alisporivir and Disease-Models--Animal

HCV infection is the primary cause of chronic liver disease. Host cell cyclophilins (Cyps) are essential for efficient HCV replication in hepatocytes, and thus Cyps are regarded as a new target for anti-HCV therapy. Alisporivir (Debio-025), a non-immunosuppressive cyclosporine A derivative that selectively inhibits Cyps, is being developed by Debiopharm SA for the potential oral treatment of HCV infection. In the HCV subgenomic replicon system, alisporivir suppressed viral replication more potently than cyclosporine A. A phase II clinical trial demonstrated that treatment with alisporivir alone or combined with PEGylated IFNalpha2a reduced the viral load in patients with chronic HCV infection. The drug was also generally well tolerated. In contrast, a phase I trial of alisporivir monotherapy in patients with HIV-1 infection suggested that the drug has a limited effect on HIV-1 viral load. Alisporivir was also investigated in animal models of muscular dystrophy, acute myocardial infarction and brain disorders. At the time of publication, two phase II trials, evaluating alisporivir alone and in combination with PEGylated IFNalpha2a or with PEGylated IFNalpha2a and ribavirin, were ongoing in treatment-naïve patients with HCV-1 infection and in patients with chronic HCV-1 infection who were prior non-responders to PEGylated IFNalpha or ribavirin.

Topics: Administration, Oral; Animals; Antiviral Agents; Clinical Trials, Phase II as Topic; Cyclophilins; Cyclosporine; Disease Models, Animal; Hepacivirus; Hepatitis C; Humans; Virus Replication

The low-density lipoprotein receptor-related protein 1 (LRP1) is an endocytic and cell signaling transmembrane protein. Endothelial LRP1 clears proteinaceous toxins at the blood-brain barrier (BBB), regulates angiogenesis, and is increasingly reduced in Alzheimer's disease associated with BBB breakdown and neurodegeneration. Whether loss of endothelial LRP1 plays a direct causative role in BBB breakdown and neurodegenerative changes remains elusive. Here, we show that LRP1 inactivation from the mouse endothelium results in progressive BBB breakdown, followed by neuron loss and cognitive deficits, which is reversible by endothelial-specific LRP1 gene therapy. LRP1 endothelial knockout led to a self-autonomous activation of the cyclophilin A-matrix metalloproteinase-9 pathway in the endothelium, causing loss of tight junctions underlying structural BBB impairment. Cyclophilin A inhibition in mice with endothelial-specific LRP1 knockout restored BBB integrity and reversed and prevented neuronal loss and behavioral deficits. Thus, endothelial LRP1 protects against neurodegeneration by inhibiting cyclophilin A, which has implications for the pathophysiology and treatment of neurodegeneration linked to vascular dysfunction.

Topics: Alzheimer Disease; Animals; Blood-Brain Barrier; Cells, Cultured; Cognitive Dysfunction; Cyclophilin A; Cyclosporine; Disease Models, Animal; Endothelial Cells; Enzyme Inhibitors; Female; Gene Knockout Techniques; Genetic Therapy; Low Density Lipoprotein Receptor-Related Protein-1; Male; Matrix Metalloproteinase 9; Mice; Mice, Transgenic; Neurons; Signal Transduction

In Alzheimer's disease (AD), the molecular mechanisms involved in the neurodegeneration are still incompletely defined, though this aspect is crucial for a better understanding of the malady and for devising effective therapies. Mitochondrial dysfunctions and altered Ca

Topics: Alzheimer Disease; Animals; Calcium; Cells, Cultured; Cyclosporine; Disease Models, Animal; Electron Transport; Glutamic Acid; Hippocampus; Ions; Membrane Potential, Mitochondrial; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mitochondria; Neurotoxins; Reactive Oxygen Species

December 2019 saw the emergence of a new epidemic of pneumonia of varying severity, called coronavirus disease 2019 (COVID-19), caused by a newly identified coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV-2). No therapeutic option is available to treat this infection that has already killed > 310 000 people worldwide. This Viewpoint summarizes the strong scientific arguments supporting the use of alisporivir, a nonimmunosuppressive analogue of cyclosporine A with potent cyclophilin inhibition properties that has reached phase 3 clinical development, for the treatment of COVID-19. They include the strong cyclophilin dependency of the life cycle of many coronaviruses, including severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, and preclinical data showing strong antiviral and cytoprotective properties of alisporivir in various models of coronavirus infection, including SARS-CoV-2. Alisporivir should be tested without delay on both virological and clinical endpoints in patients with or at risk of severe forms of SARS-CoV-2 infection.

Topics: Animals; Antiviral Agents; Clinical Trials as Topic; COVID-19; COVID-19 Drug Treatment; Cyclophilins; Cyclosporine; Disease Models, Animal; Humans; Mice; Rats; SARS-CoV-2

While severe coronavirus infections, including Middle East respiratory syndrome coronavirus (MERS-CoV), cause lung injury with high mortality rates, protective treatment strategies are not approved for clinical use.We elucidated the molecular mechanisms by which the cyclophilin inhibitors cyclosporin A (CsA) and alisporivir (ALV) restrict MERS-CoV to validate their suitability as readily available therapy in MERS-CoV infection.Calu-3 cells and primary human alveolar epithelial cells (hAECs) were infected with MERS-CoV and treated with CsA or ALV or inhibitors targeting cyclophilin inhibitor-regulated molecules including calcineurin, nuclear factor of activated T-cells (NFATs) or mitogen-activated protein kinases. Novel CsA-induced pathways were identified by RNA sequencing and manipulated by gene knockdown or neutralising antibodies. Viral replication was quantified by quantitative real-time PCR and 50% tissue culture infective dose. Data were validated in a murine MERS-CoV infection model.Both CsA and ALV reduced MERS-CoV titres and viral RNA replication in Calu-3 cells and hAECs, improving epithelial integrity. While neither calcineurin nor NFAT inhibition reduced MERS-CoV propagation, blockade of c-Jun N-terminal kinase diminished infectious viral particle release but not RNA accumulation. Importantly, CsA induced interferon regulatory factor 1 (IRF1), a pronounced type III interferon (IFNλ) response and expression of antiviral genes. Downregulation of IRF1 or IFNλ increased MERS-CoV propagation in the presence of CsA. Importantly, oral application of CsA reduced MERS-CoV replication

Topics: Alveolar Epithelial Cells; Animals; Calcineurin Inhibitors; Cell Culture Techniques; Coronavirus Infections; Cyclophilins; Cyclosporine; Disease Models, Animal; Humans; Interferon Lambda; Interferon Regulatory Factor-1; Interferons; Mice; Middle East Respiratory Syndrome Coronavirus; Virus Replication

Duchenne muscular dystrophy (DMD) is a severe muscle disease of known etiology without effective, or generally applicable therapy. Mitochondria are affected by the disease in animal models but whether mitochondrial dysfunction is part of the pathogenesis in patients remains unclear. We show that primary cultures obtained from muscle biopsies of DMD patients display a decrease of the respiratory reserve, a consequence of inappropriate opening of the permeability transition pore (PTP). Treatment with the cyclophilin inhibitor alisporivir - a cyclosporin A derivative that desensitizes the PTP but does not inhibit calcineurin - largely restored the maximal respiratory capacity without affecting basal oxygen consumption in cells from patients, thus reinstating a normal respiratory reserve. Treatment with alisporivir, but not with cyclosporin A, led to a substantial recovery of respiratory function matching improved muscle ultrastructure and survival of sapje zebrafish, a severe model of DMD where muscle defects are close to those of DMD patients. Alisporivir was generally well tolerated in HCV patients and could be used for the treatment of DMD.

Topics: Animals; Cell Respiration; Cells, Cultured; Cyclosporine; Disease Models, Animal; Humans; Membrane Potential, Mitochondrial; Mitochondria; Muscle Cells; Muscular Dystrophy, Animal; Muscular Dystrophy, Duchenne; Oxygen Consumption; Zebrafish

Currently, there is no registered treatment for infections with emerging zoonotic coronaviruses like SARS- and MERS-coronavirus. We here report that in cultured cells low-micromolar concentrations of alisporivir, a non-immunosuppressive cyclosporin A-analog, inhibit the replication of four different coronaviruses, including MERS- and SARS-coronavirus. Ribavirin was found to further potentiate the antiviral effect of alisporivir in these cell culture-based infection models, but this combination treatment was unable to improve the outcome of SARS-CoV infection in a mouse model. Nevertheless, our data provide a basis to further explore the potential of Cyp inhibitors as host-directed, broad-spectrum inhibitors of coronavirus replication.

Topics: Animals; Antiviral Agents; Cell Line; Cells, Cultured; Coronavirus Infections; Cyclosporine; Cytopathogenic Effect, Viral; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; Mice; Middle East Respiratory Syndrome Coronavirus; Severe Acute Respiratory Syndrome; Severe acute respiratory syndrome-related coronavirus; Virus Replication

Small intestinal ulceration is a frequent and potentially serious condition associated with nonselective cyclooxygenase 1/2 inhibitors (nonsteroidal anti-inflammatory drugs, NSAIDs) including diclofenac (DCF). An initial topical effect involving mitochondria has been implicated in the pathogenesis, but the exact mechanisms of NSAID-induced enteropathy are unknown. We aimed at investigating whether DCF caused enterocyte demise via the mitochondrial permeability transition (mPT) and whether inhibition of critical mPT regulators might protect the mucosa from DCF injury. Cultured enterocytes (IEC-6) exposed to DCF readily underwent mPT-mediated cell death. We then targeted mitochondrial cyclophilin D (CypD), a key regulator of the mPT, in a mouse model of NSAID enteropathy. C57BL/6J mice were treated with an ulcerogenic dose of DCF (60 mg/kg, ip), followed (+ 1 h) by a non-cholestatic dose (10 mg/kg, ip) of the CypD inhibitor, cyclosporin A (CsA). CsA greatly reduced the extent of small intestinal ulceration. To avoid potential calcineurin-mediated effects, we used the non-immunosuppressive cyclosporin analog, D-MeAla(3)-EtVal(4)-cyclosporin (Debio 025). Debio 025 similarly protected the mucosa from DCF injury. To exclude drug-drug interactions, we exposed mice genetically deficient in mitochondrial CypD (peptidyl-prolyl cis-trans isomerase F [Ppif(-/-)]) to DCF. Ppif-null mice were largely protected from the ulcerogenic effects of DCF, whereas their wild-type littermates developed typical enteropathy. Enterocyte injury was preceded by upregulation of the proapoptotic transcription factor C/EBP homologous protein (Chop). Chop-null mice were refractory to DCF enteropathy, suggesting a critical role of endoplasmic reticulum stress induced by DCF. In conclusion, mitochondrial CypD plays a key role in NSAID-induced enteropathy, lending itself as a potentially new therapeutic target for cytoprotective intervention.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Line; Cell Survival; Cyclophilins; Cyclosporine; Diclofenac; Disease Models, Animal; Enterocytes; Intestinal Diseases; Intestine, Small; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Mitochondrial Swelling; Peptidyl-Prolyl Isomerase F; Ulcer

Duchenne muscular dystrophy (DMD) is a severe muscle wasting disorder caused by the absence of the cytoskeletal protein dystrophin. This leads to muscle cell death accompanied by chronic inflammation. Cyclosporin A (CsA) is a powerful immunosuppressive drug, which has been proposed for DMD treatment. CsA also directly regulates the mitochondrial permeability transition pore (mPTP), which participates in cell death pathways through the inhibition of cyclophilin D. Here, we evaluated whether Debio 025, a cyclophilin inhibitor with no immunosuppressive activity, improves the dystrophic condition in a mouse model of DMD, through regulation of mPTP.. The potency of Debio 025 to protect mouse dystrophic cells against mitochondria-mediated death was assessed by caspase-3 activity and calcium retention capacity assays. Mdx(5Cv) mice (3-week-old) were treated daily by gavage for 2 weeks with Debio 025 (10, 30 or 100 mg kg(-1)), CsA (10 mg kg(-1)) or placebo. The effects on muscle necrosis and function were measured.. In vitro investigations showed protective effect of low concentrations of Debio 025 against cell death. Histology demonstrated that Debio 025 partially protected the diaphragm and soleus muscles against necrosis (10 and 100 mg kg(-1), respectively). Hindlimb muscles from mice receiving Debio 025 at 10 mg kg(-1) relaxed faster, showed alteration in the stimulation frequency-dependent recruitment of muscle fibres and displayed a higher resistance to mechanical stress.. Debio 025 partially improved the structure and the function of the dystrophic mouse muscle, suggesting that therapies targeting the mPTP may be helpful to DMD patients.

Topics: Animals; Animals, Newborn; Cell Death; Cyclophilins; Cyclosporine; Diaphragm; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Delivery Systems; Female; Hindlimb; Male; Mice; Mice, Inbred mdx; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Muscle, Skeletal; Muscular Dystrophy, Animal; Muscular Dystrophy, Duchenne; Necrosis

Inhibition of mitochondrial permeability transition pore (mPTP) opening by cyclosporin A or ischemic postconditioning attenuates lethal reperfusion injury. Its impact on major post-myocardial infarction events, including worsening of left ventricular (LV) function and death, remains unknown. We sought to determine whether pharmacological or postconditioning-induced inhibition of mPTP opening might improve functional recovery and survival following myocardial infarction in mice. Anesthetized mice underwent 25 min of ischemia and 24 h (protocol 1) or 30 days (protocol 2) of reperfusion. At reperfusion, they received no intervention (control), postconditioning (3 cycles of 1 min ischemia-1 min reperfusion), or intravenous injection of the mPTP inhibitor Debio-025 (10 mg/kg). At 24 h of reperfusion, mitochondria were isolated from the region at risk for assessment of the Ca(2+) retention capacity (CRC). Infarct size was measured by triphenyltetrazolium chloride staining. At 30 days of reperfusion, mortality and LV contractile function (echocardiography) were evaluated. Postconditioning and Debio-025 significantly improved Ca(2+) retention capacity (132 +/- 13 and 153 +/- 31 vs. 53 +/- 16 nmol Ca(2+)/mg protein in control) and reduced infarct size to 35 +/- 4 and 32 +/- 7% of area at risk vs. 61 +/- 6% in control (P < 0.05). At 30 days, ejection fraction averaged 74 +/- 6 and 77 +/- 6% in postconditioned and Debio-025 groups, respectively, vs. 62 +/- 12% in the control group (P < 0.05). At 30 days, survival was improved from 58% in the control group to 92 and 89% in postconditioned and Debio-025 groups, respectively. Inhibition of mitochondrial permeability transition at reperfusion improves functional recovery and mortality in mice.

Topics: Acute Disease; Animals; Calcium; Cyclosporine; Disease Models, Animal; Ischemic Preconditioning, Myocardial; Male; Mice; Mitochondria, Heart; Myocardial Infarction; Permeability; Reperfusion Injury; Survival Analysis; Ventricular Dysfunction, Left