Serum markers of collagen synthesis and degradation in skin diseases. Altered levels in diseases with systemic manifestation and during systemic glucocorticoid treatment

How do glucocorticoids compare to oligo decoys as inhibitors of collagen synthesis and potential toxicity of these therapeutics?

This article demonstrates how glucocorticoids decrease collagen synthesis. The parameters used to assess procollagen synthesis in our laboratory will be compared to those used by others. This article will note all the pertinent literature on the molecular mechanisms of this down regulation of procollagen synthesis. For example, what are the effects of glucocorticoids at the levels of transcription and translation of collagen mRNAs? Finally, we will define a molecular mechanism to inhibit Type I collagen synthesis by decreasing the binding of the TGF-beta activator protein complex to the TGF-beta element in the distal promoter of the proalpha1 Type I collagen gene, preventing the 2:1 ratio of alpha1 to alpha2 chains in the processed Type I collagen molecule. We will next ask "How do sense oligo decoys decrease Type I collagen synthesis at the in vivo and at the cell levels?" In primary fibrotic cell culture, the double-stranded phosphorothioate oligodeoxynucleotide decoys were more effective than their sense single-stranded counterparts. The molecular mechanism for the decrease in Type I collagen synthesis is the same as glucocorticoids, that is by decreasing the binding of the TGF-beta activator protein complex to the TGF-beta element in the distal promoter of the proalpha1 Type I collagen gene for the transcription of the proalpha1 mRNAs. The reason for using sense oligo decoys as anti-fibrotic agents as compared to the anti-fibrotic glucocorticoids, is that presently marketed and FDA approved glucocorticoids have many untoward side effects which the sense oligo decoys do not have.

Type I collagen N-telopeptide variation in adolescents receiving oral isotretinoin for severe acne

The prolonged use of retinoids has been reported to be associated with changes of bone biochemical markers and toxic skeletal effects. Among collagen markers, type I collagen N-telopeptide (NTx) is present in all tissues that contain type I collagen, mostly in bone and in cutaneous tissue. It is a reliable indicator of bone resorption in metabolic bone disease, but has not previously been investigated in dermatological diseases during retinoid therapy. Isotretinoin, a synthetic 13-cis-retinoic acid, is highly effective in the treatment of severe acne vulgaris. We evaluated the effect of low-dose short-term oral isotretinoin treatment on bone remodeling markers in 10 adolescents (mean age 17.8 years) affected by severe acne. We measured urinary NTx as a marker of bone resorption, alkaline phosphatase (ALP) and osteocalcin (OC) as markers of bone formation, parathyroid hormone (PTH) and metabolites of vitamin D (25OH-D3 and 1,25(OH)2D3). Clinical and laboratory tests were performed before and after three months of isotretinoin treatment at the dosage of 0.5 mg/kg/day. All patients showed a good clinical response to the treatment (7/10 marked improvement, 3/10 mild improvement). No changes were detected in serum PTH, 25OH-D3, 1,25(OH)2D3, OC and ALP, while urinary NTx concentrations were significantly reduced (p < 0.05). In conclusion, the lack of change in PTH, OC, ALP and vitamin D metabolites and the absence of increase of NTx suggest no bone effect of the isotretinoin treatment. The decrease of urinary NTx could be due to the effect of isotretinoin on the cutaneous component of type I collagen. Severe acne in the active inflammatory phase could change the levels of this marker. Thus, short-term low-dose oral isotretinoin is an effective and safe treatment for severe acne.

Circulating collagen metabolites in systemic sclerosis. Differences between limited and diffuse form and relationship with pulmonary involvement

OBJECTIVE

To study collagen metabolites in systemic sclerosis (SSc) and their relationship with clinical manifestations of the disease.

METHODS

Forty-eight SSc patients, 13 with a diffuse form (dcSSc), 23 with a limited form (lcSSc) and 12 with suspected SSc not fulfilling the ACR criteria, and 31 healthy controls were examined. Serum concentrations of aminoterminal type III procollagen peptide (PIIINP), aminoterminal and carboxyterminal type I procollagen peptides (PINP and PICP) and cross-linked carboxyterminal telopeptide of collagen I (ICTP) were determined by radioimmunoassay.

RESULTS

Increased serum concentrations of ICTP were found in SSc patients compared with controls. Distinctly higher levels of ICTP were observed in dcSSc than in lcSSc. High serum ICTP was correlated with skin score and acute phase reactants, and with reduced pulmonary function. Serum PIIINP concentration was elevated in both lcSSc and dcSSc.

CONCLUSION

Augmented collagen catabolism accompanies the increased collagen synthesis in SSc. Serum ICTP concentration is a marker of this feature and also reflects clinical severity.

Markers of collagen metabolism and insulin-like growth factor binding protein-1 in term infants

AIM

To study the relation between fetal growth and markers of collagen metabolism and insulin-like growth factor binding protein-1 (IGFBP-1) in term infants.

METHODS

Cord vein plasma was obtained from 67 term infants of gestational age 37.1-41.7 weeks (39 appropriate for gestational age (AGA), 11 large for gestational age (LGA; relative birth weight >/= 2.0 SD), and 17 small for gestational age (SGA; relative birth weight </= -2.0 SD)) for analysis of markers of metabolism of collagen type I (PICP and ICTP) and III (PIIINP) and of IGFBP-1.

RESULTS

Negative correlations existed between gestational age and PICP (r = -0.294, p = 0.0158), ICTP (r = -0.338, p = 0.0052), and PIIINP (r = -0.432, p = 0.0003). These correlations were also found in SGA infants (all p < 0.05). IGFBP-1 showed negative correlations with birth weight and relative birth weight (r = -0.644, p = 0.0001, and r = -0.693, p = 0.0001 respectively) but not with gestational age (p>0.05).

CONCLUSIONS

In the term fetus, collagen metabolism is primarily dependent on maturity and not on intrauterine growth status, whereas IGFBP-1 reflects intrauterine growth independently of maturity.

Changes in collagen I and collagen III metabolism in patients with generalized atopic eczema undergoing medium-dose ultraviolet A1 phototherapy

Fourteen patients suffering from acute, exacerbated atopic eczema were screened for changes in collagen I and collagen III metabolism in serum (n = 11), urine (n = 11) and skin biopsies (n = 9) before and after medium-dose ultraviolet (UV) A1 phototherapy (15 exposures of 50 J/cm2 over a 3-week period, total dose 750 J/cm2). Mature collagen I and, to a lesser extent, mature collagen III were found to be decreased after the therapy in skin samples from the irradiated patients. As markers of collagen I degradation, the cross-links pyridoline and deoxypyridoline were analysed in urine using high-performance liquid chromatography. Both cross-links were found to be mildly increased after UVA1 phototherapy, without reaching statistical significance. As markers of de novo collagen synthesis we screened for the procollagen I-carboxyterminal peptide (PICP) and procollagen III-aminoterminal peptide (PIIINP) levels in serum and skin. The ratio of PICP to PIIINP in serum dropped significantly after the UVA1 phototherapy, suggesting a different impact of UVA1 on the two collagens. These findings were paralleled by a diminished ratio of PICP to PIIINP in tissue samples. Staining for matrix metalloproteinase 1 (MMP-1) and its specific counterpart, tissue inhibitor of MMP-1 (TIMP-1), showed slight increases for both proteins by therapeutic UVA1; this was also seen in serum for TIMP-1 but not MMP-1. In our study, high-energy UVA1 doses induced changes of the skin collagens in patients with atopic eczema which are measurable by their metabolites in serum and urine.

Time-dependent changes of serum carboxy-terminal peptide of type I procollagen and carboxy-terminal telopeptide of type I collagen concentrations in patients with acute myocardial infarction after successful reperfusion: correlation with left ventricular volume indices

To test the hypothesis that in patients with acute myocardial infarction (AMI), changes in the concentrations of the serum carboxy-terminal peptide of type I procollagen (PICP) and the carboxy-terminal telopeptide of type I collagen (ICTP) reflect extracellular matrix reformation and degradation, respectively, in the infarct healing processes, we measured these serum concentrations by RIA and compared their values with left ventricular (LV) indices obtained by left ventriculography. We studied 13 consecutive patients with their first AMI who underwent successful reperfusion. Blood samples were taken the day of admission and on days 2, 3, 4, 5, 7, and 14. LV volume indices were determined at 1 month after AMI, when LV remodeling was almost completed. The serum concentrations of both PICP and ICTP changed in a time-dependent manner. The average serum PICP concentration was lower than 1 SD below the mean control values on days 2 and 3 and increased thereafter, returning to the lower end of the control range at day 14. The area under the curve (AUC) for PICP was significantly correlated with the LV end systolic (ES) and end diastolic (ED) volume indices and LV ejection fraction for the first 14 days after AMI. The serum PICP on days 5–14 was inversely correlated or tended to be correlated with the LVES and LVED volume indices. The average serum ICTP concentrations on admission were within the control range, began to increase on day 2, and reached maximal concentrations on day 5, remaining at a plateau concentration until day 14. Although the AUC of ICTP for 14 days, the ICTP concentrations on days 1 and 14, and the minimal and maximal concentrations were significantly correlated with creatine kinase (CK) release and the period from AMI onset to the peak CK time, the concentrations were not significantly correlated with any LV indices except for the concentration on day 4, which was weakly correlated with the LVES volume index. The serum concentrations of PICP showed a significant time-dependent change that correlated with LV indices, indicating that PICP may provide additional information for evaluating the healing process because it affects LV remodeling after AMI. Although the serum concentration of ICTP changed in association with CK release, the ICTP concentration was found to be a poor indicator for LV indices.

Monitoring of extracellular matrix metabolism and cross-linking in tissue, serum and urine of patients with chromoblastomycosis, a chronic skin fibrosis

BACKGROUND

Chromoblastomycosis is a fungal disease leading to a granulomatous reaction associated with dermal fibrosis.

METHODS

In an attempt to elucidate the mechanisms leading to improvement in the cutaneous lesions after treatment with terbinafine, a new antifungal drug, we analysed collagen content and cross-linking before and at the end of the treatment. The turnover of extracellular matrix was monitored for 1 year by following up serum and urinary metabolites.

RESULTS

The serum levels of type III collagen and its N-terminal propeptide were correlated with the lesion size (P < 0.035) after 4 and 12 months of treatment respectively. After 4 months of treatment, urinary pyridinoline was higher (P = 0.04) in patients whose lesion size was reduced by more than 50% and serum hyaluronan was lower in patients who had lesions active for less than 5 years (P < 0.05). The treatment increased pyridinoline and pentosidine cross-links in the lesions but significantly reduced the collagen content (P = 0.05).

CONCLUSION

This is the first demonstration that, in addition to its fungicidal activity, terbinafine acts in vivo as an antifibrotic drug.

Demonstration of increased collagen synthesis in irradiated human skin in vivo

Fibrosis is a common side-effect of radiation therapy. As a complex network of cytokines and other mediators plays a central role in the process leading to fibrosis, we used an in vivo method to measure skin collagen synthesis, taking into account the physiological conditions. We determined suction blister (i.e. interstitial) fluid concentrations of types I and III procollagen propeptides, reflecting types I and III collagen synthesis, in irradiated and unirradiated skin of breast cancer patients 1-5 years after surgery and radiation therapy, hence using the patients as their own controls. The mean concentrations of the measured collagen markers were approximately two times higher in the irradiated skin than in the unirradiated contralateral breast skin. The difference slowly diminishes with time. These results indicate that abundant collagen synthesis in the irradiated skin continues several years after discontinuation of the radiation therapy, leading to fibrosis. The method outlined here offers a new in vivo perspective to study events leading to radiation fibrosis.

Pathophysiology of premature skin aging induced by ultraviolet light

BACKGROUND

Long-term exposure to ultraviolet irradiation from sunlight causes premature skin aging (photoaging), characterized in part by wrinkles, altered pigmentation, and loss of skin tone. Photoaged skin displays prominent alterations in the collagenous extracellular matrix of connective tissue. We investigated the role of matrix-degrading metalloproteinases, a family of proteolytic enzymes, as mediators of collagen damage in photoaging.

METHODS

We studied 59 whites (33 men and 26 women, ranging in age from 21 to 58 years) with light-to-moderate skin pigmentation, none of whom had current or prior skin disease. Only some of the participants were included in each of the studies. We irradiated their buttock skin with fluorescent ultraviolet lights under standard conditions and obtained skin samples from irradiated and nonirradiated areas by keratome or punch biopsy. In some studies, tretinoin and its vehicle were applied to skin under occlusion 48 hours before ultraviolet irradiation. The expression of matrix metalloproteinases was determined by in situ hybridization, immunohistology, and in situ zymography. Irradiation-induced degradation of skin collagen was measured by radioimmunoassay of soluble cross-linked telopeptides. The protein level of tissue inhibitor of matrix metalloproteinases type 1 was determined by Western blot analysis.

RESULTS

A single exposure to ultraviolet irradiation increased the expression of three matrix metalloproteinases -- collagenase, a 92-kd gelatinase, and stromelysin -- in skin connective tissue and outer skin layers, as compared with nonirradiated skin. The degradation of endogenous type I collagen fibrils was increased by 58 percent in irradiated skin, as compared with nonirradiated skin. Collagenase and gelatinase activity remained maximally elevated (4.4 and 2.3 times, respectively) for seven days with four exposures to ultraviolet irradiation, delivered at two-day intervals, as compared with base-line levels. Pretreatment of skin with tretinoin (all-trans-retinoic acid) inhibited the induction of matrix metalloproteinase proteins and activity (by 70 to 80 percent) in both connective tissue and outer layers of irradiated skin. Ultraviolet irradiation also induced tissue inhibitor of matrix metalloproteinases-1, which regulates the enzyme. Induction of the inhibitor was not affected by tretinoin.

CONCLUSIONS

Multiple exposures to ultraviolet irradiation lead to sustained elevations of matrix metalloproteinases that degrade skin collagen and may contribute to photoaging. Treatment with topical tretinoin inhibits irradiation-induced matrix metalloproteinases but not their endogenous inhibitor.

Circulating connective tissue metabolites in patients with bancroftian filariasis

Sera from adults from an area of Tanzania with high endemicity for Wuchereria bancrofti infection were examined for 4 serological markers of extracellular matrix activity, namely the amino-terminal propeptide of type III procollagen (PIIINP), the carboxy-terminal propeptide of type I procollagen (PICP), the carboxy-terminal telopeptide of type I collagen (ICTP), and hyaluronan. Sera from individuals with non-filarial elephantiasis and from healthy Danes were included as controls. No association was observed between the mean serum concentration of PIIINP or PICP and the clinical, microfilarial or circulating filarial antigen status of the individuals. The mean concentration of ICTP was significantly higher (P < 0.01) in sera from individuals with filarial and non-filarial elephantiasis than in sera from individuals living in filariasis endemic areas but without elephantiasis or in the Danish control sera. Among individuals from the filariasis endemic area, the mean serum concentration of hyaluronan was significantly higher (P < 0.01) in microfilaraemic than in amicrofilaraemic individuals, and significantly higher (P < 0.01) in individuals who had circulating filarial antigens than in those who did not, but there was no relation to the clinical status. The significance of the findings are discussed in relation to the pathological processes taking place in bancroftian filariasis.

Changes in bone markers in children with asthma during inhaled budesonide and nedocromil treatments

We evaluated serum and urinary markers of bone turnover in 14 children with asthma during inhaled budesonide and nedocromil treatments. Both the markers of formation (serum carboxy- and amino-terminal propeptides of type I procollagen and serum osteocalcin) and the markers of degradation (serum carboxy-terminal telopeptide of type I collagen and urinary pyridinium cross-links) decreased (p < 0.05) during budesonide treatment for 6 months. During inhaled nedocromil treatment (for the following 6 months), the markers returned to the normal levels. These transient decreases in the markers of both formation and degradation of bone suggest that inhaled budesonide may slightly decrease the bone turnover rate. However, normal "coupling" between formation and degradation seemed to operate, e.g. a change in one resulted in a corresponding change in the other, so that net bone loss did not necessarily occur.

Serum markers of collagen type I metabolism in spontaneously hypertensive rats: relation to myocardial fibrosis

BACKGROUND

The assay of serum peptides of extracellular collagen synthesis and degradation could provide an indirect estimate of the rate of fibrillar turnover. This study was designed to investigate whether serum peptides of collagen type I synthesis and degradation are altered in spontaneously hypertensive rats (SHR) with left ventricular hypertrophy and whether these serum collagen-derived peptides are related to myocardial fibrosis.

METHODS AND RESULTS

We measured serum levels of carboxyterminal propeptide of procollagen type I (PIP) as a marker of collagen I synthesis and serum levels of the pyridinoline crosslinked telopeptide domain of collagen type I (CITP) as a marker of fibrillar collagen I degradation in ten 36-week-old normotensive Wistar-Kyoto (WKY) rats, ten 36-week-old SHR, and ten 16-week-old SHR treated with the angiotensin-converting enzyme inhibitor quinapril (10 mg /kg body wt per day, orally) for 20 weeks. PIP and CITP were determined by specific radioimmunoassays. Histomorphometric and immunohistochemical studies of the left ventricle were performed in all rats. In untreated SHR compared with WKY rats, we found a more extensive interstitial and perivascular fibrosis, an increased (P<.01) collagen volume fraction, a more marked deposition of collagen type I, an increased (P<.01) serum concentration of PIP, and a similar serum concentration of CITP. In quinapril-treated SHR compared with untreated SHR, we found an absence of left ventricular hypertrophy, a marked decrease of fibrosis, a lower (P<.01) collagen volume fraction, a diminished deposition of collagen type I, a decreased (P<.01) concentration of PIP, and a similar concentration of CITP. A direct correlation was found between the collagen volume fraction and serum PIP (r=.753, P<.05) in untreated SHR.

CONCLUSIONS

These results suggest that tissue metabolism of collagen type I is abnormal in SHR and can be normalized by treatment with quinapril. On the basis of our findings, we propose that serum PIP may be a marker of collagen type I-dependent myocardial fibrosis in rats with genetic hypertension.

Short-term treatment with growth hormone stimulates osteoblastic and osteoclastic activity in osteopenic postmenopausal women: a dose response study

To investigate the potential use of growth hormone (GH) in Activate-Depress-Free-Repeat treatment of postmenopausal osteoporosis, we measured changes in serum levels of biochemical markers of bone turnover, insulin-like growth factor-I (IGF-I), calciotropic hormones, and bone mineral density in 40 postmenopausal women with osteopenia (ages 52-73 years) in response to 7 days of treatment with either placebo or GH (0.05, 0.10, or 0.20 IU/kg/day) administered subcutaneously in the evening. GH treatment increased serum osteocalcin (p < 0.01) and C-terminal type-I procollagen propeptide (p < 0.01) and also serum levels of type-I collagen telopeptide (p < 0.001), fasting urinary hydroxyproline/creatinine (p < 0.05), pyridinoline/creatinine (p < 0.05), and deoxypyridinoline/creatinine (p < 0.01) in a dose-dependent fashion. Even the lowest dose of GH tested induced a significant increase in these parameters; however, the effects were transient lasting only 1-2 weeks. In the highest dose group, however, a somewhat prolonged effect (30 days) on serum osteocalcin was observed. Furthermore, GH increased serum levels of IGF-I, insulin, and tri-iodothyronin. No effect on serum 1,25-dihydroxyvitamin D3 or parathyroid hormone could be demonstrated. Adverse effects were mainly related to fluid retention. They were clearly dose-dependent and rapidly reversible. In conclusion, short-term GH treatment stimulates bone formation and bone resorption in postmenopausal women with osteopenia.

Seromarkers of collagen I and III metabolism in active Crohn's disease. Relation to disease activity and response to therapy

Crohn's disease is characterised by gradual development of intestinal fibrotic lesions containing large amounts of collagen type I, III, and V. Measurement of circulating connective tissue metabolites has emerged as a useful tool for assessment of fibroproliferative activity in various diseases. Serum concentrations of procollagen peptides, N-terminal propeptide of type III procollagen (PII-INP), and C-terminal propeptide of type I procollagen (PICP), reflect the synthesis rate of the parent collagens, while the C-terminal telopeptide of type I collagen (ICTP) reflects its degradation. S-PIIINP, S-PICP, and S-ICTP were measured by radioimmunoassays in 29 patients with active Crohn's disease. S-ICTP was significantly increased, median 6.2 micrograms/l (95% CI 5.2 to 8.7 micrograms/l) versus controls 2.6 micrograms/l (2.5 to 2.7 micrograms/l) (p < 0.0001), S-PICP reduced, 100 micrograms/l (80 to 110 micrograms/l) versus 132 micrograms/l (124 to 141 micrograms/l) (p = 0.001), and S-PIIINP did not differ from controls. Patients with sustained clinical remission during prednisolone therapy exhibited an increase in S-PICP (p = 0.0052). S-PIIINP changed significantly (p = 0.0002), however, exhibiting a biphasic pattern. S-ICTP decreased (p = 0.015) in treatment responders but remained above the upper normal limit even when clinical remission had been achieved. Non-responders showed no significant changes in any of the marker molecules of collagen synthesis or degradation. Correlations were found between S-PIIINP and S-PICP (p < 0.005) and S-ICTP (p < 0.02), and between S-ICTP and S-orosomucoid (p < 0.005) and S-C reactive protein (p < 0.02). By contrast, there was no relation between the connective tissue metabolites and Harvey Bradshaw Index. These data provide evidence that collagen I degradation is increased not only in active Crohn's disease, but also in patients entering clinical remission. The concurrent normal/low-normal values of markers of collagen formation may reflect a changed local or systemic elimination of the propeptides.

Serum levels of carboxyterminal propeptide of type I procollagen and pyridinoline crosslinked telopeptide of type I collagen in normal children and children with growth hormone (GH) deficiency during GH therapy

In this study, we investigated age-related changes in serum levels of both the carboxyterminal propeptide of type I procollagen (PICP) and the pyridinoline crosslinked telopeptide of type I collagen (ICTP) to elucidate bone formation and resorption, respectively, in 200 normal Japanese children (141 males and 59 females, age range 0-16 years). Furthermore, to clarify the effect of GH on bone turnover, we measured serum PICP and ICTP in 26 growth hormone (GH)-deficient children (20 males and 6 females, age range 4-15 years) who showed significant bone growth during recombinant human GH therapy. In the normal children, the curves for age-related changes in both serum PICP and ICTP levels almost paralleled that of the standard height velocity curve in both sexes. The serum levels of both peptides were higher than those in adults, and the peak increases corresponded with the timing of the adolescent growth spurt. Furthermore, the serum levels of PICP and ICTP were significantly correlated with the height velocity. In the GH-deficient patients, the serum ICTP levels before GH therapy were lower than those in age- and sex-matched controls. Both PICP and ICTP levels in serum increased significantly at the beginning of GH therapy. Furthermore, the percent increase in PICP after 1 month of GH treatment was positively correlated with the percent increase in height velocity during 1 year of GH treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of serologic markers for collagen synthesis and degradation in systemic sclerosis

BACKGROUND

Systemic sclerosis is characterized by excessive accumulation of collagen in all involved organs. Serum markers of collagen synthesis and degradation, the aminoterminal propeptide of type III procollagen (PIIINP), the carboxyterminal propeptide of type I procollagen (PICP), and the crosslinked telopeptide of type I collagen (ICTP), can be measured.

OBJECTIVE

Our purpose was to investigate these markers in different subgroups of untreated patients with systemic sclerosis and in patients before and after various types of therapy. PIIINP and PICP were also investigated in blister fluid from involved and uninvolved skin.

METHODS

Sera from 97 patients and suction blister fluid from 13 patients were radioimmunoassayed.

RESULTS

The highest levels of PIIINP and PICP were found in blister fluid from involved skin. Patients with systemic sclerosis had higher serum levels of PIIINP than control subjects. The highest levels were found in patients with diffuse cutaneous systemic (type III) sclerosis; increased serum PIIINP was also characteristic of type II limited cutaneous systemic sclerosis. Most patients with limited cutaneous type I systemic sclerosis had normal levels. Serum PICP was within normal limits in all three types of systemic sclerosis. Variations in ICTP type I collagen degradation in general followed PICP. Immunosuppressive drugs significantly reduced PIIINP, whereas no significant decrease was found after photopheresis. PICP and ICTP also diminished after treatment with D-penicillamine and cyclophosphamide given together with prednisone.

CONCLUSION

PIIINP can be recommended for monitoring collagen synthesis in systemic sclerosis. Our data support the use of immunosuppressive therapy for this disease.