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Voclosporin (Lupkynis ™ ) is an oral calcineurin inhibitor immunosuppressant that is being developed by Aurinia Pharmaceuticals. In January 2021, based on positive results from the pivotal phases II and III trials, oral voclosporin received its first approval in the USA for use in combination with a background immunosuppressive therapy regimen for adults with active lupus nephritis. Voclosporin is also being explored for the novel coronavirus disease 2019 (COVID-19) in kidney transplant recipients. This article summarizes the milestones in the development of voclosporin leading to this first approval for lupus nephritis.

Cyclosporine A (CsA) is an exceptional immunosuppressant used for the treatment of immune disorders. Niosomal vesicles are promising drug carriers that are formed by self-association of nonionic surfactants and cholesterol in an aqueous phase. The objective of the study was to formulate combined nonionic surfactant based vesicles and to evaluate their in vitro characterization, release studies and in vivo studies. Five niosomal formulations (F to F ) were prepared using the thin film hydration method. The molar ratio of cholesterol and non-ionic surfactant taken was 1:1. In formulation F , the combination of surfactants Span 20 and Brij 35 was used. The niosomes were characterized by zeta sizer and SEM for particle size analysis, in vitro drug release and stability studies. The pharmacokinetic studies were conducted on healthy albino rabbits. The size of niosome was found in the range of 427.1 nm to 972.3 nm. SEM image of optimized formulations F exhibit the spherical nature of niosomal vesicles. DSC thermograms of niosomal formulations exhibited a broadened endothermic peak. The stability study exhibited that all formulations are stable and negligible change of vesicle size and entrapment was observed with time. The percentage drug release was significantly higher as compared to CsA plain dispersion for all niosomal formulations at pH 1.2 and 7.4. The release kinetic behavior showed that all preparations were best described by zero order and can release active ingredient in a sustained manner. The pharmacokinetic data showed the test formulation (F10) possessed greater bioavailability as compared to the reference formulation (CsA aqueous dispersion). The formulation F demonstrated a comparatively more delayed rate of release with enhanced dissolution as compared to a single surfactant scheme. The F formulation can be a remarkable nanotechnology for prolonged delivery of CsA orally with improved dissolution profile and bioavailability.

Background The aberrant formation of neutrophil extracellular traps (NETs) has been implicated in ulcerative colitis (UC), a chronic recurrent intestinal inflammation. Cyclosporine A (CsA) is now applied as rescue therapy for acute severe UC. In addition, it has been certained that CsA inhibits the formation of NETs in vitro and the mechanism of which was still vague. The study aimed to explore the mechanism CsA inhibits the NETs formation of colitis in vivo and in vitro . Methods NETs enrichment in clinical samples was analyzed using databases from Gene Expression Omnibus and verified in our center. Dextran sulfate sodium (DSS)-induced acute colitis mice model was used to investigate the effect of CsA on NETs of colonic tissue expression. To clarify the mechanism, intracellular energy metabolites were examined by Liquid Chromatograph Mass Spectrometer, and reactive oxygen species (ROS) levels were examined by fluorescence intensity in neutrophils treated with CsA after LPS stimulation. The transcriptional level and activity of G6PD of neutrophils were also assessed using qRT-PCR and WST-8. RNA Sequencing was used to detect differentially expressed genes of neutrophils stimulated by LPS with or without CsA. The expression levels of related proteins were detected by western blot. Results NETs enrichment was especially elevated in moderate-to-severe UC patients compared to HC. NETs expression in the colon from DSS colitis was decreased after CsA treatment. Compared with neutrophils stimulated by LPS, NETs formation and cellular ROS levels were decreased in LPS + CsA group. Cellular ribulose 5-phosphate and NADPH/NADP + related to the pentose phosphate pathway (PPP) were reduced in LPS + CsA group. In addition, CsA could decrease G6PD activity in neutrophils stimulated with LPS, and the results were further verified by inhibiting G6PD activity. At last, P53 protein was highly expressed in LPS + CsA group compared with the LPS group. Intracellular G6PD activity, ROS level and NETs formation, which were downregulated by CsA, could be reversed by a P53 inhibitor. Conclusion Our results indicated CsA could alleviate the severity of colitis by decreasing the formation of NETs in vivo . In vitro , CsA reduced ROS-dependent NETs release via downregulating PPP and cellular ROS levels by decreasing G6PD activity directly by activating the P53 protein.

Purpose To apply physiologically-based pharmacokinetic (PBPK) modeling to investigate the consequences of reduction in activity of hepatic and intestinal uptake and efflux transporters by cyclosporine and its metabolite AM1. Methods Inhibitory potencies of cyclosporine and AM1 against OATP1B1, OATP1B3 and OATP2B1 were investigated in HEK293 cells +/− pre-incubation. Cyclosporine PBPK model implemented in Matlab was used to assess interaction potential (+/− metabolite) against different processes (uptake, efflux and metabolism) in liver and intestine and to predict quantitatively drug-drug interaction with repaglinide. Results Cyclosporine and AM1 were potent inhibitors of OATP1B1 and OATP1B3, IC 50 ranging from 0.019–0.093 μM following pre-incubation. Cyclosporine PBPK model predicted the highest interaction potential against liver uptake transporters, with a maximal reduction of >70% in OATP1B1 activity; the effect on hepatic efflux and metabolism was minimal. In contrast, 80–97% of intestinal P-gp and CYP3A4 activity was reduced due to the 50-fold higher cyclosporine enterocytic concentrations relative to unbound hepatic inlet. The inclusion of AM1 resulted in a minor increase in the predicted maximal reduction of OATP1B1/1B3 activity. Good predictability of cyclosporine-repaglinide DDI and the impact of dose staggering are illustrated. Conclusions This study highlights the application of PBPK modeling for quantitative prediction of transporter-mediated DDIs with concomitant consideration of P450 inhibition.

JC-1, a cationic fluorescent dye when added to living cells, is known to be localized exclusively in mitochondria, particularly in good physiological conditions characterized by sufficient mitochondrial membrane potential (ΔΨ). The accumulation of JC-1 in these organelles leads to the formation J-aggregates (with a specific red fluorescence emission maximum at 590 nm), which is in addition to the typical green fluorescence of J-monomers (emission maximum of ∼529 nm). The lack of mitochondrial ΔΨ leads to the depression of JC-1 mitochondrial accumulation and a decrease in J-aggregate formation. Therefore, the ratio between the red and green fluorescence of cells loaded with JC-1 is often used for the detection of the mitochondrial membrane potential. However, JC-1 represents a suitable substrate of the multidrug transporter P-glycoprotein (P-gp). Therefore, the depression of the JC-1 content in intracellular space and particularly in the mitochondria to a level that is inefficient for J-aggregate formation could be expected in P-gp-positive cells. In the current paper, we proved this behavior on parental P-gp-negative L1210 (S) cells and their P-gp-positive variants obtained by either selection with vincristine (R) or transfection with the human gene encoding P-gp (T). P-glycoprotein inhibitors cyclosporine A and verapamil fail to restore JC-1 loading of the R and T cells to an extent similar to that observed in S cells. In contrast, the noncompetitive high affinity P-gp inhibitor tariquidar fully restored JC-1 accumulation and the presence of the typical red fluorescence of J-aggregates. In the presence of tariquidar, measurement of the JC-1 fluorescence revealed similar levels of mitochondrial membrane potential in P-gp-negative (S) and P-gp-positive cells (R and T).

Death receptor–mediated apoptosis requires the mitochondrial apoptosis pathway in many mammalian cells. In response to death receptor signaling, the truncated BH3-only protein BID can activate the proapoptotic BCL-2 proteins BAX and BAK and trigger the permeabilization of the mitochondria. BAX and BAK are inhibited by prosurvival BCL-2 proteins through retrotranslocation from the mitochondria into the cytosol, but a specific resistance mechanism to truncated BID-dependent apoptosis is unknown. Here, we report that hexokinase 1 and hexokinase 2 inhibit the apoptosis activator truncated BID as well as the effectors BAX and BAK by retrotranslocation from the mitochondria into the cytosol. BCL-2 protein shuttling and protection from TRAIL- and FasL-induced cell death requires mitochondrial hexokinase localization and interactions with the BH3 motifs of BCL-2 proteins but not glucose phosphorylation. Together, our work establishes hexokinase-dependent retrotranslocation of truncated BID as a selective protective mechanism against death receptor–induced apoptosis on the mitochondria.

Drug development in traumatic brain injury (TBI) has been impeded by the complexity and heterogeneity of the disease pathology, as well as limited understanding of the secondary injury cascade that follows the initial trauma. As a result, patients with TBI have an unmet need for effective pharmacological therapies. One promising drug candidate is cyclosporine, a polypeptide traditionally used to achieve immunosuppression in transplant recipients. Cyclosporine inhibits mitochondrial permeability transition, thereby reducing secondary brain injury, and has shown neuroprotective effects in multiple preclinical models of TBI. Moreover, the cyclosporine formulation NeuroSTAT® displayed positive effects on injury biomarker levels in patients with severe TBI enrolled in the Phase Ib/IIa Copenhagen Head Injury Ciclosporin trial (NCT01825044). Future research on neuroprotective compounds such as cyclosporine should take advantage of recent advances in fluid-based biomarkers and neuroimaging to select patients with similar disease pathologies for clinical trials. This would increase statistical power and allow for more accurate assessment of long-term outcomes.

Cyclophilins (Cyps), a family of peptidyl-prolyl isomerases, play essential roles in the life cycle of coronaviruses by interacting with viral proteins and modulating host immune responses. In this systematic review, we examined cell culture, animal model, and clinical studies assessing the anti-viral efficacy of cyclosporine A (CsA, PubChem CID: 5284373) and its non-immunosuppressive derivatives against coronaviruses. CsA demonstrated robust anti-viral activity in vitro across a broad range of coronaviruses, including but not limited to HCoV-229E, SARS-CoV, MERS-CoV, and SARS-CoV-2, with potent EC50 values in the low micromolar range. Non-immunosuppressive analogs such as Alisporivir and NIM811 exhibited similar inhibitory effects. In vivo, CsA treatment significantly reduced viral load, ameliorated lung pathology, and improved survival in coronavirus-infected animals. Clinical studies further indicated that CsA administration was associated with improved outcomes in COVID-19 patients, including reduced mortality and shorter hospital stays. Mechanistic studies revealed that CsA disrupts the formation of viral replication complexes, interferes with critical Cyp–viral protein interactions, and modulates innate immune signaling. These findings collectively demonstrate the therapeutic potential of cyclophilin inhibitors as broad-spectrum anti-virals against current and emerging coronaviruses.

The calcineurin inhibitors ciclosporin (cyclosporine) and tacrolimus are immunosuppressant drugs used for the prevention of organ rejection following transplantation. Both agents are metabolic substrates for cytochrome P450 (CYP) 3A enzymes — in particular, CYP3A4 and CYP3A5 — and are transported out of cells via P-glycoprotein ( ABCB1 ). Several single nucleotide polymorphisms (SNPs) have been identified in the genes encoding for CYP3A4, CYP3A5 and P-glycoprotein, including CYP3A4 —392A>G (rs2740574), CYP3A5 6986A>G (rs776746), ABCB1 3435C>T (rs1045642), ABCB1 1236C>T (rs1 128503) and ABCB1 2677G>T/A (rs2032582). The aim of this review is to provide the clinician with an extensive overview of the recent literature on the known effects of these SNPs on the pharmacodynamics of ciclosporin and tacrolimus in solid-organ transplant recipients. Literature searches were performed and all relevant primary research articles were critiqued and summarized. There is no evidence that the CYP3A4 —392A>G SNP has an effect on the pharmacodynamics of either ciclosporin or tacrolimus; however, studies have been limited. For patients prescribed ciclosporin, the CYP3A5 6986A>G SNP may influence long-term survival, possibly because of a different metabolite pattern over time. This SNP has no clear association with acute rejection during ciclosporin therapy. Despite a strong association between the CYP3A5 6986A>G SNP and tacrolimus pharmacokinetics, there is no consistent evidence of organ rejection as a result of genotype-related under-immunosuppression. This is likely to be explained by the practice of performing tacrolimus dose adjustments in the early phase after transplantation. The effect of the CYP3A5 6986A>G SNP on ciclosporin-and tacrolimus-related nephrotoxicity and development of hypertension is unclear. Similarly, the ABCB1 SNPs exert no clear influence on either ciclosporin or tacrolimus pharmacodynamics, with studies showing conflicting results in regard to the main parameters of acute rejection and nephrotoxicity. In kidney transplant patients, consideration of the donor kidney genotype rather than the recipient genotype may be more important when assessing development of nephrotoxicity. Studies with low patient numbers may account for many inconsistent results to date. The majority of studies have only evaluated the effects of individual SNPs; however, multiple polymorphisms may interact to produce a combined effect. Further haplotype analyses are likely to be useful, particularly ones that consider both donor and recipient genotype. The effects of polymorphisms associated with the pregnane X receptor, organic anion transporting polypeptides, calcineurin inhibitor target sites and immune response pathways need to be further investigated. A large standardized clinical trial is now required to evaluate the relationship between the pharmacokinetics and pharmacodynamics of CYP3A5-mediated tacrolimus metabolism, particularly in regard to the outcomes of acute rejection and nephrotoxicity. It is not yet clear whether pharmacogenetic profiling of calcineurin inhibitors will be a useful clinical tool for personalizing immunosuppressant therapy.

Ser/thr phosphatases dephosphorylate their targets with high specificity, yet the structural and sequence determinants of phosphosite recognition are poorly understood. Calcineurin (CN) is a conserved Ca(2+)/calmodulin-dependent ser/thr phosphatase and the target of immunosuppressants, FK506 and cyclosporin A (CSA). To investigate CN substrate recognition we used X-ray crystallography, biochemistry, modeling, and in vivo experiments to study A238L, a viral protein inhibitor of CN. We show that A238L competitively inhibits CN by occupying a critical substrate recognition site, while leaving the catalytic center fully accessible. Critically, the 1.7 Å structure of the A238L-CN complex reveals how CN recognizes residues in A238L that are analogous to a substrate motif, \"LxVP.\" The structure enabled modeling of a peptide substrate bound to CN, which predicts substrate interactions beyond the catalytic center. Finally, this study establishes that \"LxVP\" sequences and immunosuppressants bind to the identical site on CN. Thus, FK506, CSA, and A238L all prevent \"LxVP\"-mediated substrate recognition by CN, highlighting the importance of this interaction for substrate dephosphorylation. Collectively, this work presents the first integrated structural model for substrate selection and dephosphorylation by CN and lays the groundwork for structure-based development of new CN inhibitors.