CALCINEURIN INHIBITOR-INDUCED RENAL ALLOGRAFT NEPHROTOXICITY

Potential role of circular RNA in cyclosporin A-induced cardiotoxicity in rats

Cyclosporin A (CsA) is a well-known and effective drug that is commonly used in autoimmune diseases and allotransplantation. However, kidney toxicity and cardiotoxicity limit its use. Circular RNAs (circRNAs) play a crucial role in disease, especially cardiovascular disease. We aimed to explore the circRNA expression profiles and potential mechanisms during CsA-induced cardiotoxicity. Sixty male adult Wistar rats were randomly divided into two groups. The CsA group was injected with CsA (15 mg/kg/day body weight) intraperitoneally (ip) for 2 weeks, whereas the control group was injected ip with the same volume of olive oil. We assessed CsA-induced cardiotoxicity by light microscopy, transferase-mediated dUTP nick-end labeling (TUNEL) staining, and electron microscopy. Microarray analysis was used to detect the expression profiles of circRNAs deregulated in the heart during CsA-induced cardiotoxicity. We confirmed the changes in circRNAs by quantitative PCR. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the microarray data were performed. A conventional dose of CsA induced cardiotoxicity in rats. We identified 67 upregulated and 37 downregulated circRNAs compared with those in the control group. Six of 12 circRNAs were successfully verified by quantitative real-time polymerase chain reaction (qRT-PCR). GO analyses of the differentially expressed circRNAs indicated that these molecules might play important roles in CsA-induced cardiotoxicity. KEGG pathway analyses showed that the differentially expressed circRNAs in CsA-induced cardiotoxicity may be related to autophagy or the Hippo signaling pathway. We identified differential circRNA expression patterns and provided more insight into the mechanism of CsA-induced cardiotoxicity. CircRNAs may serve as potential biomarkers or therapeutic targets of CsA-mediated cardiotoxicity in the future.

Calcineurin Inhibitors Nephrotoxicity Prevention Strategies With Stress on Belatacept-Based Rescue Immunotherapy: A Review of the Current Evidence

BACKGROUND

A traditional narrative review was performed to evaluate clinical studies that have examined the clinical implications, risk factors, and prevention of calcineurin inhibitors (CNIs) nephrotoxicity with stress on a belatacept-based rescue regimen.

METHODS

The Cochrane Library, PubMed/MEDLINE, EBSCO (Academic Search Ultimate), ProQuest (Central), and Excerpta Medical databases and Google scholar were searched using the keywords (CNI AND Nephrotoxicity prevention) OR ("Calcineurin inhibitor" AND Nephrotoxicity) OR (Tacrolimus AND Nephrotoxicity) OR (Ciclosporin AND Nephrotoxicity) OR (cyclosporine AND Nephrotoxicity) OR (Belatacept) OR (CNI Conversion) for the period from 1990 to 2020. Fifty-five related articles and reviews were found.

CONCLUSION

A better understanding of the mechanisms underlying calcineurin inhibitor nephrotoxicity could help in the individualization of therapy for and prevention of CNI nephrotoxicity. Identification of high-risk patients for CNI nephrotoxicity before renal transplantation enables better use and selection of immunosuppression with reduced adverse effects and, eventually, successful treatment of the kidney recipients. Belatacept conversion is a good and safe option in patients with deteriorating renal function attributed to CNI nephrotoxicity.

Cyclosporin A inhibits mitochondrial biogenesis in Hep G2 cells

Dysregulation of mitochondrial biogenesis is associated with pathogenesis in many diseases, including liver diseases. Cyclosporine A (CsA), one of the most commonly used drug to treat many autoimmune diseases and to prevent allograft rejection after organ transplantation, has been reported to cause mitochondrial dysfunction. However, the cellular mechanisms underlying CsA on mitochondrial dysfunction remain at present not completely elucidated. In this study, we found that CsA reduced the expression of PGC-1α at both the mRNA and protein levels in HepG2 cells. Correspondingly, the expressions of its target genes NRF 1 and TFAM were reduced in response to CsA treatment. In addition, mtDNA/nDNA, mitochondria mass, ATP production, and cytochrome C oxidase activity were significantly reduced by treatment with CsA. Over-expression of PGC-1α was found to rescue the negative effect of CsA administration on mitochondrial biogenesis. Mechanistically, CREB was involved in the inhibitory effects of CsA in mitochondrial biogenesis.

Two Decades of Tacrolimus in Renal Transplant: Basic Science and Clinical Evidences

Tacrolimus, a calcineurin inhibitor, has been the cornerstone of immunosuppressive regimens in renal transplant over 2 decades. This has significantly improved the outcomes of renal transplant, including reduction of acute rejection episodes, improvement of renal function and graft survival, and reduction of some of the adverse effects associated with cyclosporine. However, use of tacrolimus is associated with a number of undesirable effects, such as nephrotoxicity, posttransplant diabetes mellitus, neurotoxicity, and cosmetic and electrolyte disturbances. To alleviate these effects, several strategies have been adopted to minimize or eliminate tacrolimus from maintenance regimens of immunosuppression, with some success. This review focuses on advancements in the understanding of the basic science related to tacrolimus and the clinical evidences that have examined the efficacy and safety of tacrolimus in renal transplant over the past 2 decades and highlights the future directions.

Senescence in chronic allograft nephropathy

Despite increasing numbers of patients on dialysis, the numbers of renal transplants performed yearly have remained relatively static. During the last 50 years, there have been many advances in the pharmacology of prevention of organ rejection. However, most patients will suffer from a slow but steady decline in renal function leading to graft loss. The most common cause of long-term graft loss is chronic allograft nephropathy (CAN). Therefore, elucidating and understanding the mechanisms involved in CAN is crucial for achieving better posttransplant outcomes. It is thought that the development of epithelial to mesenchymal transition (EMT) in proximal tubules is one of the first steps towards CAN, and has been shown to be a result of cellular senescence. Cells undergoing senescence acquire a senescence associated secretory phenotype (SASP) leading to the production of interleukin-1 alpha (IL-1α), which has been implicated in several degenerative and inflammatory processes including renal disease. A central mediator in SASP activation is the production of reactive oxygen species (ROS), which are produced in response to numerous physiological and pathological stimuli. This review explores the connection between SASP and the development of EMT/CAN in an effort to suggest future directions for research leading to improved long-term graft outcomes.

Indirect treatment comparison of belatacept versus tacrolimus from a systematic review of immunosuppressive therapies for kidney transplant patients

OBJECTIVE

End-stage renal disease is the final and irreversible stage in chronic kidney disease, leading to patient mortality, unless managed by dialysis or transplantation (the treatment of choice). This study aimed to compare a currently recommended immunosuppressive treatment, tacrolimus, against a newer treatment, belatacept, using indirect treatment comparison (ITC) techniques since no head-to-head randomized controlled trials (RCTs) comparing tacrolimus against belatacept currently exist.

METHODS

ITC was employed to calculate estimates for the relative risks and mean difference of tacrolimus against belatacept. The choice of the Bucher ITC model was driven by the available data and the simple indirect treatment comparison involving three treatments was considered appropriate.

RESULTS

The results of the indirect analysis showed no significant differences between belatacept and tacrolimus treatments for mortality and graft loss. The acute rejection rate was significantly lower with tacrolimus (Prograf* and Advagraf (*) ) compared with belatacept (0.22 [0.13, 0.39] to 0.44 [0.20, 0.99]).

CONCLUSIONS

The results of this systematic review and meta-analysis suggests that tacrolimus is significantly superior to belatacept in terms of acute rejection outcomes but comparable for graft and patient survival. Further research should include a properly designed clinical trial comparing tacrolimus against belatacept directly.

LIMITATIONS

These include variations in terms of clinical and design differences among the trials, weaknesses in the Bucher method and the lack of long-term clinical trial data with tacrolimus to compare with the recent long-term (7 years) belatacept trial data.

Comparison of pharmacokinetics and pathology for low-dose tacrolimus once-daily and twice-daily in living kidney transplantation: prospective trial in once-daily versus twice-daily tacrolimus

BACKGROUND

A prolonged-release formulation of tacrolimus (Tacrolimus QD) was developed to allow once-daily dosing and to have similar safety and efficacy profiles to twice-daily tacrolimus (Tacrolimus BID). This study compared the pharmacokinetics (PK) and renal pathology by protocol biopsy in de novo living kidney transplant recipients treated with either low-dose Tacrolimus QD or Tacrolimus BID.

METHODS

Between November 2009 and January 2011, 102 consecutive adult patients were randomized to receive either low-dose Tacrolimus QD or Tacrolimus BID. All patients underwent PK study and protocol biopsy on postoperative day 14. Additional protocol biopsies were performed between 6 and 12 months after renal transplantation.

RESULTS

During the 1-year follow up, the incidence of biopsy-proven acute rejection and toxic tubulopathy was low and similar in both groups. Twenty-four hours area under the curve (AUC0-24) was not different in both groups (285 ± 78.7 and 281 ± 62.4 ng hr/mL in Tacrolimus QD and Tacrolimus BID, respectively). C0 was well correlated with AUC0-24 in both groups and AUC0-24 between 260 and 280 in the Tacrolimus QD group was achieved by 6 to 8 ng/mL of C0. Acute nephrotoxicity was less than 10% in both groups without any clinical manifestation.

CONCLUSION

Clinical efficacy, safety, and PK profile of Tacrolimus QD is same as those of Tacrolimus BID.

Rationale of mesenchymal stem cell therapy in kidney injury

Numerous preclinical and clinical studies suggest that mesenchymal stem cells, also known as multipotent mesenchymal stromal cells (MSCs), may improve pathologic conditions involving different organs. These beneficial effects initially were ascribed to the differentiation of MSCs into organ parenchymal cells. However, at least in the kidney, this is a very rare event and the kidney-protective effects of MSCs have been attributed mainly to paracrine mechanisms. MSCs release a number of trophic, anti-inflammatory, and immune-modulatory factors that may limit kidney injury and favor recovery. In this article, we provide an overview of the biologic activities of MSCs that may be relevant for the treatment of kidney injury in the context of a case vignette concerning a patient at high immunologic risk who underwent a second kidney transplantation followed by the development of ischemia-reperfusion injury and acute allograft rejection. We discuss the possible beneficial effect of MSC treatment in the light of preclinical and clinical data supporting the regenerative and immunomodulatory potential of MSCs.

Anti-apoptotic and anti-oxidant effects of grape seed proanthocyanidin extract in preventing cyclosporine A-induced nephropathy

AIM

Although the pathogenesis of cyclosporine (CsA) nephropathy is not completely understood, it is attributed to oxidative damage and apoptosis. Grape seed proanthocyanidin extract (GSPE) is a molecule with anti-oxidant and anti-apoptotic properties. Our aim was to demonstrate the effects of GSPE in preventing CsA nephropathy.

METHODS

Twenty-four Sprague-Dawley rats were divided into four groups. The control, GSPE, CsA and CsA+GSPE groups were given 1 mL olive oil, 100 mg/kg GSPE, 25 mg/kg CsA and 100 mg/kg GSPE+25 mg/kg CsA, respectively. On day 21, blood samples were taken for blood urea nitrogen (BUN), creatinine and CsA levels, and renal tissue was used for total oxidant system (TOS), total anti-oxidant system (TAS), oxidative stress index (OSI) and malondialdehyde (MDA) measurements. In addition to renal histopathology, apoptosis staining was performed on renal tissue.

RESULTS

The BUN, creatinine, TOS, OSI, MDA, histopathological score, and apoptotic index exhibited increases in the CsA group. In the CsA+GSPE group, however, BUN, creatinine, OSI, MDA, renal histopathological score and apoptotic index (AI) decreased and TAS levels increased. In addition, there was no difference between the CsA and CsA+GSPE groups with regard to CsA levels.

CONCLUSION

We demonstrated that GSPE prevents CsA nephropathy and that this effect is achieved by anti-apoptotic and anti-oxidant activity. We also achieved a significant recovery in kidney functions without affecting CsA plasma levels.