STIM1 Regulates Platelet-Derived Growth Factor-Induced Migration and Ca2+ Influx in Human Airway Smooth Muscle Cells

It is suggested that migration of airway smooth muscle (ASM) cells plays an important role in the pathogenesis of airway remodeling in asthma. Increases in intracellular Ca²⁺ concentrations ([Ca²⁺]_i) regulate most ASM cell functions related to asthma, such as contraction and proliferation. Recently, STIM1 was identified as a sarcoplasmic reticulum (SR) Ca²⁺ sensor that activates Orai1, the Ca²⁺ channel responsible for store-operated Ca²⁺ entry (SOCE). We investigated the role of STIM1 in [Ca²⁺]_i and cell migration induced by platelet-derived growth factor (PDGF)-BB in human ASM cells. Cell migration was assessed by a chemotaxis chamber assay. Human ASM cells express STIM1, STIM2, and Orai1 mRNAs. SOCE activated by thapsigargin, an inhibitor of SR Ca²⁺-ATPase, was significantly blocked by STIM1 siRNA and Orai1 siRNA but not by STIM2 siRNA. PDGF-BB induced a transient increase in [Ca²⁺]_i followed by sustained [Ca²⁺]_i elevation. Sustained increases in [Ca²⁺]_i due to PDGF-BB were significantly inhibited by a Ca²⁺ chelating agent EGTA or by siRNA for STIM1 or Orai1. The numbers of migrating cells were significantly increased by PDGF-BB treatment for 6 h. Knockdown of STIM1 and Orai1 by siRNA transfection inhibited PDGF-induced cell migration. Similarly, EGTA significantly inhibited PDGF-induced cell migration. In contrast, transfection with siRNA for STIM2 did not inhibit the sustained elevation of [Ca²⁺]_i or cell migration induced by PDGF-BB. These results demonstrate that STIM1 and Orai1 are essential for PDGF-induced cell migration and Ca²⁺ influx in human ASM cells. STIM1 could be an important molecule responsible for airway remodeling.     

β-Hydroxy-α-ketobutyric acid in Drosophila melanogaster,with reference to biosynthesis of drosopterins

A substance designated as compound D, which reacts spontaneously with 7,8-dihydropterin to give drosopterins, is found in Drosophila melanogaster. The compound was partially purified from the extract of flies by column chromatography and identified as β-hydroxy-α-ketobutyric acid by analysis of its 2,4-dinitrophenylhydrazone, mass spectrometry and reactivity with 7,8-dihydropterin. A highly significant correlation (r = 0.969, p < 0.001) was found between the amounts of the compound and drosopterins in the eye-pigment mutants of Drosophila. Changes of the compound during development of flies were also closely related to those of drosopterins. Based on these observations, a role of the compound in biosynthesis of drosopterins has been discussed.     

Spinal Cord Stimulation Exerts Neuroprotective Effects against Experimental Parkinson’s Disease

In clinical practice, deep brain stimulation (DBS) is effective for treatment of motor symptoms in Parkinson’s disease (PD). However, the mechanisms have not been understood completely. There are some reports that electrical stimulation exerts neuroprotective effects on the central nervous system diseases including cerebral ischemia, head trauma, epilepsy and PD, although there are a few reports on neuroprotective effects of spinal cord stimulation (SCS). We investigated the neuroprotective effects of high cervical SCS on PD model of rats. Adult female Sprague-Dawley rats received hour-long SCS (2, 50 or 200 Hz) with an epidural electrode at C1–2 level for 16 consecutive days. At 2 days after initial SCS, 6-hydroxydopamine (6-OHDA) was injected into the right striatum of rats. Behavioral evaluations of PD symptoms were employed, including cylinder test and amphetamine-induced rotation test performed at 1 and 2 weeks after 6-OHDA injection. Animals were subsequently euthanized for immunohistochemical investigations. In order to explore neurotrophic and growth factor upregulation induced by SCS, another cohort of rats that received 50 Hz SCS was euthanized at 1 and 2 weeks after lesion for protein assays. Behavioral tests revealed that the number of amphetamine-induced rotations decreased in SCS groups. Immunohistochemically, tyrosine hydroxylase (TH)-positive fibers in the striatum were significantly preserved in SCS groups. TH-positive neurons in the substantia nigra pars compacta were significantly preserved in 50 Hz SCS group. The level of vascular endothelial growth factor (VEGF) was upregulated by SCS at 1 week after the lesion. These results suggest that high cervical SCS exerts neuroprotection in PD model of rats, at least partially by upregulation of VEGF. SCS is supposed to suppress or delay PD progression and might become a less invasive option for PD patients, although further preclinical and clinical investigations are needed to confirm the effectiveness and safety.     

Different mechanisms explain feeding type-specific patterns of latitudinal variation in herbivore damage among diverse feeding types of herbivorous insects

To determine whether latitudinal variation in herbivore impact exists, we examined three major herbivorous insect feeding types (chewers, gallers, and miners) on/in leaves of Japanese beech. Herbivores were collected with litter traps deployed in forests across a latitudinal gradient of 10°. Leaf litter analyses demonstrated that chewing herbivory increased with increasing latitude of collection site. However, the densities of miners and gallers decreased with latitude. To test whether latitudinal variation in herbivore damage occurs in the absence of geographically differentiated environmental cueing (e.g., physical stresses or herbivore damage), we measured both genetically determined constitutive leaf traits and herbivore damage in a common-garden experiment. In this experiment, miner density decreased with latitude, but chewing herbivory did not vary latitudinally. Galler density was higher on trees from native provenances than on trees from unrelated provenances likely because of local adaptations. Leaf mass per unit area (LMA), tannin, and phenolics all decreased with latitude of provenance. The latitudinal variation in one constitutive leaf trait (LMA) best explained latitudinal variation in chewing herbivory. Thus, different mechanisms account for feeding type-specific patterns of latitudinal variation in herbivore damage among different herbivore feeding types.     

Enantioselective Henry (nitroaldol) reaction catalyzed by axially chiral guanidines

The enantioselective activation of nitroalkanes was attempted on the basis of the complexation between chiral guanidinium and nitronate through two hydrogen bonds. The proposed enantioselective activation was applied to the diastereo- and enantioselective Henry (nitroaldol) reaction of nitroalkanes with aldehydes using axially chiral guanidine bases as the catalyst. Optically active nitroaldol products were obtained in acceptable yields with fairly good enantio- and diastereoselectivities at low temperature.     

Radiation Dose Reduction Efficiency of Buildings after the Accident at the Fukushima Daiichi Nuclear Power Station

Numerous radionuclides were released from the Fukushima Daiichi Nuclear Power Station (F1-NPS) in Japan following the magnitude 9.0 earthquake and tsunami on March 11, 2011. Local residents have been eager to calculate their individual radiation exposure. Thus, absorbed dose rates in the indoor and outdoor air at evacuation sites in the Fukushima Prefecture were measured using a gamma-ray measuring devices, and individual radiation exposure was calculated by assessing the radiation dose reduction efficiency (defined as the ratio of absorbed dose rate in the indoor air to the absorbed dose rate in the outdoor air) of wood, aluminum, and reinforced concrete buildings. Between March 2011 and July 2011, dose reduction efficiencies of wood, aluminum, and reinforced concrete buildings were 0.55±0.04, 0.15±0.02, and 0.19±0.04, respectively. The reduction efficiency of wood structures was 1.4 times higher than that reported by the International Atomic Energy Agency. The efficiency of reinforced concrete was similar to previously reported values, whereas that of aluminum structures has not been previously reported. Dose reduction efficiency increased in proportion to the distance from F1-NPS at 8 of the 18 evacuation sites. Time variations did not reflect dose reduction efficiencies at evacuation sites although absorbed dose rates in the outdoor air decreased. These data suggest that dose reduction efficiency depends on structure types, levels of contamination, and evacuee behaviors at evacuation sites.     

Caspase cleavage releases a nuclear protein fragment that stimulates phospholipid scrambling at the plasma membrane

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Lipase-catalyzed asymmetric synthesis of naphtho[2,3-c]furan-1(3H)-one derivatives by a one-pot dynamic kinetic resolution/intramolecular Diels–Alder reaction: Total synthesis of (−)-himbacine

One-pot sequential reactions using the acyl moieties installed by enzymatic dynamic kinetic resolution of alcohols have been little investigated. In this work, the acryloyl moiety installed via the lipase/oxovanadium combo-catalyzed dynamic kinetic resolution of a racemic dienol [4-(cyclohex-1-en-1-yl)but-3-en-2-ol or 1-(cyclohex-1-en-1-yl)but-2-en-1-ol] with a (Z)-3-(phenylsulfonyl)acrylate underwent an intramolecular Diels–Alder reaction in a one-pot procedure to produce an optically active naphtho[2,3-c]furan-1(3H)-one derivative (98% ee). This method was successfully applied to the asymmetric total synthesis of (?)-himbacine.