Establishment of knockdown of superoxide dismutase 2 and expression of CYP3A4 cell system to evaluate drug-induced cytotoxicity

Drug-induced hepatotoxicity is a major problem in drug development, and oxidative stress is known as one of the causes. Superoxide dismutases (SODs) are important antioxidant enzymes against reactive oxygen species (ROS). Mitochondria are the major source of superoxide production, and SOD2 is mainly localized in mitochondria and, with other SODs, plays an important role in scavenging superoxide. In this study, we established SOD2-knockdown cells. An adenovirus vector with short hairpin RNA against rat SOD2 (AdSOD2-shRNA) was constructed, and infection of AdSOD2-shRNA to rat hepatic BRL3A cells resulted in significant decreases of SOD2 mRNA and protein by 60%, and SOD2 activity by 50% after 3 days infection. We previously constructed an adenovirus expressing cytochrome P450 3A4 (AdCYP3A4). Co-infection of AdSOD2-shRNA and AdCYP3A4 to BRL3A cells was carried out to evaluate the superoxide- and CYP3A4-mediated formation of active metabolites, and mitochondrial toxicity, ROS and superoxide radical production and lipid peroxidation were selected to assess the cell viability. Albendazole, carbamazepine, dapsone, flutamide, isoniazid, nifedipine, sulfamethoxazole, trazodone, troglitazone, and zidovudine demonstrated significant increases of SOD2- and CYP3A4-mediated cytotoxicity. In conclusion, we constructed a highly sensitive cell system to evaluate oxidative stress and CYP3A4 mediated cytotoxicity that could be useful in preclinical drug development.     

Topical thermal therapy with hot packs suppresses physical inactivity-induced mechanical hyperalgesia and up-regulation of NGF

We focused on the analgesic effect of hot packs for mechanical hyperalgesia in physically inactive rats. Male Wistar rats were randomly divided into four groups: control, physical inactivity (PI), PI + sham treatment (PI + sham), and PI + hot pack treatment (PI + hot pack) groups. Physical inactivity rats wore casts on both hind limbs in full plantar flexed position for 4 weeks. Hot pack treatment was performed for 20 min a day, 5 days a week. Although mechanical hyperalgesia and the up-regulation of NGF in the plantar skin and gastrocnemius muscle were observed in the PI and the PI + sham groups, these changes were significantly suppressed in the PI + hot pack group. The present results clearly demonstrated that hot pack treatment was effective in reducing physical inactivity-induced mechanical hyperalgesia and up-regulation of NGF in plantar skin and gastrocnemius muscle.     

Effects of topiroxostat in hyperuricemic patients with chronic kidney disease

Background

Hyperuricemia is associated with chronic kidney disease (CKD). Although topiroxostat, a novel, non-purine, selective xanthine oxidase inhibitor, has a strong effect against hyperuricemia, limited data are available on its renoprotective effect against CKD.

Methods

This study was conducted between October 2014 and May 2016. Thirty patients (20 male, 10 female) were administered 40 mg/day of topiroxostat twice daily. All patients were followed for a year. To elucidate the effects of topiroxostat, we evaluated the clinically documented primary indication of progression, viz. laboratory evidence of kidney function decline (reference indicator), uric acid, and hypertension in different patient groups, separated according to their baseline uProt levels and baseline eGFR.

Results

Topiroxostat treatment resulted in significant reduction in SUA (?1.53 mg/dL), systolic blood pressure (?8.9 mmHg), diastolic blood pressure (?5.0 mmHg), and urinary protein excretion (?795.5 mg/gCr) compared with baseline values. However, serum creatinine and urinary NAG levels, and estimated glomerular filtration rate did not change significantly.

Conclusions

Topiroxostat reduced SUA levels effectively and may exhibit renoprotective effect in hyperuricemic patients with CKD. Further studies are required to clarify whether topiroxostat prevents the progression of renal disease and improves the prognosis of CKD patients.

     

Estradiol and progesterone modulate halothane-induced liver injury in mice

Drug-induced liver injury (DILI) is one of the major problems in drug development and clinical drug therapy. In general, it is believed that women exhibit worse outcomes from DILI than men. It is known that halothane (HAL), an inhaled anesthetic, rarely induces severe liver injury. The risk factors for severe HAL-induced liver injury (HILI) are female sex, genetics and adult age. To investigate the underlying mechanism by which women are more susceptible to HILI, we focused on two major female sex hormones, estradiol (E2) and progesterone (Prog). In this study, we first found that pretreatment of mice with E2 attenuated HILI, whereas pretreatment with Prog exacerbated HILI. E2 and Prog had no effects on the degree of metabolic activation, the ratio of GSH/GSSG or oxidative stress in the liver. We observed higher numbers of neutrophils infiltrated into the liver and increased hepatic mRNA levels of proinflammatory cytokines, tumor necrosis factor (TNF) α, interleukin (IL)-1β and IL-6 and chemokines, CXCL1 and CXCL2 by pretreatment with Prog, whereas E2 pretreatment resulted in the opposite effects. These results suggest that E2 and Prog play a critical role in HILI via immune-related responses and female sex hormone balance might represent a risk factor for HILI.     

Quantitative effects of using compressed sensing in dynamic contrast enhanced MRI

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) involves the acquisition of images before, during and after the injection of a contrast agent. In order to perform quantitative modeling on the resulting signal intensity time course, data must be acquired rapidly, which compromises spatial resolution, signal to noise and/or field of view. One approach that may allow for gains in temporal or spatial resolution or signal to noise of an individual image is to use compressed sensing (CS) MRI. In this study, we demonstrate the accuracy of extracted pharmacokinetic parameters from DCE-MRI data obtained as part of pre-clinical and clinical studies in which fully sampled acquisitions have been retrospectively undersampled by factors of 2, 3 and 4 in Fourier space and then reconstructed with CS. The mean voxel-level concordance correlation coefficient for K(trans) (i.e. the volume transfer constant) obtained from the 2× accelerated and the fully sampled data is 0.92 and 0.90 for mouse and human data, respectively; for 3×, the results are 0.79 and 0.79, respectively; for 4×, the results are 0.64 and 0.70, respectively. The mean error in the tumor mean K(trans) for the mouse and human data at 2× acceleration is 1.8% and -4.2%, respectively; at 3×, 3.6% and -10%, respectively; at 4×, 7.8% and -12%, respectively. These results suggest that CS combined with appropriate reduced acquisitions may be an effective approach to improving image quality in DCE-MRI.     

Clearance of hepatitis C virus after living-donor liver transplantation in spite of residual viremia on end date of interferon therapy before transplantation

Interferon （IFN） therapy is the only treatment strategy for hepatitis C virus （HCV） infection after liver transplantation （LT）, but prophylactic and treatable IFN therapy after LT has been shown to be insufficient due to the adverse effects of IFN and rivabirin. In this paper, we describe the disappearance of HCV after LT without IFN therapy in the presence of residual viremia on the day of LT. We herein report our findings since this is considered an important case for the anti-HCV strategy of post LT. A 60-year old woman with LC and HCC was referred to Nagasaki University Hospital in August 2004. After she underwent LT on February 18, 2005, we injected peg- IFN-α-2a the 11th time at 18 wk and HCV-RNA was still positive in the serum at LT. The serum HCV-RNA was negative one month after operation and subsequently dissolved 15 mo after operation without IFN therapy. As a result, we speculate that if HCV-RNA is positive while HCV core antigen is negative before LT, then it may lead to dearance of HCV after LT. Therefore long acting peg-IFN- α-2a is thus considered a potentially effective agent for the treatment of HCV-related cirrhosis before LT.     

Influence of nasal resistance on initial acceptance of continuous positive airway pressure in treatment for obstructive sleep apnea syndrome

BACKGROUND: Continuous positive airway pressure (CPAP) is considered as the standard therapy for obstructive sleep apnea syndrome (OSAS), but some patients with OSAS are unable to accept CPAP due to nasal obstruction and poor nasal airflow. OBJECTIVES: We assessed the influence of nasal resistance before beginning CPAP treatment on the initial acceptance of CPAP in OSAS patients. METHODS: The study subjects comprised 77 patients (74 males, 3 females) with primary OSAS, all of whom received CPAP treatment with nasal masks. Before trials, all subjects underwent overnight polysomnography, and nasal resistance was measured with active anterior rhinomanometry in the seated position on the first day of CPAP trial. RESULTS: The CPAP treatment was accepted by 56 patients after the initial trials with overnight polysomnography. Body mass index, the number of apnea/hypopnea episodes per hour (apnea/hypopnea index; AHI), and the number of episodes per hour with an oxygen desaturation of >3% (oxygen desaturation index) were significantly higher (p<0.01) and nasal resistance was lower (p=0.003) in patients who accepted CPAP than in those who did not. Logistic regression analysis, with patient age, body mass index, Epworth sleepiness scale score, AHI, oxygen desaturation index, and nasal resistance before CPAP treatment as explanatory variables, showed that nasal resistance (OR+0.1 Pa/cm3/s: 1.48; p=0.002) and AHI (OR+1 event/h: 0.93; p=0.003) were significant factors for CPAP non-acceptance. CONCLUSIONS: Nasal resistance before the beginning of CPAP treatment has a significant effect on the acceptance of CPAP in OSAS patients, and hence, could be a predictive parameter for the initial acceptance of CPAP.     

Development of plasmacytoid dendritic cells in bone marrow stromal cell niches requires CXCL12-CXCR4 chemokine signaling

Plasmacytoid dendritic cells (pDCs), also known as type I interferon (IFN)-producingcells, are thought to play central roles in antiviral immunity and the pathogenesis of some autoimmune diseases. pDCs are produced from hematopoietic stem cells in bone marrow. However, the environmental regulation of the development of pDCs is not fully understood. Here, we show that the numbers of pDCs and their earliest progenitors are severely reduced in the absence of CXCR4, the primary physiologic receptor for CXC chemokine ligand 12 (CXCL12), also known as stromal cell-derived factor-1 (SDF-1) in vivo. In vitro, CXCL12 induces a significant increase in pDC numbers generated from primitive hematopoietic cells, and pDCs and their progenitors migrate to CXCL12. In addition, most pDCs are in contact with CXCL12-abundant reticular (CAR) cells in the intersinal space of bone marrow, although many primitive hematopoietic cells adjoin CAR cells surrounding sinusoidal endothelial cells or residing near the bone surface. Thus we identified CXCL12 as a key regulator of pDC development produced by cellular niches, providing new targets for pDC therapeutic control.