Berberine induces G1 arrest and apoptosis in human glioblastoma T98G cells through mitochondrial/caspases pathway

Berberine is an isoquinoline plant alkaloid with a long history of being used for the treatment of many diseases in Chinese herbal medicine. Berberine has a wide range of biochemical and pharmacological effects, including antitumor activities, but its mechanism of action is not clearly understood. In this study, we investigated that the relationship between the antiproliferative activities of berberine and the apoptotic pathway associated with its molecular mechanism of action in human glioblastoma T98G cells. Berberine treatment of T98G cell lines inhibited cell proliferation and induced cell death in a dose (50-200 microg/ml) dependent manner with an IC50 value of 134 microg/ml, which was associated with an increase in G1 arrest. Western blot analysis showed that the berberine-induced G1 arrest was mediated through the increased expression of P27 and the decreased expression of cyclin-dependent kinase (CDK) 2, CDK4, cyclin D, and cyclin E proteins. Berberine treatment also markedly enhanced apoptosis in T98G cells through the induction of a higher ratio of the Bax/Bcl-2 proteins, the disruption of mitochondrial membrane potential, and the activation of procaspase-9, caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP). Berberine can inhibit T98G cell proliferation by inducing G1 arrest and apoptosis. These results demonstrate that the berberine-induced apoptosis of T98G cells is primarily mediated through the mitochondrial/caspases-dependent pathway.     

Treatment with N-tosyl-l-phenylalanine chloromethyl ketone after the onset of collagen-induced arthritis reduces joint erosion and NF-kappaB activation

N-tosyl-l-phenylalanine chloromethyl ketone (TPCK) is known to inhibit NF-kappaB activation and the expression of inflammation mediators in cultured cells. We measured the potential of TPCK to inhibit the pathogenesis of collagen-induced arthritis by blocking NF-kappaB activation. Arthritis was induced in DBA/1J mice by the injection of bovine type II collagen in adjuvant on days 0 and 14. Mice received either TPCK (3 or 10 mg/kg, i.p.) or vehicle three times a week for 3 weeks starting on day 21. TPCK moderately reduced clinical disease activity scores, whereas it markedly suppressed histological indications of joint destruction. In vitro production of tumor necrosis factor-alpha, interleukin-6, and monocyte chemotactic protein-1 from lipopolysaccharide-stimulated spleen cells was also reduced by in vivo treatment with TPCK. Proliferation of cells isolated from spleen or draining lymph nodes and production of interferon-gamma and interleukin-17 in response to stimulation with type II collagen was decreased by TPCK. Moreover, nuclear NF-kappaB activity induced by collagen immunization was significantly reduced in mice treated with TPCK. Finally, osteoclast differentiation of bone marrow cells induced by macrophage colony-stimulating factor and receptor activator of NF-kappaB ligand was completely inhibited by TPCK. These results indicate that TPCK attenuates collagen-induced arthritis and bone erosion by suppressing NF-kappaB activation and thus expression of inflammatory and osteoclastogenic genes.     

Slow delayed rectifier K+ current block by HMR 1556 increases dispersion of repolarization and promotes Torsades de Pointes in rabbit ventricles

Background and purpose:

The slow delayed rectifier K⁺ current (I_Ks) contributes to ventricular repolarization when the action potential (AP) is prolonged. I_Ks block during drug-induced AP prolongation may promote Torsades de Pointes (TdP), but whether this is due to additional AP prolongation is uncertain.

Experimental approach:

In bradycardic perfused rabbit ventricles, the incidence of spontaneous TdP, monophasic AP duration at 90% repolarization (MAPD₉₀) and ECG interval between the peak and the end of T wave (T_peak−end) (index of dispersion of repolarization) were measured after the administration of veratridine (125 nM, slows Na⁺ channel inactivation), dofetilide (7.5 or 10 nM, a rapid delayed rectifier blocker) and HMR 1556 (HMR, 100 nM, an I_Ks blocker), alone or in combinations (n=6 each).

Key results:

HMR did not prolong MAPD₉₀, whereas veratridine or 7.5 nM dofetilide prolonged MAPD₉₀ (P<0.01) without inducing TdP. Veratridine+7.5 nM dofetilide additively prolonged MAPD₉₀ (P<0.05), induced 4±6 TdP per heart and prolonged T_peak−end by 12±10 ms. Subsequent addition of HMR did not further prolonged MAPD₉₀, but increased the number of TdP to 22±18 per heart and increased T_peak−end by 39±21 ms (P<0.05). Increasing dofetilide concentration from 7.5 to 10 nM (added to veratridine) produced a longer MAPD₉₀, but fewer TdP (5±5 per heart) and less T_peak−end prolongation (17±8 ms) compared to the veratridine+7.5 nM dofetilide+HMR group (P<0.05).

Conclusions and implications:

Adding I_Ks block markedly increases TdP incidence in hearts predisposed to TdP development by increasing the dispersion of repolarization, but without additional AP prolongation.     

Predictive Value of Echocardiographic Abnormalities and the Impact of Diastolic Dysfunction on In-hospital Major Cardiovascular Complications after Living Donor Kidney Transplantation

Patients with end-stage renal disease (ESRD) show characteristic abnormalities in cardiac structure and function. We evaluated the influence of these abnormalities on adverse cardiopulmonary outcomes after living donor kidney transplantation in patients with valid preoperative transthoracic echocardiographic evaluation. We then observed any development of major postoperative cardiovascular complications and pulmonary edema until hospital discharge. In-hospital major cardiovascular complications were defined as acute myocardial infarction, ventricular fibrillation/tachycardia, cardiogenic shock, newly-onset atrial fibrillation, clinical pulmonary edema requiring endotracheal intubation or dialysis. Among the 242 ESRD study patients, 9 patients (4%) developed major cardiovascular complications, and 39 patients (16%) developed pulmonary edema. Diabetes, ischemia-reperfusion time, left ventricular end-diastolic diameter (LVEDd), left ventricular mass index (LVMI), right ventricular systolic pressure (RVSP), left atrium volume index (LAVI), and high E/E'' ratios were risk factors of major cardiovascular complications, while age, LVEDd, LVMI, LAVI, and high E/E'' ratios were risk factors of pulmonary edema. The optimal E/E'' cut-off value for predicting major cardiovascular complications was 13.0, showing 77.8% sensitivity and 78.5% specificity. Thus, the patient''s E/E'' ratio is useful for predicting in-hospital major cardiovascular complications after kidney transplantation. We recommend that goal-directed therapy employing E/E'' ratio be enacted in kidney recipients with baseline diastolic dysfunction to avert postoperative morbidity. (http://Clinical Trials.gov number: {"type":"clinical-trial","attrs":{"text":"NCT02322567","term_id":"NCT02322567"}}NCT02322567)     

Genetic Variants in the Wnt Signaling Pathway Are Not Associated with Survival Outcome of Non-Small Cell Lung Cancer in a Korean Population

Recently, genetic variants in the WNT signaling pathway have been reported to affect the survival outcome of Caucasian patients with early stage non-small cell lung cancer (NSCLC). We therefore attempted to determine whether these same WNT signaling pathway gene variants had similar impacts on the survival outcome of NSCLC patients in a Korean population. A total of 761 patients with stages I–IIIA NSCLC were enrolled in this study. Eight variants of WNT pathway genes were genotyped and their association with overall survival and disease-free survival were analyzed. None of the eight variants were significantly associated with overall survival or disease-free survival. There were no differences in survival outcome after stratifying the subjects according to age, gender, smoking status, and histological type. These results suggest that genetic variants in the WNT signaling pathway may not affect the survival outcome of NSCLC in a Korean population.     

Enrichment of pathogenic variants in genes associated with inborn errors of metabolism in psychiatric populations

Many genetic conditions can mimic mental health disorders, with psychiatric symptoms that are difficult to treat with standard psychotropic medications. This study tests the hypothesis that psychiatric populations are enriched for pathogenic variants associated with selected inborn errors of metabolism (IEMs). Using next‐generation sequencing, 2046 psychiatric patients were screened for pathogenic variants in genes associated with four IEMs, Niemann‐Pick disease type C (NPC), Wilson disease (WD), homocystinuria (HOM), and acute intermittent porphyria (AIP). Among the 2046 cases, carrier rates of 0.83, 0.98, and 0.20%, for NPC, WD and HOM, and affected rates of 0.10 and 0.24% for NPC and AIP were seen, respectively. An enrichment of known and predicted pathogenic variants in the genes associated with NPC and AIP was found in the psychiatric cohort and especially in schizophrenia patients. The results of this study support that pathogenic variants in genes associated with IEMs are enriched in psychiatric populations. Underlying undiagnosed IEMs could account for the psychiatric symptomatology in a subset of psychiatric patients. Further studies are warranted to investigate the possibility that carriers for IEMs may have an increased risk for psychiatric disorders, particularly in the context of poor treatment response.