Triggering receptor expressed on myeloid cells 2 (TREM2) is known to be involved in the anti-inflammatory response and osteoclast development. However, the role of TREM2 in adipogenesis or obesity has not yet been defined. The effect of TREM2 on adipogenesis and obesity was investigated in TREM2 transgenic (TG) mice on a high-fat diet (HFD). To block TREM2 signaling, a neutralizing fusion protein specific for TREM2 (TREM2-Ig) was used. TG mice were much more obese than wild-type mice after feeding with an HFD, independent of the quantity of food intake. These HFD-fed TG mice manifested adipocyte hypertrophy, glucose and insulin resistance, and hepatic steatosis. The expression of adipogenic regulator genes, such as peroxisome proliferator-activated receptor g and CCAAT/enhancerbinding protein a, was markedly increased in HFD-fed TG mice. Additionally, HFD-fed TG mice exhibited decreased Wnt10b expression and increased GSK-3b (glycogen synthase kinase-3b)-mediated b-catenin phosphorylation. In contrast, the blockade of TREM2 signaling using TREM2-Ig resulted in the inhibition of adipocyte differentiation in vitro and a reduction in body weight in vivo by downregulating the expression of adipogenic regulators. Our data demonstrate that TREM2 promotes adipogenesis and diet-induced obesity by upregulating adipogenic regulators in conjunction with inhibiting the Wnt10b/b-catenin signaling pathway.
BackgroundFructus mume (F. mume) has been used as a traditional medicine for many years in Asian countries. The present study was designed to determine the effect of a 70% ethanol extract of F. mume on white matter and hippocampal damage induced by chronic cerebral hypoperfusion.MethodsPermanent bilateral common carotid artery occlusion (BCCAo) was performed on male Wistar rats to induce chronic cerebral hypoperfusion. Daily oral administration of F. mume (200 mg/kg) was initiated 21 days after BCCAo and continued for 42 days. The experimental groups in this study were divided into three groups: a sham-operated group, a BCCAo group, and a BCCAo group that was administered with the F. mume extract. The activation of glial cells, including microglia and astrocytes, and the levels of myelin basic protein (MBP), inflammatory mediators, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and p38 mitogen-activated protein kinase (MAPK) phosphorylation were measured in brains from rats subjected to chronic BCCAo.ResultsOur results revealed that F. mume alleviates the reduction in MBP expression caused by chronic BCCAo in the white matter and the hippocampus and significantly attenuates microglial and astrocytic activation induced by chronic BCCAo in the optic tract of white matter. In addition, F. mume treatment reduced the increased expression of cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β) and interleukin-6 (IL-6), as well as the activation of TLR4/MyD88 and p38 MAPK signaling, in the hippocampus of rats subjected to chronic BCCAo.ConclusionTaken together, our findings demonstrate that brain injury induced by chronic BCCAo is ameliorated by the anti-inflammatory effects of F. mume via inhibition of MBP degradation, microglial and astrocytic activation, increased inflammatory mediator expression, and activated intracellular signalings, including TLR4 and p38 MAPK, implying that F. mume is potentially an effective therapeutics for the treatment of vascular dementia.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-015-0652-1) contains supplementary material, which is available to authorized users.
BackgroundThe cardiotonic pill (CP) is a herbal medicine composed of Salvia miltiorrhiza (SM), Panax notoginseng (PN), and Dryobalanops aromatica Gaertner (DAG) that is widely used to treat cardiovascular diseases. The present experiment was conducted to examine the effects of CP on white matter and hippocampal damage induced by chronic cerebral hypoperfusion.MethodsChronic cerebral hypoperfusion was induced in male Wistar rats by permanent bilateral common carotid artery occlusion (BCCAo). Daily oral administration of CP (200 mg/kg) began 21 days after BCCAo and continued for 42 days. The levels of microglial activation and myelin basic protein (MBP) were measured in the white matter and hippocampus of rats with chronic BCCAo, and the expression levels of mitogen-activated protein kinases (MAPKs) and inflammatory markers such as cyclooxygenase-2, interleukin-1β, and interleukin-6 were examined.ResultsMBP expression was reduced in the white matter and hippocampal regions of rats that received BCCAo. In contrast, reduced levels of MBP were not observed in BCCAo rats given CP treatments. The administration of CP alleviated microglial activation, the alteration of ERK and p38 MAPK signaling, and inflammatory mediator expression in rats with chronic BCCAo.ConclusionThese results suggest that CP may have protective effects against chronic BCCAo-induced white matter and hippocampal damage by inhibiting inflammatory processes including microglial activation and proinflammatory mediator expression, and downreguating the hyperphosphorylation of ERK and p38 MAPK signaling.
Objectives : The aim of this study was to examine anti-thrombotic effect of traditional herbal extracts in a rat model of ferric chloride (FeCl3)-induced carotid arterial thrombosis. Methods : Thirty minutes prior to a 35% FeCl3 application, Sprague Dawley(SD) rats were injected with the 10 types of traditional herbal extracts (100mg/kg, intraperitoneal injection), respectively. The effect of these herbal extracts was examined for time to occlusion(TTO) using the Laser doppler flow meter and measured for thrombus weight (TW) in FeCl3-induced thrombosis model. Results : In the TTO, Salvia miltiorrhiza (Sm, 2.30±0.28 min, p<0.001) and Santalum album (Sa, 2.19±0.19 min, p<0.001) showed significantly delayed TTO more than twice compared with Saline-treated group. Cnidium officinale (Co), Psoralea corylifolia (Pc), Scutellatia baicalensis (Sba), Panax notoginseng (Pn), Angelica tenuissima (At), Scrophularia buergeriana (Sbu), Rhus verniciflua (Rv) and Picrasma quassioides (Pq), except for Rhus verniciflua (Rv) also meaningfully impeded TTO more than one fold. In addition, Salvia miltiorrhiza, Santalum album, Cnidium officinale, Psoralea corylifolia and Scutellatia baicalensis significantly reduced TW more than 10% compared with Saline-treated group. Especially, Salvia miltiorrhiza and Santalum album showed the most excellent anti-thrombotic effect among the 10 herbal extracts tested on the restoration of altered TTO and TW. Conclusions : These results suggest that Sm and Sa extracts have outstanding anti-thrombotic effect in FeCl3-induced thrombosis model and is potentially useful as herbal medicines for the treatment and prevention of thrombosis.
This study examined the effects of 8 types of herbal prescriptions prescribed to alleviate dementia symptoms in a rat model of arterial thrombosis induced by ferric chloride (FeCl 3 ). Methods: Thirty minutes before 35% FeCl 3 treatment, SD rats were intraperitoneally injected with the 8 types of herbal prescriptions, respectively. We tested the effects of the herbal prescriptions on time to occlusion (TTO) in an arterial thrombosis model using a laser Doppler flow meter. In addition, thrombus weight (TW) and collagen fiber damages were evaluated in the same condition. Results: Herbal prescriptions showed the following rank-order based on their TTO: Chong-myung-tang (CMT) > modified Jangwonhan 02 (LMK02) > Toki-shakuyaku-san (TSS)Oren-gedoku-to (OGT) Yokukansan (YKS). In particular, CMT (100 mg/kg, i.p.) and LMK02 (100 mg/kg, i.p.) delayed the TTO the most (14.83 ± 0.98 and 13.67 ± 1.03 min, respectively) compared with the vehicle group (7.95 ± 0.78 min, P<0.001). In addition, CMT, LMK02, and OGT treatment (0.63 ± 0.01, 0.66 ± 0.02 and 0.67 ± 0.01 mg/mm, respectively) significantly reduced thrombus weight compared with the vehicle treatment (0.78 ± 0.03, P<0.001) and also alleviated collagen fiber damage (CMT; 28.40 ± 2.22%, LMK02; 30.79 ± 4.07%, OGT; 26.20 ± 1.48%) in the vessels injured by FeCl 3 . Therefore, CMT and LMK02 showed the greatest preventive activity in rat model of arterial thrombosis induced by FeCl 3 . Conclusions: These results provide experimental evidence for traditional use of herbal prescriptions, suggesting that CMT and LMK02 extracts could be used to prevent vascular injury and thrombosis in the early stages of dementia.
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