Cyclosporine renal dysfunction

In Silico Evaluation of Cyclophilin Inhibitors as Potential Treatment for SARS-CoV-2

BACKGROUND

The advent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provoked researchers to propose multiple antiviral strategies to improve patients' outcomes. Studies provide evidence that cyclosporine A (CsA) decreases SARS-CoV-2 replication in vitro and decreases mortality rates of coronavirus disease 2019 (COVID-19) patients. CsA binds cyclophilins, which isomerize prolines, affecting viral protein activity.

METHODS

We investigated the proline composition from various coronavirus proteomes to identify proteins that may critically rely on cyclophilin's peptidyl-proline isomerase activity and found that the nucleocapsid (N) protein significantly depends on cyclophilin A (CyPA). We modeled CyPA and N protein interactions to demonstrate the N protein as a potential indirect therapeutic target of CsA, which we propose may impede coronavirus replication by obstructing nucleocapsid folding.

RESULTS

Finally, we analyzed the literature and protein-protein interactions, finding evidence that, by inhibiting CyPA, CsA may impact coagulation proteins and hemostasis.

CONCLUSIONS

Despite CsA's promising antiviral characteristics, the interactions between cyclophilins and coagulation factors emphasize risk stratification for COVID patients with thrombosis dispositions.

Protecting Intestinal Microenvironment Alleviates Acute Graft-Versus-Host Disease

Acute gut graft-versus-host disease (aGVHD) is a leading threat to the survival of allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Abnormal gut microbiota is correlated with poor prognosis in allo-HSCT recipients. A disrupted intestinal microenvironment exacerbates dysbiosis in GVHD patients. We hypothesized that maintaining the integrity of the intestinal barrier may protect gut microbiota and attenuate aGVHD. This hypothesis was tested in a murine aGVHD model and an in vitro intestinal epithelial culture. Millipore cytokine array was utilized to determine the expression of proinflammatory cytokines in the serum. The 16S rRNA sequencing was used to determine the abundance and diversity of gut microbiota. Combining Xuebijing injection (XBJ) with a reduced dose of cyclosporine A (CsA) is superior to CsA alone in improving the survival of aGVHD mice and delayed aGVHD progression. This regimen also reduced interleukin 6 (IL-6) and IL-12 levels in the peripheral blood. 16S rRNA analysis revealed the combination treatment protected gut microbiota in aGVHD mice by reversing the dysbiosis at the phylum, genus, and species level. It inhibited enterococcal expansion, a hallmark of GVHD progression. It inhibited enterococcal expansion, a hallmark of GVHD progression. Furthermore, Escherichia coli expansion was inhibited by this regimen. Pathology analysis revealed that the combination treatment improved the integrity of the intestinal tissue of aGVHD mice. It also reduced the intestinal permeability in aGVHD mice. Besides, XBJ ameliorated doxorubicin-induced intestinal epithelial death in CCK-8 assay. Overall, combining XBJ with CsA protected the intestinal microenvironment to prevent aGVHD. Our findings suggested that protecting the intestinal microenvironment could be a novel strategy to manage aGVHD. Combining XBJ with CsA may reduce the side effects of current aGVHD prevention regimens and improve the quality of life of allo-HSCT recipients.

Evaluation of 10 Urinary Biomarkers for Renal Safety With 5 Nephrotoxicants in Nonhuman Primates

To date, there has been very little published data evaluating the performance of novel urinary kidney biomarkers in nonhuman primates (NHPs). To assess the biomarker performance and characterize the corresponding histomorphologic patterns of tubular renal injury in the NHP, several studies were conducted using mechanistically diverse nephrotoxicants including cefpirome, cisplatin, naproxen, cyclosporine, and a combination of gentamicin with everninomicin. An evaluation of 10 urinary biomarkers (albumin, clusterin, cystatin C, kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, N-acetyl-β-D-glucosaminidase, osteopontin, retinol binding protein 4 and total protein) was performed on urine collected from these studies. Each of these 5 treatments resulted in kidney proximal tubule injury of various severities. Histomorphologic features observed following treatment were generally consistent with analogous drug-induced changes in humans described in the literature. Most of the analyzed biomarkers were able to detect the injury earlier and with greater sensitivity than blood urea nitrogen and serum creatinine. Across all studies, KIM-1 and clusterin showed the highest overall performance. Differences in the patterns of biomarker responsiveness were noted among certain studies that may be informing tubular injury severity and recovery potential, underlying histopathologic processes, and prognosis. These findings demonstrate the utility of urinary kidney translational safety biomarkers in NHPs and provide additional supporting evidence for translating these biomarkers for use in clinical trial settings to further ensure patient safety.

Bone Mineral Density in Relation to Chronic Kidney Disease After Heart Transplantation: A Retrospective Single-center Study at Skåne University Hospital in Lund 1988-2016

Background.

Our aim was to investigate the bone mineral density (BMD) evolution and incidence of osteoporosis in relation to chronic kidney disease (CKD) up to 10 years after heart transplantation (HT).

Methods.

A retrospective analysis was performed on 159 HT patients at Skåne University Hospital in Lund 1988–2016.

Results.

The median follow-up time was 6.1 years (interquartile range = 7.5 y). HT patients with CKD stage <3 or normal kidney function before HT exhibited a greater mean BMD loss in the lumbar spine, compared to patients with CKD stage ≥3 before HT, at the first (−6.6% versus −2.5%, P = 0.029), second (−3.7% versus 2.1%, P = 0.018), and third (−2.0% versus 4.1%, P = 0.047) postoperative years, respectively. All included HT patients exhibited a BMD loss in the femoral neck at the first postoperative year (−8.8% [−10.3 to −7.3] in patients with CKD stage <3 or normal kidney function and −9.3% [−13.2 to −5.5] in patients with CKD stage ≥3 before HT), which was not fully reversed up to 10 years after HT. In adjusted models, CKD stage <3 before HT did not predict osteopenia and osteoporosis in the lumbar spine or femoral neck.

Conclusions.

CKD before HT did not predict BMD loss or osteoporosis development after HT. The study is, however, limited by a lack of data on fractures, and further studies on the relationship between CKD and postoperative bone strength are encouraged.

The immunosuppressive activity of polymeric micellar formulation of cyclosporine A: in vitro and in vivo studies

We have previously developed micelles of methoxy poly(ethylene oxide)-b-poly(ε-caprolactone) as vehicles for the solubilization and delivery of cyclosporine A (CsA). These micelles were able to reduce the renal uptake and nephrotoxicity of CsA. The purpose of the current study was to test the efficacy of polymeric micellar formulation of CsA (PM-CsA) in suppressing immune responses by either T cells or dendritic cells (DCs). The performance of PM-CsA was compared to that of the commercially available formulation of CsA (Sandimmune®). Our results demonstrate that PM-CsA could exert a potent immunosuppressive effect similar to that of Sandimmune® both in vitro and in vivo. Both formulations inhibited phenotypic maturation of DCs and impaired their allostimulatory capacity. Furthermore, both PM-CsA and Sandimmune® have shown similar dose-dependent inhibition of in vitro T cell proliferative responses. A similar pattern was observed in the in vivo study, where T cells isolated from both PM-CsA-treated and Sandimmune®-treated mice have shown impairment in their proliferative response and IFN-γ production at similar levels. These results highlight the potential of polymeric micelles to serve as efficient vehicles for the delivery of CsA.

The NRF2-heme oxygenase-1 system modulates cyclosporin A-induced epithelial-mesenchymal transition and renal fibrosis

Epithelial-mesenchymal transition (EMT) is an underlying mechanism of tissue fibrosis, generating myofibroblasts, which serve as the primary source of extracellular matrix production from tissue epithelial cells. Recently, EMT has been implicated in immunosuppressive cyclosporin A (CsA)-induced renal fibrosis. In this study, the potential role of NRF2, which is the master regulator of genes associated with the cellular antioxidant defense system, in CsA-induced EMT renal fibrosis has been investigated. Pretreatment of rat tubular epithelial NRK-52E cells with sulforaphane, an activator of NRF2, could prevent EMT gene changes such as the loss of E-cadherin and the increase in alpha-smooth muscle actin (alpha-SMA) expression. Conversely, genetic inhibition of NRF2 in these cells aggravated changes in CsA-induced EMT markers. These in vitro observations could be confirmed in vivo: CsA treatment resulted in severe renal damage and fibrosis with increased expression of alpha-SMA in NRF2-deficient mice compared to wild-type mice. NRF2-mediated amelioration of CsA-caused EMT changes could be accounted for in part by the regulation of heme oxygenase-1 (HO-1). CsA treatment increased HO-1 expression in an NRF2-dependent manner in NRK cells as well as in murine fibroblasts. Induction of HO-1 by CsA seems to be advantageous in that it counteracts EMT gene changes: specific increase in HO-1 expression caused by cobalt protoporphyrin prevented CsA-mediated alpha-SMA induction, whereas genetic inhibition of HO-1 by siRNA substantially enhanced alpha-SMA induction compared to control cells. Collectively, our results suggest that the NRF2-HO-1 system plays a protective role against CsA-induced renal fibrosis by modulating EMT gene changes.

A 50% reduction in cyclosporine exposure in stable renal transplant recipients: renal function benefits

BACKGROUND

Although cyclosporine maintenance therapy reduces the risk of acute rejection and increases short-term graft survival in renal transplant recipients, its associated nephrotoxicity increases the risk of chronic graft dysfunction. The dose that allows an optimal risk-to-benefit ratio has not been established.

METHODS

This multicentre study enrolled stable renal allograft recipients receiving cyclosporine and mycophenolate mofetil without corticosteroids in their second year post-transplant. Patients were randomized to a cyclosporine dose targeted to a standard area under the concentration-time curve (AUC)(0-12 h) (usual exposure, n = 104) or 50% of the study standard AUC(0-12 h) (low exposure, n = 108) using a three-point pharmacokinetic sampling. The primary endpoint was the percentage of patients with treatment failure at 24 months (graft loss/acute rejection/nephrotoxicity/>15% serum creatinine level increase).

RESULTS

Treatment failure was reported in 37 out of 101 (37%) patients in the usual-exposure and 19 out of 106 (18%) patients in the low-exposure groups (P = 0.003). Mean estimated glomerular filtration rate decreased from baseline to 2 years with usual exposure and increased with low exposure (P < 0.001). Mean systolic and diastolic blood pressures were lower with low exposure (P = 0.03 and P = 0.008, respectively).

CONCLUSION

In renal transplant recipients receiving maintenance therapy without corticosteroids, a minimization strategy using three-point pharmacokinetic sampling to reduce and maintain cyclosporine exposure to 50% of the usual levels is safe and reduces the risk of graft dysfunction.

Differential proteomic analysis of cyclosporine A-induced toxicity in renal proximal tubule cells

BACKGROUND

The use of cyclosporine A (CsA) as a potent immunosuppressant has been limited by its severe nephrotoxic effects. The mechanisms involved are haemodynamic but also related to direct toxic effects of CsA on proximal tubule epithelial cells. We focused on defining a proteomic profile in CsA-treated proximal tubule cells to distinguish the direct impact of CsA on these cells from overlapping haemodynamically mediated phenomena that occur in an in vivo system.

METHODS

By means of high-throughput differential proteomic analyses and mass spectrometry techniques in CsA and vehicle-treated proximal tubule-derived cell lines of human and mouse origin, we determined proteins that change their expression in the presence of CsA.

RESULTS

CsA-induced toxicity analyses revealed that 10 mM CsA for 24 h was the threshold condition to induce significant changes in cell viability and proteomic profile. We identified 38 differentially expressed proteins on CsA-treated mouse PCT3 and human HK-2 cells, related to protein metabolism, response to damage, cell organization and cytoskeleton, energy metabolism, cell cycle and nucleobase/nucleoside/nucleotidic metabolism. 1D and 2D western blot assays in crude extracts from CsA-treated cells or kidneys with impaired function upon CsA treatment revealed a correlation with proteomic changes or differential isoform expression, in randomly selected proteins.

CONCLUSIONS

Proteins identified in this work might be useful markers to eventually distinguish CsA toxicity from chronic allograft nephropathy in protocol biopsies of transplanted patients, facilitating the adjustment of CsA doses to non-toxic ranges, as well as to study the impact of potential therapeutic interventions in an animal model.

Complications post renal transplantation: literature focus on BK virus nephropathy and diagnostic tools actually available

Clinical diagnosis of kidney transplants related illnesses is not a simple task. Several studies were conducted to define diseases and complications after renal transplantation, but there are no comprehensive guidelines about diagnostic tools for their prevention and detection.

The Authors of this review looked for the medical literature and pertinent publications in particular to understand the role of Human Polyomavirus BK (BKV) in renal failure and to recognize analytical techniques for BK virus associated nephropathy (BKVAN) detection.

Ischaemic heart disease is a risk factor for renal failure after heart transplantation

BACKGROUND

The improvement of a long-term outcomes of heart transplantation (HTx) has resulted in a new phenomenon; specifically, the development of renal dysfunction secondary to calcineurin inhibitor toxicity. This study was designed to assess the participation of risk factors in the development of renal dysfunction in HTx.

METHODS

Data from 310 patients undergoing HTx in our center between 1988-1998 with a post-operation survival period for minimum 5 years (n=155) were analyzed retrospectively. Study cohort was divided into two groups according to renal function estimated by serum creatinine in the fifth year (Group I n=72; serum creatinine > or = 150 micromol/l, Group II: n=83, serum creatinine < 150 micromol/l).

RESULTS

We noted that patients with serum creatinine > or = 150 micromol/l at 5 years post-HTx had renal function significantly worse as early as 1 month (p<0.01), and 1 year post-HTx (p<0.001). The risk for developing renal dysfunction after HTx was doubled in patients with a history of coronary artery disease (CAD), and 2.5 times higher in those with small body weight gain. End stage renal disease developed in 16 patients (10.3%) and renal transplantation was performed in 13 (8.4%) of them.

CONCLUSION

Our data documented that a history of CAD and limited weight gain is a major risk factor for development of renal dysfunction after HTx. Aggressive modification of risk factors for CAD may reduce the occurrence of this complication.

Dual effect of nitrate therapy for cyclosporine-induced hypertension on vascular and platelet morphofunctional markers; an animal model

The present study sought to evaluate the prevention and reversion effects of isosorbide-5-mononitrate (Is-5-Mn) on the development of hypertension (HT) and on the underlying vascular and platelet morphofunctional disturbances, using an animal model of cyclosporine (CsA)-induced HT. The following rat groups (n = 8) were tested: (1) a control group (orange juice, for 7 weeks); (2) the CsA group (5 mg/kg/d for 7 weeks); (3) the Is-5-Mn group (150 mg/kg/d, twice a day for 7 weeks); (4) the prevention group (Is-5-Mn + CsA) treated for 2 weeks with Is-5-Mn only and thereafter with both drugs for 7 weeks; (5) the curative group (CsA + Is-5-Mn) beginning 7 weeks after CsA and following thereafter with both drugs for 5 weeks. Blood pressure, lipid profile, vascular lesion, platelet aggregation and morphology, and platelet thromboxane A(2)/vascular prostacyclin equilibrium were evaluated. Is-5-Mn + CsA therapy prevented (systolic blood pressure [SBP]: 114.3 +/- 1.9 mm Hg, P < .001; diastolic blood pressure [DBP]: 97.0 +/- 3.3 mm Hg, P < .001) the CsA-induced HT (SBP: 146.2 +/- 4.5 mm Hg, P < .001; DBP: 124.9 +/- 4.5 mm Hg, P < .001 vs control: SBP: 111.6 +/- 0.7 mm Hg; DBP: 94.6 +/- 1.0 mm Hg), as well as the vascular lesion and the platelet morphofunctional disturbances. The curative group did not show attenuated CsA-induced BP increase; it showed further enhancement of the HT effect (SBP: 159.7 +/- 5.5 mm Hg, P < .05; DBP: 132.8 +/- 2.8 mm Hg), as well as worsened vascular lesions and platelet function, namely a disruption in the TXA(2)/PGI(2) equilibrium. Our data suggested that Is-5-Mn therapy may be a valid choice to prevent the morphofunctional changes associated with CsA-induced HT, when used as a preventive therapy. A careful evaluation of the impact of nitrate therapy should be considered, particularly the negative effect on cardiovascular hemodynamics, when considering its use after previous CsA disturbances have been established.

Everolimus (Certican) in Heart Transplantation: Optimizing Renal Function Through Minimizing Cyclosporine Exposure

The proliferation signal inhibitor everolimus is efficacious for reducing the incidence of acute rejection and cardiac allograft vasculopathy (CAV) in heart transplantation; and it has the potential to facilitate cyclosporine (CsA) minimization in this setting. Reducing CsA dose in heart transplantation is dependent on everolimus trough blood levels of 3 to 8 ng/mL being achieved. Physicians experienced in the use of everolimus aim for CsA trough blood levels of 175 to 200 ng/mL in everolimus-treated patients during the initial 3 months following heart transplantation. Modeling data from the heart pivotal study suggest that CsA trough blood levels of 100 ng/mL at 6 months posttransplant could be targeted without loss of efficacy, and antibody induction therapy may assist with this approach. Target CsA trough blood levels for maintenance patients could possibly be reduced from the current 80 to 100 ng/mL to 50 to 80 ng/mL. Maintenance patients with renal dysfunction or CAV may benefit from conversion to everolimus and subsequent reduction in CsA trough blood levels (eg, by 50%). Initial experience of everolimus with reduced CsA trough blood levels in heart transplantation is favorable, but there is scope for further study.

Improvement of renal dysfunction by conversion from calcineurin inhibitors to sirolimus after heart transplantation

BACKGROUND

Chronic renal dysfunction is a common occurrence after heart transplantation in patients treated with calcineurin inhibitors (CIs). We evaluated the renal-sparing effects of converting stable heart transplant patients with renal dysfunction from a CI to sirolimus.

METHODS

Beginning in 2000, heart transplant patients with renal dysfunction were converted from a CI to sirolimus. CI was abruptly discontinued and sirolimus added at 5 mg twice a day for 2 days and then 2 mg daily. The treatment goal was a 24-hour level of 6 to 12 ng/ml. All patients were also managed with mycophenolate mofetil (MMF) at 1,000 mg twice daily.

RESULTS

Eighty from a total of 235 cardiac transplant patients were converted to sirolimus. The average time post-transplant for conversion was 4.78 years (range 3 days to 16 years). The average age at transplant was 55.43 years (range 15 to 70). At a mean of 304 days post-conversion, the mean serum creatinine (sCr) decreased from 2.04 +/- 0.57 mg/dl pre-conversion to 1.64 +/- 0.48 mg/dl (p < 0.001). In patients whose sCr was <2.5 mg/dl before conversion, the mean SCr level decreased from 1.81 +/- 0.39 to 1.62 +/- 0.5 mg/dl post-conversion (p = 0.01), with no patient developing end-stage renal disease (ESRD). Four patients with sCr > or =2.5 developed ESRD requiring dialysis despite conversion. In the remaining 15 patients with sCr > or =2.5 mg/dl, the sCr decreased from 2.85 +/- 0.29 to 1.73 +/- 0.43 mg/dl (p = 0.001).

CONCLUSIONS

Conversion to sirolimus from CI is safe and has a renal-sparing effect in the management of heart transplant patients with chronic renal dysfunction. Based on these results, sirolimus has a role as a first-line immunosuppressive agent in heart transplant patients with renal dysfunction.