Colchicine decreases apoptotic cell death in chronic cyclosporine nephrotoxicity

Immunomodulatory agents for COVID-19 treatment: possible mechanism of action and immunopathology features

The novel coronavirus pandemic has emerged as one of the significant medical-health challenges of the current century. The World Health Organization has named this new virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first detection of SARS-CoV-2 in November 2019 in Wuhan, China, physicians, researchers, and others have made it their top priority to find drugs and cures that can effectively treat patients and reduce mortality rates. The symptoms of Coronavirus Disease 2019 (COVID-19) include fever, dry cough, body aches, and anosmia. Various therapeutic compounds have been investigated and applied to mitigate the symptoms in COVID-19 patients and cure the disease. Degenerative virus analyses of the infection incidence and COVID-19 have demonstrated that SARS-CoV-2 penetrates the pulmonary alveoli's endothelial cells through Angiotensin-Converting Enzyme 2 (ACE2) receptors on the membrane, stimulates various signaling pathways and causes excessive secretion of cytokines. The continuous triggering of the innate and acquired immune system, as well as the overproduction of pro-inflammatory factors, cause a severe condition in the COVID-19 patients, which is called "cytokine storm". It can lead to acute respiratory distress syndrome (ARDS) in critical patients. Severe and critical COVID-19 cases demand oxygen therapy and mechanical ventilator support. Various drugs, including immunomodulatory and immunosuppressive agents (e.g., monoclonal antibodies (mAbs) and interleukin antagonists) have been utilized in clinical trials. However, the studies and clinical trials have documented diverging findings, which seem to be due to the differences in these drugs' possible mechanisms of action. These drugs' mechanism of action generally includes suppressing or modulating the immune system, preventing the development of cytokine storm via various signaling pathways, and enhancing the blood vessels' diameter in the lungs. In this review article, multiple medications from different drug families are discussed, and their possible mechanisms of action are also described.

Colchicine attenuates renal ischemia-reperfusion-induced liver damage: implication of TLR4/NF-κB, TGF-β, and BAX and Bcl-2 gene expression

Ischemia-reperfusion injury (IRI) is typically associated with a vigorous inflammatory and oxidative stress response to hypoxia and reperfusion that disturbs the function of the organ. The remote effects of renal IRI on the liver, however, require further study. Renal damage associated with liver disease is a common clinical problem. Colchicine, a polymerization inhibitor of microtubules, has been used as an anti-inflammatory and anti-fibrotic drug for liver diseases. The goal of the current study was to investigate the possible protective mechanisms of colchicine on liver injury following renal IRI. Forty rats were divided randomly into four groups: sham group, colchicine-treated group, IRI group, and colchicine-treated + IRI group. Treatment with colchicine significantly reduced hepatic toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB) transcription factor, myeloid differentiation factor 88 (MyD88), and tumor necrosis factor-alpha (TNF-α) contents; downregulated BCL2 associated X apoptosis regulator (BAX) gene expression, transforming growth factor-β (TGF-β) content, and upregulated hepatic B cell lymphoma 2 (Bcl-2) gene expression as compared with the IRI group. Finally, hepatic histopathological examinations have confirmed the biochemical results. Renal IRI-induced liver damage in rats was alleviated by colchicine through its anti-inflammatory, anti-apoptotic, and anti-fibrotic actions.

Colchicine reduces atherosclerotic plaque vulnerability in rabbits

Background and aims

The anti-inflammatory agent colchicine is gaining interest as a treatment for coronary artery disease. However, the effects of colchicine in atherosclerotic animal models are mostly unknown. This study aimed to evaluate colchicine in a rabbit model of atherosclerosis.

Methods

Twenty-two rabbits were fed a 0.5% cholesterol-enriched diet for 10 weeks and then randomized to receive either oral saline (n=11) or colchicine (350 μg/kg/day; n=11) for 6 weeks, with 0.2% cholesterol-diet during the treatment period. We performed intravascular ultrasound imaging (at start and end of treatment) and histology analyses of the descending thoracic aorta. Leucocyte activation was assessed in vitro on blood samples obtained during treatment.

Results

Colchicine prevented positive aortic vascular remodelling (p=0.029 vs placebo). This effect was even more marked at high plasma cholesterol level (third quartile of plasma cholesterol, p=0.020). At high cholesterol level, both atherosclerotic plaque and media areas on histomorphology were reduced by colchicine compared to placebo (p=0.031 and p=0.039, respectively). Plaque fibrosis and macrophage area were reduced by colchicine (Masson's trichrome stain: p=0.038; RAM-11: p=0.026). The plaque vulnerability index, assessed by histology, was reduced by colchicine (p=0.040). Elastin/type I collagen ratio in media was significantly higher with colchicine compared to placebo (p=0.013). At a high level of plasma cholesterol, in vitro LPS challenge revealed a decrease in monocyte activation following treatment with colchicine (p<0.001) and no change in the placebo group (p=0.353).

Conclusions

Colchicine decreases plaque vulnerability with reductions in plaque inflammation, medial fibrosis, outward vascular remodelling and ex vivo monocyte activation.

Repurposing of metformin and colchicine reveals differential modulation of acute and chronic kidney injury

Acute kidney injury (AKI) is a major health problem affecting millions of patients globally. There is no effective treatment for AKI and new therapies are urgently needed. Novel drug development, testing and progression to clinical trials is overwhelmingly expensive. Drug repurposing is a more cost-effective measure. We identified 2 commonly used drugs (colchicine and metformin) that alter inflammatory cell function and signalling pathways characteristic of AKI, and tested them in models of acute and chronic kidney injury to assess therapeutic benefit. We assessed the renoprotective effects of colchicine or metformin in C57BL/6 mice challenged with renal ischemia reperfusion injury (IRI), treated before or after injury. All animals underwent analysis of renal function and biomolecular phenotyping at 24 h, 48 h and 4 weeks after injury. Murine renal tubular epithelial cells were studied in response to in vitro mimics of IRI. Pre-emptive treatment with colchicine or metformin protected against AKI, with lower serum creatinine, improved histological changes and decreased TUNEL staining. Pro-inflammatory cytokine profile and multiple markers of oxidative stress were not substantially different between groups. Metformin augmented expression of multiple autophagic proteins which was reversed by the addition of hydroxychloroquine. Colchicine led to an increase in inflammatory cells within the renal parenchyma. Chronic exposure after acute injury to either therapeutic agent in the context of reduced renal mass did not mitigate the development of fibrosis, with colchicine significantly worsening an ischemic phenotype. These data indicate that colchicine and metformin affect acute and chronic kidney injury differently. This has significant implications for potential drug repurposing, as baseline renal disease must be considered when selecting medication.

Novel colchicine derivatives enhance graft survival after transplantation via suppression of T-cell differentiation and activity

Immunosuppressants are crucial in organ transplantation but their side effects are a trade-off for long-term use. Colchicine has been shown to be effective in various diseases, albeit with many side effects. To enhance the immunosuppressive effects of colchicine, in addition to minimizing its side effects, we attempted to synthesize new colchicine derivatives (KR compounds). In rat cardiac and pancreatic islet allograft, long-term graft survival was identified in KR compound-treated groups. The use of cyclosporine A (CsA) or colchicine inhibited the CD3⁺ and CD4⁺ T-cell proliferation, whereas KR compounds inhibited the CD8⁺ T cells as well as CD4⁺ T cells. KR compounds reduced the apoptosis, interleukin-2 receptor expression, and signal transducer and activator of transcription 3 phosphorylation more than CsA. These results indicate that KR compounds have a potential therapeutic value as novel agents for prevention of graft deterioration by allograft of rejection.

Effects of colchicine on renal fibrosis and apoptosis in obstructed kidneys

BACKGROUND/AIMS

Colchicine is an established drug for microtubule stabilization that may reduce tissue injury. No data were available that its effects may depend on the dosage of colchicine. We investigated the anti-fibrotic and apoptotic effects of various dose of colchicine in a unilateral ureteral obstruction (UUO) model.

METHODS

Thirty-six Sprague-Dawley rats were randomly assigned into six groups. Two sham groups were divided into a vehicle-treated or colchicine-treated group (100 μg/kg/day). Four UUO groups were treated with either vehicle or three different doses of colchicine for 7 days (30, 60, and 100 μg/kg/day, intraperitoneally). All of the animals were sacrificed on day 7.

RESULTS

Colchicine treatment diminished acetylated α-tubulin and tumor growth factor-β immunoreactivities in the cortical area of the 7-day obstructed kidneys, which was in dose dependent manner. Colchicine attenuated tubulointerstitial damage and apoptosis in both cortical and medullary area, and beneficial effects of colchicine therapy were dramatically shown at the higher dosage of colchicine. The expression levels of cleaved caspase-3, ED-1, and fibronectin were decreased in UUO animals.

CONCLUSIONS

We found that the proper dosage of colchicine may have anti-fibrotic and anti-apoptotic effects in obstructed kidneys. For clinical applications, an optimal dose of colchicine should be evaluated to maximize the prevention of renal disease progression.

Colchicine--Update on mechanisms of action and therapeutic uses

OBJECTIVES

To review the literature and provide an update on the mechanisms of action and therapeutic uses of oral colchicine in arthritis and inflammatory conditions.

METHODS

We performed PubMed database searches through June 2014 for relevant studies in the English literature published since the last update of colchicine in 2008. Searches encompassed colchicine mechanisms of action and clinical applications in medical conditions. A total of 381 articles were reviewed.

RESULTS

The primary mechanism of action of colchicine is tubulin disruption. This leads to subsequent down regulation of multiple inflammatory pathways and modulation of innate immunity. Newly described mechanisms include various inhibitory effects on macrophages including the inhibition of the NACHT-LRRPYD-containing protein 3 (NALP3) inflammasome, inhibition of pore formation activated by purinergic receptors P2X7 and P2X2, and stimulation of dendritic cell maturation and antigen presentation. Colchicine also has anti-fibrotic activities and various effects on endothelial function. The therapeutic use of colchicine has extended beyond gouty arthritis and familial Mediterranean fever, to osteoarthritis, pericarditis, and atherosclerosis.

CONCLUSION

Further understanding of the mechanisms of action underlying the therapeutic efficacy of colchicine will lead to its potential use in a variety of conditions.

Mechanisms of cyclosporine-induced renal cell apoptosis: a systematic review

BACKGROUND/AIMS

Chronic cyclosporine A (CsA) nephrotoxicity (CCN) is an important cause of chronic renal dysfunction with no effective clinical intervention. To further elucidate the mechanisms of renal cell apoptosis in CCN, all relevant in vivo studies on this subject were analyzed.

METHODS

We searched for in vivo studies on the mechanisms of CsA-induced renal cell apoptosis in Medline (1966-July 2010), Embase (1980-July 2010) and ISI (1986-July 2010). The studies were evaluated for their quality according to a set of in vivo standards, data extracted according to PICOS, and then synthesized.

RESULTS

Renal cell apoptosis was an important feature of CCN and an important factor of renal dysfunction. First, CsA could upregulate Fas/Fas ligand, downregulate Bcl-2/Bcl-XL, and increase caspase-1 and caspase-3. Second, it could induce oxidative stress and damage the antioxidant defense system. Third, it could increase endoplasmic reticulum stress protein in a dose- and time-dependent manner. Fourth, CsA could impair the urine concentration and decrease the expression of hypertonicity-induced genes. Fifth, CsA-induced renal cell apoptosis was significantly decreased by blocking the angiotensin II type 1 receptor using losartan.

CONCLUSIONS

The in vivo mechanisms for CCN are more complex than those found in vitro. CsA can induce renal cell apoptosis using five pathways in vivo and activated caspases might be the ultimate intersection of these pathways and the common intracellular pathway mediating apoptosis. These data provide new potential points for intervention and need to be confirmed by further studies.

The high glucose-induced stimulation of B1R and B2R expression via CB(1)R activation is involved in rat podocyte apoptosis

AIMS

We examined renal kallikrein-kinin system (KKS) apoptosis and its related signaling pathway in rat podocytes. In addition, we studied the relationship of cannabinoid receptor 1 (CB(1)R) with high glucose and BK receptors.

MAIN METHODS

Cell viability was determined by an MTT assay and apoptosis by DNA fragmentation assay, while gene expression was investigated by RT-PCR. Protein expression was analyzed by Western blot analysis. A chemical inhibitor or siRNA transfection was used to inhibit B1R, B2R, and CB(1)R signaling.

KEY FINDINGS

High glucose (25 mM) treatment decreased cell viability and increased DNA fragmentation. High glucose-induced DNA fragmentation and PARP and caspase-3 activations were blocked by both [des-Arg(10)]-HOE 140 (a B1R antagonist) and HOE 140 (a B2R antagonist). High glucose also increased Akt phosphorylation, ER stress-related protein expression, and NF-κB/I-κB phosphorylation in podocytes, which was blocked by both [des-Arg(10)]-HOE 140 and HOE 140. In addition, B1R and B2R siRNA transfections prevented high glucose-induced Akt and NF-κB activations in rat podocytes. Moreover, AM251 (a CB(1)R antagonist) treatment and CB(1)R siRNA transfection blocked the high glucose-induced stimulation of BK receptor expression, Akt activation, and NF-κB activation.

SIGNIFICANCE

Our study suggests that hyperglycemia induces apoptosis via the stimulation of B1R and B2R expression through CB(1)R activation in rat podocytes in vitro, which is associated with the development of diabetic nephropathy.

Colchicine-induced apoptosis in human normal liver L-02 cells by mitochondrial mediated pathways

Colchicine is an alkaloid that has been widely used to treat gout. It also has a curative effect on cancer. Although many studies have shown that its effect on cell apoptosis was mediated by the activation of caspase-3, the pathways involved in the process remained obscure. Here we show some evidence regarding the missing information using human normal liver cells L-02 in our study. The effect of colchicine on apoptosis in L-02 cells and the apoptosis-associated signaling pathways were determined using different tests including cell viability assay, Annexin V and propidium idodide binding, PI staining, Hoechst 33342 staining, mitochondrial membrane potential assay, caspase activity assay and Western blot analysis. We found that colchicine-induced a dose-dependent drop of cell viability in L-02 cells; early apoptosis happened when cells were treated with 0.1μM of colchicine. The colchicine-induced loss of mitochondrial membrane potential, activation of caspase-3 and 9, up-regulation of Bax and down-regulation of Bcl-2 showed an evidence for the colchicine activity on apoptosis, at least, by acting via the intrinsic apoptotic pathway.

Melatonin suppresses cyclosporine A-induced autophagy in rat pituitary GH3 cells

Cyclosporine A (CsA) is a powerful immunosuppressive drug with side effects including the induction of chronic nephrotoxicity including endoplasmic reticulum (ER) stress in tubular cells. Recently, it was reported that autophagy is induced by ER stress and serves to alleviate the associated deleterious effects. In the current study, CsA treatment (0-100 microm) decreased cell survival of rat pituitary GH3 cells in a dose-dependent manner. At concentrations ranging from 1.0 to 10 microm, CsA induced a dose-dependent increase in the expression of microtubule-associated protein 1 light chain 3 (LC3)-I and LC3-II. Cells treated with 2.5 microm CsA exhibited cytoplasmic vacuolation, indicating that CsA induces autophagy in rat pituitary GH3 cells. In the presence of 1.0-10 microm CsA, the expression of catalase decreased while that of the ER stress markers, ER luminal binding protein (BiP) and inositol-requiring enzyme 1 alpha (IRE1alpha), increased as compared those levels in untreated cells. These results suggested that CsA-induced autophagy is dependent on ER stress. To determine whether melatonin would protect cells against CsA-induced autophagy, we treated rat pituitary GH3 cells with melatonin in the presence of CsA. Melatonin treatment (100 and 200 microm) suppressed autophagy induced by 2.5 and 5 microm CsA. Furthermore, co-treatment with 100 microm melatonin inhibited LC3-II expression, and increased catalase and phosphorylated p-ERK levels in the presence of 2.5 and 5 microm CsA. BiP and IRE1alpha expression in melatonin-co-treated cells was superior to that in cells treated with 2.5 and 5 microm CsA alone. Thus, melatonin suppresses CsA-mediated autophagy in rat pituitary GH3 cells.

Colchicine treatment in autosomal dominant polycystic kidney disease: many points in common

Autosomal dominant polycystic kidney disease (ADPKD) is the most common of the inherited renal cystic diseases and constitutes 10% of the end stage kidney disease population. ADPKD is caused by PKD1 and PKD2 gene mutations in 85% and 15% of the cases respectively. Its high prevalence and negative impact on health outcomes fostered efforts to explain pathophysiologic pathways of cyst formation in kidneys. Among these are increased apoptosis, unopposed proliferation of tubule cells, impaired polarization and planar cell polarity, impaired cAMP pathway, cilier dysfunction, activated mTOR pathway, increased tumor necrosis factor-alpha (TNF-alpha) production. Many drugs have been tried in an attempt to halt cystogenesis in some point. Despite success to some extent in experimental studies, none reached clinical armamentarium yet. Colchicine, originally extracted from Colchicum autunale, is an anti-inflammatory drug that has been in continuous use for more than 3000 years. It has been used successfully to prevent attacks of familial mediterranien fever and amyloidosis, to treat gout and pseudogout attacks for a few decades. Colchicine principally is a microtubule inhibitor, thus prevents cell migration, division, and polarization. It also has anti-apoptotic, anti-proliferative and anti-inflammatory effects and down-regulates (TNF-alpha) receptors. As can easily be seen, many of the effects of colchicine have pathophysiologic counterparts in ADPKD. Thus, we hypothesized that colchicine would be beneficial to prevent or at least delay cyst formation in ADPKD patients. Indirect evidence also support our hypothesis, in which taxol and paclitaxel, other two microtubule inhibitors, were shown to delay cyst formation in experimental models of ADPKD. To our opinion, despite its narrow therapeutic index, widespread experience makes colchicine a suitable candidate for prolonged clinical use, should experimental studies show any benefit in ADPKD.

The pathogenesis and treatment of chronic allograft nephropathy

Despite improvements in immunosuppressive therapy, long-term allograft survival after kidney transplantation remains as low as 50%. Chronic allograft nephropathy (CAN) is a major cause of late graft loss in renal transplant recipients. The histopathologic signs of CAN-interstitial fibrosis, tubular atrophy, glomerulopathy and vasculopathy-are nonspecific; therefore, the 2007 Banff classification dispensed with the term CAN in favor of 'interstitial fibrosis and tubular atrophy without evidence of any specific etiology'. In this Review, however, the term CAN is used to describe a clinical syndrome that is characterized by progressive decline in renal function from 3 months after transplantation, accompanied by the development of proteinuria and hypertension. The pathogenesis of CAN is complex and incompletely understood, and involves several immunological and non-immunological factors. We discuss the contributory roles of acute rejection, donor age, anti-human-leukocyte-antigen antibodies, calcineurin inhibitor nephrotoxic effects, viral infection, hypertension and hyperlipidemia. The prevention and treatment of CAN needs multidisciplinary strategies. Early detection by means of protocol biopsy and calculation of glomerular filtration rate is the first step, followed by management of modifiable risk factors.

Established and newly proposed mechanisms of chronic cyclosporine nephropathy

Cyclosporine (CsA) has improved patient and graft survival rates following solid-organ transplantation and has shown significant clinical benefits in the management of autoimmune diseases. However, the clinical use of CsA is often limited by acute or chronic nephropathy, which remains a major problem. Acute nephropathy depends on the dosage of CsA and appears to be caused by a reduction in renal blood flow related to afferent arteriolar vasoconstriction. However, the mechanisms underlying chronic CsA nephropathy are not completely understood. Activation of the intrarenal renin-angiotensin system (RAS), increased release of endothelin-1, dysregulation of nitric oxide (NO) and NO synthase, up-regulation of transforming growth factor-beta1 (TGF-beta1), inappropriate apoptosis, stimulation of inflammatory mediators, enhanced innate immunity, endoplasmic reticulum stress, and autophagy have all been implicated in the pathogenesis of chronic CsA nephropathy. Reducing the CsA dosage or using other renoprotective drugs (angiotensin II receptor antagonist, mycophenolate mofetil, and statins, etc.) may ameliorate chronic CsA-induced renal injury. This review discusses old and new concepts in CsA nephropathy and preventive strategies for this clinical dilemma.

Colchicine attenuates inflammatory cell infiltration and extracellular matrix accumulation in diabetic nephropathy

Recent studies have demonstrated that an inflammatory mechanism contributes to the pathogenesis of diabetic nephropathy (DN). It is also known that colchicine (Col) can prevent various renal injuries via its anti-inflammatory action. However, the effect of colchicine on DN has never been explored. This study was undertaken to elucidate the effect of colchicine on inflammation and extracellular matrix accumulation in DN. In vivo, 64 rats were injected with diluent (C; n = 32) or streptozotocin intraperitoneally (DM, n = 32). Sixteen rats from each group were treated with Col. In vitro, rat mesangial cells and NRK-52E cells were cultured in media with 5.6 mM glucose (NG) or 30 mM glucose (HG) with or without 10(-8) M Col. Monocyte chemotactic protein-1 (MCP-1) mRNA expression was determined by real-time PCR (RT-PCR), and the levels of MCP-1 in renal tissue and culture media were measured by ELISA. RT-PCR and Western blotting were also performed for intercellular adhesion molecule-1 (ICAM-1) and fibronectin (FN) mRNA and protein expression, respectively, and immunohistochemical staining (IHC) for ICAM-1, FN, and ED-1 with renal tissue. Twenty-four-hour urinary albumin excretion at 6 wk and 3 mo were significantly higher in DM compared with C rats (P < 0.05), and colchicine treatment significantly reduced albuminuria in DM rats (P < 0.05). Col significantly inhibited the increase in MCP-1 mRNA expression and protein levels under diabetic conditions both in vivo and in vitro. ICAM-1 and FN expression showed a similar pattern to the expression of MCP-1. IHC revealed that the number of ED-1(+) cells were significantly higher in DM compared with C kidney (P < 0.005), and this increase was significantly attenuated by Col treatment (P < 0.01). In conclusion, Col prevents not only inflammatory cell infiltration via inhibition of enhanced MCP-1 and ICAM-1 expression but also ECM accumulation in DN. These findings provide a new perspective on the renoprotective effects of Col in DN.

Colchicine update: 2008

OBJECTIVES

To review recent advances in the understanding of molecular mechanisms of drug disposition and cellular mechanisms of action and targets of colchicine, and disease applications and guidelines for oral colchicine use.

METHODS

Summarized and interpreted here is the pertinent English and non-English language literature on MEDLINE since the last update of colchicine in this journal in 1998 and published up to July 2008 regarding colchicine pharmacology, toxicology, mechanisms of action, and clinical applications in gout and other medical conditions.

RESULTS

Assessment, after review of 1512 publications, is that oral colchicine therapy is being refined by attention to novel targets such as NALP3 and pyrin. The drug has a narrow therapeutic-toxicity window, and potentially serious drug-drug interactions (eg, with clarithromycin and cyclosporine) are better recognized and therefore preventable. Reviewed here are recent advances in colchicine pharmacogenomics, and recognition of drug-drug interactions and predictors of potential toxicities, including alterations in the P-glycoprotein multidrug transporter ABCB1, cytochrome P450 3A4 isoenzyme, and hepatobiliary and renal function. Current understanding of optimization of colchicine dosing is reviewed, as are recent findings on colchicine therapy of nonrheumatic cardiovascular, hepatic, and renal diseases (eg, lowering of C-reactive protein, and treatment of acute and recurrent pericarditis). Finally, the article reviews the recent U.S. Food and Drug Administration-mandated cessation of marketing of injectable colchicine.

CONCLUSIONS

Oral colchicine has unique anti-inflammatory and antiproliferative effects with broad ramifications for rheumatic and nonrheumatic disease applications. Significant advances in the last decade have increased understanding of predictors of both colchicine efficacy and toxicity.

Induction of apoptosis by lupeol and mango extract in mouse prostate and LNCaP cells

Prostate cancer (PCA) is one of the most invasive malignancy and second leading cause of cancer related deaths in United States and some other countries. Long latency period makes PCA an ideal disease for pharmacologic or nutritional chemoprevention. Lupeol, a triterpene present in mango and other fruits, has shown to possess anticancer properties in in vivo and in vitro assays. Here, we recorded the apoptogenic activity in mouse prostate by lupeol and mango pulp extract (MPE). Testosterone was injected subcutaneously (5 mg/kg body weight) for 14 consecutive days to male Swiss albino mice. Lupeol/MPE supplementation resulted in arrest of prostate enlargement in testosterone-treated animals. In mouse prostate tissue, lupeol and MPE supplementation resulted in a significantly high percentage of apoptotic cells in the hypodiploid region. The induction of apoptosis in mouse prostate cells was preceded by the loss of mitochondrial transmembrane potential and DNA laddering. In testosterone-induced mouse prostate, upregulation of antiapoptotic B-cell non-Hodgkin lymphoma-2 and downregulation of proapoptotic Bcl-2-associated X protein and caspase-3 were also recorded. We further observed apoptogenic activities of lupeol in an in vitro model using human prostate cancer cells [lymph node carcinoma of the prostate (LNCaP)]. The apoptogenic response of lupeol-induced changes in LNCaP cells can be summarized as early increase of reactive oxygen species followed by induction of mitochondrial pathway leading to cell death. Thus, the results of this study demonstrate that lupeol/MPE is effective in combating testosterone-induced changes in mouse prostate as well as causing apoptosis by modulating cell-growth regulators.

Blockade of angiotensin II with losartan attenuates transforming growth factor-beta1 inducible gene-h3 (betaig-h3) expression in a model of chronic cyclosporine nephrotoxicity

BACKGROUND

We recently demonstrated that upregulation of the transforming growth factor (TGF)-beta1 inducible gene-h3 (betaig-h3) is associated with tubulointerstitial fibrosis (TIF) in a rat model of chronic cyclosporine A (CsA) nephrotoxicity. This study investigated the association between betaig-h3 expression and TIF during losartan treatment in this model.

METHODS

Adult Sprague-Dawley rats kept on a salt-depleted diet (0.05% sodium) were treated daily for 4 weeks with vehicle (olive oil, 1 ml/kg), CsA (15 mg/kg) or both CsA and losartan (10 mg/kg in drinking water). The effect of losartan on betaig-h3 expression was evaluated using in situ hybridization, immunohistochemistry and immunoblotting. Histopathology, expressions of TGF-beta1 and intrarenal angiotensin II were compared across treatment groups.

RESULTS

Concurrent administration of losartan significantly attenuated betaig-h3 mRNA and protein expression within the tubulointerstitium of CsA-treated kidneys. This was accompanied by the retardation of TIF (18 +/- 5 vs. 39 +/- 5%, p < 0.01 vs. CsA) and the expression of TGF-beta1 mRNA (336 +/- 49 vs. 685 +/- 63%, p < 0.01 vs. CsA) and the number of angiotensin II-positive glomeruli (18 +/- 5 vs. 38 +/- 6, p < 0.05 vs. CsA).

CONCLUSION

Losartan is capable of abrogating the upregulation of TGF-beta1 and betaig-h3 expression, and this is associated with attenuated tubulointerstitial fibrosis in chronic CsA nephrotoxicity.

Protective effect of peroxisome proliferator activated receptor gamma agonists on diabetic and non-diabetic renal diseases

Peroxisome proliferator activated receptor gamma (PPARgamma) agonist has not only antidiabetic effect but also a protective effect against various types of injury of the kidney. The protective effects of PPARgamma agonists are observed in diabetic nephropathy and non-diabetic renal diseases such as 5/6 ablation model of renal failure, experimental glomerulonephritis, ischemia-reperfusion injury, hypertensive nephropathy and cyclosporin-induced renal injury. The mechanism of renoprotection by PPARgamma agonist is multifactorial. Anti-fibrotic and anti-inflammatory effects, suppression of renin-angiotensin system, vascular protective effect and antiapoptotic effect were proposed.

Effect of colchicine on cyclosporine nephrotoxicity, reduction of TGF-beta overexpression, apoptosis, and oxidative damage: an experimental animal study

BACKGROUND

Proinflamatory and profibrotic cytokines may be responsible for the cyclosporine A nephrotoxicity. Increased levels of apoptosis, free oxygen redicals, and transforming growth factor beta (TGF-beta), may play an important roles in the pathogenesis of nephrotoxicity. In this experimental animal study, we sought to investigate the effects of colchicine on the cyclosporine nephrotoxicity.

METHOD

Twenty-four Wistar albino rats were divided into three groups: cyclosporine 15 mg/kg subcutaneously (SC); cyclosporine 15 mg/kg SC plus colchicine 30 mcg/kg orally; and a control group; equal doses of olive oil orally were administered to groups 1, 2, and 3. Renal function, cyclosporine levels, and serum malonyldialdehyde (MDA) levels were measured at the end of 4 weeks. Apoptosis, TGF-beta, and other findings were detected in renal tissue with the TUNEL method, with a immunohistochemical method, and with routine staining procedures, respectively.

RESULTS

There were significant differences in the values of mean creatinine clearance between group 1 and group 3 and between group 2 and group 3 (P < .05 for each comparison), but not between group 1 and group 2 (P > .05). MDA levels in group 1 were high compared with the control group (P < .05) with a trend toward elevation relative to group 2 but the results were not statistically significant (P > .05). Renal tubular vacuolization in group 1 and group 2 animal were greater than in the control group, but no significant difference were observed between any of the groups (P > .05). Mononuclear cell infiltration in group 1 and group 2 hosts were higher than the control group, but there was no significant differences between the groups (P > .05). Afferent arteriolar hyalinization was observed group 1 and 2 but not group 3. There was a statistically significant difference between group 1 and group 3 and between group 2 and group 3 (P < .05 for each comparison). The expression level of TGF-beta was higher in group 1 than group 2 or group 3 (P <.05 for each comparison) but group 2 and group 3 were similar (P > .05). Apoptotic cell death count of group 1 was higher than that in group 2 or group 3 (P < .05, for each comparison); moreover, group 2 also showed greater numbers of apoptotic cells than group 3 (P < .001). At the end of the 4 weeks, there was no intersititial fibrosis in any of the hosts.

CONCLUSION

While cyclosporine caused increased TGF-beta expression and apoptotic cell death in the renal tissue of rats colchicine prevented the increase in MDA serum levels, TGF-beta expression, and apoptosis in renal tissue. Our study suggests that colchicine may diminish the cyclosporine nephrotoxicity by its suppressing the expression of TGF-beta, apoptotic cell death, and MDA production.

The effect of alpha-melanocyte-stimulating hormone on renal tubular cell apoptosis and tubulointerstitial fibrosis in cyclosporine A nephrotoxicity

BACKGROUND

The pathogenesis of cyclosporine A (CsA)-induced nephrotoxicity has been known to be secondary to hemodynamic changes, but increasing evidence indicates that CsA has a direct toxicity to renal tubular cells, leading to their apoptosis and tubulointerstitial fibrosis. This study evaluated the mechanism for CsA-induced tubular cell apoptosis, tubulointerstitial fibrosis and its associated proteins, and the therapeutic effects of alpha-melanocyte-stimulating hormone (MSH) on them.

METHODS

Male Sprague-Dawley rats fed with a low-sodium diet were divided into three treatment groups: group A (vehicle-injected group), group B (CsA 15 mg/kg-injected group), and group C(CsA+alpha-MSH-injected group). After 42 days, creatinine clearance; blood CsA level; apoptosis; inflammation and tubulointerstitial fibrosis in renal tissue; and the expression of Bax, Bcl2, Fas, FasL, and transforming growth factor (TGF)-beta protein were determined.

RESULTS

CsA-induced tubular cell apoptosis; cellular infiltration; and increase of Fas, Bax, TGF-beta protein expression with significant tubulointerstitial fibrosis, and reduced Bcl2 protein expression. alpha-MSH treatment prevented the Bax and TGF-beta protein increase and induced Bcl2 protein increase, together with reduction of apoptosis, inflammation, and tubulointerstitial fibrosis.

CONCLUSIONS

These findings suggest that chronic CsA nephrotoxicity is related to Bax and Bcl2-related apoptosis pathways, and that alpha-MSH can attenuate the CsA-induced tubulointerstitial fibrosis as well as tubular cell apoptosis.

Attenuation of interstitial inflammation and fibrosis by recombinant human erythropoietin in chronic cyclosporine nephropathy

BACKGROUND

Evidence suggests that recombinant human erythropoietin (rHuEPO) protects neurons and cardiomyocytes from acute insults. We investigated the protective effect of rHuEPO on cyclosporine (CsA)-induced renal injury.

METHODS

CsA (15 mg/kg/day) was given to rats for 1 or 4 weeks, and rHuEPO was concurrently administered at a dose of 100 units/kg (thrice weekly). Effects of rHuEPO on CsA-induced renal injury were evaluated with tubulointerstitial fibrosis (TIF) score, macrophage infiltration, expression of proinflammatory and profibrotic cytokines, and apoptotic cell death.

RESULTS

Administration of rHuEPO decreased TIF score and the number of macrophages, which increased significantly in CsA-treated rat kidneys. At the molecular level, rHuEPO treatment decreased proinflammatory mediators (osteopontin and C-reactive protein) and profibrotic mediators (transforming growth factor-beta1 and transforming growth factor-beta1-inducible gene-h3). Increased apoptotic cell death in CsA-treated rat kidneys was significantly decreased with rHuEPO cotreatment, and apoptosis-related genes were regulated in favor of cell survival (increased Bcl-2 and suppressed caspase-3).

CONCLUSION

rHuEPO has a renoprotective effect against chronic CsA-induced renal injury.

Apoptosis in Hep2 cells treated with etoposide and colchicine

When malignant cells undergo apoptosis, they exhibit many distinct patterns of behavior, with blebbing being one of the most spectacular and mysterious features. Despite huge advancements in our understanding of cell death, the mechanisms of apoptosis associated blebbing have not been elucidated. In order to verify the putative involvement of actin and tubulin in this process, Hep2 cells were treated with a combination of etoposide (10 microg/ml) and colchicine (0.2 microg/ml) for 24 h. Blebbing was analyzed using immunofluorescence staining of actin and tubulin, and the course of apoptosis was followed by time-lapse videomicroscopy, immunofluorescence detection of caspase-3 and cytokeratin fragment 18. The results indicate that microfilaments (actin) and not microtubules (tubulin) are involved in blebbing of Hep2 cells. Furthermore, despite the different mechanisms by which both chemicals act, their combined effects are not additive, but rather eliminate each other.

Reversibility of chronic cyclosporine nephropathy in rats after withdrawal of cyclosporine

Renal interstitial inflammation is an important factor in the pathogenesis of chronic cyclosporin A (CsA) nephropathy. We studied the expression of the chemoattractant osteopontin (OPN) and the relationship between OPN expression and tubulointerstitial injury in a rat model of chronic CsA nephropathy. Chronic CsA nephropathy was induced in Sprague-Dawley rats by administering CsA (15 mg/kg sc) for 5 wk and then withdrawing it for 5 or 10 wk. Renal function, histopathology (arteriolopathy, ED-1-positive cells, and tubulointerstitial fibrosis), renin-angiotensin system (RAS) activity, and OPN expression were observed during the follow-up period. Renal function deteriorated in CsA-treated rats, with the development of typical histopathology and activation of RAS. After CsA withdrawal, these parameters were significantly reversed (all P < 0.05). The upregulation of OPN mRNA and protein expression seen in CsA-treated rat kidneys was decreased 5 wk after CsA withdrawal and was further decreased after 10 wk. Of note, OPN mRNA expression correlated with the number of infiltrating macrophage (r = 0.651, P < 0.01) and tubulointerstitial fibrosis (r = 0.729, P < 0.01). These findings suggest that OPN expression and macrophage infiltration decrease after long-term CsA withdrawal in rats with established chronic CsA nephropathy, and this is closely associated with recovery from renal injury.