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Abstract Background Loss of ovarian function, as in menopause or after ovariectomy (OVX), is closely associated with obesity and white adipose tissue (WAT) inflammation. Estrogen replacement protects against postmenopausal obesity but increases the risks of carcinogenesis. In the present study, we investigated the effects of long-term treatment of raloxifene (RAL), a selective estrogen receptor modulator, on the features of estrogen deficiency-induced obesity and explored the involvement of canonical and non-canonical Wnt regulation in vivo and in vitro. Methods Adult female rats received bilateral OVX and divided into 5 groups: (1) Sham, (2) OVX, (3) OVX + E2: OVX rats were administered with E2 (50 μg/kg, s.c., 3 times/week), (4) OVX + RAL: OVX rats were treated with RAL (gavage, 1 mg/kg/day) suspended in 0.8% carboxymethylcellulose (CMC), (5) OVX + CMC: 0.8% CMC as vehicle control. All treatments were given for 8 weeks beginning at 1 week after OVX. In 3 T3-L1 cells, the effects of RAL on adipogenesis and lipopolysaccharide (LPS)-induced inflammation were evaluated. Results Treatment with RAL significantly decreased body weight, visceral fat pad mass, adipocyte size and plasma levels of glucose but increased plasma adiponectin. RAL reduced the elevation of HIF-1α, VEGF-A and proinflammatory cytokines (MCP-1 and TNF-α) expression by inhibition of NF-κB p65 and JNK cascades in retroperitoneal WAT. This anti-inflammatory capacity of RAL may result from upregulation of secreted frizzle-related protein 5 (SFRP5), an adipokine that repressed Wnt5a signaling. Furthermore, RAL inhibited adipogenic factors such as PPAR-γ, C/EBP-α, and FABP4, and preserved canonical Wnt10b/β-catenin protein expression. In 3 T3-L1 adipocytes, RAL (20 μM) diminished lipid accumulation and inhibited adipogenic factors accompanied with the induction of β-catenin, which were effectively reversed by the β-catenin inhibitor IWR-1-endo. In addition, RAL reduced LPS-induced NF-κB p65 and p-IκB expression as well as TNF-α secretion. Suppression of SFRP5 by small interfering RNA significantly abrogated the anti-inflammatory effects of RAL. Conclusions Distinct activation of canonical β-catenin on inhibition of adipogenesis and non-canonical SFRP5 on suppression of WAT inflammation may contribute to the beneficial effects of RAL. Therefore, this study provides a rationale for the therapeutic potential of RAL for postmenopausal obesity.

Heat stroke (HS) is a life-threatening illness and defined as when body temperature elevates above 40°C accompanied by the systemic inflammatory response syndrome that results in multiple organ dysfunctions. α-Lipoic acid (ALA) acts as a cofactor of mitochondrial enzymes and exerts anti-inflammatory and antioxidant properties in a variety of diseases. This study investigates the beneficial effects of ALA on myocardial injury and organ damage caused by experimental HS and further explores its underlying mechanism. Male Wistar rats were exposed to 42°C until their rectal core temperature reached 42.9°C and ALA was pretreared 40 or 80 mg/kg (i.v.) 1.5 h prior to heat exposure. Results showed that HS-induced lethality and hypothermia were significantly alleviated by ALA treatment that also improved plasma levels of CRE, LDH, and CPK and myocardial injury biomarkers myoglobin and troponin. In addition, ALA reduced cardiac superoxide anion formation and protein expression of cleaved caspase 3 caused by HS. Proinflammatory cytokine TNF-α and NF-κB pathways were significantly reduced by ALA treatment which may be associated with the upregulation of Hsp70. ALA significantly increased the Atg5-12 complex and LC3B II/LC3B I ratio, whereas the p62 and p-mTOR expression was attenuated in HS rats, indicating the activation of autophagy by ALA. In conclusion, ALA ameliorated the deleterious effects of HS by exerting antioxidative and anti-inflammatory capacities. Induction of Hsp70 and activation of autophagy contribute to the protective effects of ALA in HS-induced myocardial injury.

Much evidence has indicated that matrix metalloproteinases (MMPs) participate in the progression of neuroinflammatory disorders. The present study was undertaken to investigate the inhibitory effect and mechanism of the antipsychotic haloperidol on MMP activation in the stimulated THP-1 monocytic cells. Haloperidol exerted a strong inhibition on tumor necrosis factor- (TNF-) α-induced MMP-9 gelatinolysis of THP-1 cells. A concentration-dependent inhibitory effect of haloperidol was observed in TNF-α-induced protein and mRNA expression of MMP-9. On the other hand, haloperidol slightly affected cell viability and tissue inhibition of metalloproteinase-1 levels. It significantly inhibited the degradation of inhibitor-κB-α (IκBα) in activated cells. Moreover, it suppressed activated nuclear factor-κB (NF-κB) detected by a mobility shift assay, NF-κB reporter gene, and chromatin immunoprecipitation analyses. Consistent with NF-κB inhibition, haloperidol exerted a strong inhibition of lipopolysaccharide- (LPS-) induced MMP-9 gelatinolysis but not of transforming growth factor-β1-induced MMP-2. In in vivo studies, administration of haloperidol significantly attenuated LPS-induced intracerebral MMP-9 activation of the brain homogenate and the in situ in C57BL/6 mice. In conclusion, the selective anti-MMP-9 activation of haloperidol could possibly involve the inhibition of the NF-κB signal pathway. Hence, it was found that haloperidol treatment may represent a bystander of anti-MMP actions for its conventional psychotherapy.

Sepsis is a systemic inflammatory disorder, accompanied with elevated oxidative stress, leading to multiple organ dysfunction syndrome (MODS), and disseminated intravascular coagulation. 17-Dimethylaminoethylamino- 17-demethoxygeldanamycin (17-DMAG), a heat shock protein (HSP) 90 inhibitor, has been reported to possess anti-inflammatory effects. In this study, the beneficial effects of 17-DMAG on lipopolysaccharide (LPS) induced MODS and DIC was evaluated in anesthetized rats. 17-DMAG (5 mg/kg, i.p.) was significantly increased survival rate, and prevented hypotension in LPS (30 mg/kg i.v. infused for 4 h) induced endotoxemia. The elevated levels of alanine aminotransferase (ALT), creatine phosphokinase (CPK), lactate dehydrogenase, creatinine, nitric oxide (NO) metabolites, IL-6, and TNF-α in LPS-exposed rat plasma were significantly reduced by 17-DMAG. Moreover, 17-DMAG suppressed LPS-induced superoxide anion production and caspase 3 activation in heart tissues. LPS induced the prolongation of prothrombin time, and a pronounced decrease in platelet count, which were improved by 17-DMAG. 17-DMAG markedly induced HSP70 and heme oxygenase (HO)-1, and suppressed inducible nitric oxide synthase (iNOS) and phosphorylated NF-κB p65 protein expression in organs 6 h after LPS initiation. Pretreatment with high dose of quercetin (300 mg/kg, i.p.), as an HSP70 inhibitor, reversed the beneficial effects of 17-DMAG on survival rate, plasma levels of ALT, CPK, creatinine, IL-6, and NO metabolites, iNOS induction, and caspase-3 activation in LPS-treated rats. In conclusion, 17-DMAG possesses the anti-inflammatory and antioxidant effects that were proved through LPS-induced acute inflammation, which is associated with induction of HSP70 and HO-1, leading to prevent MODS in sepsis.

Neurodegenerative brain disorders such as Alzheimer's disease (AD) have been well investigated. However, significant methods for the treatment of the progression of AD are unavailable currently. Heat shock protein 70 (Hsp70) plays important roles in neural protection from stress by assisting cellular protein folding. In this study, we investigated the effect and the molecular mechanism of YC-1, an activator of guanylyl cyclase (GC), on Aβ25-35-induced cytotoxicity in differentiated PC12 cells. The results of this study showed that Aβ25-35 (10 µM) significantly increased p25 protein production in a pattern that was consistent with the increase in μ-calpain expression. Moreover, Aβ25-35 significantly increased tau hyperphosphorylation and induced differentiated PC12 cell death. YC-1 (0.5-10 µM) prevented the cell death induced by Aβ25-35. In addition, YC-1 (1, 10 µM) significantly blocked Aβ25-35-induced μ-calpain expression and decreased the formation of p25 and tau hyperphosphorylation. Moreover, YC-1 (5-20 µM) alone or combined with Aβ25-35 (10 µM) significantly increased the expression of Hsp70 in differentiated PC12 cells. The neuroprotective effect of YC-1 was significantly attenuated by an Hsp70 inhibitor (quercetin, 50 µM) or in PC12 cells transfected with an Hsp70 small interfering RNA. However, pretreatment of cells with the GC inhibitor ODQ (10 µM) did not affect the neuroprotective effect of YC-1 against Aβ25-35 in differentiated PC12 cells. These results suggest that the neuroprotective effect of YC-1 against Aβ25-35-induced toxicity is mainly mediated by the induction of Hsp70. Thus, YC-1 is a potential agent against AD.

Sepsis can cause myocardial dysfunction, which contributes to the high mortality of sepsis. Hypertonic saline (HS) has been reported to increase myocardial contractility in sepsis. In the present study, mechanisms of action of HS resuscitation (4 mL of 7.5% NaCl per kilogram) on cardiac function have been evaluated in septic rats. HS was administered 1 h after LPS (10 mg/kg, i.v.) challenge. The mean arterial blood pressure significantly decreased 4 h after LPS challenge, and septic shock was observed at the end of experiment (6h). Posttreatment with HS prevented hypotension caused by LPS and significantly improved cardiac function, evidenced by increases in left ventricular developed pressure, mean +dP/dt and -dP/dt. The amplitude of electricalstimulated intracellular Ca2+ transient in isolated single cardiomyocytes was significantly reduced after 6 h LPS insult, which was recovered by HS. In addition, LPS resulted in significant increases in neutrophil myeloperoxidase activity, macrophage migration inhibitory factor (MIF), and NF-κBphospho-p65 protein levels in myocardium at 6 h, which were significantly attenuated by HS. In conclusion, HS improved myocardial contractility and prevented circulatory failure induced by endotoxemia, which may attribute to improvement of intracellular calcium handling process and inhibitory effects on neutrophil infiltration and MIF production in hearts. [ABSTRACT FROM AUTHOR]

Background: Receptor-interacting protein 140 (RIP140) is a corepressor for nuclear receptors with an important role in the inhibition of energy expenditure. Postmenopausal women have increased white adipose tissue (WAT), and excessive accumulation of adipose tissue (obesity) implies a health risk. The aim of the present work was to investigate the time course of RIP140 expression in WAT during the development of ovariectomy (OVX)-induced obesity in rats. Methods: OVX was performed in female Sprague-Dawley (SD) rats 8 weeks old. Body weight and food intake were determined once a week. WAT of sham-operated, OVX and OVX plus 17β-estradiol therapy (OVX/E2) female SD rats was weighed and used to analyse RIP140 and uncoupling protein 1 (UCP-1) expression by Western blot. Results: Food intake and body weight were significantly increased during the 2-8 weeks after OVX. Even though body weight increased until killing, food intake progressively decreased from 9 to 16 weeks after OVX in rats. Meanwhile, increased WAT mass and decreased RIP140 expression in WAT were observed in OVX rats. In contrast, the expression of UCP-1, a key target gene of RIP140, in WAT of OVX rats was significantly higher than in sham-operated rats. All of these alterations caused by OVX were mostly reversed by the replacement of 17β-estradiol. Conclusions: The down-regulation of RIP140 in WAT may play a compensatory role in OVX-induced obesity in rat. [ABSTRACT FROM AUTHOR]

BackgroundMatrix metalloproteinases (MMPs) activity may modulate hypertension-related accumulation of extracellular matrix (ECM) in arteries. We tested whether estrogen deficiency induces alterations of vascular collagen, MMP-2, membrane-type 1-MMP (MT1-MMP), or tissue inhibitor of metalloproteinases-2 (TIMP-2) expression in ovariectomized rats, which may be associated with postmenopausal hypertension.MethodsEstrogen deficiency was induced by ovariectomy (Ovx) in female rats. Time-course changes of aortic MMPs protein expression were evaluated. Treatment with tempol or aminoguanidine was used to examine the role of oxidative stress and nitric oxide (NO) on these changes.ResultsThe level of the active-form MMP-2 was markedly reduced during 1–4 weeks after Ovx, with a significant increase in collagen accumulation and increased MT1-MMP expression. Although active-form MMP-2 and collagen progressively returned to normal levels, the markedly increased collagen deposition appeared again at 8 weeks and persisted until 12 weeks, followed by induction of MMP-2 and MT1-MMP at 12 weeks. The TIMP-2 level reduced for 2 weeks after Ovx, but soon returned to normal. Treatment with 17β-estradiol (E2), tempol, or aminoguanidine for 6 weeks prevented Ovx-induced blood pressure elevation and apparently reversed the MMPs changes.ConclusionsIn an initial period, E2 deficiency induces a reduction of active-form MMP-2 leading to collagen accumulation, and induction of MT1-MMP, which may be a compensatory response to degrade collagen. At a latter stage, the concurrent elevation of active-form MMP-2 and MT1-MMP expression may be adaptive responses to regulate ECM composition in the vascular wall. Oxidative stress and NO contribute to activity modulation of vascular MMPs in Ovx rats.American Journal of Hypertension (2009). doi:10.1038/ajh.2008.306American Journal of Hypertension (2009); 22, 1, 27–34. doi:10.1038/ajh.2008.306 [ABSTRACT FROM AUTHOR]

1 The effects of ovariectomy (Ovx), menopause and oestrogen replacement on the haemodynamics remain controversial. The present study employed the technique of arterial impedance analysis to measure and calculate the steady and pulsatile haemodynamics. The purpose was to determine the haemodynamic consequence of ovariectomy and oestrogen replacement. 2 Ovariectomy was carried out under anaesthesia on female Sprague Dawley rats aged 9 weeks. Oestrogen (17 β-estradiol or E[sub 2]) replacement started 1 week after ovariectomy for 4 weeks. Ovx increased the body weight (BW), while it greatly reduced the uterus weight. Left ventricular weight (LVW) was slightly increased, but LVW/BW ratio was slightly reduced. These changes were reversed after E[sub 2] replacement. 3 Compared to sham group, Ovx with or without E[sub 2] replacement did not significantly affect the systolic, mean and diastolic pressure. In Ovx, pulse pressure (PP) and heart rate were significantly increased, while stroke volume and cardiac output were slightly decreased. Total peripheral resistance (TPR) was largely elevated, indicating Ovx induced systemic vasoconstriction. These changes all returned to close normal values (sham group) after E[sub 2] replacement, except PP. 4 Ovx increased the characteristic input impedance (Zc) and pulse wave reflection, while it decreased arterial compliance. E[sub 2] treatment reversed these changes, except Zc. 5 These results demonstrate that Ovx influences both the resistance and Windkessel functions of the artery. E[sub 2] treatment effectively reverses most the effects of Ovx both on the steady and pulsatile haemodynamics. [ABSTRACT FROM AUTHOR]