Severity and organ distribution of chronic graft-versus-host disease with posttransplant cyclophosphamide-based versus methotrexate/calcineurin inhibitor-based allogeneic hematopoietic cell transplantation.

The reduced risk of chronic graft-versus-host-disease (GVHD) with posttransplant cyclophosphamide (ptCy) in the setting of haploidentical related donor and more recently, with HLA-matched related and matched and mismatched unrelated donor allogeneic transplantation has been established. There is, however, paucity of data to show if ptCy impacts chronic GVHD pathogenesis, its phenotype and evolution after HCT regardless of the donor status. We examined the differences in chronic GVHD incidence and presentation in 314 consecutive patients after receiving their first allogeneic transplantation (HCT) using ptCy-based GVHD prophylaxis (ptCy-HCT; n = 120; including 95 with haploidentical related donor) versus conventional calcineurin inhibitor-based prophylaxis (CNI-MUD; n = 194) between 2012 and 2019. The 1-year cumulative incidence of all-grade chronic GVHD and moderate/severe chronic GVHD was 24% and 12%, respectively, after ptCy-HCT and 40% and 23% in the CNI-MUD recipients (p = 0.0003 and 0.007). Multivariable analysis confirmed that use of CNI-based GVHD prophylaxis and peripheral blood stem cell graft as the risk factors for chronic GVHD. The cumulative incidence of visceral (involving ≥1 of the following organs: liver, lungs, gastrointestinal tract, serous membranes) chronic GVHD was significantly higher with CNI-MUD vs. ptCy-HCT (27% vs. 15% at 1 year, p = 0.009). The incidence of moderate/severe visceral chronic GVHD was 20% in CNI-MUD group vs. 7.7% in the ptCy-HCT group at 1 year (p = 0.002). In addition, significantly fewer ptCy-HCT recipients developed severe chronic GVHD in ≥3 organs (0.8%) vs. 8.8% in the CNI-MUD group at 1-year posttransplant (p = 0.004). There was no significant different in relapse, non-relapse mortality, and relapse-free and overall survival between the two groups. Further investigation is needed to confirm that reduced risk and severity of chronic GVHD, less visceral organ distribution with ptCy-HCT leads to improved quality of life.

[Evidence-based recommendations for the treatment of rheumatic and immunologic diseases with calcineurin inhibitors: a consensus statement].

Calcineurin inhibitors (CNI), including oral cyclosporin A and tacrolimus, are intensive immunosuppressants that are extensively used in the treatment of rheumatic and immunologic diseases in China. CNI selectively inhibit the activation and proliferation of T lymphocytes and the transcription of cytokines [such as tumor necrosis factor-α, interleukin (IL)-6, and IL-17] through inhibiting the activation of calcineurin in cells and reducing the release of IL-2. To standardize the use of CNI in the field of rheumatic and immunologic diseases, this consensus statement was developed by the National Clinical Research Center for Dermatologic and Immunologic Diseases (Peking Union Medical College Hospital), in conjunction with the Chinese Association of Rheumatology and Immunology Physicians, the Chinese Research Hospital Association, the Rheumatology and Immunology Professional Committee, and the Chinese Association of Rehabilitation Medicine. The 2011 Oxford Centre for Evidence-Based Medicine Levels of Evidence was used to rate the quality of the evidence and the strength of the recommendations, and the RIGHT (Reporting Items for practice Guidelines in HealThcare) checklist was followed to report the consensus. The consensus offers recommendations addressing nine clinical challenges to Chinese clinicians. The primary objective of this consensus is to deliver scientific and detailed guidance on CNI for Chinese clinicians, and to improve the quality of patient-centered medical services.

Calcineurin inhibitor inhibits tolerance induction by suppressing terminal exhaustion of donor T cells after allo-HCT.

Calcineurin inhibitor-based graft-versus-host disease (GVHD) prophylaxis is standard in allogeneic hematopoietic stem cell transplantation (HCT) but fails to induce long-term tolerance without chronic GVHD (cGVHD) in a considerable number of patients. In this study, we addressed this long-standing question in mouse models of HCT. After HCT, alloreactive donor T cells rapidly differentiated into PD-1+ TIGIT+ terminally exhausted T cells (terminal Tex). GVHD prophylaxis with cyclosporine (CSP) suppressed donor T-cell expression of TOX, a master regulator to promote differentiation of transitory exhausted T cells (transitory Tex), expressing both inhibitory receptors and effector molecules, into terminal Tex, and inhibited tolerance induction. Adoptive transfer of transitory Tex, but not terminal Tex, into secondary recipients developed cGVHD. Transitory Tex maintained alloreactivity and thus PD-1 blockade restored graft-versus-leukemia (GVL) activity of transitory Tex and not terminal Tex. In conclusion, CSP inhibits tolerance induction by suppressing the terminal exhaustion of donor T cells, while maintaining GVL effects to suppress leukemia relapse.

Preclinical safety evaluation of calcineurin inhibitors delivered through an intraductal route to prevent post-ERCP pancreatitis demonstrates endocrine and systemic safety.

OBJECTIVE: There is an urgent need for safe and targeted interventions to mitigate post-ERCP pancreatitis (PEP). Calcineurin inhibitors (CnIs) offer therapeutic promise as calcineurin signaling within acinar cells is a key initiating event in PEP. In previous proof-of-concept studies using experimental models, we showed that concurrent intra-pancreatic ductal administration of the CnIs, tacrolimus (Tac) or cyclosporine A (CsA) with the ERCP radiocontrast agent (RC) prevented PEP. To translate this finding clinically, we investigated potential toxic effects of intraductal delivery of a single-dose RC-CnI formulation on endocrine pancreas function and systemic toxicities in a preclinical PEP model. METHODS: C57BL/6J mice underwent ductal cannulation and received a single, intra-pancreatic ductal infusion of RC or RC with Tac or CsA (treatment groups) or underwent ductal cannulation without infusion ('sham' group). To assess endocrine function, intraperitoneal glucose tolerance test (IPGTT) was performed at two days before infusion and on day 2 and 14 post-surgery. To evaluate off-target tissue toxicities, renal and hepatic function-related parameters including blood urea nitrogen, plasma creatinine, potassium, aspartate aminotransferase, alanine aminotransferase, and total bilirubin were measured at the same time-points as IPGTT. Histological and biochemical indicators of pancreas injury and inflammation were also evaluated. RESULTS: No abnormalities in glucose metabolism, hepatic or renal function were observed on day 2 or 14 in mice administered with intraductal RC or RC with Tac or CsA. CONCLUSION: Intraductal delivery of RC-CnI formulation was safe and well-tolerated with no significant acute or subacute endocrine or systemic toxicities, underscoring its clinical utility to prevent PEP.

Low-dose Pimecrolimus, an FDA-approved Calcineurin Inhibitor, Sensitizes Drug-resistant Cancer Cells via Strong P-gp Inhibition.

BACKGROUND/AIM: Co-treatment with calcineurin inhibitors, such as tacrolimus and cyclosporin A, can sensitize chemotherapy-resistant cancer cells with P-glycoprotein (P-gp)-over-expression. Pimecrolimus (PIME) is a clinically available calcineurin inhibitor with a structure similar to that of tacrolimus. Whether PIME can sensitize P-gp-over-expressing resistant cancer cells remains unclear. MATERIALS AND METHODS: Cell viability assay, annexin V analyses, cellular morphology and density observation with a microscope, western-blotting, fluorescence-activated cell sorting (FACS), and analysis for P-gp inhibitory activity were performed to investigate the mechanism of action. RESULTS: PIME exhibited strong cytotoxicity to vincristine (VIC)-treated drug-resistant cell lines (KBV20C and MCF-7/ADR) over-expressing P-gp. Co-treatment with VIC and PIME increased apoptosis and down-regulated the ERK signaling pathway, resulting in G2 arrest. PIME could be co-administered with vinorelbine or eribulin to sensitize resistant KBV20C or MCF-7/ADR cancer cells. Moreover, PIME strongly inhibited the efflux of both rhodamine 123 and calcein-AM substrates through P-gp after 4 h of treatment, indicating that VIC+PIME sensitized cancer cells by inhibiting VIC efflux via direct PIME binding to P-gp. Low doses of PIME, tacrolimus, and cyclosporin A showed similar sensitizing efficiencies in resistant KBV20C cells. These drugs showed similar P-gp inhibitory activities using both rhodamine 123 and calcein-AM substrates, suggesting that calcineurin inhibitors generally have strong P-gp inhibitory activities that sensitize drug-resistant cancer cells with P-gp over-expression. CONCLUSION: PIME, currently used in clinics, can be repositioned for treating patients with P-gp-over-expressing resistant cancer (stem) cells.

Sirolimus Attenuates Calcineurin Inhibitor-Induced Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma.

BACKGROUND: Calcineurin inhibitors (CNIs), which are potent immunosuppressants (ISs), increase the risk for hepatocellular carcinoma (HCC) recurrence after liver transplantation (LTx). Epithelial-mesenchymal transition (EMT) is a key process in which epithelial cancer cells lose their polarity, resulting in cancer progression and metastasis. The aim of this study was to evaluate the effect of sirolimus (SRL) individually and in combination with other ISs to reduce EMT. METHODS: HCC SK-Hep1 cells were used and various ISs (SRL, tacrolimus, cyclosporine A, or mycophenolate mofetil) were administered at 2 dosages and in combination therapies. Mice were transplanted with SK-Hep1 cells (in the liver) and were monitored after 2 weeks. RESULTS: The in vitro treatment with SRL showed a dose-dependent attenuation of cell proliferation and migration in case of the individual and IS combination treatments; further, decreased levels of pro-EMT proteins, namely, N-cadherin, transforming growth factor-ß, ZEB1, Slug, and Snail were observed. In contrast, E-cadherin expression was upregulated after both the individual and IS combination treatments. These results were also observed in the samples from mice transplanted with the SK-Hep1 cells. CONCLUSION: The present study demonstrated that SRL reduced HCC metastasis by inhibiting EMT. Thus, our findings provide a rationale for the use of SRL in combination with ISs in HCC LTx patients.

IL-2 receptor engineering enhances regulatory T cell function suppressed by calcineurin inhibitor.

Clinical trials utilizing regulatory T cell (Treg) therapy in organ transplantation have shown promising results, however, the choice of a standard immunosuppressive regimen is still controversial. Calcineurin inhibitors (CNIs) are one of the most common immunosuppressants for organ transplantation, although they may negatively affect Tregs by inhibiting IL-2 production by conventional T cells. As a strategy to replace IL-2 signaling selectively in Tregs, we have introduced an engineered orthogonal IL-2 (ortho IL-2) cytokine/cytokine receptor (R) pair that specifically binds with each other but does not bind with their wild-type counterparts. Murine Tregs were isolated from recipients and retrovirally transduced with ortho IL-2Rß during ex vivo expansion. Transduced Tregs (ortho Tregs) were transferred into recipient mice in a mixed hematopoietic chimerism model with tacrolimus administration. Ortho IL-2 treatment significantly increased the ortho IL-2Rß(+) Treg population in the presence of tacrolimus without stimulating other T cell subsets. All the mice treated with tacrolimus plus ortho IL-2 achieved heart allograft tolerance, even after tacrolimus cessation, whereas those receiving tacrolimus treatment alone did not. These data demonstrate that Treg therapy can be adopted into a CNI-based regimen by utilizing cytokine receptor engineering.

Calcineurin inactivation inhibits pyruvate dehydrogenase complex activity and induces the Warburg effect.

Calcineurin is a calcium- and calmodulin-dependent serine/threonine protein phosphatase that connects the Ca2+-dependent signalling to multiple cellular responses. Calcineurin inhibitors (CNIs) have been widely used to suppress immune response in allograft patients. However, CNIs significantly increase cancer incidence in transplant recipients compared with the general population. Accumulating evidence suggests that CNIs may promote the malignant transformation of cancer cells in addition to its role in immunosuppression, but the underlying mechanisms remain poorly understood. Here, we show that calcineurin interacts with pyruvate dehydrogenase complex (PDC), a mitochondrial gatekeeper enzyme that connects two key metabolic pathways of cells, glycolysis and the tricarboxylic acid cycle. Mitochondrial-localized calcineurin dephosphorylates PDHA1 at Ser232, Ser293 and Ser300, and thus enhances PDC enzymatic activity, remodels cellular glycolysis and oxidative phosphorylation, and suppresses cancer cell proliferation. Hypoxia attenuates mitochondrial translocation of calcineurin to promote PDC inactivation. Moreover, CNIs promote metabolic remodelling and the Warburg effect by blocking calcineurin-mediated PDC activation in cancer cells. Our findings indicate that calcineurin is a critical regulator of mitochondrial metabolism and suggest that CNIs may promote tumorigenesis through inhibition of the calcineurin-PDC pathway.

Conversion From Calcineurin Inhibitors to Mammalian Target of Rapamycin Inhibitors in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: A systematic review and meta-analysis were performed to investigate the efficacy and safety of conversion from calcineurin inhibitors (CNIs) to mammalian target of rapamycin inhibitors (mTORi) in kidney transplant recipients (KTRs). Methods: MEDLINE, EMBASE, PubMed, and Cochrane Library were searched to identify randomized controlled trials (RCTs) that compared the continuation of CNI with conversion to mTORi therapy. Results: Twenty-nine RCTs (5,747 KTRs) were included in our analysis. Meta-analysis of the glomerular filtration rate (SMD 0.20; 95%CI 0.10-0.31; P<0.01) and malignancy (RR 0.74; 95%CI 0.55-0.99; P=0.04) demonstrated a significant advantage of mTORi conversion over CNI continuation. However, the risk of acute rejection (RR 1.58; 95%CI 1.22-2.04; P<0.01), infection (RR 1.55; 95%CI 1.01-1.31; P=0.04), proteinuria (RR 1.87; 95%CI 1.34-2.59; P<0.01), leukopenia (RR 1.56; 95%CI 1.27-1.91; P<0.01), acne (RR 6.43; 95%CI 3.43-12.04; P<0.01), and mouth ulcer (RR 11.70; 95%CI 6.18-22.17; P<0.01) were higher in the mTORi group. More patients in the conversion group had to discontinue study medication (RR 2.52; 95%CI 1.75-3.63; P<0.01). There was no significant difference between the two groups with regard to death, graft loss, diabetes, chronic allograft nephropathy, and interstitial fibrosis/tubular atrophy. Conclusions: Posttransplant patients have a better graft function and lower incidence of malignancy after conversion from CNI to mTORi therapy. However, this conversion strategy may be prevented by the higher drug discontinuation rate due to mTORi-associated adverse events, such as more acute rejection, infection, proteinuria, leukopenia, acne, and mouth ulcer, indicating that conversion therapy may only be a treatment option in selected patients.

Identification of pimavanserin tartrate as a potent Ca2+-calcineurin-NFAT pathway inhibitor for glioblastoma therapy.

Glioblastoma multiforme (GBM) is the most common and malignant type of primary brain tumor, and 95% of patients die within 2 years after diagnosis. In this study, aiming to overcome chemoresistance to the first-line drug temozolomide (TMZ), we carried out research to discover a novel alternative drug targeting the oncogenic NFAT signaling pathway for GBM therapy. To accelerate the drug's clinical application, we took advantage of a drug repurposing strategy to identify novel NFAT signaling pathway inhibitors. After screening a set of 93 FDA-approved drugs with simple structures, we identified pimavanserin tartrate (PIM), an effective 5-HT2A receptor inverse agonist used for the treatment of Parkinson's disease-associated psychiatric symptoms, as having the most potent inhibitory activity against the NFAT signaling pathway. Further study revealed that PIM suppressed STIM1 puncta formation to inhibit store-operated calcium entry (SOCE) and subsequent NFAT activity. In cellula, PIM significantly suppressed the proliferation, migration, division, and motility of U87 glioblastoma cells, induced G1/S phase arrest and promoted apoptosis. In vivo, the growth of subcutaneous and orthotopic glioblastoma xenografts was markedly suppressed by PIM. Unbiased omics studies revealed the novel molecular mechanism of PIM's antitumor activity, which included suppression of the ATR/CDK2/E2F axis, MYC, and AuroraA/B signaling. Interestingly, the genes upregulated by PIM were largely associated with cholesterol homeostasis, which may contribute to PIM's side effects and should be given more attention. Our study identified store-operated calcium channels as novel targets of PIM and was the first to systematically highlight the therapeutic potential of pimavanserin tartrate for glioblastoma.

Nuclear factor of activated T-cells (NFAT) regulation of IL-1ß-induced retinal vascular inflammation.

Chronic low-grade retinal inflammation is an essential contributor to the pathogenesis of diabetic retinopathy (DR). It is characterized by increased retinal cell expression and secretion of a variety of inflammatory cytokines; among these, IL-1ß has the reputation of being a major driver of cytokine-induced inflammation. IL-1ß and other cytokines drive inflammatory changes that cause damage to retinal cells, leading to the hallmark vascular lesions of DR; these include increased leukocyte adherence, vascular permeability, and capillary cell death. Nuclear factor of activated T-cells (NFAT) is a transcriptional regulator of inflammatory cytokines and adhesion molecules and is expressed in retinal cells. Consequently, it may influence multiple pathogenic steps early in DR. We investigated the NFAT-dependency of IL-1ß-induced inflammation in human Müller cells (hMC) and human retinal microvascular endothelial cells (hRMEC). Our results show that an NFAT inhibitor, Inhibitor of NFAT-Calcineurin Association-6 (INCA-6), decreased IL-1ß-induced expression of IL-1ß and TNFα in hMC, while having no effect on VEGF, CCL2, or CCL5 expression. We also demonstrate that INCA-6 attenuated IL-1ß-induced increases of IL-1ß, TNFα, IL-6, CCL2, and CCL5 (inflammatory cytokines and chemokines), and ICAM-1 and E-selectin (leukocyte adhesion molecules) expression in hRMEC. INCA-6 similarly inhibited IL-1ß-induced increases in leukocyte adhesion in both hRMEC monolayers in vitro and an acute model of retinal inflammation in vivo. Finally, INCA-6 rescued IL-1ß-induced permeability in both hRMEC monolayers in vitro and an acute model of retinal inflammation in vivo. Taken together, these data demonstrate the potential of NFAT inhibition to mitigate retinal inflammation secondary to diabetes.

NFAT transcription factors are essential and redundant actors for leukemia initiating potential in T-cell acute lymphoblastic leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy with few available targeted therapies. We previously reported that the phosphatase calcineurin (Cn) is required for LIC (leukemia Initiating Capacity) potential of T-ALL pointing to Cn as an interesting therapeutic target. Calcineurin inhibitors have however unwanted side effect. NFAT transcription factors play crucial roles downstream of calcineurin during thymocyte development, T cell differentiation, activation and anergy. Here we elucidate NFAT functional relevance in T-ALL. Using murine T-ALL models in which Nfat genes can be inactivated either singly or in combination, we show that NFATs are required for T-ALL LIC potential and essential to survival, proliferation and migration of T-ALL cells. We also demonstrate that Nfat genes are functionally redundant in T-ALL and identified a node of genes commonly deregulated upon Cn or NFAT inactivation, which may serve as future candidate targets for T-ALL.

Therapeutic concentrations of calcineurin inhibitors do not deregulate glutathione redox balance in human renal proximal tubule cells.

The calcineurin inhibitors (CNI) cyclosporine A and tacrolimus comprise the basis of immunosuppressive regimes in all solid organ transplantation. However, long-term or high exposure to CNI leads to histological and functional renal damage (CNI-associated nephrotoxicity). In the kidney, proximal tubule cells are the only cells that metabolize CNI and these cells are believed to play a central role in the origin of the toxicity for this class of drugs, although the underlying mechanisms are not clear. Several studies have reported oxidative stress as an important mediator of CNI-associated nephrotoxicity in response to CNI exposure in different available proximal tubule cell models. However, former models often made use of supra-therapeutic levels of tissue drug exposure. In addition, they were not shown to express the relevant enzymes (e.g., CYP3A5) and transporters (e.g., P-glycoprotein) for the metabolism of CNI in human proximal tubule cells. Moreover, the used methods for detecting ROS were potentially prone to false positive results. In this study, we used a novel proximal tubule cell model established from human allograft biopsies that demonstrated functional expression of relevant enzymes and transporters for the disposition of CNI. We exposed these cells to CNI concentrations as found in tissue of stable solid organ transplant recipients with therapeutic blood concentrations. We measured the glutathione redox balance in this cell model by using organelle-targeted variants of roGFP2, a highly sensitive green fluorescent reporter protein that dynamically equilibrates with the glutathione redox couple through the action of endogenous glutaredoxins. Our findings provide evidence that CNI, at concentrations commonly found in allograft biopsies, do not alter the glutathione redox balance in mitochondria, peroxisomes, and the cytosol. However, at supra-therapeutic concentrations, cyclosporine A but not tacrolimus increases the ratio of oxidized/reduced glutathione in the mitochondria, suggestive of imbalances in the redox environment.

Transient Receptor Potential Ankyrin 1 (TRPA1)-An Inflammation-Induced Factor in Human HaCaT Keratinocytes.

Transient receptor potential ankyrin 1 (TRPA1) is an ion channel mainly studied in sensory neurons where it mediates itch, pain and neurogenic inflammation. Recently, some nonneuronal cells have also been shown to express TRPA1 to support inflammatory responses. To address the role of TRPA1 in skin inflammation, we aimed to investigate TRPA1 expression in keratinocytes. HaCaT cells (a model of human keratinocytes) and skin biopses from wild-type and TRPA1 deficient mice were used in the studies. TRPA1 expression in nonstimulated keratinocytes was very low but significantly inducible by the proinflammatory cytokine tumor necrosis factor (TNF) in an nuclear factor kappa B (NF-κB), and mitogen-activated protein (MAP) kinase (p38 and c-Jun N-terminal kinase, JNK)-dependent manner. Interestingly, drugs widely used to treat skin inflammation, the calcineurin inhibitors tacrolimus and cyclosporine and the glucocorticoid dexamethasone, significantly decreased TRPA1 expression. Furthermore, pharmacological inhibition and genetic deletion of TRPA1 reduced the synthesis of TNF-induced monocyte chemoattractant protein 1 (MCP-1) in keratinocytes and mouse skin biopsies. In conclusion, these findings point to an inflammatory role for TRPA1 in keratinocytes and present TRPA1 as a potential drug target in inflammatory skin diseases.

Effects of tacrolimus on c-fos in hippocampus and memory performances in streptozotocin model of Alzheimer's disease of rats

Background/aim: Calcineurin, an inhibitor of calcium dependent phosphatase is highly presented in a brain of an Alzheimer's disease. Aging brain gets more sensitive to hyperactivation of calcineurin, and this event causes tau neurofibrillary plaque accumulation, which is one of the outcomes of this disease. The regions of hippocampus are much effected from the results of this process. Our hypothesis is that a calcineurin inhibitor, tacrolimus, could prevent the accumulation and the decrease of the neuronal cells. Therefore, this immunosuppressive drug could be a candidate for an early treatment of Alzheimer disease. Materials and methods: Fifteen male Wistar albino rats were divided to three groups; control, Alzheimer, and Alzheimer+Tacrolimus. The Alzheimer group received an injection of streptozotocin intracerebroventricularly for the purpose of modelling the disease via generating free radicals leading a cognitive impairment. Alzheimer+Tacrolimus group first received an oral drug, a calcineurin inhibitor for 10 days afterwards prepared for the model as same as the Alzheimer group received. Finally, all groups performed the Morris water maze test for four days then sacrificed. For the aim of counting neurons in the hippocampus stereological methods, as well as for an evaluation of cellular response to stress in dentate gyrus, a c-Fos immunohistochemistry was performed. Results: According to the probe trial of Morris water maze test, the latency time was dramatically higher at both Alzheimer and Alzheimer+Tacrolimus group (p < 0.01). We confirmed these results with our stereology data. The results from stereology technique indicate that there was a neuronal decrease at the hippocampus regions in Alzheimer and Alzheimer+Tacrolimus group. Our outcomes from immunohistochemical data showed a significant increase in the number of c-Fos-positive cells in Alzheimer group when comparing with Alzheimer+Tacrolimus group (p < 0.001). Conclusion: There was none preventive effect for neuronal loss in the hippocampus under the effect of tacrolimus drug according to stereological results. However, tacrolimus administration may have reduced cellular stress and cell damage.

Inpatient Therapy With Calcineurin Inhibitors in Severe Ulcerative Colitis.

BACKGROUND: Inpatient management of severe ulcerative colitis is complicated by the use of prior immunosuppressant therapies. Our aim was to determine the rate of 1-year colectomy among individuals receiving inpatient calcineurin inhibitor (CNI)-based therapy stratified by prior biologic therapy. METHODS: A retrospective cohort study was performed between January 1, 2013 and April 1, 2018. Only individuals requiring inpatient administration of intravenous cyclosporine or oral tacrolimus were included in the analysis. Individuals were stratified according to prior biologic therapy exposure. The primary outcome of interest was 1-year risk of colectomy. Kaplan-Meier curves were generated for time-to-event data, and regression models were performed to examine the effects of covariates on the clinical endpoint. RESULTS: Sixty-nine (62.3% male) patients were treated with an inpatient CNI-based therapy and were included in the analysis. Fifteen (21.7%) patients were biologic-naïve, 42 (60.9%) patients had prior exposure to 1 class of biologic therapy, and 12 (17.4%) patients had prior exposure to 2 classes of biologic therapy (third-line CNI therapy). Third-line CNI therapy showed a greater risk of 1-year colectomy risk when compared with the risk for patients who were biologic-naïve (hazard ratio, 3.63; 95% confidence interval, 1.17-13.45; P = 0.025). In a multivariate proportional hazards model, third-line CNI therapy remained significantly associated with 1-year colectomy risk (hazard ratio, 7.94; 95% confidence interval, 1.97-39.76; P = 0.003). CONCLUSIONS: The use of CNI-based therapy in individuals exposed to multiple classes of prior biologic therapies leads to a significantly increased risk of 1-year colectomy. Future studies will be required to compare inpatient management strategies with the expanding novel therapies in UC.

Histone deacetylase 4 mediates high glucose-induced podocyte apoptosis via upregulation of calcineurin.

Hyperglycemia promotes podocyte apoptosis and plays an important role in the pathogenesis of diabetic nephropathy (DN). Calcium/calcineurin (CaN) signaling is critical for podocyte apoptosis. Therefore, it is essential to elucidate the mechanisms underlying the regulation of CaN signaling. Recent studies reported that histone deacetylase 4 (HDAC4) is involved in podocyte apoptosis in DN. The aim of this study was to determine whether HDAC4 mediates the regulation of CaN and to elucidate the function of HDAC4 in high glucose (HG)-induced podocyte apoptosis. First, we identified the expression of HDAC4 was upregulated in podocytes of patients with DN. In vitro, the results also indicate that the mRNA and protein expression levels of HDAC4 were increased in HG-cultured podocytes. Silencing and overexpression of HDAC4 markedly decreased and increased CaN expression, respectively. Meanwhile, HG-induced podocyte apoptosis was abrogated by HDAC4-knockdown with subsequent decreased Bax expression and increased Bcl-2 expression. In contrast, overexpression of HDAC4 increased podocyte apoptosis and Bax expression, as well as decreased Bcl-2 expression. In addition, podocyte apoptosis induced by HDAC4 overexpression was effectively rescued by FK506, a pharmacological inhibitor of CaN, which was accompanied by decreased Bax and increased Bcl-2 expression. As a novel finding, HG-induced podocyte apoptosis is mediated by the HDAC4/CaN signaling pathway, which presents a promising target for therapeutic intervention in DN.

A Peptidyl Inhibitor that Blocks Calcineurin-NFAT Interaction and Prevents Acute Lung Injury.

Acute respiratory distress syndrome (ARDS) is an inflammatory lung disease with a high morbidity and mortality rate, for which no pharmacologic treatment is currently available. Our previous studies discovered that a pivotal step in the disease process is the activation of the nuclear factor of activated T cells (NFAT) c3 in lung macrophages, suggesting that inhibitors against the upstream protein phosphatase calcineurin should be effective for prevention/treatment of ARDS. Herein, we report the development of a highly potent, cell-permeable, and metabolically stable peptidyl inhibitor, CNI103, which selectively blocks the interaction between calcineurin and NFATc3, through computational and medicinal chemistry. CNI103 specifically inhibited calcineurin signaling in vitro and in vivo and exhibited a favorable pharmacokinetic profile, broad tissue distribution following different routes of administration, and minimal toxicity. Our data indicate that CNI103 is a promising novel treatment for ARDS and other inflammatory diseases.

Calcineurin inhibitor (CNI)-associated skin cancers: New insights on exploring mechanisms by which CNIs downregulate DNA repair machinery.

The use of the calcineurin inhibitors (CNI) cyclosporine (CsA) and tacrolimus remains a cornerstone in post-transplantation immunosuppression. Although these immunosuppressive agents have revolutionized the field of transplantation medicine, its increased skin cancer risk poses a major concern. A key contributor to this phenomenon is a reduced capacity to repair DNA damage caused by exposure to ultraviolet (UV) wavelengths of sunlight. CNIs decrease DNA repair by mechanisms that remain to be fully explored. Though CsA is known to decrease the abundance of key DNA repair enzymes, less is known about how tacrolimus yields this effect. CNIs hold the capacity to inhibit both of the main catalytic calcineurin isoforms (CnAα and CnAß). However, it is unknown which isoform regulates UV-induced DNA repair, which is the focus of this review. It is with hope that this insight spurs investigative efforts that conclusively addresses these gaps in knowledge. Additionally, this research also raises the possibility that newer CNIs can be developed that effectively blunt the immune response while mitigating the incidence of skin cancers with immunosuppression.

CpG-ODN-mediated TLR9 innate immune signalling and calcium dyshomeostasis converge on the NFκB inhibitory protein IκBß to drive IL1α and IL1ß expression.

Sterile inflammation contributes to many pathological states associated with mitochondrial injury. Mitochondrial injury disrupts calcium homeostasis and results in the release of CpG-rich mitochondrial DNA. The role of CpG-stimulated TLR9 innate immune signalling and sterile inflammation is well studied; however, how calcium dyshomeostasis affects this signalling is unknown. Therefore, we interrogated the relationship beτween intracellular calcium and CpG-induced TLR9 signalling in murine macrophages. We found that CpG-ODN-induced NFκB-dependent IL1α and IL1ß expression was significantly attenuated by both calcium chelation and calcineurin inhibition, a finding mediated by inhibition of degradation of the NFκB inhibitory protein IκBß. In contrast, calcium ionophore exposure increased CpG-induced IκBß degradation and IL1α and IL1ß expression. These results demonstrate that through its effect on IκBß degradation, increased intracellular Ca2+ drives a pro-inflammatory TLR9-mediated innate immune response. These results have implications for the study of innate immune signalling downstream of mitochondrial stress and injury.