Colchicine-induced modulation of collagenase in human skin fibroblast cultures. I. Stimulation of enzyme synthesis in normal cells

From polarity to pathology: Decoding the role of cell orientation in osteoarthritis

Cell polarity refers to the orientation of tissue and organelles within a cell and the direction of its function. It is one of the most critical characteristics of metazoans. The development, growth, and functional tissue distribution are closely related to holistic tissue or organ homeostasis. However, the connection between cell polarity and osteoarthritis (OA) is less well-known. In OA, multiple chondrocyte clusters and tissue disorganisation can be observed in the degraded cartilage tissue. The excessive upregulation of the planar cell polarity (PCP) signalling pathway leads to the loss of cell polarity and organisation in OA progression and aetiology. Recent research has become increasingly aware of the importance of cell polarity and its correlation with OA. Several cell polarity-related treatments have shed light on OA. A thorough understanding of cell polarity and OA would provide more insights for future investigations to treat this worldwide disease.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Understanding cell polarity, associated signalling pathways, organelle changes, and cell movement in the development of OA could lead to advances in precision medicine and enhanced treatment strategies for OA patients.

Pharmacological treatment for keloids

INTRODUCTION

Keloids are fibroproliferative disorders that are characterized by histological accumulation of collagens and fibroblasts, refractory clinical symptoms such as itching, topical invasiveness, and frequent postsurgical recurrence. At present, to treat or prevent keloids, new drugs are currently being designed and the pharmaceutical indications of known drugs are being expanded.

AREAS COVERED

The current pharmacological interventions for keloids are mainly described on the basis of the various hypotheses on keloid etiology and the keloid ingredients that are targeted. These interventions include angiotension-converting enzyme inhibitors and calcium-channel blockers (based on hypertension hypothesis), selective estrogen receptor modulator (based on endocrinological hypothesis), vitamins and essential fatty acids (based on immunonutritional hypothesis), and transglutaminase inhibitor (based on metabolic hypothesis). Drugs that directly target the reduction or destruction of the major extracellular matrix or cellular constituents of keloids are also included. Besides, drugs that indirectly modulate the biochemical microenvironment are described. These include growth factors, immunomodulators, and anti-inflammation and anti-allergy drugs.

EXPERT OPINION

Due to the unclear etiology of keloids and the lack of animal models, efficient, reliable, and specific pharmaceutical interventions for keloids continue to be lacking. The reliability of current data and clinical observations must be strengthened by large-scale, randomized, controlled clinical trials.

A case of familial Mediterranean fever-associated systemic amyloidosis

Familial Mediterranean fever (FMF) is a chronic inflammatory disease, characterized by recurrent fever and polyserositis (pleuritis and/or peritonitis). The most important complication of FMF is amyloidosis, which causes chronic renal failure. Colchicine is the most effective treatment in acute attacks and amyloidosis development. However, the majority of patients with amyloidosis have a relentless progression to end-stage renal disease despite initiation of colchicine treatment. We present the case of a 38-year-old man with FMF-associated chronic renal failure due to systemic amyloidosis. The patient suffered from periodic fever and renal insufficiency, and was admitted to our hospital. Laboratory examination revealed an inflammatory reaction, renal dysfunction (serum creatinine 2.5 mg/dl), and proteinuria. Renal biopsy revealed segmental mesangial AA amyloid deposits in several glomeruli and the walls of several vessels. Genetic analysis showed that the patient was heterozygous for the MEFV gene (E148Q/M694I). Thus, he was diagnosed with FMF, and colchicine treatment was initiated. He remained almost attack free, with decreasing serum creatinine levels (1.6 mg/dl) and diminishing urinary protein excretion. In conclusion, renal amyloidosis is the most important long-term complication of FMF, and treatment with colchicine is effective for preventing progression. Therefore, colchicine treatment should be initiated as early as possible after the diagnosis of FMF.

Renal amyloidosis in children

Renal amyloidosis is a detrimental disease caused by the deposition of amyloid fibrils. A child with renal amyloidosis may present with proteinuria or nephrotic syndrome. Chronic renal failure may follow. Amyloid fibrils may deposit in other organs as well. The diagnosis is through the typical appearance on histopathology. Although chronic infections and chronic inflammatory diseases used to be the causes of secondary amyloidosis in children, the most frequent cause is now autoinflammatory diseases. Among this group of diseases, the most frequent one throughout the world is familial Mediterranean fever (FMF). FMF is typically characterized by attacks of clinical inflammation in the form of fever and serositis and high acute-phase reactants. Persisting inflammation in inadequately treated disease is associated with the development of secondary amyloidosis. The main treatment is colchicine. A number of other monogenic autoinflammatory diseases have also been identified. Among them cryopyrin-associated periodic syndrome (CAPS) is outstanding with its clinical features and the predilection to develop secondary amyloidosis in untreated cases. The treatment of secondary amyloidosis mainly depends on the treatment of the disease. However, a number of new treatments for amyloid per se are in the pipeline.

New Insights into the Pathogenesis and Treatment of Idiopathic Pulmonary Fibrosis: A Potential Role for Stem Cells in the Lung Parenchyma and Implications for Therapy

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and often fatal form of interstitial lung disease. It is characterized by injury with loss of lung epithelial cells and abnormal tissue repair, resulting in replacement of normal functional tissue, abnormal accumulation of fibroblasts and myofibroblasts, deposition of extracellular matrix, and distortion of lung architecture which results in respiratory failure. Despite improvements in the diagnostic approach to IPF and active research in recent years, the molecular mechanisms of the disease remain poorly understood. This highly lethal lung disorder continues to pose major clinical challenges since an effective therapeutic regimen has yet to be identified and developed. For example, a treatment modality has been based on the assumption that IPF is a chronic inflammatory disease, yet most available anti-inflammatory drugs are not effective in treating it. Hence researchers are now focusing on understanding alternative underlying mechanisms involved in the pathogenesis of IPF in the hope of discovering potentially new pharmaceutical targets. This paper will focus on lung tissue repair, regeneration, remodeling, and cell types that may be important to consider in therapeutic interventions and includes a more detailed discussion of the potential targets of current therapeutic attack in pulmonary fibrosis. The discovery that adult bone marrow stem cells can contribute to the formation of differentiated cell types in other tissues, especially after injury, implies that they have the potential to participate in tissue remodeling, and perhaps regeneration. The current promise of the use of adult stem cells for tissue regeneration, and the belief that once irreversibly damaged tissue could be restored to a normal functional capacity using stem cell-based therapy, suggests a novel approach for treatment of diverse chronic diseases. However this optimism is tempered by current evidence that the pathogenesis of pulmonary fibrosis may involve the recruitment of bone marrow-derived fibroblasts, which are the key contributors to the pathogenesis of this chronic progressive disorder. Nevertheless, stem cell-related therapies are widely viewed as promising treatment options for patients suffering from various types of pulmonary diseases. Gender mismatched bone marrow or lung transplant recipients serve as natural populations in which to study the role of bone marrow-derived stem cells in recovery from pulmonary diseases. Understanding the mechanism of recruitment of stem cells to sites of injury, and their involvement in tissue repair, regeneration, and remodeling may offer a novel therapeutic target for developing more effective treatments against this fatal disorder. This article reviews the new concepts in the pathogenesis, current and future treatment options of pulmonary fibrosis, and the recent advances regarding the roles of stem cells in lung tissue repair, regeneration, and remodeling.

Disassembly of the vimentin cytoskeleton disrupts articular cartilage chondrocyte homeostasis

Articular cartilage functions in dissipating forces applied across joints. It comprises an extracellular matrix containing primarily collagens, proteoglycans and water to maintain its functional properties, and is interspersed with chondrocytes. The chondrocyte cytoskeleton comprises actin microfilaments, tubulin microtubules and vimentin intermediate filaments. Previous studies have determined the contribution of actin and tubulin in regulating the synthesis of the extracellular matrix components aggrecan and type II collagen. The contribution of vimentin to extracellular matrix biosynthesis in any cell type has not previously been addressed. Therefore the aim of this study was to assess the role of vimentin in cartilage chondrocyte metabolism. Vimentin intermediate filaments were disrupted in high-density monolayer articular chondrocyte cultures using acrylamide for 7 days. De novo protein and collagen synthesis were measured by adding [3H]-proline, and sulphated glycosaminoglycan (sGAG) synthesis measured by adding [35S]-sulphate to cultures. Vimentin disruption resulted in decreased collagen synthesis, whilst sGAG synthesis was unaffected. In addition, there was a significant reduction in type II collagen and aggrecan gene transcription suggesting that the effects observed occur at both the transcriptional and translational levels. A 3-day cold chase demonstrated a significant inhibition of collagen and sGAG degradation; the reduction in collagen degradation was corroborated by the observed reduction in both pro-MMP 2 expression and activation. We have demonstrated that an intact vimentin intermediate filament network contributes to the maintenance of the chondrocyte phenotype and thus an imbalance favouring filament disassembly can disturb the integrity of the articular cartilage, and may ultimately lead to the development of pathologies such as osteoarthritis.

Fibroblast heterogeneity in collagenolytic response to colchicine

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are important in various physiological and pathological conditions, including those that involve homeostasis of collagen. Drug induced regulation of MMP-1, other MMPs and TIMPs is critical in treatment of various diseases, e.g. the use of the plant alkaloid, colchicine. One possible factor that might explain the failure in colchicine-treatment of some patients is interindividual variability on the cellular level. To investigate the possible individual heterogeneity in response to colchicine, we studied the effect of colchicine-induced synthesis of collagenase from 32 different human skin fibroblast strains derived from both healthy individuals as well as individuals with different skin diseases. We showed that colchicine induced an increased synthesis of collagenase in 22 of 32 cases. This heterogeneity occurred in fibroblasts from healthy as well as diseased individuals. To determine if colchicine also affected the fibroblast synthesis of gelatinase, stromelysin and tissue inhibitors of MMPs, we investigated several individuals from a single family. The results showed that both colchicine responsive and non-responsive fibroblasts with respect to collagenase synthesis responded to colchicine by an increased stromelysin synthesis, while the synthesis of gelatinase and TIMP-1 were unaffected. As a whole, our results indicate that individual heterogeneity in collagenase response to colchicine treatment may partly explain some of the controversial results obtained with colchicine as a drug.

Treatment of idiopathic pulmonary fibrosis: Is there anything new?

Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic fibrosing interstitial pneumonia of unknown aetiology and is associated with the histological picture of usual interstitial pneumonia. Treatment in most cases is unsatisfactory and the prognosis remains poor. There is insufficient evidence to suggest that any treatment, apart from lung transplantation, improves survival or halts disease progression for IPF patients. Data on treatment response are limited by the paucity of clinical trails, the lack of homogenous clinical features, the small number of patients, and the absence of histological and radiological documentation in many cases. Anti-inflammatory medications such as corticosteroids, azathioprine and cyclophosphamide remain the commonly used medications. More recently, it has been proposed that IPF is a primary fibrotic disease rather than an inflammatory condition. Antifibrotic agents such as colchicine, pirfenidone and interferon-gamma (IFN-gamma) have been tried. However, a recent placebo-controlled trial has failed to demonstrate a significant effect of IFN-gamma on disease progression, lung function or quality of life in IPF patients, though a clinically significant survival benefit of the drug could not be ruled out.

Colchicine treatment of alcoholic cirrhosis: a randomized, placebo-controlled clinical trial of patient survival

BACKGROUND & AIMS

Colchicine improved survival and reversed cirrhosis in several small clinical trials. We compared the efficacy and safety of long-term colchicine, as compared with placebo, in patients with advanced alcoholic cirrhosis.

METHODS

Five hundred forty-nine patients with advanced (Pugh B or C) alcoholic cirrhosis were randomized to receive either colchicine 0.6 mg twice per day (n = 274) or placebo (n = 275). Treatment lasted from 2 to 6 years. The primary outcome was all-cause mortality. Secondary outcomes were liver-related morbidity and mortality. Liver biopsy was requested prior to entry and after 24 months of treatment.

RESULTS

Attendance at scheduled clinic visits and adherence with study medication were similar in colchicine and placebo groups. Alcohol intake was less than 1 drink per day in 69% of patients. In an intention-to-treat analysis, all-cause mortality was similar in colchicine (49%) and placebo (45%) patients (P = .371). Mortality attributed to liver disease was 32% in colchicine and 28% in placebo patients (P = .337). Fewer patients receiving colchicine developed hepatorenal syndrome. In 54 patients with repeat liver biopsies after 24 or more months of treatment, cirrhosis improved to septal fibrosis in 7 patients (3 colchicine, 4 placebo) and to portal fibrosis in 1 patient (colchicine).

CONCLUSIONS

In patients with advanced alcoholic cirrhosis, colchicine does not reduce overall or liver-specific mortality. Liver histology improves to septal fibrosis in a minority of patients after 24 months of treatment, with similar rates of improvement in patients receiving placebo and colchicine. Colchicine is not recommended for patients with advanced alcoholic cirrhosis.

S100A4 regulates membrane induced activation of matrix metalloproteinase-2 in osteosarcoma cells

To study the role of the metastasis associated protein S100A4, an osteosarcoma cell line (OHS) with a high level of this protein was transfected with a vector containing a ribozyme that degrades S100A4 mRNA and, as controls, OHS cells were transfected with the vector alone. We have followed up our previous investigation (Bjørnland et al. 1999) by a detailed investigation of these cell lines' synthesis of MMP and TIMP proteins at different cell densities. It is shown that the cell lines with a low S100A4 level produced a reduced amount of immunoreactive MMP-2 at cellular subconfluence, while at confluence there was no difference compared to the control cells. The cell lines with a reduced S100A4 level produced less of the activated form of MMP-2 (62-kDa) and less TIMP-1 than the corresponding control cells, independent of cell density. Isolated cell membranes from cell lines with a reduced S100A4 level contained less MT1-MMP, MMP-2 and TIMP-2 compared to the control cells. Activation of exogenously added proMMP-2 was less effective with the former membrane preparations. It appeared that the mechanism behind the S100A4 dependent activation of proMMP-2 varied with cell density, as SN50, a peptide inhibitor of NF-kappaB nuclear translocation reduced the activation of MMP-2 at low cell density, but had no effect at high cell density. Thus, one of the mechanisms by which S100A4 may exert its effect on metastasis of some tumors is by regulating the MMP-2 activity.

Colchicine induces membrane-associated activation of matrix metalloproteinase-2 in osteosarcoma cells in an S100A4-independent manner

Like the metastasis-associated protein S100A4, matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are important in physiological and pathological conditions. Previously, we showed that S100A4 is involved in the regulation of MMPs and TIMPs, and in the present work we have investigated whether the anti-inflammatory and microtubule-disrupting drug colchicine has an effect on the expression of these proteins in osteosarcoma cell lines (OHS) with high and low levels of S100A4. Colchicine treatment of the various OHS cells resulted in an increased expression of MT1-MMP and TIMP-2 mRNA, and a corresponding increase of these two proteins in isolated cell membranes. Colchicine-treated cells produced more of the activated form of MMP-2 than control cells. However, the drug did not affect the amount of MMP-2 and TIMP-1 mRNA or protein, and it reduced the S100A4 mRNA expression. Isolated cell membranes from the colchicine-treated cells were more effective in activating exogenous proMMP-2 than membranes from control cells, and inhibitory studies indicated that it was the colchicine-induced increase in MT1-MMP that caused the increased activation of endogenous MMP-2. A peptide inhibitor of nuclear factor kappaB nuclear translocation, SN50, blocked the colchicine-induced activation of proMMP-2 and reduced the synthesis of MMP-2 in colchicine-treated cells, but not in control cells. It can be concluded that colchicine modulates the expression of MT1-MMP and TIMP-2 and hence the activation of proMMP-2 independently of the S100A4 level in osteosarcoma cells.

Efficacy of colchicine therapy in amyloid nephropathy of familial Mediterranean fever

The aim of this study was to investigate the effect of colchicine therapy on the outcome of amyloid nephropathy of familial Mediterranean fever (FMF) in childhood. The diagnosis of amyloidosis type AA was confirmed by renal biopsy in 38 patients. During a mean follow-up period of 30.5 months (range 6-88 months), the patients received colchicine therapy. While 24 of these patients were compliant with the treatment, 14 patients remained non-compliant. Of the 24 compliant patients, 19 had normal renal function at the onset; in 13 the proteinuria improved, in 5 patients it remained stable, and in 1 patient it deteriorated from a proteinuric to nephrotic stage. Partial resolution of amyloidosis was demonstrated by repeat renal biopsy in 1 patient who showed complete resolution of proteinuria. In contrast, none of 14 non-compliant patients improved, and while only 1 patient was in renal failure initially, 10 patients deteriorated to renal failure during the follow-up period. The presence of tubulointerstitial injury at presentation adversely affected the prognosis. In conclusion, when used appropriately, colchicine can improve proteinuria and prevent chronic renal failure in patients with amyloid nephropathy of FMF. The presence of renal failure or tubulointerstitial injury at presentation and non-compliance with therapy are the factors decreasing the success of therapy.

Treatment issues in interstitial lung disease in tropical countries

Management of interstitial lung disease, especially idiopathic pulmonary fibrosis, is both difficult and unsatisfactory. In many patients, only supportive therapy can be instituted. Attempts have been made to use anti-inflammatory therapy to reverse inflammation, provide symptomatic relief, stop disease progression, and prolong survival; the results of such treatment have varied from no improvement to significant prolongation of survival. Corticosteroids are the most frequently used anti-inflammatory agents. Cytotoxic drugs, such as oral azathioprine or intermittent intravenous cyclophosphamide, have also been shown to be effective both alone and in combination with low-dose oral corticosteroids. Of the other antifibrotic drugs that have been used, colchicine seems to provide some benefit. It is especially useful in aged persons and those with corticosteroid-induced problems or concomitant illnesses that are likely to be worsened by steroids. Anti-inflammatory therapy is costly to administer and monitor, particularly in the developing world. It is therefore important to consider these issues before instituting treatment. Younger patients and patients with less-severe disease of recent onset are most likely to respond to treatment. Similarly, patients with lymphocytic alveolitis or desquamative interstitial pneumonia respond better. Despite the use of newer strategies for treatment, the overall prognosis for patients with interstitial lung disease has not really changed, and the median population survival remains almost the same as it was about 30 years ago.

Colchicine in dermatology

Colchicine is a medication most often used to treat symptoms of gout. This drug has also been shown to have beneficial effects on cutaneous conditions, including leukocytoclastic vasculitis, psoriasis, and Sweet's syndrome. Colchicine inhibits the function of polymorphonuclear leukocytes, and dermatoses with a strong presence of these cells may benefit the most from the administration of this medication. A review of the pharmacology, mechanism of action, and adverse reactions of colchicine is also presented.

Colchicine, D-penicillamine, and prednisone in the treatment of idiopathic pulmonary fibrosis: a controlled clinical trial

STUDY OBJECTIVE

We compared the long-term efficacy of the combination of colchicine and/or D-penicillamine with prednisone, in comparison to prednisone alone in patients with idiopathic pulmonary fibrosis (IPF).

DESIGN

Nonrandomized prospective study in patients with IPF confirmed by biopsy specimen.

SETTING

National Institute of Respiratory Diseases, Mexico.

PATIENTS

Fifty-six IPF patients were included in this study. Patients received either colchicine/ prednisone (n=19), D-penicillamine/prednisone (n=11), D-penicillamine/colchicine/prednisone (n=11), or prednisone alone (n=15). Prednisone therapy was started at 1.0 mg/kg/d for 1 month followed by a biweekly taper to a maintenance dose of 15 mg/d. Colchicine was administered at a daily dose of 1.0 mg, and D-penicillamine was given at a daily dose of 600 mg.

MEASUREMENTS AND RESULTS

Response to therapy was assessed by changes in lung function test results as measured by total and vital lung capacities, arterial blood gas analysis at rest breathing room air, and survival. No significant differences either in lung mechanics or in arterial gases were found in any group relative to the baseline measurement. Thirteen of the 56 patients died during the first 2 years, and 29 were dead at 5 years follow-up. Comparison of survival curves by Cox regression model showed no statistically significant difference among the four groups. Known side effects attributable to prednisone were more common and severe than those attributable to the other drugs.

CONCLUSIONS

Our results suggest that neither colchicine nor D-penicillamine modified the progressive course of prednisone-treated IPF, and that the search for new drugs is imperative.

Effect of adenosine analogues on the expression of matrix metalloproteinases and their inhibitors from human dermal fibroblasts

The effect of the cytostatic and antiviral adenosine analogues 3-deazaadenosine (c3Ado) and 3-deaza-(+/-)-aristeromycin (c3Ari) on human skin fibroblasts was studied. Variables examined were cell morphology, viability, DNA fragmentation, expression of matrix metalloproteinases (MMPs) and matrix metalloproteinase inhibitors (TIMPs). None of these variables were changed when cells were exposed to c3Ari concentrations ranging from 10(-5) to 10(-3) M or 10(-5) M c3Ado. However, large changes in cell morphology, viability and expression of MMPs and MMP inhibitors occurred when fibroblasts were treated with 10(-4) or 10(-3) M c3Ado. Cells rounded up, shrank in volume, some detached and viability was lost without any detectable fragmentation of DNA. These changes in morphology and viability were associated with a differentiated expression of MMPs and MMP inhibitors. A large increase in collagenase activity occurred, and depending on the concentration of the adenosine analogue and the length of treatment, this change in activity could be shown to be due to one or a combination of the following factors: an increased synthesis of the collagenase protein, a decreased production of TIMP-1 or an increased activity of the collagenase superactivator, stromelysin. In contrast to this, treatment with c3Ado resulted in a decreased gelatinase activity, which in part could be attributed to an increased production of an inhibitor that seemed to affect gelatinase but not collagenase. The cellular changes induced by c3Ado seemed to reflect some of the alteration in the metabolic machinery that appears during a drug-induced or programmed/controlled death of a dermal cell. The different effects exerted by these two adenosine analogues on dermal fibroblasts can at least in part explain why c3Ado have previously been shown to be more toxic than c3Ari in animal models.

Colchicine for epidermolysis bullosa acquisita

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a chronic subepidermal blistering disease that is difficult to treat. Recently one patient with severe EBA was described who responded dramatically to colchicine.

OBJECTIVE

Our purpose was to determine the efficacy of colchicine in the treatment of EBA.

METHODS

Four patients with severe EBA refractory to conventional therapy were treated with colchicine 0.6 to 1.5 mg a day for up to 4 years.

RESULTS

In all four patients the lessening of skin fragility and the decrease in spontaneous blister formation were dramatic; few side effects were noted.

CONCLUSION

Colchicine should be considered in the treatment of EBA.

Idiopathic sclerosing inflammation of the orbit. A distinct clinicopathologic entity

BACKGROUND

Idiopathic sclerosing inflammation of the orbit is a poorly delineated, fibrosing, immune-mediated entity resulting in significant ocular disability. To characterize this process and propose more specific and effective therapy, clinical and pathologic findings in 16 cases are reviewed.

METHODS

The clinical records of 16 patients with biopsy-proven disease were retrospectively reviewed to determine demographic and clinical features, radiologic features, course, management, and outcome. These findings were correlated with pathologic features to describe this unique entity. Immunohistologic characteristics were compared with those of a clinically and histopathologically similar process, retroperitoneal fibrosis.

RESULTS

The study included 11 male and 5 female patients, ranging in age from 8 to 81 years. Disease onset was usually unilateral (14/16) and chronic (11/15), with two distinct anatomic presentations, lacrimal (11/16) and apical (3/16), characterized by infiltration (15/16), mass effect (12/16), and visual loss (3/16). The most common signs and symptoms were dull pain (13/16), proptosis (11/16), mild inflammation (11/16), restricted motility (9/16), swelling (9/16), and diplopia (8/16). Two features, a sparse, chronic inflammatory infiltrate, the immunopathologic characteristics of which suggested a cell-mediated process, and a desmoplastic stroma of early onset, dominated the pathologic picture. Treatment with corticosteroids (11/16), radiotherapy for steroid failures (8/11), and observation alone (3/16) was inadequate, resulting in blindness in 3/16 cases, restricted movement in 10/16, and complete resolution in only 2/16 patients.

CONCLUSION

Idiopathic sclerosing inflammation of the orbit is a unique clinicopathologic entity, similar to retroperitoneal fibrosis, that is characterized by primary, chronic, and immunologically mediated fibrosis, poor response to corticosteroid treatment or radiotherapy, and frequent visual disability. Early and aggressive immunosuppressive therapy is recommended.

The degradation of collagen in pig synovium in vitro and the effect of colchicine

Colchicine induced a rapid destruction of the collagenous matrix of pig synovial explants in culture in the presence of serum. The most efficacious doses were 0.01-0.1 micrograms/ml (2.5 x 10(-8) M - 2.5 x 10(-7) M). The histological progression of the tissue breakdown induced by colchicine was very similar, although faster, to that described for other agents (Fell et al., 1986), with cells having basophilic nuclei accumulating in areas of fibril degradation. The loss of collagen correlated with an increase in collagenase production and at the peak of resorption (6 to 8 days) active collagenase was present in the culture media. Immunocytochemical methods demonstrated active collagenase bound to collagen fibrils after only 4 days in culture, before significant collagen degradation could be observed histologically. Collagen breakdown was completely inhibited by cortisol, and partially inhibited by indomethacin: only the inhibition by indomethacin could be reversed by exogenous prostaglandin E2. Vinblastine at a higher dose was as effective as colchicine but the lumicolchicines, which do not disrupt microtubules, were ineffective. Although the precise mechanism of action of colchicine is unknown, this culture system provides a useful in vitro model for increasing our understanding of the cellular mechanisms of tissue breakdown and for elucidating the roles of active collagenase and related metalloproteinases.

Clinical and statistical analyses of new and evolving therapies for primary biliary cirrhosis

Primary biliary cirrhosis is a chronic, progressive, cholestatic liver disease thought to be related to abnormalities in immune regulation. The disease is associated with granulomatous bile duct destruction, cholestasis, hepatic copper overloading and the development of hepatic fibrosis or cirrhosis or both. There have been numerous therapeutic trials evaluating immunosuppressive, antifibrotic and cupruretic agents. Prednisolone, D-penicillamine, azathioprine, colchicine and chlorambucil have been evaluated in controlled clinical trials, and biochemical improvement of liver function has been noted with all of the agents, except D-penicillamine. Improved survival has also been reported in patients treated long-term with azathioprine and colchicine. However, none of the therapeutic agents has been demonstrated to halt histologic progression of the disease or to induce a complete clinical, biochemical and histologic remission as has been reported in patients with autoimmune chronic active hepatitis treated with corticosteroids. Many of the trials did not use a double-blind design, failed to use the "intent to treat" rule or failed to define an objective time to analyze results. Many of the studies involved small numbers of patients with short-term follow-up and thus potentially were inadequate to appreciate drug effects that might be of clinical benefit. Currently, there is no totally effective therapy for primary biliary cirrhosis. We believe that well-designed clinical trials can provide important information to better understand this disease until a totally effective therapy is available. New clinical trials should use well-established methodologic guidelines in study design and well-accepted statistical standards in the analysis and interpretation of results.

Cutaneous tissue repair: practical implications of current knowledge. II

This article reviews the scientific basis for the certain factors that delay wound repair in the clinical setting. A brief history of wound healing is given, followed by a discussion of endogenous local factors (bacterial infection, hypoxia, foreign body, and desiccation) and endogenous systemic factors (nutritional deficiencies, aging, coagulation disorders, and the Ehlers-Danlos syndromes) associated with poor wound repair. Also reviewed are the mechanisms by which exogenously administered agents (glucocorticoids, antineoplastic agents, and anticoagulants) may delay healing. Commonly used topical antimicrobials, their spectrum of activity, and evidence of effects on wound healing are examined. Finally, properties of commercially available wound coverings and wound care in the future are discussed.

Sclerodermoid changes of porphyria cutanea tarda: possible relationship to urinary uroporphyrin levels

From 1950 to 1982, fifteen patients were seen at the Mayo Clinic with a diagnosis of sclerodermoid changes of porphyria cutanea tarda. Fourteen patients had changes similar to scleroderma limited to the skin, and one patient had scleroderma-like skin changes accompanied by visceral abnormalities. Both light-exposed and unexposed areas of the body were affected. Areas of involvement included the chest, the V-shaped area of the neck, and the back, face, and shoulders. In six patients, morpheaform changes represented the presenting cutaneous sign of porphyria cutanea tarda. Follow-up examination, after treatment that included abstinence from alcohol and phlebotomy, revealed that the sclerodermoid skin changes had disappeared in six patients and improved in four. Generally, the degree of improvement of the sclerodermoid changes was proportional to the reduction of the urinary uroporphyrin levels toward normal (p = 0.02).

Colchicine-induced modulation of collagenase in human skin fibroblast cultures. II. A probe for defective regulation in epidermolysis bullosa

The addition of colchicine to cultures of normal human skin fibroblasts produces a significant stimulation of collagenase. Because this finding implies a role for the microtubule system in the regulation of normal collagenase synthesis, we have used colchicine as a probe for aberrations in this enzyme in epidermolysis bullosa. In fibroblast cultures from the dominant simplex, dominant dystrophic, and recessive letalis forms of epidermolysis bullosa, 10(-6) M colchicine produced approximately a 2-fold increase in collagenase in the culture medium, a finding shown by biosynthetic studies to be attributable to enhanced synthesis of enzyme protein. In the case of typical recessive dystrophic epidermolysis bullosa, a disease characterized by excessive collagenase synthesis, the fibroblasts could also be stimulated to produce additional collagenase, despite having elevated baseline synthetic rates. In contrast, fibroblasts isolated from one recessive epidermolysis bullosa patient were resistant to the stimulatory effects of colchicine in concentrations up to 5 x 10(-6) M. In the absence of colchicine, collagenase synthesis in this patient's cells (termed REBc-) was 3-4 times that of normal controls, suggesting that the as yet undefined cellular function that is abrogated (or stimulated) by colchicine in normal cells may have been genetically impaired in these REBc- cells. Despite the resistance to colchicine, as manifested by the failure to stimulate collagenase, gross parameters of microtubular function, such as cell replication, were intact. Phenotypically, this patient had a form of epidermolysis bullosa intermediate between typical recessive dystrophic and recessive letalis forms of the disease. Although an experimentally induced blister was located in the lamina lucida, hypoplastic anchoring fibrils were also observed. These findings, in addition to the marked increase in collagenase synthesis, suggest the possibility that this patient may represent a compound heterozygote of two forms of epidermolysis bullosa and that colchicine may be useful in defining other such patients.