieroglyphic fibrils. Partial cleavage of the pNcollagen-ex6 by N-proteinase allows the N-propeptides to be incorporated within the body of the fibrils. The model provides an explanation for the morphology and molecular composition of collagen fibrils in the tissues of patients with EDS type VII.

Amino Acid Sequence↗

PubMed1994

Ehlers-Danlos syndrome type VII: phenotype and genotype.

A patient suffering from a severe form of Ehlers-Danlos syndrome is presented (EDS type VII). The presence of bilateral congenital hip dislocation, generalized joint hypermobility and a soft hyperelastic skin with abnormal scarring suggested a specific collagen type I defect. SDS-PAGE analysis of collagens secreted into the medium of fibroblast cultures showed a retarded migration of more than half of the alpha 2(I) chains. CNBr peptide mapping of the HPLC-purified altered chain localized the mutant locus to the N-terminal region of the protein. cDNA analysis of the corresponding gene COL1A2 revealed, in addition to the expected collagen sequence, a transcript missing the entire exon 6. This exon encodes a major crosslinking site within collagen fibres as well as the N-propeptidase cleavage site. The skipping of exon 6 is caused by a splice site mutation substituting an A for a G at the first nucleotide of intron 6.

Base Sequence↗

PubMed2003

Intraventricular brain injection of adeno-associated virus type 1 (AAV1) in neonatal mice results in complementary patterns of neuronal transduction to AAV2 and total long-term correction of storage lesions in the brains of beta-glucuronidase-deficient mice.

Inherited metabolic disorders that affect the central nervous system typically result in pathology throughout the brain; thus, gene therapy strategies need to achieve widespread delivery. We previously found that although intraventricular injection of the neonatal mouse brain with adeno-associated virus serotype 2 (AAV2) results in dispersed gene delivery, many brain structures were poorly transduced. This limitation may be overcome by using different AAV serotypes because the capsid proteins use different cellular receptors for entry, which may allow enhanced global targeting of the brain. We tested this with AAV1 and AAV5 vectors. AAV5 showed very limited brain transduction after neonatal injection, even though it has different transduction patterns than AAV2 in adult brain injections. In contrast, AAV1 vectors, which have not been tested in the brain, showed robust widespread transduction. Complementary patterns of transduction between AAV1 and AAV2 were established and maintained in the adult brain after neonatal injection. In the majority of structures, AAV1 transduced many more cells than AAV2. Both vectors transduced mostly neurons, indicating that differential expression of receptors on the surfaces of neurons occurs in the developing brain. The number of cells positive for a vector-encoded secreted enzyme (beta-glucuronidase) was notably greater and more widespread in AAV1-injected brains. A comprehensive analysis of AAV1-treated brains from beta-glucuronidase-deficient mice (mucopolysaccharidosis type VII) showed complete reversal of pathology in all areas of the brain for at least 1 year, demonstrating that the combination of this serotype and experimental strategy is therapeutically effective for treating global neurometabolic disorders.

Animals↗

PubMed1988

H-ras oncogene-transformed human bronchial epithelial cells (TBE-1) secrete a single metalloprotease capable of degrading basement membrane collagen.

H-ras-transformed human bronchial epithelial cells (TBE-1) secrete a single major extracellular matrix metalloprotease which is not found in the normal parental cells. The enzyme is secreted in a latent form of 72 kDa, which can be activated to catalyze the cleavage of the basement membrane macromolecule type IV collagen. The substrates in their order of preference are: gelatin, type IV collagen, type V collagen, fibronectin, and type VII collagen; but the enzyme does not cleave the interstitial collagens or laminin. This protease is identical to gelatinase isolated from normal human skin explants, normal human skin fibroblasts, and SV40-transformed human lung fibroblasts. Based on its ability to initiate the degradation of type IV collagen in a pepsin-resistant portion of the molecule, it will be referred to as type IV collagenase. This enzyme is most likely the human analog of type IV collagenase detected in several rodent tumors, which has the same molecular mass and has been linked to their metastatic potential. Type IV collagenase consists of three domains. Two of them, the amino-terminal domain and the carboxyl-terminal domain, are homologous to interstitial collagenase and human and rat stromelysin. The middle domain, of 175 residues, is organized into three 58-residue head-to-tail repeats which are homologous to the type II motif of the collagen-binding domain of fibronectin. Type IV collagenase represents the third member of a newly recognized gene family coding for secreted extracellular matrix metalloproteases, which includes interstitial fibroblast collagenase and stromelysin.

Amino Acid Sequence↗

PubMed1997

Interactions of the amino-terminal noncollagenous (NC1) domain of type VII collagen with extracellular matrix components. A potential role in epidermal-dermal adherence in human skin.

Type VII collagen, the major component of anchoring fibrils, consists of a central collagenous triple-helical domain flanked by two noncollagenous domains, NC1 and NC2. The NC1 domain contains multiple submodules with homology to known adhesive molecules including fibronectin type III-like repeats and the A domain of von Willebrand factor. In this study, we produced the entire NC1 domain of human type VII collagen in the stably transfected human kidney 293 cell clones and purified large quantities of the recombinant NC1 protein from serum-free culture media. The recombinant NC1 formed interchain disulfide-bonded dimers and trimers and was N-linked glycosylated. Tunicamycin inhibited the cellular secretion of NC1, suggesting that N-linked glycosylation may play a role in NC1 secretion. The recombinant NC1 was indistinguishable from the authentic NC1 obtained from human amnions or WISH cells with respect to N-linked sugar content, electrophoretic mobility, rotary shadow imaging, and binding affinity to type IV collagen. Purified recombinant NC1, like authentic NC1, also bound specifically to fibronectin, collagen type I, and a laminin 5/6 complex. Both monomeric and trimeric forms of NC1 exhibited equal affinity for these extracellular matrix components, suggesting that the individual arms of NC1 can function independently. The multiple interactions of NC1 with other extracellular matrix components may support epidermal-dermal adhesion.

Amnion↗

PubMed1990

Surfactant abnormalities and adult respiratory failure.

Surfactant abnormalities have been implicated in the development of the acute respiratory distress syndrome in adults. Experimental studies show that surfactant inhibition by protein-leak into the alveolar space is of major importance under these circumstances. Fibrin(ogen)-surfactant-interaction appears to contribute to disturbances of surfactant function with subsequent alveolar instability and ventilation-perfusion-mismatch. In a prospective study in severely injured patients, the surfactant in serially obtained bronchoalveolar lavage fluids was investigated. An early leakage of plasma proteins into the alveolar space was noted in those patients, who developed severe ARDS. Moreover, deterioration of surfactant function was markedly more pronounced in those patients than in trauma victims who developed only mild pulmonary dysfunction. In addition to the protein-leakage, a progressive decrease of the surfactant-specific dipalmitoyl-phosphatidylcholine was noted, significantly correlated with the deterioration of surfactant function and the severity of respiratory failure. In conclusion, experimental and clinical studies show surfactant abnormalities in the adult respiratory distress syndrome. Plasma protein-leakage and progressive alteration of alveolar type II surfactant secretion appear to be of major importance.

Adult↗

PubMed1987

Cells of the human myelomonocytic line RC-2A synthesize tissue factor-like procoagulant and urokinase-type plasminogen activator.

Cells of the myelomonocytic leukemia cell line RC-2A were studied for their ability to synthesize clotting-promoting and fibrinolytic factors. The cells were observed to generate procoagulant activity (PCA) in readily measurable quantities. Incubation of RC-2A cells with phorbol myristate acetate (PMA; 3 ng/ml) or phytohemagglutinin (PHA, 10 micrograms/ml) for 18 h resulted in a 4-5-fold increase in PCA relative to unstimulated control. The PCA of RC-2A cells was tissue factor-like in that it was dependent on factor VII but not on factors VIII or IX. RC-2A cells also produced plasminogen activator (PA). Secreted PA was approximately 70% of the PA of an identical number of human monocyte-derived macrophages; fresh isolated monocytes synthesized virtually no PA. Compared to macrophages, RC-2A cells secreted less or no PA-inhibitors. Lysates of RC-2A cells contained over three times more PA than lysed macrophages. Stimulation of the cells with lectins (PHA, concanavalin A) or PMA was followed by a modest (2-3-fold) increase in PA. Enzyme immunoassay with antibodies to urokinase (u-PA) or tissue-type PA (t-PA) identified the RC-2A plasminogen activator as being of urokinase type.

Blood Coagulation Factors↗

PubMedDate not supplied

In utero fetal liver cell transplantation without toxic irradiation alleviates lysosomal storage in mice with mucopolysaccharidosis type VII.

Lysosomal storage diseases, such as Mucopolysaccharidosis type VII (MPS VII), cause progressive loss of mobility and intellect and result in early death. Treatment of progressive diseases must occur before the blood-brain barrier closes. In MPS VII mice, normal donor hematopoietic cells secrete the missing enzyme beta-glucuronidase (GUSB) that reverses disease manifestations. Correction of lysosomal storage is limited to the visceral organs unless transplantation is preceded by high-dose irradiation. We hypothesize that irradiation opens the blood-brain barrier allowing passage of corrective cells. Here we transplanted genetically myeloablated MPS VII fetuses to determine whether earlier treatment without toxic irradiation is systemically corrective. Cells with a selective advantage in utero were identified. Donor fetal liver cells (FLC), a substitute for difficult to obtain murine cord blood cells, were increased 10-fold in the host peripheral blood over equivalent numbers of adult marrow cells injected simultaneously and were stable long term in both primary and secondary hosts. GUSB- MPS VII fetuses injected with GUSB+ FLC were assessed longitudinally after birth. Donor FLC replaced host stem cell descendants, prolonged life dramatically, and reduced bone dysplasia and lysosomal storage in all tissues long term. GUSB, donor leptomeningeal cells, and microglia were present in the brain at 11 months postinjection. Lysosomal storage in cortical neurons and glia, although not completely corrected, was reduced. We conclude that in utero intervention without toxic pretreatment in this model reduces the storage disease long term and improves the length and quality of life despite exerting only minor effects on the brain.

Animals↗

PubMed2001

Role of neuronal nicotinic receptors in the transmission and processing of information in neurons of the central nervous system.

The properties of nicotinic acetylcholine receptors (nAChRs) were studied following exogenous expression in a host system or using whole-cell recordings in brain slices, autoradiography and immunohistochemistry. When expressed in HEK-293 cells, alpha 4 beta 2 nAChRs displayed both a high and a low affinity component. The ratio of these two states was modified by chronic nicotine exposure, resulting in an enhanced sensitivity and a marked reduction in desensitization. Mutations in the gene coding for the alpha 4 subunit are responsible for a particular form of nocturnal epilepsy. When expressed in Xenopus oocytes, alpha 4 beta 2 nAChRs containing these mutations displayed distinct alterations in agonist affinity, desensitization and calcium permeability. Magnocellular endocrine neurons in the supraoptic (SO) nucleus of the hypothalamus were found to express functional alpha 7-containing nAChRs, which could play a role in regulating neurohypophysial peptide secretion. Facial (VII), hypoglossal (XII) and vagal (X) motoneurons of young rats responded to ACh by a fast inward current. The nAChRs present in VII and XII nuclei were of the non-alpha 7-containing type, whereas those present in the X nucleus contained the alpha 7 subunit. In Bcl-2 transgenic mice, facial nerve axotomy caused nAChRs downregulation by interfering negatively with the expression of the alpha 4 subunit. Binding sites corresponding to alpha 7-containing nAChRs were also detected in spinal motor nuclei and axotomy provoked a reduction of the binding. Together, these data indicate that long-term exposure to nicotine can promote neuroadaptive changes in nAChRs and that genetic alterations of neuronal nAChRs can result in transmissible neurological diseases. They also suggest that these receptors probably play a role in the central regulation of autonomic functions, as well as in motor control.

Animals↗

PubMed1986

Large complex globular domains of type VII procollagen contribute to the structure of anchoring fibrils.

Type VII collagen, in the form of an antiparallel dimer, is a major protein component of anchoring fibrils. The ultrastructural appearance of these fibrils suggests that they may serve to anchor the basement membrane zone to the underlying connective tissue matrix. We report here the identification and initial characterization of Type VII procollagen, recovered from the media of epidermoid carcinoma cell cultures. Immunoblotting using monospecific antibodies to Type VII procollagen identifies a single, homogeneous band of at least Mr 320,000 following disulfide bond reduction. This chain contains 170 kDa of collagen triple helix and 150 kDa of non-helical domain at the carboxyl terminus. Pepsin digestion of this material yields Type VII collagen identical to that isolated from whole tissue and a series of quasi-stable peptides derived from the carboxyl-terminal region. Cell extracts contain procollagen chains identical in size to those secreted into the media. There is no evidence for processing of this material in cell culture. Partial purification by velocity sedimentation and transmission electron microscopic observation following rotary shadowing reveals both monomers (426 nm) and dimers (785 nm). Dimers are antiparallel and interact through 60-nm overlap, with amino-terminal globular domains present at the ends of the overlap. The multi-domain carboxyl-terminal region appears as three similar arms originating from a centralized globular region adjacent to the collagen helix. The carboxyl globular domain is present in whole tissue and may participate in the unique fibril form of this collagen. The amino-terminal globule may function in the antiparallel assembly of dimers.

Antibodies↗

PubMed1991

Sertoli cell function varies along the seminiferous tubule: the proportion and response of transferrin secretors differ between stage-associated tubule segments.

Recent studies from our laboratory demonstrated clearly that only a portion of all Sertoli cells secrete transferrin (TF). These findings raised the possibility that differences in the functional type of Sertoli cells from one location to another may account in part for the stage-related variation in TF release along the seminiferous tubule. In order to address this, Sertoli cells derived from tubule segments corresponding to stages III-V, VII, IX-XI, and XIII of the seminiferous epithelial cycle were subjected to reverse hemolytic plaque assays to determine whether the proportion of TF cells present in those segments were similar or different. We found 21.4 +/- 1.8%, 20.3 +/- 2.0%, 48.3 +/- 2.5%, and 49.2 +/- 3.2% of all cells secreted TF in III-V, VII, IX-XI, and XIII staged segments, respectively. Results obtained from immunocytochemical staining of cells from different sections agreed well with those obtained with plaque assays, indicating that we had detected most, if not all, TF cells in these cultures. In additional experiments, we found that cultured cells from stage III-V and VII responded to FSH or isoproterenol with a large increase in the rate of TF plaque formation, whereas cells from IX-XI and XIII segments appeared to be unaffected. In contrast, bovine fibroblast growth factor caused a marked increase in the rate of TF plaque formation with IX-XI cells and only a slight increase with cells from III-V staged segments. Thus, the manner in which Sertoli cells respond to several modulatory agents appears not only to be stage-dependent, but also to be specific to the agent in question. When taken together, our observations demonstrate that cultured TF secretors obtained from different staged segments of the seminiferous tubule differ in proportion and responsiveness. These findings, when viewed in light of reports of a constant number of Sertoli cells along the seminiferous tubule, suggest that Sertoli cells may acquire and lose the ability to secrete TF or respond to modulation as the seminiferous cycle progresses.

Alkaline Phosphatase↗

PubMed2001

Structure, properties and enhanced expression of galactose-binding C-type lectins in mucous cells of gills from freshwater Japanese eels (Anguilla japonica).

Using a Japanese-eel (Anguilla japonica) gill cDNA subtraction library, two novel beta-d-galactose-binding lectins were identified that belong to group VII of the animal C-type lectin family. The eel C-type lectins, termed eCL-1 and eCL-2, are simple lectins composed of 163 amino acid residues, including a 22-residue signal peptide for secretion and a single carbohydrate-recognition domain (CRD) of approximately 130 residues typical of C-type lectins. The galactose specificity of the CRD was suggested by the presence of a QPD motif and confirmed by a competitive binding assay. Using Ruthenium Red staining, the lectins were shown to bind Ca(2+) ions. SDS/PAGE showed that native eCL-1 and eCL-2 have an SDS-resistant octameric structure (a tetramer of disulphide-linked dimers). Northern and Western blot analyses demonstrated high-level expression of eCL-1 and eCL-2 mRNAs and their protein products in gills from freshwater eels, which decreased markedly when the eels were transferred from freshwater to seawater. Immunohistochemistry showed that the eel lectins are localized in the exocrine mucous cells of the gill.

Amino Acid Motifs↗

PubMed1991

Influence of fetal pulmonary epithelium on thrombin activity.

Epithelial injury and intra-alveolar fibrin are present in lung injury. To determine whether healthy fetal and neonatal lung epithelium could regulate thrombin activity (hence fibrin formation) we collected amniotic and postnatal endotracheal tube fluids from humans and directly sampled lung and amniotic fluids from fetal guinea piglets, rabbit pups, and lambs. The coagulant properties of the cell surface and media conditioned by rat fetal type II alveolar epithelium were assessed. All fluids contained glycosaminoglycans (GAGs), but mass and biological assays demonstrated only some (heparan sulfate and to a lesser extent dermatan sulfate) had antithrombin activity. The presence of proteoglycans (greater than 1,000 kDa) yielding active GAGs with less than 100 kDa after base elimination were demonstrated by Sepharose CL4B chromatography. Epithelial-derived fluids contained a factor VII-dependent procoagulant activity, but concentrated conditioned media overlying primary cultures of type II epithelium demonstrated a net antithrombin effect. These studies demonstrate that the lungs of human and nonprimate mammalian fetuses and fetal type II epithelium secrete GAGs, some of which possess antithrombin activity, which would oppose intra-alveolar fibrin formation.

Amniotic Fluid↗

PubMed1990

Intra-alveolar fibrosis of idiopathic bronchiolitis obliterans-organizing pneumonia. Cell-matrix patterns.

Idiopathic bronchiolitis obliterans-organizing pneumonia (BOOP) is characterized by air space fibrosis of unknown origin. Clinical resolution under steroid treatment suggests the removal of the fibrotic lesion. Open lung biopsies of four patients with idiopathic BOOP were studied by immunochemistry and electron microscopy. Three distinct cell-matrix patterns of intra-alveolar bud were found to represent the sequential evolution of the fibrotic process: fibrinoid inflammatory cell clusters in which immunoglobulins and procoagulant factors (fibrinogen, factors VII and X) were identified; fibroinflammatory buds in which desmin-containing fibroblasts were observed migrating, proliferating, and secreting matrix proteins; fibrotic buds in which myofibroblasts organized a loose connective matrix predominantly composed of fibronectin and type III collagen. Extending forms of fibrotic buds may join contiguous alveoli. Fibrotic bud remodeling ability is correlated to the nature and organization of the matrix components but the factors permitting intra-alveolar matrix degradation must be characterized.

Blood Coagulation Factors↗