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Summary Aims Baicalin (BAI), a flavonoid compound isolated from the root of Scutellaria baicalensis Georgi, has been established to have potent anti‐inflammation and neuroprotective properties; however, its effects during Alzheimer's disease ( AD ) treatment have not been well studied. This study aimed to investigate the effects of BAI pretreatment on cognitive impairment and neuronal protection against microglia‐induced neuroinflammation and to explore the mechanisms underlying its anti‐inflammation effects. Methods To determine whether BAI plays a positive role in ameliorating the memory and cognition deficits in APP (amyloid beta precursor protein)/PS1 (presenilin‐1) mice, behavioral experiments were conducted. We assessed the effects of BAI on microglial activation, the production of proinflammatory cytokines, and neuroinflammation‐mediated neuron apoptosis in vivo and in vitro using Western blot, RT ‐ PCR , ELISA , immunohistochemistry, and immunofluorescence. Finally, to elucidate the anti‐inflammation mechanisms underlying the effects of BAI , the protein expression of NLRP 3 inflammasomes and the expression of proteins involved in the TLR 4/ NF ‐κB signaling pathway were measured using Western blot and immunofluorescence. Results The results indicated that BAI treatment attenuated spatial memory dysfunction in APP / PS 1 mice, as assessed by the passive avoidance test and the Morris water maze test. Additionally, BAI administration effectively decreased the number of activated microglia and proinflammatory cytokines, as well as neuroinflammation‐mediated neuron apoptosis, in APP / PS 1 mice and LPS (lipopolysaccharides)/Aβ‐stimulated BV 2 microglial cells. Lastly, the molecular mechanistic study revealed that BAI inhibited microglia‐induced neuroinflammation via suppression of the activation of NLRP 3 inflammasomes and the TLR 4/ NF ‐κB signaling pathway. Conclusion Overall, the results of the present study indicated that BAI is a promising neuroprotective compound for use in the prevention and treatment of microglia‐mediated neuroinflammation during AD progression.

Rationale In the myocardium, redox/cysteine modification of proteins regulating Ca2+ cycling can affect contraction and may have therapeutic value. Nitroxyl (HNO), the one electron reduced form of nitric oxide, enhances cardiac function in a manner that suggests reversible cysteine modifications of the contractile machinery. Objective To determine the effects of HNO modification in cardiac myofilament proteins. Methods and Results The HNO-donor, 1-nitrosocyclohexyl acetate (NCA), was found to act directly on the myofilament proteins increasing maximum force (Fmax) and reducing the concentration of Ca2+ for 50% activation (Ca50) in intact and skinned cardiac muscles. The effects of NCA are reversible by reducing agents and distinct from those of another HNO-donor Angeli’s salt (AS), which was previously reported to increase Fmax without affecting Ca50. Using a new mass spectrometry capture technique based on the biotin switch assay, we identified and characterized the formation by HNO of a disulfide linked actin-tropomyosin and myosin heavy chain (MHC)-myosin light chain 1 (MLC1). Comparison of the NCA and AS effects with the modifications induced by each donor indicated the actin-tropomyosin and MHC-MLC1 interactions independently correlated with increased Ca2+ sensitivity and force generation, respectively. Conclusions HNO exerts a direct effect on cardiac myofilament proteins increasing myofilament Ca2+ responsiveness by promoting disulfide bond formation between critical cysteine residues. These findings indicate a novel, redox-based modulation of the contractile apparatus which positively impacts myocardial function, providing further mechanistic insight for HNO as a therapeutic agent.

In addition to O-phosphorylation, O-linked modifications of serine and threonine by ␤-N-acetyl-D-glucosamine (GlcNAc) may regulate muscle contractile function. This study assessed the potential role of O-GlcNAcylation in cardiac muscle contractile activation. To identify specific sites of O-GlcNAcylation in cardiac myofilament proteins, a recently developed methodology based on GalNAz-biotin labeling followed by dithiothreitol replacement and light chromatography/tandem mass spectrometry site mapping was adopted. Thirty-two O-GlcNAcylated peptides from cardiac myofilaments were identified on cardiac myosin heavy chain, actin, myosin light chains, and troponin I. To assess the potential physiological role of the GlcNAc, force- [Ca 2؉ ] relationships were studied in skinned rat trabeculae. Exposure to GlcNAc significantly decreased calcium sensitivity (pCa50), whereas maximal force (F max ) and Hill coefficient (n) were not modified. Using a pan-specific O-GlcNAc antibody, it was determined that acute exposure of myofilaments to GlcNAc induced a significant increase in actin O-GlcNAcylation. This study provides the first identification of O-GlcNAcylation sites in cardiac myofilament proteins and demonstrates their potential role in regulating myocardial contractile function. D iabetes mellitus is a risk factor for the development of heart failure, 1 and abnormal glucose metabolism may contribute directly to depressed cardiac function. Studies in humans and animal models of diabetes mellitus have demonstrated abnormal myofilament function 2 and impaired excitation-contraction coupling, 3,4 which may depress myocardial function. Posttranslational modifications of myofilament proteins regulate cardiac function and phosphorylation of myofilament proteins may result in functional abnormalities in heart failure. [5][6][7] In addition to O-linked phosphorylation of serine (Ser) and threonine (Thr) residues of proteins, dynamic Materials and Methods Mass Spectrometric Identification of O-GlcNAc-Modified ProteinsTo label the specific sites (further details are in the online data supplement, available at http://circres.ahajournals.org), GlcNAcmodified peptides were labeled with GalNAz-biotin and enriched by avidin chromatography, and then dithiothreitol (DTT) was used to replace the GlcNAc-GalNAz-biotin by ␤-elimination and Michael addition (BEMAD) as previously described. 14 Isolated Skinned Fiber StudiesFor skinned fiber studies, cardiac trabeculae were isolated and mounted as previously described. 5 ImmunoblotsMyofilament proteins were isolated as previously described, 15 with minor modifications. To determine the global GlcNAc modifications of myofilament proteins, a pan-GlcNAc antibody (CTD 110.6, Covance) was used as previously described. 16 To assess cardiac troponin I (cTnI) phosphorylation, a phospho-TnI (Ser23/Ser24) antibody (Cell Signaling, Danvers, Mass) was used as previously described. 5 Results and Discussion Myofilament Proteins Are Modified by O-GlcNAcWith the enrichment and BEMAD experiments describ...

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The classical axis of renin-angiotensin system (RAS), angiotensin (Ang)-converting enzyme (ACE)/Ang II/AT1, contributes to the development of non-alcoholic fatty liver disease (NAFLD). However, the role of bypass axis of RAS (Angiotensin-converting enzyme 2 (ACE2)/Ang-(1–7)/Mas) in hepatic steatosis is still unclear. Here we showed that deletion of ACE2 aggravates liver steatosis, which is correlated with the increased expression of hepatic lipogenic genes and the decreased expression of fatty acid oxidation-related genes in the liver of ACE2 knockout (ACE2−/y) mice. Meanwhile, oxidative stress and inflammation were also aggravated in ACE2−/y mice. On the contrary, overexpression of ACE2 improved fatty liver in db/db mice, and the mRNA levels of fatty acid oxidation-related genes were up-regulated. In vitro, Ang-(1–7)/ACE2 ameliorated hepatic steatosis, oxidative stress and inflammation in free fatty acid (FFA)-induced HepG2 cells, and what’s more, Akt inhibitors reduced ACE2-mediated lipid metabolism. Furthermore, ACE2-mediated Akt activation could be attenuated by blockade of ATP/P2 receptor/Calmodulin (CaM) pathway. These results indicated that Ang-(1–7)/ACE2/Mas axis may reduce liver lipid accumulation partly by regulating lipid-metabolizing genes through ATP/P2 receptor/CaM signaling pathway. Our findings support the potential role of ACE2/Ang-(1–7)/Mas axis in prevention and treatment of hepatic lipid metabolism.

BackgroundVisceral adipose tissue (VAT) is a unique pathogenic fatty deposit, in that it is closely correlated with risk of cardiovascular diseases. The present study is to investigate the usefulness of neck circumference (NC) to indicate VAT.MethodsParticipants aged 35 to 75 years who had taken abdomen and neck computer tomography (CT) examination were included in this study. Neck adipose tissue, abdominal VAT and subcutaneous adipose tissue (SAT) areas, as well as sagittal abdominal diameter (SAD) were measured by CT. Body anthropometrics and metabolic parameters including blood glucose, lipid profiles and blood pressure were also measured.ResultsA lower abdomen CT examination was carried out on a total of 177 patients (87 male and 90 female) with a mean age of 59 years. Of the 177 participants, 15 men and 15 women also took a neck CT examination. With a comparable age and BMI, neck adipose area was correlated with abdominal VAT area significantly in men (r = 0.57, p = 0.028) and women (r = 0.53, p = 0.041). NC is positively correlated with VAT both in men (r = 0.49, p < 0.001) and women (r = 0.25, p = 0.012). Meanwhile, SAD is the best predictor for visceral fat both in men (r = 0.83, p < 0.001) and women (r = 0.73, p < 0.001). Body mass index (BMI), waist circumference (WC), and waist to height ratio (WHtR) correlated significantly with VAT both in men and women (r = 0.68, 0.42, 0.46 in men and 0.50, 0.23, 0.39 in women, p < 0.001), while waist hip ratio (WHR) displayed the weakest least correlation in men (r = 0.32, p = 0.001) and no correlation in women (r = 0.08, p = 0.442). Additionally, BMI was more strongly correlated with VAT than NC in both sexes (both p < 0.01).ConclusionSignificant correlation between NC and VAT was present in Chinese men and women, which may be accounted by the fact that neck fat area is significantly correlated with abdominal VAT. Meanwhile, SAD is the best predictor for visceral fat in the Chinese population.

ObjectivesThe study aimed to determine the exact risk factors for diabetic retinopathy (DR) in the Chinese population using a cohort of 17  985 individuals from Beijing, China.DesignCross-sectional study.SettingA hospital.Participants17  985 individuals from Beijing, China.Primary and secondary outcome measuresThis was a cross-sectional study of permanent residents from the Changping area (Beijing, China) recruited from July 2010 to March 2011 and from March 2014 to February 2015 during a routine health examination at the Tongren Hospital of Beijing. Eye examinations were conducted by experienced ophthalmologists. Medical history, height, weight, body mass index (BMI) and blood pressure were recorded. Routine laboratory examinations were performed.ResultsThe prevalence of DR was 1.5% in the general study population and 8.1% among individuals with diabetes. Compared with the non-DR group, individuals in the DR group in the diabetes population had longer disease duration, higher systolic blood pressure (SBP), fasting plasma glucose (FPG) and uric acid (UA) (in men) and lower UA (in women) (all p<0.05). The multivariate analysis showed that disease duration (p<0.001), BMI (p=0.046), SBP (p=0.012), creatinine clearance rate (CCR) (p=0.014), UA (p=0.018) and FPG (p<0.001) were independently associated with DR in patients with diabetes.ConclusionThe prevalence of DR was 8.1% among patients with diabetes. Disease duration, BMI, SBP, CCR, UA and FPG were independently associated with DR.