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Oestrogens have been reported to attenuate acute inflammation in sepsis. In this study, the effects of long‐term oestrogen replacement with 17β‐oestradiol (E2) on endotoxaemia‐induced circulatory dysfunction and multiple organ dysfunction syndrome were evaluated in ovariectomized (Ovx) rats. E2 (50 μg/kg, s.c., 3 times/week) was administered for 8 weeks, followed by the induction of endotoxaemia by intravenous infusion of lipopolysaccharides (LPS; 30 mg/kg/4 hrs). Oestrogen deficiency induced by ovariectomy for 9 weeks augmented the LPS‐induced damage, including endotoxic shock, myocardial contractile dysfunction, renal dysfunction and rhabdomyolysis. Cardiac levels of NF‐κB p65, iNOS and oxidized glutathione, free radical production in skeletal muscles, myoglobin deposition in renal tubules, and plasma levels of plasminogen activator inhibitor‐1, TNF‐α, and IL‐6 were more pronounced in the Ovx + LPS group than in the Sham + LPS group. Long‐term treatment of E2 prevented this amplified damage in Ovx rats. Six hours after LPS initiation, activation of the autophagic process, demonstrated by increases in Atg12 and LC3B‐II/LC3B‐I ratios, and induction of haem oxygenase (HO)‐1 and heat‐shock protein (HSP) 70 protein expression in myocardium were increased significantly in the Ovx + E2 + LPS group. These results suggest that activation of autophagy and induction of HO‐1 and HSP70 contribute to the protective effect of long‐term E2 replacement on multiple organ dysfunction syndrome in endotoxaemia.

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. Electronic supplementary material The online version of this article (10.1186/s12929-019-0556-3) contains supplementary material, which is available to authorized users.

Heat shock protein 70 (Hsp70) preconditioning induces thermotolerance, and adenosine monophosphate (AMP)‐activated protein kinase (AMPK) plays a role in the process of autophagy. Here, we investigated whether 17‐dimethylaminoethylamino‐17‐demethoxy‐geldanamycin (17‐DMAG) protected against heat stroke (HS) in rats by up‐regulation of Hsp70 and phosphorylated AMPK (pAMPK). To produce HS, male Sprague–Dawley rats were placed in a chamber with an ambient temperature of 42°C. Physiological function (mean arterial pressure, heart rate and core temperature), hepatic and intestinal injury, inflammatory mediators and levels of Hsp70, pAMPK and light chain 3 (LC3B) in hepatic tissue were measured in HS rats or/and rats pre‐treated with 17‐DMAG. 17‐DMAG pre‐treatment significantly attenuated hypotension and organ dysfunction induced by HS in rats. The survival time during HS was also prolonged by 17‐DMAG treatment. Hsp70 expression was increased, whereas pAMPK levels in the liver were significantly decreased in HS rats. Following pre‐treatment with 17‐DMAG, Hsp70 protein levels increased further, and pAMPK levels were enhanced. Treatment with an AMPK activator significantly increased the LC3BII/LC3BI ratio as a marker of autophagy in HS rats. Treatment with quercetin significantly suppressed Hsp70 and pAMPK levels and reduced the protective effects of 17‐DMAG in HS rats. Both of Hsp70 and AMPK are involved in the 17‐DMAG‐mediated protection against HS. 17‐DMAG may be a promising candidate drug in the clinical setting.

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.

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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. Inin vivostudies, 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.

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.

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 beta-estradiol or E(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(2) replacement. 3. Compared to sham group, Ovx with or without E(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(2) replacement, except PP. 4. Ovx increased the characteristic input impedance (Zc) and pulse wave reflection, while it decreased arterial compliance. E(2) treatment reversed these changes, except Zc. 5. These results demonstrate that Ovx influences both the resistance and Windkessel functions of the artery. E(2) treatment effectively reverses most the effects of Ovx both on the steady and pulsatile haemodynamics.

The goal of the present study is to investigate the role of tetrahydrobiopterin (BH4) in the vascular response in ovariectomized rats. Rats were randomly assigned to two groups: (1) sham group: sham-operated female rats, and (2) Ovx group: rats were ovariectomized. Our results have shown that the plasma 17 beta-estradiol levels in the Ovx group at the end of the experiment were significantly lower than in the sham group. Vasoreactivity assessed with intact aortic rings indicated that the phenylephrine-induced vasocontractile response to aortic rings from the Ovx group was greater than that of the sham group. In contrast, the vasodilator responses to acetylcholine and L-arginine (L-Arg) in the sham group were significantly greater than in the Ovx group. Differences in vasoreactivity in denuded aorta between the two groups were not noted. Moreover, exogenous BH4 significantly restored L-Arg-induced vasodilator responses in the Ovx group. However, this improvement effect was not found in the sham group. In addition, there were significant increases in superoxide anion production in aortic tissue and significant decreases in plasma nitric oxide levels in the Ovx group. Furthermore, BH4 contents in the aorta in the Ovx group were significantly decreased compared with the sham group. In conclusion, the present study demonstrates that the impairment of vascular reactivity was found in the ovariectomized rats. The possible mechanism of this defect may have resulted from the deficiency of available BH4. Thus, this study may provide a novel therapeutic strategy for the treatment of postmenopausal cardiovascular disorders.

Alpha-lipoic acid (ALA), a naturally occurring disulfide derivative of octanoic acid, serves as a strong antioxidant and has been reported to possess anti-inflammatory effects. The aim of the present study is to investigate the preventive and therapeutic effects of ALA on multiple organ dysfunction syndrome (MODS) caused by endotoxemia in rats. Male Wistar rats were intravenously infused with lipopolysaccharide (LPS) (10 mg/kg) to induce endotoxemia. Alpha-lipoic acid 10, 20, or 40 mg/kg was administered intravenously 60 min before (pretreatment) LPS challenge, and ALA 40 mg/kg was administered intravenously 30 min after (posttreatment) LPS challenge. Pretreatment and posttreatment with ALA significantly improved the deleterious hemodynamic changes 8 h after LPS challenge, including hypotension and bradycardia. Alpha-lipoic acid reduced the plasma levels of glutamic pyruvic transaminase, blood urea nitrogen, lactate dehydrogenase, tumor necrosis factor-α, nitric oxide metabolites, and thrombin-antithrombin complex, which increased markedly after LPS challenge. The induction of inducible nitric oxide synthase both in the liver and the lung and vascular superoxide anion production were also significantly suppressed by ALA. Moreover, ALA significantly attenuated LPS-induced caspase-3 activation in cardiomyocytes and improved survival rate. In conclusion, ALA effectively attenuated LPS-induced acute inflammatory response and improved MODS. The antioxidant and anti-inflammatory effects of ALA may contribute to these beneficial effects. Alpha-lipoic acid might be considered as a novel therapeutic strategy in the prevention of sepsis-induced MODS and inflammatory vascular diseases.

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 (6 h). Posttreatment with HS prevented hypotension caused by LPS and significantly improved cardiac function, evidenced by increases in left ventricular developed pressure, mean and . The amplitude of electrical-stimulated intracellular Ca 2+ 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- B phospho-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.

BACKGROUND Matrix 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. METHODS Estrogen 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. RESULTS The 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 17beta-estradiol (E(2)), tempol, or aminoguanidine for 6 weeks prevented Ovx-induced blood pressure elevation and apparently reversed the MMPs changes. CONCLUSIONS In an initial period, E(2) 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.

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 beta-estradiol or E(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(2) replacement. 3. Compared to sham group, Ovx with or without E(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(2) replacement, except PP. 4. Ovx increased the characteristic input impedance (Zc) and pulse wave reflection, while it decreased arterial compliance. E(2) treatment reversed these changes, except Zc. 5. These results demonstrate that Ovx influences both the resistance and Windkessel functions of the artery. E(2) treatment effectively reverses most the effects of Ovx both on the steady and pulsatile haemodynamics.