Estrogen alleviates neuropathic pain induced after spinal cord injury by inhibiting microglia and astrocyte activation

Neuropathic pain after spinal cord injury (SCI) is developed in about 80% of SCI patients and there is no efficient therapeutic drug to alleviate SCI-induced neuropathic pain. Here we examined the effect of estrogen on SCI-induced neuropathic pain at below-level and its effect on neuroinflammation as underlying mechanisms. Neuropathic pain is developed at late phase after SCI and a single dose of 17β-estradiol (100, 300?μg/kg) were administered to rats with neuropathic pain after SCI through intravenous injection. As results, both mechanical allodynia and thermal hyperalgesia were significantly reduced by 17β-estradiol compared to vehicle control. Both microglia and astrocyte activation in the lamina I and II of L4-5 dorsal horn was also inhibited by 17β-estradiol. In addition, the levels of p-p38MAPK and p-ERK known to be activated in microglia and p-JNK known to be activated in astrocyte were significantly decreased by 17β-estradiol. Furthermore, the mRNA expression of inflammatory mediators such as Il-1β, Il-6, iNos, and Cox-2 was more attenuated in 17β-estradiol-treated group than in vehicle-treated group. Particularly, we found that the analgesic effect by 17β-estradiol was mediated via estrogen receptors, which are expressed in dorsal horn neurons. These results suggest that 17β-estradiol may attenuate SCI-induced neuropathic pain by inhibiting microglia and astrocyte activation followed inflammation.     

RING-POSITION AND FREQUENCY OF ADJACENT DISTRIBUTION OF MEIOTIC CHROMOSOMES IN RHOEO SPATHACEA

The morphological sequence of the twelve chromosomes around the ring as worked out by Sax is reaffirmed with slight corrections of the centromere position on three chromosomes: Aa, fA, and Dd. Adjacent distribution was found in 53/120 MI PMC (44.2%). Ring-position analysis was achieved in 34 of the 53. There were 127 chromosomes and 66 arm-pairs involved in adjacent distribution in these 34 MI PMC. Adjacent distributions occurred at random among the twelve chromosome positions and among the twelve arm-pair positions. There were eleven instances among the 66 arm-pairs (16.7%) of adjacent distribution despite free ends due to chiasma failure. Up to four consecutive chromosomes may pass to the same pole. Not all cells with 6–6 distribution are genetically balanced. Distribution of 7–5 occurred in 24/120 AI PMC (20.0%). Another nine (7.5%) in the same sample had one or more lagging chromosomes. At MI, three PMC had 8–4 distribution, but none such were seen at AI.     

An extremely alkaline mannanase from <Emphasis Type="Italic">Streptomyces</Emphasis> sp. CS428 hydrolyzes galactomannan producing series of mannooligosaccharides

An alkaline-thermostable mannanase from Streptomyces sp. CS428 was produced, purified, and biochemically characterized. The extracellular mannanase (Mn428) was purified to homogeneity with 12.4 fold, specific activity of 2406.7 U/mg, and final recovery of 37.6 %. The purified β-mannanase was found to be a monomeric protein with a molecular mass of approximately 35 kDa as analyzed by SDS-PAGE and zymography. The first N-terminal amino acid sequences of mannanase enzyme were HIRNGNHQLPTG. The optimal temperature and pH for enzyme were 60 °C and 12.5, respectively. The mannanase activities were significantly affected by the presence of metal ions, modulators, and detergents. K_m and V_max values of Mn428 were 1.01 ± 3.4 mg/mL and 5029 ± 85 µmol/min mg, respectively when different concentrations (0.6–10 mg/mL) of locust bean gum galactomannan were used as substrate. The substrate specificity of enzyme showed its highest specificity towards galactomannan which was further hydrolyzed to produce mannose, mannobiose, mannotriose, and a series of mannooligosaccharides. Mannooligosaccharides can be further converted to ethanol production, thus the purified β-mannanase isolated from Streptomyces sp. CS428 was found to be attractive for biotechnological applications.     

Structural analysis of the phototactic transducer protein HtrII linker region from Natronomonas pharaonis

Halobacterial pharaonis phoborhodopsin [ppR, also called Natronomonas pharaonis sensory rhodopsin II (NpSRII)] is a phototaxis protein which transmits a light signal to the cytoplasm through its transducer protein (pHtrII). pHtrII, a two-transmembrane protein that interacts with ppR, belongs to the group of methyl-accepting chemotaxis proteins (MCPs). Several mutation studies have indicated that the linker region connecting the transmembrane and methylation regions is necessary for signal transduction. However, the three-dimensional (3D) structure of an MCP linker region has yet to be reported, and hence, details concerning the signal transduction mechanism remain unknown. Here the structure of the pHtrII linker region was investigated biochemically and biophysically. Following limited proteolysis, only one trypsin resistant fragment in the pHtrII linker region was identified. This fragment forms a homodimer with a Kd value of 115 microM. The 3D structure of this fragment was determined by solution NMR, and only one alpha-helix was found between two HAMP domains of the linker region. This alpha-helix was significantly stabilized within transmembrane protein pHtrII as revealed by CW-EPR. The presence of Af1503 HAMP domain-like structures in the linker region was supported by CD, NMR, and ELDOR data. The alpha-helix determined here presumably works as a mechanical joint between two HAMP domains in the linker region to transfer the photoactivated conformational change downstream.     

Antioxidative and Proapoptotic Effects of Riluzole on Cultured Cortical Neurons

Abstract : Riluzole is used clinically in patients with amyotrophic lateral sclerosis. As oxidative stress, in addition to excitotoxicity, may be a major mechanism of motoneuron degeneration in patients with amyotrophic lateral sclerosis, we examined whether riluzole protects against nonexcitotoxic oxidative injury. Probably reflecting its weak antiexcitotoxic effects, riluzole (1-30 μ M ) attenuated submaximal neuronal death induced by 24-h exposure to 30 μ M kainate or NMDA, but not that by 100 μ M NMDA, in cortical cultures. Riluzole also attenuated nonexcitotoxic oxidative injury induced by exposure to FeCl₃ in the presence of MK-801 and CNQX. Consistent with its antioxidative effects, riluzole reduced Fe³⁺-induced lipid peroxidation, and inhibited cytosolic phospholipase A₂. By contrast, riluzole did not attenuate neuronal apoptosis induced by staurosporine. Rather unexpectedly, 24-48-h exposure to 100-300 μ M riluzole induced neuronal death accompanied by nuclear and DNA fragmentations, which was attenuated by caspase inhibitor carbobenzyloxy-Val-Ala-Asp-fluoromethyl ketone but not by protein synthesis inhibitor cycloheximide. The present study demonstrates that riluzole has direct antioxidative actions, perhaps in part by inhibiting phospholipase A₂. However, in the same neurons, riluzole paradoxically induces neuronal apoptosis in a caspase-sensitive manner. Considering current clinical use of riluzole, further studies are warranted to investigate its potential cytolethal effects.     

Microbiome engineering: Current applications and its future

Microbiomes exist in all ecosystems and are composed of diverse microbial communities. Perturbation to microbiomes brings about undesirable phenotypes in the hosts, resulting in diseases and disorders, and disturbs the balance of the associated ecosystems. Engineering of microbiomes can be used to modify structures of the microbiota and restore ecological balance. Consequently, microbiome engineering has been employed for improving human health and agricultural productivity. The importance and current applications of microbiome engineering, particularly in humans, animals, plants and soil is reviewed. Furthermore, we explore the challenges in engineering microbiome and the future of this field, thus providing perspectives and outlook of microbiome engineering.     

Greater efficacy of alfacalcidol in the red than in the yellow marrow skeletal sites in adult female rats

The present study compared the bone anabolic effects of graded doses of alfacalcidol in proximal femurs (hematopoietic, red marrow skeletal site) and distal tibiae (fatty, yellow marrow skeletal site). One group of 8.5-month-old female Sprague-Dawley rats were killed at baseline and 4 groups were treated 5 days on/2 days off/week for 12 weeks with 0, 0.025, 0.05 and 0.1 microg alfacalcidol/kg by oral gavage. The proximal femur, bone site with hematopoietic marrow, as well as the distal tibia bone site with fatty marrow, were processed undecalcified for quantitative bone histomorphometry. In the red marrow site of the proximal femoral metaphysis (PFM), 0.1 microg alfacalcidol/kg induced increased cancellous bone mass, improved architecture (decreased trabecular separation, increased connectivity), and stimulated local bone formation of bone 'boutons' (localized bone formation) on trabecular surfaces. There was an imbalance in bone resorption and formation, in which the magnitude of depressed bone resorption greater than depressed bone formation resulted in a positive bone balance. In addition, bone 'bouton' formation contributed to an increase in bone mass. In contrast, the yellow marrow site of the distal tibial metaphysis (DTM), the 0.1 microg alfacalcidol/kg dose induced a non-significant increased cancellous bone mass. The treatment decreased bone resorption equal to the magnitude of decreased bone formation. No bone 'bouton' formation was observed. These findings indicate that the highest dose of 0.1 microg alfacalcidol/kg for 12 weeks increased bone mass (anabolic effect) at the skeletal site with hematopoietic marrow of the proximal femoral metaphysis, but the increased bone mass was greatly attenuated at the fatty marrow site of the distal tibial metaphysis. In addition, the magnitude of the bone gain induced by alfacalcidol treatment in red marrow cancellous bone sites of the proximal femoral metaphysis was half that of the lumbar vertebral body. The latter data were from a previous report from the same animal and protocol. These findings indicated that alfacalcidol as an osteoporosis therapy is less efficacious as a positive bone balance agent that increased trabecular bone mass in a non-vertebral skeletal site where bone marrow is less hematopoietic.     

Effect of Sibutramine on Weight Loss and Blood Pressure: A Meta‐analysis of Controlled Trials

Objective: Sibutramine causes weight loss by suppressing the appetite and by promoting energy expenditure, but it can also increase blood pressure through a norepinephrine effect. The aim of this study was to provide a comprehensive meta‐analysis of randomized, controlled trials on the effects of sibutramine on blood pressure and weight loss. Research Methods and Procedures: Twenty‐one placebo‐controlled, double‐blind, randomized trials of sibutramine were identified using MEDLINE, EMBASE, and a manual search. The effect sizes of sibutramine on weight and systolic (SBP) and diastolic (DBP) blood pressure changes were estimated. Subgroup analyses were undertaken to explore the relationship between effect sizes and the study characteristics. Results: The effect size of sibutramine on weight change was ?1.00 (?1.17 to ?0.84), whereas the effect sizes on SBP and DBP changes were 0.16 (0.08 to 0.24) and 0.26 (0.18 to 0.33), respectively. By subgroup analysis, the effect sizes on weight loss were significantly larger when the dosage was ≥15 mg. The effect sizes on increased SBP were significantly larger when the initial body weight was ≥92 kg and the age was <44 years; similarly, the effect sizes on increased DBP were significantly larger when the initial weight was ≥92 kg. Discussion: Sibutramine showed a large effect on weight loss. Because blood pressure was found to be increased slightly, but significantly, sibutramine should be used cautiously in patients with borderline or high blood pressure. Additional studies on its effect on blood pressure are needed.     

SAHA treatment overcomes the anti-apoptotic effects of Bcl-2 and is associated with the formation of mature PML nuclear bodies in human leukemic U937 cells

Bcl-2 protects tumor cells from the apoptotic effects of various antineoplastic agents. Increased expression of Bcl-2 has been associated with poor response to chemotherapy in various malignancies, including leukemia. Therefore, bypassing the resistance conferred by anti-apoptotic factors such as Bcl-2 represents an attractive therapeutic strategy against cancer cells, including leukemic cells. We undertook this study to examine whether SAHA (suberoylanilide hydroxamic acid) overcomes the resistance by Bcl-2 in human leukemic cells, with a specific focus on the involvement of PML-NBs. Experiments were conducted with Bcl-2-overexpressing human leukemic U937 cells. Since we previously demonstrated that overexpression of Bcl-2 attenuates resveratrol-induced apoptosis in human leukemic U937 cells, resveratrol-treated U937 cells were used as a negative control. The present study indicates that SAHA at 1-7 μM, the dose range known to induce apoptosis in various cancer cells, overcomes the anti-apoptotic effects of Bcl-2 in Bcl-2-overexpressing human leukemic U937 cells. Notably, we observed that SAHA-induced formation of mature promyelocytic leukemia (PML) nuclear bodies (NBs) correlates with overcoming the anti-apoptotic effects of Bcl-2 in human leukemic U937 cells. Thus, PML protein and the formation of mature PML-NBs could be considered as therapeutic targets that could help bypass the resistance to apoptosis conferred by Bcl-2. Elucidating exactly how PML regulates Bcl-2 will require further work.