Olokizumab versus Placebo or Adalimumab in Rheumatoid Arthritis.

BACKGROUND: The cytokine interleukin-6 is involved in the pathogenesis of rheumatoid arthritis. Olokizumab, a humanized monoclonal antibody targeting the interleukin-6 cytokine directly, is being tested for the treatment of rheumatoid arthritis. METHODS: In a 24-week, phase 3, multicenter, placebo- and active-controlled trial, we randomly assigned (in a 2:2:2:1 ratio) patients with rheumatoid arthritis and an inadequate response to methotrexate to receive subcutaneous olokizumab at a dose of 64 mg every 2 or 4 weeks, adalimumab (40 mg every 2 weeks), or placebo; all patients continued methotrexate therapy. The primary end point was an American College of Rheumatology 20 (ACR20) response (≥20% fewer tender and swollen joints and ≥20% improvement in three of five other domains) at week 12, with each olokizumab dose tested for superiority to placebo. We also tested the noninferiority of each olokizumab dose to adalimumab with respect to the percentage of patients with an ACR20 response (noninferiority margin, -12 percentage points in the lower boundary of the 97.5% confidence interval for the difference between groups). RESULTS: A total of 464 patients were assigned to receive olokizumab every 2 weeks, 479 to receive olokizumab every 4 weeks, 462 to receive adalimumab, and 243 to receive placebo. An ACR20 response at week 12 occurred in 44.4% of the patients receiving placebo, in 70.3% receiving olokizumab every 2 weeks (difference vs. placebo, 25.9 percentage points; 97.5% confidence interval [CI], 17.1 to 34.1), in 71.4% receiving olokizumab every 4 weeks (difference vs. placebo, 27.0 percentage points; 97.5% CI, 18.3 to 35.2), and in 66.9% receiving adalimumab (difference vs. placebo, 22.5 percentage points; 95% CI, 14.8 to 29.8) (P<0.001 for the superiority of each olokizumab dose to placebo). Both olokizumab doses were noninferior to adalimumab with respect to the percentage of patients with an ACR20 response at week 12 (difference, 3.4 percentage points [97.5% CI, -3.5 to 10.2] with olokizumab every 2 weeks and 4.5 percentage points [97.5% CI, -2.2 to 11.2] with olokizumab every 4 weeks). Adverse events, most commonly infections, occurred in approximately 70% of the patients who received olokizumab. Antibodies against olokizumab were detected in 3.8% of the patients receiving the drug every 2 weeks and in 5.1% of those receiving it every 4 weeks. CONCLUSIONS: In patients with rheumatoid arthritis who were receiving maintenance methotrexate, olokizumab was superior to placebo and noninferior to adalimumab in producing an ACR20 response at 12 weeks. Larger and longer trials are required to determine the efficacy and safety of olokizumab in patients with rheumatoid arthritis. (Supported by R-Pharm; CREDO2 ClinicalTrials.gov number, NCT02760407.).

Olokizumab plus methotrexate: safety and efficacy over 106 weeks of treatment.

OBJECTIVE: To report long-term safety and tolerability of olokizumab (OKZ) in combination with methotrexate (MTX) in subjects with active rheumatoid arthritis (RA), using pooled data from three randomised clinical trials (RCT) followed by open-label extension (OLE) study. METHODS: Cumulative data from three phase 3 core trials and their OLE were analysed. Safety variables assessed included treatment-emergent adverse events (AEs), serious AEs (SAEs), AEs of special interest and laboratory results. Efficacy assessments included ACR20/50/70 responses, Disease Activity Score 28 (C-reactive protein) <3.2, CDAI remission and low disease activity (LDA), SDAI remission and LDA, HAQ-DI decrease of 0.22 unit and Boolean 2.0 remission. RESULTS: A total of 2304 patients received OKZ in combination with MTX either once every 2 weeks or once every 4 weeks. Event rates per 100 patient-years in OKZ every 2 weeks and OKZ every 4 weeks, respectively, were 9.57 and 9.13 for SAEs; 2.95 and 2.34 for serious infections; 0.09 and 0.05 for gastrointestinal perforations; 0.58 and 0.83 for major adverse cardiovascular events; and 0.45 and 0.50 for malignancies. No increase in the rate of any AE was observed over 106 weeks of treatment. The evaluation of laboratory variables demonstrated the expected changes, like neutropenia, elevation of liver enzymes and blood lipids. Clinical response rates remained stable during the OLE. CONCLUSION: The long-term safety and tolerability of OKZ in combination with MTX remained stable. The efficacy of OKZ was maintained through week 106. These findings support OKZ as a treatment option for patients with active RA.

Inflammation-mediated drug interactions of olokizumab and cytochrome P450 activities in patients with rheumatoid arthritis.

AIMS: In patients with rheumatoid arthritis (RA), interleukin (IL)-6 affects the activity of cytochrome P450 (CYP) enzymes. Treatment with anti-IL-6 therapy can reverse the IL-6-mediated downregulation of CYP enzymes, resulting in changes in plasma levels of CYP substrates. The primary objective of this study was to evaluate the impact of the IL-6 inhibitor olokizumab on the pharmacokinetics of CYP probe substrates in subjects with active RA. METHODS: Seventeen patients with active RA were orally administered a phenotyping cocktail of midazolam (CYP3A4 substrate), omeprazole (CYP2C19 substrate), warfarin (CYP2C9 substrate) and caffeine (CYP1A2 substrate) alone and 2 weeks after a single subcutaneous injection of 128 mg olokizumab. The pharmacokinetic parameters of each substrate were calculated using noncompartmental analysis. RESULTS: Sixteen of 17 enrolled patients received the complete doses of the cocktail drugs and olokizumab and were eligible for the pharmacokinetic evaluations. After single-dose administration of olokizumab, the exposure of midazolam and omeprazole decreased by 30-33% and 26-32%, respectively, compared to when the substrates were administered along via cocktail. In the presence of olokizumab, caffeine exposure increased by 19-23% compared to caffeine administration alone. There were no significant changes in S-warfarin exposure. CONCLUSION: In patients with active RA, olokizumab potentially reverses the IL-6-mediated suppression of CYP3A4 and CYP2C19. According to FDA guidance, olokizumab is considered a weak inducer of CYP3A4 and CYP2C19.

Long-Term Experimental Hyperglycemia Does Not Impair Macrovascular Endothelial Barrier Integrity and Function in vitro.

Hyperglycemia is a hallmark of type 2 diabetes implicated in vascular endothelial dysfunction and cardiovascular complications. Many in vitro studies identified endothelial apoptosis as an early outcome of experimentally modeled hyperglycemia emphasizing cell demise as a significant factor of vascular injury. However, endothelial apoptosis has not been observed in vivo until the late stages of type 2 diabetes. Here, we studied the long-term (up to 4 weeks) effects of high glucose (HG, 30 mM) on human umbilical vein endothelial cells (HUVEC) in vitro. HG did not alter HUVEC monolayer morphology, ROS levels, NO production, and exerted minor effects on the HUVEC apoptosis markers. The barrier responses to various clues were indistinguishable from those by cells cultured in physiological glucose (5 mM). Tackling the key regulators of cytoskeletal contractility and endothelial barrier revealed no differences in the histamine-induced intracellular Ca2+ responses, nor in phosphorylation of myosin regulatory light chain or myosin light chain phosphatase. Altogether, these findings suggest that vascular endothelial cells may well tolerate HG for relatively long exposures and warrant further studies to explore mechanisms involved in vascular damage in advanced type 2 diabetes.

Olokizumab, a monoclonal antibody against interleukin-6, in combination with methotrexate in patients with rheumatoid arthritis inadequately controlled by tumour necrosis factor inhibitor therapy: efficacy and safety results of a randomised controlled phase III study.

OBJECTIVES: To assess the efficacy and safety of olokizumab (OKZ), a monoclonal antibody against the interleukin-6 (IL-6) cytokine, versus placebo (PBO) in patients with prior inadequate response to tumour necrosis factor inhibitors (TNFi-IRs). METHODS: In this 24-week multicentre, placebo-controlled, double-blind study, the patients were randomised in a 2:2:1 ratio to receive subcutaneously administered OKZ 64 mg once every 2 weeks (q2w), OKZ 64 mg once every 4 weeks (q4w) or PBO plus methotrexate. At week 16, the patients on PBO were randomised to receive either OKZ regime. The primary endpoint was the proportion of patients achieving an American College of Rheumatology 20% (ACR20) response at week 12. Disease Activity Score 28-joint count C-reactive protein (DAS28 (CRP))<3.2 at week 12 was the major secondary efficacy endpoint. Safety and immunogenicity were assessed. RESULTS: In 368 patients randomised, ACR20 response rates were 60.9% in OKZ q2w, 59.6% in OKZ q4w and 40.6% in PBO (p<0.01 for both comparisons). Achievement of DAS28 (CRP) <3.2 was significantly different, favouring the OKZ arms. Improvements in efficacy and patient-reported outcomes were maintained throughout 24 weeks and were noted after week 16 in patients who switched from PBO.Dose-related treatment-emergent serious adverse events were 7% in OKZ q2w, 3.2% in OKZ q4w and none in the PBO group. CONCLUSIONS: Direct inhibition of IL-6 with OKZ resulted in significant improvements in the signs and symptoms of rheumatoid arthritis compared with PBO in TNF-IR patients with a similar safety profile as observed for monoclonal antibodies to the IL-6 receptor. TRIAL REGISTRATION NUMBER: NCT02760433.

Olokizumab, a monoclonal antibody against interleukin 6, in combination with methotrexate in patients with rheumatoid arthritis inadequately controlled by methotrexate: efficacy and safety results of a randomised controlled phase III study.

OBJECTIVE: To evaluate the efficacy and safety of olokizumab (OKZ) in patients with active rheumatoid arthritis despite treatment with methotrexate (MTX). METHODS: In this 24-week multicentre, placebo-controlled, double-blind study, patients were randomised 1:1:1 to receive subcutaneously administered OKZ 64 mg once every 2 weeks, OKZ 64 mg once every 4 weeks, or placebo plus MTX. The primary efficacy endpoint was the proportion of patients achieving an American College of Rheumatology 20% (ACR20) response at week 12. The secondary efficacy endpoints included percentage of subjects achieving Disease Activity Score 28-joint count based on C reactive protein <3.2, Health Assessment Questionnaire Disability Index at week 12, ACR50 response and Clinical Disease Activity Index ≤2.8 at week 24. Safety and immunogenicity were assessed throughout the study. RESULTS: A total of 428 patients were randomised. ACR20 responses were more frequent with OKZ every 2 weeks (63.6%) and OKZ every 4 weeks (70.4%) than placebo (25.9%) (p<0.0001 for both comparisons). There were significant differences in all secondary efficacy endpoints between OKZ-treated arms and placebo. Treatment-emergent serious adverse events (TESAEs) were reported by more patients in the OKZ groups compared with placebo. Infections were the most common TESAEs. No subjects developed neutralising antidrug antibodies. CONCLUSIONS: Treatment with OKZ was associated with significant improvement in signs, symptoms and physical function of rheumatoid arthritis without discernible differences between the two regimens. Safety was as expected for this class of agents. Low immunogenicity was observed. Trial registration number NCT02760368.

PCSK9 as a Target for Development of a New Generation of Hypolipidemic Drugs.

PCSK9 has now become an important target to create new classes of lipid-lowering drugs. The prevention of its interaction with LDL receptors allows an increase in the number of these receptors on the surface of the cell membrane of hepatocytes, which leads to an increase in the uptake of cholesterol-rich atherogenic LDL from the bloodstream. The PCSK9 antagonists described in this review belong to different classes of compounds, may have a low molecular weight or belong to macromolecular structures, and also demonstrate different mechanisms of action. The mechanisms of action include preventing the effective binding of PCSK9 to LDLR, stimulating the degradation of PCSK9, and even blocking its transcription or transport to the plasma membrane/cell surface. Although several types of antihyperlipidemic drugs have been introduced on the market and are actively used in clinical practice, they are not without disadvantages, such as well-known side effects (statins) or high costs (monoclonal antibodies). Thus, there is still a need for effective cholesterol-lowering drugs with minimal side effects, preferably orally bioavailable. Low-molecular-weight PCSK9 inhibitors could be a worthy alternative for this purpose.

AICAR Protects Vascular Endothelial Cells from Oxidative Injury Induced by the Long-Term Palmitate Excess.

Hyperlipidemia manifested by high blood levels of free fatty acids (FFA) and lipoprotein triglycerides is critical for the progression of type 2 diabetes (T2D) and its cardiovascular complications via vascular endothelial dysfunction. However, attempts to assess high FFA effects in endothelial culture often result in early cell apoptosis that poorly recapitulates a much slower pace of vascular deterioration in vivo and does not provide for the longer-term studies of endothelial lipotoxicity in vitro. Here, we report that palmitate (PA), a typical FFA, does not impair, by itself, endothelial barrier and insulin signaling in human umbilical vein endothelial cells (HUVEC), but increases NO release, reactive oxygen species (ROS) generation, and protein labeling by malondialdehyde (MDA) hallmarking oxidative stress and increased lipid peroxidation. This PA-induced stress eventually resulted in the loss of cell viability coincident with loss of insulin signaling. Supplementation with 5-aminoimidazole-4-carboxamide-riboside (AICAR) increased endothelial AMP-activated protein kinase (AMPK) activity, supported insulin signaling, and prevented the PA-induced increases in NO, ROS, and MDA, thus allowing to maintain HUVEC viability and barrier, and providing the means to study the long-term effects of high FFA levels in endothelial cultures. An upgraded cell-based model reproduces FFA-induced insulin resistance by demonstrating decreased NO production by vascular endothelium.

Planar compression of extracellular substrates induces S phase arrest via ATM-independent CHK2 activation.

Cell proliferation is regulated not only by soluble chemical factors but also by mechanical cues surrounding cells. Mechanical stretch of extracellular substrates is known to promote cell proliferation by driving exit from the G0 phase and entry into the S phase. Here, we report that planer compression of extracellular substrates induces cell cycle arrest in the S phase. The compression-induced S phase arrest is mediated by the checkpoint kinase 2 (CHK2)-p53 pathway. In contrast to the canonical S phase checkpoint pathway activated by DNA damage, CHK2 activation by the substrate compression is independent of ataxia telangiectasia mutated (ATM). We further find that disassembly of the actin cytoskeleton is required for the compression-induced S phase arrest. Notably, cancer cells do not exhibit S phase arrest upon the substrate compression. Our results suggest a novel mechanism for homeostatic control of cell growth under mechanical perturbations.

Design of peptidase-resistant peptide inhibitors of myosin light chain kinase.

Myosin light chain kinase (MLCK) is a key regulator of various forms of cell motility including smooth muscle contraction, cell migration, cytokinesis, receptor capping, secretion, etc. Inhibition of MLCK activity in endothelial and epithelial monolayers using cell-permeant peptide Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys (PIK, Peptide Inhibitor of Kinase) allows protecting the barrier capacity, suggesting a potential medical use of PIK. However, low stability of L-PIK in a biological milieu prompts for development of more stable L-PIK analogues for use as experimental tools in basic and drug-oriented biomedical research. Previously, we designed PIK1, H-(Nα Me)Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys-NH2 , that was 2.5-fold more resistant to peptidases in human plasma in vitro than L-PIK and equal to it as MLCK inhibitor. In order to further enhance proteolytic stability of PIK inhibitor, we designed the set of six site-protected peptides based on L-PIK and PIK1 degradation patterns in human plasma as revealed by 1 H-NMR analysis. Implemented modifications increased half-live of the PIK-related peptides in plasma about 10-fold, and these compounds retained 25-100% of L-PIK inhibitory activity toward MLCK in vitro. Based on stability and functional activity ranking, PIK2, H-(Nα Me)Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-D-Arg-Lys-NH2 , was identified as the most stable and effective L-PIK analogue. PIK2 was able to decrease myosin light chain phosphorylation in endothelial cells stimulated with thrombin, and this effect correlated with the inhibition by PIK2 of thrombin-induced endothelial hyperpermeability in vitro. Therefore, PIK2 could be used as novel alternative to other cell-permeant inhibitors of MLCK in cell culture-based and in vivo studies where MLCK catalytic activity inhibition is required. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

Analysis of Clinical Success and Molecular Mechanisms of Action of Novel Anti-glioblastoma Drugs: A Review.

BACKGROUND: Gliomas and glioblastomas (GBM) are common primary malignant brain tumors, which are highly malignant and have a poor prognosis. The presence of cancer stem cells with unrestricted proliferative capacity and ability to generate glial neoplastic cells, the diffuse nature of GBM, and other specific factors of GBM contribute to poor results of drug therapy in patients with GBM. Despite the worldwide efforts to improve the treatment, many novel anti-GBM drugs are active just in vitro, in silico, and in preclinical trials, and they sometimes demonstrate poor or no activity in clinical trials. In this paper, we have casually selected and analyzed the most promising evidence-based results related to glioblastoma treatment at FDA and Clinical Trials.gov databases. It was observed that the most prospective trend in the development of anti-GBM drugs is combination therapy vs. monotherapy. Our analysis of clinical trials has allowed us to predict that the most promising combination therapy that has shown the best results in patient's surveillance should include drugs that block different growth-promoting signals in glioblastoma cells and that are activated by the V600E BRAF mutation. One drug should inhibit signals from the BRAF protein, whereas the second drug in combination should inhibit signals from the MEK protein Methods: The content of this review is based on information obtained from PubMed, ClinicalTrials. gov, and the U.S. Food and Drug Administration (https://www.fda.gov/). In ClinicalTrials.gov, we retrieved studies published from January 1, 2015. In the data search, "Glioblastoma" was used as the keyword. A study was deleted if it studied remedies for concomitant tumor diseases, as well as if it did not include descriptions of treatment methods and/or if GBM was not mentioned. The analysis of the effectiveness of treatment was carried out according to the increasing overall survival in GBM patients, compared to the gold standard for this cancer. RESULTS: GBM patients treated with novel immunotherapy agents and drugs acting on epigenetic factors and receptor tyrosine kinase inhibitors have shown encouraging potential for future development in clinic. However, combinations of drugs have led to more significant improvements in the results and an increase in life expectancy of patients. For example, the combination of nivolumab and ipilimumab showed a 72% increase in life expectancy compared to using nivolumab alone (9.8 vs. 16.85). CONCLUSION: Combining anti-GBM drugs appears to be a key direction for increasing treatment effectiveness and overall survival. Radiotherapy of GBM can increase the effect of combination drug therapy.

Shear Stress and the AMP-Activated Protein Kinase Independently Protect the Vascular Endothelium from Palmitate Lipotoxicity.

Saturated free fatty acids are thought to play a critical role in metabolic disorders associated with obesity, insulin resistance, type 2 diabetes (T2D), and their vascular complications via effects on the vascular endothelium. The most abundant saturated free fatty acid, palmitate, exerts lipotoxic effects on the vascular endothelium, eventually leading to cell death. Shear stress activates the endothelial AMP-activated protein kinase (AMPK), a cellular energy sensor, and protects endothelial cells from lipotoxicity, however their relationship is uncertain. Here, we used isoform-specific shRNA-mediated silencing of AMPK to explore its involvement in the long-term protection of macrovascular human umbilical vein endothelial cells (HUVECs) against palmitate lipotoxicity and to relate it to the effects of shear stress. We demonstrated that it is the α1 catalytic subunit of AMPK that is critical for HUVEC protection under static conditions, whereas AMPK-α2 autocompensated a substantial loss of AMPK-α1, but failed to protect the cells from palmitate. Shear stress equally protected the wild type HUVECs and those lacking either α1, or α2, or both AMPK-α isoforms; however, the protective effect of AMPK reappeared after returning to static conditions. Moreover, in human adipose microvascular endothelial cells isolated from obese diabetic individuals, shear stress was a strong protector from palmitate lipotoxicity, thus highlighting the importance of circulation that is often obstructed in obesity/T2D. Altogether, these results indicate that AMPK is important for vascular endothelial cell protection against lipotoxicity in the static environment, however it may be dispensable for persistent and more effective protection exerted by shear stress.

Treatment of Idiopathic Recurrent Pericarditis With Goflikicept: Phase II/III Study Results.

BACKGROUND: Idiopathic recurrent pericarditis (IRP) is a rare autoinflammatory disease. Interleukin (IL)-1α and IL-1ß are the pivotal cytokines in the pathophysiology of acute pericarditis and its recurrence. We created a phase II/III study with a new IL-1 inhibitor-goflikicept in IRP. OBJECTIVES: This study sought to evaluate the efficacy and safety of goflikicept treatment in patients with IRP. METHODS: We conducted a 2-center open-label study of goflikicept in patients with IRP with and without recurrence at time of enrollment. The study consisted of 4 periods: screening, run-in (open-label treatment period), randomized withdrawal, and follow-up. Patients with clinical response to goflikicept in the run-in period were randomized (1:1) to a placebo-controlled withdrawal period, where the time to first pericarditis recurrence (primary endpoint) was evaluated. RESULTS: We enrolled 22 patients, and 20 of these patients were randomized. Reduction of C-reactive protein level accompanied by reduction of chest pain and pericardial effusion compared to baseline was demonstrated during the run-in period. Recurrence of pericarditis occurred in 9 of 10 patients in the placebo group, and there were no recurrence events in goflikicept group within 24 weeks after randomization (P < 0.001). A total of 122 adverse events were reported in 21 patients (95.5%), with no deaths and no new safety signals identified for goflikicept. CONCLUSIONS: Treatment with goflikicept prevented recurrences and maintained IRP remission with a favorable risk-benefit ratio. Goflikicept reduced the risk of recurrence compared with placebo. (Study to Evaluate the Efficacy and Safety of RPH-104 Treatment in Patients With Idiopathic Recurrent Pericarditis; NCT04692766).

Combination of immune checkpoint inhibitors with radiation therapy in cancer: A hammer breaking the wall of resistance.

Immuno-oncology is an emerging field in the treatment of oncological diseases, that is based on recruitment of the host immune system to attack the tumor. Radiation exposure may help to unlock the potential of the immune activating agents by enhancing the antigen release and presentation, attraction of immunocompetent cells to the inflammation site, and eliminating the tumor cells by phagocytosis, thereby leading to an overall enhancement of the immune response. Numerous preclinical studies in mouse models of glioma, murine melanoma, extracranial cancer, or colorectal cancer have contributed to determination of the optimal radiotherapy fractionation, as well as the radio- and immunotherapy sequencing strategies for maximizing the antitumor activity of the treatment regimen. At the same time, efficacy of combined radio- and immunotherapy has been actively investigated in clinical trials of metastatic melanoma, non-small-cell lung cancer and renal cell carcinoma. The present review summarizes the current advancements and challenges related to the aforementioned treatment approach.

Preclinical Characterization of a Novel Anti-Cancer PD-L1 Inhibitor RPH-120.

RPH-120 is a novel fully human anti-PD-L1 IgG1 monoclonal antibody with specifically designed Asn300Ala mutation in Fc fragment. Surface plasmon resonance assay showed that affinity of the RPH-120 to the dimeric form of human PD-L1-Fc fusion protein was much higher than affinity to the monomeric His-tagged PD-L1. Further binding studies demonstrated that RPH-120 is able to bind to human and monkey but not mouse PD-L1. Tissue cross-reactivity study showed good comparability of human and Cynomolgus monkeys tissue staining. Bioactivity was assessed using mixed lymphocyte reaction assay. This study revealed that RPH-120 was able to activate T cells preventing PD1/PD-L1 interaction. Antitumor efficacy was analyzed in HCC-827 lung cancer xenografts in humanized CD34+ mice at three dosage levels: 20, 80, and 200 mg/kg. RPH-120 demonstrated significant tumor growth inhibition, and this inhibition was comparable to that of atezolizumab. In a single dose toxicity, toxicokinetic and dose range finding study performed in Cynomolgus monkeys, RPH-120 was administered via intravenous (IV) bolus or 60-min IV infusion, followed by 8-weeks recovery period. An acceptable toxicokinetic profile was demonstrated and administration at doses of up to 200 mg/kg was well tolerated by all animals. In conclusion, RPH-120 revealed promising in vitro and in vivo activity and safety. RPH-120 is a potent anti-PD-L1 drug candidate for cancer immunotherapy.

The 5α-Reductase Inhibitor Finasteride Exerts Neuroprotection Against Ischemic Brain Injury in Aged Male Rats.

Progesterone (P4) exerts potent neuroprotection both in young and aged animal models of stroke. The neuroprotection is likely to be mediated by allopregnanolone (ALLO) metabolized from P4 by 5α-reductase, since the neuroprotection is attenuated by the 5α-reductase inhibitor finasteride, which was done only with young animals though. Thus, we do not know the contribution of ALLO to the P4-induced neuroprotection in aged animals. We examined effects of finasteride on the P4-induced neuroprotection in aged (16-18-month-old) male rats subjected to transient focal cerebral ischemia. Transient focal cerebral ischemia was induced by left middle cerebral artery occlusion (MCAO) and occlusion of the bilateral common carotid arteries. MCAO rats were given an 8 mg/kg P4 6 h after MCAO followed by the same treatment once a day for successive 3 days. Finasteride, a 5α-reductase inhibitor, at 20 mg/kg was intraperitoneally injected 30 min prior to the P4-injections. P4 markedly reduced neuronal damage 72 h after MCAO, and the P4-induced neuroprotection was apparently suppressed by finasteride in the aged animals. However, post-ischemic administration of finasteride alone (20 mg/kg) significantly prevented neuronal damage and the impairment of Rotarod performance after MCAO in aged male rats, but not in young ones. The androgen receptor antagonist flutamide markedly suppressed the neuroprotection of finasteride in the cerebral cortex, but not in the striatum, suggesting the androgen receptor-dependent mechanism of the finasteride-induced neuroprotection in the cerebral cortex. Our findings suggested, for the first time, the potential of finasteride as a therapeutic agent in post-ischemic treatment of strokes in aged population.

Nestorone exerts long-term neuroprotective effects against transient focal cerebral ischemia in adult male rats.

Progesterone (P4) exerts long-term neuroprotective effects in animal models of stroke, and P4 receptors play a crucial role in this neuroprotection. However, it currently remains unclear whether the activation of P4 receptors alone is sufficient to exert long-term neuroprotection because P4 exhibits other steroidogenic and GABAergic activities via several of its metabolites. Nestorone is a potent selective P4 receptor agonist without other steroidogenic and GABAergic activities. Therefore, we examined the effects of nestorone in adult male rats subjected to transient middle cerebral artery occlusion (MCAO). The dose-response relationship of nestorone showed that the 6-h post-ischemic administration of 10 µg/kg nestorone resulted in greater reductions in infarct sizes 48 h after MCAO than the other two doses tested (5 and 80 µg/kg), and this dose of nestorone significantly decreased astrocyte activation in the peri-infarct cortical region. Moreover, 10 µg/kg nestorone significantly prevented functional impairments on the 28th and 29th days and slightly reduced infarct size on the 30th day after MCAO. The present results suggest that the activation of P4 receptors alone is sufficient to exert neuroprotection against transient cerebral ischemia in adult male rats; therefore, nestorone is a promising agent in post-stroke treatment due to its potent progestational effects without other steroid-related activities.

Progesterone improves functional outcomes after transient focal cerebral ischemia in both aged male and female rats.

Progesterone hormone (P4) is a promising agent against strokes because post-ischemic administration of P4 exerts neuroprotective effects in several young and aged animal models of stroke. However, in contrast to a majority of the studies using male animals, female animals remain underrepresented. In addition, we do not know whether the same administration way of P4 is effective in both male and female animals because there are gender different responses to steroid hormones and stroke. In this study, we thus evaluated long-term histological and functional outcomes in the same treatment with P4 in both 18-month old male and age-matched female rats subjected to transient middle cerebral artery occlusion (MCAO). MCAO aged male and female rats were given a subcutaneous injection of P4 (4 mg/kg) 6 h after MCAO followed by once daily for successive 7 days. The post-ischemic administration of P4 significantly improved the impairments of spatial working memory and motor coordination 28-29 days after MCAO in both aged male and age-matched female rats. However, the P4 administration slightly but not significantly reduced infarct sizes 30 days after MCAO in aged female rats, in contrast to significant better histological outcome in P4-treated aged males. On the other hand, these histological and behavioral analyses showed no adverse effects of P4 in aged rats of both sexes. Collectively, our study provides preclinical evidence to prompt further preclinical studies for post-stroke treatment with P4 and the translation of its clinical trials in old stroke patients of both sexes.

Mechanoregulation and pathology of YAP/TAZ via Hippo and non-Hippo mechanisms.

Yes-associated protein (YAP) and its paralog WW domain containing transcription regulator 1 (TAZ) are important regulators of multiple cellular functions such as proliferation, differentiation, and survival. On the tissue level, YAP/TAZ are essential for embryonic development, organ size control and regeneration, while their deregulation leads to carcinogenesis or other diseases. As an underlying principle for YAP/TAZ-mediated regulation of biological functions, a growing body of research reveals that YAP/TAZ play a central role in delivering information of mechanical environments surrounding cells to the nucleus transcriptional machinery. In this review, we discuss mechanical cue-dependent regulatory mechanisms for YAP/TAZ functions, as well as their clinical significance in cancer progression and treatment.

Actomyosin contractility provokes contact inhibition in E-cadherin-ligated keratinocytes.

Confluence-dependent inhibition of epithelial cell proliferation, termed contact inhibition, is crucial for epithelial homeostasis and organ size control. Here we report that among epithelial cells, keratinocytes, which compose the stratified epithelium in the skin, possess a unique, actomyosin-dependent mechanism for contact inhibition. We have observed that under actomyosin-inhibited conditions, cell-cell contact itself through E-cadherin promotes proliferation of keratinocytes. Actomyosin activity in confluent keratinocytes, however, inhibits nuclear localization of ß-catenin and YAP, and causes attenuation of ß-catenin- and YAP-driven cell proliferation. Confluent keratinocytes develop E-cadherin-mediated punctate adhesion complexes, to which radial actin cables are connected. Eliminating the actin-to-E-cadherin linkage by depleting α-catenin increases proliferation of confluent keratinocytes. By contrast, enforced activation of RhoA-regulated actomyosin or external application of pulling force to ligated E-cadherin attenuates their proliferation, suggesting that tensile stress at E-cadherin-mediated adhesion complexes inhibits proliferation of confluent keratinocytes. Our results highlight actomyosin contractility as a crucial factor that provokes confluence-dependent inhibition of keratinocyte proliferation.