Serum aminoterminal type III procollagen peptide

A novel noninvasive formula for predicting cirrhosis in patients with chronic hepatitis C

Evaluating liver fibrosis is crucial for disease severity assessment, treatment decisions, and hepatocarcinogenic risk prediction among patients with chronic hepatitis C. In this retrospective multicenter study, we aimed to construct a novel model formula to predict cirrhosis. A total of 749 patients were randomly allocated to training and validation sets at a ratio of 2:1. Liver stiffness measurement (LSM) was made via transient elastography using FibroScan. Patients with LSM ≥12.5 kPa were regarded as having cirrhosis. The best model formula for predicting cirrhosis was constructed based on factors significantly and independently associated with LSM (≥12.5 kPa) using multivariate regression analysis. Among the 749 patients, 198 (26.4%) had LSM ≥12.5 kPa. In the training set, multivariate analysis identified logarithm natural (ln) type IV collagen 7S, ln hyaluronic acid, and ln Wisteria floribunda agglutinin positive Mac-2-binding protein (WFA⁺-Mac-2 BP) as the factors that were significantly and independently associated with LSM ≥12.5 kPa. Thus, the formula was constructed as follows: score = −6.154 + 1.166 × ln type IV collagen 7S + 0.526 × ln hyaluronic acid + 1.069 × WFA⁺-Mac-2 BP. The novel formula yielded the highest area under the curve (0.882; optimal cutoff, −0.381), specificity (81.5%), positive predictive values (62.6%), and predictive accuracy (81.6%) for predicting LSM ≥12.5 kPa among fibrosis markers and indices. These results were almost similar to those in the validated set, indicating the reproducibility and validity of the novel formula. The novel formula scores were significantly, strongly, and positively correlated with LSM values in both the training and validation data sets (correlation coefficient, 0.721 and 0.762; p = 2.67 × 10⁻⁸¹ and 1.88 × 10⁻⁴⁸, respectively). In conclusion, the novel formula was highly capable of diagnosing cirrhosis in patients with chronic hepatitis C and exhibited better diagnostic performance compared to conventional fibrosis markers and indices.

The effects of kiwifruit dressing on hypertrophic scars in a rabbit ear model

AIMS

Hypertrophic scars show abnormal responses during healing. These scars, associated with dysregulated growth and excessive collagen formation, can have both functional and cosmetic consequences for patients. The present study evaluated the effects of kiwifruit on hypertrophic scars in a rabbit ear model.

METHODS

This study included 13 New Zealand albino rabbits with full thickness wounds down to the cartilage (four wounds per ear; total: 104 scars). Sixteen days after initial wound formation, one ear of each rabbit was treated with daily kiwifruit dressing, while the other ear (control group) was dressed after normal saline irrigation for 10 days. Harvested skin samples were examined for histopathological, morphometric and immunohistochemical results.

RESULTS

In comparison with the control group, early kiwifruit dressing significantly reduced the scar elevation index, fibroblast count and dermal collagen organisation. The ratio of collagen type III to total collagen immunoreactivity, inflammation and dermal capillary count increased significantly in the treated group, compared to the untreated controls.

CONCLUSION

Based on the findings, early kiwifruit dressing improved the histological features of cutaneous wounds in rabbits. Therefore, this approach may be effective in clinical practice.

Effects of DMSO on a rabbit ear hypertrophic scar model: A controlled randomized experimental study

Dimethyl sulfoxide (DMSO) is an anti-inflammatory, antibacterial, analgesic drug widely used to treat several diseases as reported in the literature. It has a detractive effect on collagen deposition in the abnormal tissue. This study aimed to investigate the possible therapeutic effects of DMSO on hypertrophic scar formation in rabbits. Twenty-four New Zealand male albino rabbits were randomly divided into four groups: control, sham, DMSO, and TRA (triamcinolone acetonide). Except the control group, punch biopsy defects were created on each animal's right ear. Following the hypertrophic scar formation on day 28, intralesional DMSO and triamcinolone acetonide were administered once a week for 4 weeks into these scars of the DMSO and TRA groups, respectively. No therapeutic agent was administered to the control and sham groups. One week after the last injection, ear samples were collected for histopathological, immunohistochemical, and real-time polymerase chain reaction gene expression analyses. Histopathological examination revealed that the epithelium in the DMSO group was thicker than that in the control and TRA groups, but thinner than that in the sham group. Connective tissue thickness and vascularity level of the sham group were higher than those of the control, DMSO, and TRA groups. The collagen type I immunoreactivity level of the sham and TRA groups was higher than those of the control and DMSO groups. The collagen type III immunoreactivity level was higher in the sham group than in all other groups. Collagen type I/type III immunoreactivity ratios were lower in the DMSO group. The alignment of collagen fibers was normal in the DMSO group, but was irregular in the sham and TRA groups. The collagen type I gene expression levels of the DMSO and TRA groups were lower than that of the sham group. Collagen type III and IFN-γ mRNA expression levels were almost similar among the groups. TGF-1β mRNA expression levels were higher in the DMSO and TRA groups than in the control and sham groups. On the basis of the results, it can be concluded that intralesional administration of DMSO decreases hypertrophic scar formation easily and safely.

Protective effect of Sheng-Mai Yin, a traditional Chinese preparation, against doxorubicin-induced cardiac toxicity in rats

Background

Sheng-Mai Yin (SMY), a modern Chinese formula based on Traditional Chinese Medicine theory, has been used to treat cardiovascular diseases in Eastern Asia. Our study focuses on the cardioprotection of SMY against doxorubicin (DOX)-induced cardiac toxicity in vivo.

Methods

Rats were injected with DOX (2.5 mg/kg) in six injections over a 2-week period. SMY was administrated intragastrically at the dose of 8.35, 16.7 and 33.4 g/kg, or 16.7 g/kg only twice a day concurrently with DOX for the 2-weeks. A series of assays were performed to detect the effects of SMY on: (i) heart weight index (HWI) and left ventricular mass index (LVMI); (ii) cardiac function; (iii) heart tissue morphology; (iv) the contents of carboxy terminal propeptide of procollagen typeI (PICP), amino terminal propeptide of procollagen type III (PШNP), transforming growth factor-β1 (TGF-β1), B-type natriuretic peptide (BNP), monocyte chemoattractant protein-1 (MCP-1), interferon gamma (INF-γ) and interleukin 6 (IL-6) by ELISA; (v) the mRNA levels of TGF-β1 and toll-like receptor-2 (TLR2); and (vi) protein level of TGF-β1.

Results

Rats treated with SMY displayed the reductions of BNP and CK-MB increased by DOX in a dose-dependent manner. Moderate dose of SMY exhibited the correction for the increased HWI, LVMI, and the injured cardiac function, as well as the collagen accumulation. In addition, cardioprotection of SMY against DOX-induced cardiac toxicity was demonstrated by the reduction of myocardial fibrosis, characterized by the suppression of PICP, PШNP and TGF-β1, as well as the anti-inflammation and the regulation for cardiac immune microenvironment, characterized by the inhibition of TLR2, MCP-1, INF-γ and IL-6.

Conclusions

SMY may protect heart function through the restriction of myocardial fibrosis induced by DOX, which suggests the potentially therapeutic effect of SMY on DOX-induced cardiomyopathy.

Tenascin-C in human cardiac pathology

Tenascin-C (TN-C), a hexameric extracellular matrix glycoprotein, is a pleiotropic regulator of a variety of cell functions associated with embryogenesis, wound healing, cell proliferation, differentiation, motility, and nerve regeneration. Due to its role in remodeling processes, TN-C is involved with many pathologic states including cardiac and vascular diseases as well as inflammation and cancer. Assessment of circulating TN-C may help with identification of heart disease, especially in conjunction other cardiac biomarkers. It may be considered a specific biomarker useful in detecting cardiac pathology, especially in early disease stages and subsequent monitoring of cardiologic therapy. This review will highlight the biochemistry and usefulness of TN-C in clinical laboratory diagnostics to date.

Plasma amino-terminal propeptide of procollagen type III is associated with subclinical left ventricular systolic dysfunction in aortic stenosis

OBJECTIVE

The aim of the study was to investigate the association of plasma amino-terminal propeptide of procollagen type III (PIIINP) with subclinical left ventricular (LV) systolic dysfunction in patients with aortic stenosis (AS) and normal LV ejection fraction.

METHODS

The study was performed in 57 AS patients with normal LV ejection fraction and in 30 control subjects with normal aortic valve and normal LV ejection fraction. Tissue Doppler and speckle tracking image were performed to assess LV diastolic and systolic function. Plasma PIIINP level was measured by specific radioimmunoassay.

RESULTS

In AS patients, LV systolic longitudinal strain was significantly reduced (-17.1 ± 2.1 vs. -18.8 ± 1.4%, P<0.001) and plasma PIIINP was increased compared with controls (2.5 ± 0.6 vs. 2.1 ± 0.4 μg/l, P<0.001). A significant correlation was found between LV systolic longitudinal strain and PIIINP (r=-0.67, P<0.001). In patients with abnormal LV diastolic function, LV systolic longitudinal strain was reduced compared with patients with normal LV diastolic function (-16.3 ± 1.5 vs. -18.8 ± 2.1%, P<0.001) and plasma PIIINP was increased (2.8 ± 0.5 vs. 2.0 ± 0.3 μg/l, P<0.001). A stepwise multivariate regression analysis revealed that LV systolic longitudinal strain and diastolic blood pressure were independent predictors of plasma PIIINP (multiple r=0.71, P<0.001).

CONCLUSIONS

Plasma PIIINP is associated with subclinical LV systolic dysfunction (the impaired LV systolic long axis function) in patients with AS and normal LV ejection fraction. In addition, the impaired LV systolic long axis function and increased plasma PIIINP concentration are most marked in patients with abnormal LV diastolic function.

Circulating tenascin-C levels in patients with idiopathic dilated cardiomyopathy

Circulating serum tenascin-C (an extracellular matrix glycoprotein) levels in patients with idiopathic dilated cardiomyopathy (IDC) were measured. Serum tenascin-C levels were increased in proportion to the severity of left ventricular dysfunction in patients with IDC. The associations of serum tenascin-C levels with serum troponin T and procollagen type III aminoterminal peptide levels suggest that increased levels of serum tenascin-C indicate ongoing replacement fibrosis after myocardial damage in IDC.

Relationship between serum amino-terminal propeptide of type III procollagen and changes of left ventricular function after acute myocardial infarction

BACKGROUND

The amino-terminal propeptide of type III procollagen (PIIINP) is a marker of type III collagen synthesis, which has previously been shown to correlate with infarct size in nonthrombolyzed myocardial infarction (MI) and to provide prognostic information after MI.

METHODS AND RESULTS

The relationship between PIIINP and changes of left ventricular (LV) function was studied in 47 consecutive patients with first acute MI and 16 control subjects. Serum PIIINP analysis was measured daily during hospitalization and on days 90, 180, and 360. LV function was assessed by echocardiography on days 1, 5, 90, and 360. Patients with MI were stratified according to their serum PIIINP value at day 4 (group A, </=5.0 microg/L; group B, >5.0 microg/L). On arrival, LV function and size were comparable between groups A (n=31) and B (n=16). LV ejection fraction, initially depressed (day 1: group A, 47+/-7% versus group B, 47+/-8%; P=NS), increased significantly in group A (day 360: 54+/-8%, P<0.001) but was unchanged in group B (day 360: 43+/-8%, P=NS). LV volumes increased significantly in group B (P<0. 05) but not in group A. Furthermore, patients in group B developed signs of restrictive LV diastolic filling. Multivariate regression analysis identified PIIINP >5.0 microg/L and deceleration </=140 ms as independent predictors of cardiac death or complicating heart failure during follow-up.

CONCLUSIONS

PIIINP assessed in the subacute phase of MI relates to long-term changes of LV function and provides clinical prognostic information.

Changes in biochemical markers of joint tissue metabolism in a randomized controlled trial of glucocorticoid in early rheumatoid arthritis

OBJECTIVE

To determine the effects of low-dose prednisolone on joint tissue metabolism in early rheumatoid arthritis (RA).

METHODS

In addition to a range of biochemical markers of cartilage, bone and synovial tissue turnover, levels of pro-matrix metalloproteinase 3 (pro-MMP-3), pro-MMP-1, and cytidine deaminase (CD) were measured in serum from 79 of 128 patients with early RA who took part in the Arthritis and Rheumatism Council Low-Dose Glucocorticoid Study. Serum concentrations of joint tissue metabolites on treatment and off treatment were compared using Student's t-test.

RESULTS

Levels of the keratan sulfate epitope, 5D4, and glycosaminoglycan (GAG) were similar on and off treatment. However, the levels of synovium-derived markers, hyaluronate (HA) and N-propeptide of type III procollagen (PIIINP), were reduced by 23.9% (P < 0.01) and 25.2% (P < 0.001), respectively, during treatment with prednisolone. Serum osteocalcin (OC) was reduced by 25.8% (P < 0.001), while the levels of CD and pro-MMP-3 increased by 31.2% (P < 0.01) and 53.7% (P < 0.001) during prednisolone treatment compared with the off-treatment period.

CONCLUSION

Low-dose prednisolone had no significant effect on markers of cartilage turnover (GAG, 5D4) in early RA, suggesting that early erosions do not involve cartilage surfaces. The reduction in the markers of bone turnover (OC) and synovial tissue turnover (HA and PIIINP) support the general view that prednisolone reduces synovitis and suppresses bone turnover.

Early detection of type III procollagen peptide in acute lung injury. Pathogenetic and prognostic significance

The fibroproliferative reaction to acute lung injury may limit restoration of normal lung function and increase mortality in patients with acute lung injury. A biologic marker of collagen synthesis in the lung may be useful for studying the pathogenesis of acute lung injury and for identifying patients with acute lung injury who are at high risk for death and might benefit from new therapeutic modalities. Using an immunoassay, type III procollagen NH2 terminal peptide was measured in the pulmonary edema fluid of 44 patients with either acute lung injury or hydrostatic pulmonary edema (control group) within the first 24 h after endotracheal intubation for acute respiratory failure. Patients with acute lung injury (n = 33) or hydrostatic edema (n = 11) had the same degree of lung dysfunction as measured by the severity of oxygenation defect, the level of positive end-expiratory pressure, the decrease in static lung compliance, and the extent of infiltrates on the chest radiograph. However, the median procollagen III level was 5-fold higher in the pulmonary edema fluid of patients with acute lung injury than in the patients with hydrostatic pulmonary edema (p = 0.0001). Of the 33 patients with acute lung injury, 21 patients died and 12 lived. Nonsurvivors had significantly higher procollagen III levels than did survivors (p = 0.05). The positive and negative predictive values for nonsurvival for a procollagen III level > or = 1.75 U/ml were 74 and 83%, respectively. The relative risk of dying in the presence of a procollagen III value > or = 1.75 U/ml was 4.5 (95% CI, 0.7 to 27). Collagen synthesis in the lung, as reflected by elevated levels of procollagen III in pulmonary edema fluid, begins within the first 24 h of acute lung injury concurrent with the acute phase of increased endothelial and epithelial permeability to protein. This evidence suggests that fibrosing alveolitis begins much earlier in the course of clinical acute lung injury than has previously been appreciated. In addition, the presence of an elevated level of procollagen III is an early predictor of poor outcome. Thus, elevation of procollagen III in pulmonary edema fluid may have both pathogenetic and prognostic significance in patients with acute lung injury.

Glucocorticoids inhibit the synthesis rate of type III collagen, but do not affect the hepatic clearance of its aminoterminal propeptide (PIIINP)

The aminoterminal propeptide of type III procollagen (PIIINP) is a marker of type III collagen metabolism. The serum concentration of PIIINP is increased during inflammation, probably reflecting stimulated biosynthesis of type III collagen. Serum PIIINP decreases during glucocorticoid treatment. This has been interpreted as an inhibited biosynthesis of type III collagen. However, circulating PIIINP is extracted by the liver, and the decrease in serum PIIINP may also be caused by an increased hepatic elimination. In the present study we investigated the influence of intravenous methylprednisolone on the serum PIIINP level in pigs combined with a simultaneous determination of the hepatic extraction of PIIINP. The serum level of PIIINP decreased by approximately 30% within 2 h following glucocorticoid injection (p < 0.01). The initial hepatic extraction ratio of PIIINP was 0.15 (range 0.05-0.33) and neither changed after administration of methylprednisolone nor differ from that of the controls. Injection of methylprednisolone did not influence the gel filtration profile. The results of this study confirm the previous finding of serum PIIINP being decreased following glucocorticoid administration, but disprove the hypothesis that alterations in the liver extraction of PIIINP explain the decrease.

Immunohistochemistry of the intercellular matrix components and the epithelio-mesenchymal junction of the human tooth germ

The immunohistochemical localization of heparan sulphate, collagen type I, III and IV, laminin, tenascin, plasma- and cellular fibronectin was studied in tooth germs from human fetuses. The lamina basalis ameloblastica or membrana preformativa, which separates the pre-ameloblasts from the pre-dentin and dentin, contained heparan sulphate, collagen type IV, laminin and fibronectin. Enamel reacted with antifibronectin, but the reaction varied depending on the type of fibronectin and the source of antibody. In early pre-dentin, collagen type I, laminin, tenascin and fibronectin were present. In late pre-dentin and dentin collagen type I was found in intertubular dentin and in the zone between enamel and dentin. The close relationship between collagen type I in dentin and fibronectin in immature enamel is interesting, as it may contribute to the stabilization of the amelodentinal interface. In dental pulp, collagen type IV and laminin were found in the endothelial basement membranes. Collagen type I and III, tenascin and fibronectin were localized to the mesenchymal intercellular matrix. The results of this study have supported the assumption that the lamina basalis ameloblastica is a basement membrane, and have lead to the suggestion that ameloblasts are producers of fibronectin or a fibronectin-like substance.

Serum type III procollagen peptide in patients with Pneumocystis carinii infection. The Copenhagen-Amsterdam PCP-Prednisolone Study Group

Inflammation may play a central role in the pathogenesis of HIV-related Pneumocystis carinii pneumonia (PCP). Serum levels of the amino-terminal propeptide of Type III procollagen (PIIINP) reflect inflammatory activity in granulation tissue and in chronic rheumatic and liver disorders. To investigate changes in PIIINP serum levels during an episode of HIV-related PCP, consecutive serum samples were taken from 48 HIV-infected patients with PCP in a randomized, placebo-controlled study of the effect of adjunctive methylprednisolone therapy (26 in corticosteroid [CS] group and 22 in control group). All patients were treated with co-trimoxazole. In the control group, PIIINP serum levels at day of initiation of therapy (Day 0) were significantly higher in patients requiring mechanical ventilation and/or dying during the course of the pneumonia, and serum levels of PIIINP higher than 5 ng/ml were associated with a higher mortality than levels below 5 ng/ml. The level of PIIINP increased from Day 0 to Day 5. There was a significant correlation between changes in PIIINP levels and changes in the alveolar-arterial oxygen gradient from Day 0 to Day 5. In the CS group, the PIIINP levels decreased while steroid was administered. At Days 21 to 28 there were no difference in the levels of PIIINP between the two groups. PIIINP serum levels may predict the clinical outcome of PCP. The antimicrobial therapy may exacerbate the inflammatory reaction in HIV-related PCP, leading to respiratory failure. CS prevents this increased inflammatory activity.

Collagen metabolism during wound healing in rats. The aminoterminal propeptide of type III procollagen in serum and wound fluid in relation to formation of granulation tissue

The aminoterminal propeptide of type III procollagen (PIIINP) in serum has been shown to correlate with fibrillogenesis, and thus to be a potential direct marker of type III collagen deposition. The aim of the study was to investigate the correlation between changes in serum PIIINP and formation of granulation tissue during pharmacological suppression. Granulation tissue was induced in rats by the implantation of viscose cellulose sponges. Pharmacological suppression was achieved by cyclophosphamide treatment. To distinguish between the isolated effect of cyclophosphamide and the influence of the weight loss caused by treatment, weight loss caused by starvation was investigated. In untreated rats, serum PIIINP and wound fluid PIIINP were related to formation of granulation tissue (serum: r = 0.58, p < 0.05; wound fluid: r = 0.56, p < 0.05). In rats treated with cyclophosphamide, collagen deposition and formation of granulation tissue were markedly reduced, as compared within the untreated rats (6% vs 33%, p = 0.01). Wound fluid PIIINP reflected the sparse collagen deposition (r = 0.48, p < 0.05), whereas serum PIIINP decreased (-35%, p < 0.01) and was not correlated with the formation of granulation tissue. In starved rats, with a weight loss of 8%, formation of granulation tissue, vascular density, and collagen deposition were not reduced. Wound fluid PIIINP reflected the formation of granulation tissue (r = 0.52, p < 0.05), whereas serum PIIINP remained unchanged despite normal formation of granulation tissue. Starvation of rats without implants caused a decrease in serum PIIINP (-33%(-)-48%, p < 0.01). We conclude that during cyclophosphamide treatment and after a moderate weight loss, serum PIIINP is not a valid marker of fibrillogenesis. However, in normal rats with free access to food, changes in serum PIIINP mirror fibrillogenesis. Furthermore, our study provides experimental evidence consistent with the hypothesis that wound fluid PIIINP directly mirrors the local formation of granulation tissue, independent of weight loss and cyclophosphamide treatment.

Collagen I carboxyterminal propeptide in human gingival crevicular fluid before and after periodontal treatment

The amount of procollagen I carboxyterminal propeptide (PICP) in crevicular fluid (CF) was measured in three periodontitis patients. Samples were collected from 29 sites before treatment (scaling, root planing, and curettage) and 2, 5, 10, 20, and 40 days after treatment, by placing two paper strips in periodontal pockets for 5 s. The amount of fluid in strips was measured by the Periotron device. Control samples were collected from subjects with minimal gingival inflammation. PICP was extracted into saline solution and determined by a radioimmunologic method. Plaque index, papilla bleeding index, and pocket depth were recorded before and 40 days after treatment. The CF PICP mean concentration was 4.2 mg/l in the pretreatment samples. Five days after treatment a statistically significant increase in PICP concentration was seen in all subjects. The peak appeared on days 5 or 10 in 27 sites. The mean peak PICP concentrations of the subjects were 5-10 times higher than the pretreatment values. Twenty days after treatment, mean PICP concentration decreased to pretreatment level. PICP concentrations did not correlate with the clinical parameters. In control samples PICP amounts were below the detection limit. CF PICP is a new marker of type I collagen metabolism in periodontal tissues. It was concluded that elevated PICP concentrations in CF after periodontal treatment reflected increased type I collagen synthesis in periodontal tissues and that the peak in type I collagen synthesis takes place 5-10 days after treatment.

Changes in collagen metabolites in serum after cemented hip and knee arthroplasty

Markers of types I and III collagen turnover were measured in serial blood samples collected preoperatively and 60 days after surgery in 13 patients undergoing cemented total hip arthroplasty and 11 patients undergoing cemented total knee arthroplasty. The markers were the carboxyterminal extension peptide of type I procollagen (PICP) and the aminoterminal extension peptide of type III procollagen (PIIINP). The course of serum PICP and serum PIIINP in the two treatment groups were uniform. Serum PICP showed an initial fall on day 4, thereafter increasing up to days 14-28 and was still elevated on day 60. Serum PIIINP was increased on day 4, reaching its maximum on days 14-21, and thereafter declined but remained elevated above initial values. Serum osteocalcin, a serological marker of osteoblast activity, showed no significant changes in the two treatment groups during the observational period. We suggest that the changes in serum PICP and serum PIIINP reflect collagen formation in healing soft connective tissue 60 days after cemented hip or knee arthroplasty.

Hepatic extraction of the aminoterminal propeptide of type III procollagen before and after bile duct ligation in pigs

The aminoterminal propeptide of type III procollagen is extracted from the circulation by the liver, and PIIINP is found in bile. This study was performed in order to investigate whether biliary excretion contributes substantially to the hepatic extraction of circulating PIIINP. Hepatic extraction before and during a 4-h period after ligation of the common bile duct was assessed from serum PIIINP concentrations in a systemic artery, the portal vein and a hepatic vein of seven healthy anaesthetized pigs. Seven sham-operated anaesthetized pigs served as controls. Ligation of the bile duct did not cause a decrease in the hepatic extraction ratio of circulating PIIINP. The PIIINP serum levels of the cholestatic pigs and of the controls were similar throughout the investigation period. The PIIINP concentrations in bile were only 10% of the corresponding serum values. Gel filtration of sera showed that the lower PIIINP concentration in the hepatic vein, as compared to the artery and the portal vein was due to a selective decrease in the concentration of the intact propeptide. The study shows that biliary excretion does not contribute significantly to the hepatic extraction of circulating PIIINP in the normal liver. Furthermore, the hepatic extraction of circulating PIIINP preferentially affects the intact propeptide, rather than the somewhat larger PIIINP related molecule in serum.

Synthesis of collagen types I and III in reincised wounds in humans

The problem of the biochemical quantification of long term human wound healing was approached by measuring collagen synthesis in reincisions using specific radioimmunoassays for the wound fluid concentrations of the carboxyterminal propeptide of type I procollagen (PICP) and the aminoterminal propeptide of type III procollagen (PIIINP). First-day wound fluid PICP concentration after reincising a 3 week old scar was 25 times higher than the mean value in 20 reference standard incisions but scars older than 3 months did not show this difference. Wound fluid taken in subsequent days demonstrated that the initial acceleration of synthesis disappeared by the fourth day. When wound fluid PIIINP was assessed, high concentrations were found in reincisions of wounds for up to 5 months after the previous operation. The acceleration was also lost more slowly during the first postoperative week. The duration of a high rate of type I collagen synthesis compares well with studies in experimental wounds which show increased gain of strength if they are made not more than 6 weeks after previous surgery. The longer activity of the metabolism of type III collagen related antigens could reflect their function in the regulation of collagen fibril formation.

Collagen distribution in developing experimentally induced granulation tissue. A morphometric study

Viscose cellulose sponges were implanted subcutaneously on the back of full-grown Sprague-Dawley rats. Seven, 14, 21, 28, 42, 60 and 90 days after implantation, groups of 12 animals decapitated and the sponges were removed and processed for light microscopy. Five microns sections were stained with Picro-Sirius Red. Morphometry was performed on the zone of ingrowth and the collagen. The intersectional variation in the morphometrically determined collagen density within the sponges was below 20%. The hydroxyproline content was determined biochemically in 5 microns sections of sponges implanted for 14, 42, 60 and 90 days. A positive correlation (rho = 0.79, p less than 0.0001) was observed between the biochemically and morphometrically determined collagen contents. The morphometric determinations showed a steady increase in the granulation tissue ingrowth. At day 60 the ingrowth was complete. There was an increasing collagen density from days 7 and 14 through days 21 and 28, followed by a nearly steady state up to day 90 and a significantly higher collagen density peripherally than centrally in the day 42 sponges. The study has shown that morphometric collagen determination at light microscopical level using Sirius Red-stained sections may add quantitative data describing the dynamic changes in collagen content and distribution within developing granulation tissue.

Lipoprotein binding of crosslinked type III collagen aminopropeptide and fractions of its antigen in blood

When [125I] labelled bovine type III collagen aminopropeptide (PIIIP) is incubated with tissue transglutaminase (TGase) mixed with hyperlipemic rabbit plasma and subjected to ultracentrifugation the labelled fraction with density less than 1.2 g/ml is larger than when either lipoprotein or TGase is omitted. Chromatography of the fraction with density less than 1.2 g/ml shows the presence of peaks which are not present in the denser material. Since their elution positions indicate that they have higher molecular weights than PIIIP it is concluded that they consist of [125I]PIIIP which had been crosslinked by TGase and bound to lipoprotein. Low concentrations of similar low density, high molecular weight PIIIP antigens were found in normal human plasma and pooled sera from angiography subjects. In two out of seven infarct patients an unusually large fraction of the PIIIP antigen in the serum was found in a very high molecular weight peak containing low density material. It is speculated that this may arise from atherosclerotic lesions.

Splanchnic and renal extraction of circulating type III procollagen aminoterminal propeptide in patients with normal liver function and in patients with alcoholic cirrhosis

Splanchnic and renal extraction of circulating aminoterminal propeptide of type III procollagen and related antigens were studied in 12 patients with normal liver function and in 19 patients with alcoholic cirrhosis during catheterization. Type III procollagen peptide in serum was measured in two assays: the Type III Procollagen Peptide Radioimmunoassay Kit, a new assay that selectively determines the intact propeptide (and larger type III propeptide-holding antigens) and the Type III procollagen Fab assay that measures both the intact propeptide and the smaller fragments that quantitatively dominate in serum. A significant decrease in the concentration of the intact propeptide between the artery and the hepatic vein was found in the group with normal liver function (p less than 0.01) and in patients with cirrhosis (p less than 0.01). In patients with cirrhosis, however, the splanchnic extraction ratio of the intact propeptide (median = 0.04, range = -0.03 to 0.16) was significantly lower than in patients with normal liver function (median = 0.17, range = 0.05 to 0.36, p less than 0.01). The concentration of the intact propeptide in the hepatic vein was positively correlated to hepatic pressure (n = 18, r = 0.51, p less than 0.05) and inversely correlated to indocyanine green clearance (n = 15, r = -0.61, p less than 0.05). No splanchnic extraction could be demonstrated in the Type III propeptide Fab assay. A significant renal extraction was found in the Fab assay, but not in Type III Procollagen Peptide Radioimmunoassay Kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum aminoterminal type III procollagen peptide reflects repair after acute myocardial infarction

In 16 patients with acute myocardial infarction and in 15 controls, procollagen type III aminoterminal peptide in serum (PIIINP) was measured consecutively. Serum PIIINP was increased on the second to third postinfarction day (p less than 0.01) and remained elevated for more than 4 months. Peak values were observed on the third to seventh postinfarction day. The individual peak changes were correlated to infarction size calculated from serum CK-MB and serum lactate dehydrogenase (p = 0.60, p = 0.02). The changes in distribution of PIIINP-related antigens in serum after gel chromatography were similar to changes observed during wound healing in humans. PIIINP is cleaved off procollagen type III during the biosynthesis of type III collagen, which characterizes the early stages of repair and inflammation. Our findings suggest that serum PIIINP reflects the repair processes and scar formation following acute myocardial infarction. The serum PIIINP alterations in acute myocardial infarction differ essentially from the changes in myocardial enzymes reflecting myocardial injury. Serum PIIINP may therefore provide new and clinically relevant information on the healing of myocardial infarction.

Serum aminoterminal type III procollagen peptide in inflammatory and degenerative rheumatic disorders

Measurement of the aminoterminal type III procollagen peptide in serum has been suggested as a marker of the biosynthesis of collagen type III, a major connective tissue component in repair processes. In the present study the propeptide level correlated with the inflammatory synovial mass in rheumatoid arthritis and osteoarthritis. This implies that the propeptide level reflects the collagen type III synthesis occurring in the synovial repair processes, whether they were caused by inflammatory or degenerative rheumatic disorders. Physical activity did not enhance the transition of the propeptide from the synovial fluid or the inflamed synovial membrane to the blood. Normal serum propeptide values were observed in most patients with ankylosing spondylitis and degenerative diseases of the spine. This may reflect the lower amount of inflammatory tissue in these diseases and hence the sensitivity of the assays.