BMAL1 deletion protects against obesity and non-alcoholic fatty liver disease induced by a high-fat diet.

OBJECTIVES: Obesity and non-alcoholic fatty liver disease (NAFLD) are major health concerns. The circadian rhythm is an autonomous and intrinsic timekeeping system closely associated with energy metabolism and obesity. Thus, this study explored the role of brain and muscle aryl hydrocarbon receptor nuclear translocator-like1 (BMAL1), a circadian clock regulator, in the development of obesity and NAFLD. METHODS: We generated BMAL1 knockout (BMAL1 KO) mice to imitate circadian rhythm disruption. The study comprised three groups from the same litter: BMAL1 KO mice fed a high-fat diet (to establish obesity and NAFLD phenotypes), wild-type mice fed normal chow, and wild-type mice fed a high-fat diet. The metabolic and NAFLD phenotypes were assessed via physiological measurements and histological examinations. Quantitative polymerase chain reaction and western blotting were used to identify and validate changes in the signaling pathways responsible for the altered NAFLD phenotypes in the wild-type and BMAL1 KO mice. RESULTS: BMAL1 depletion protected against obesity and metabolic disorders induced by a high-fat diet. BMAL1 depletion also prevented hepatic steatosis and inhibited cluster of differentiation 36 and peroxisome proliferator-activated receptor gamma (i.e., PPARγ) expression. CONCLUSIONS: BMAL1 plays an important role in the development of obesity and NAFLD and, thus, is a potential therapeutic target for these conditions.

Cooling-activated dorsomedial hypothalamic BDNF neurons control cold defense in mice.

BDNF and its expressing neurons in the brain critically control feeding and energy expenditure (EE) in both rodents and humans. However, whether BDNF neurons would function in thermoregulation during temperature challenges is unclear. Here, we show that BDNF neurons in the dorsomedial hypothalamus (DMHBDNF ) of mice are activated by afferent cooling signals. These cooling-activated BDNF neurons are mainly GABAergic. Activation of DMHBDNF neurons or the GABAergic subpopulations is sufficient to increase body temperature, EE, and physical activity. Conversely, blocking DMHBDNF neurons substantially impairs cold defense and reduces energy expenditure, physical activity, and UCP1 expression in BAT, which eventually results in bodyweight gain and glucose/insulin intolerance. Therefore, we identify a subset of DMHBDNF neurons as a novel type of cooling-activated neurons to promote cold defense. Thus, we reveal a critical role of BDNF circuitry in thermoregulation, which deepens our understanding of BDNF in controlling energy homeostasis and obesity.

Sleeve gastrectomy decreases high-fat diet induced colonic pro-inflammatory status through the gut microbiota alterations.

Background: High-fat diet (HFD) induced obesity is characterized with chronic low-grade inflammation in various tissues and organs among which colon is the first to display pro-inflammatory features associated with alterations of the gut microbiota. Sleeve gastrectomy (SG) is currently one of the most effective treatments for obesity. Although studies reveal that SG results in decreased levels of inflammation in multiple tissues such as liver and adipose tissues, the effects of surgery on obesity related pro-inflammatory status in the colon and its relation to the microbial changes remain unknown. Methods: To determine the effects of SG on the colonic pro-inflammatory condition and the gut microbiota, SG was performed on HFD-induced obese mice. To probe the causal relationship between alterations of the gut microbiota and improvements of pro-inflammatory status in the colon following SG, we applied broad-spectrum antibiotics cocktails on mice that received SG to disturb the gut microbial changes. The pro-inflammatory shifts in the colon were assessed based on morphology, macrophage infiltration and expressions of a variety of cytokine genes and tight junction protein genes. The gut microbiota alterations were analyzed using 16s rRNA sequencing. RNA sequencing of colon was conducted to further explore the role of the gut microbiota in amelioration of colonic pro-inflammation following SG at a transcriptional level. Results: Although SG did not lead to pronounced changes of colonic morphology and macrophage infiltration in the colon, there were significant decreases in the expressions of several pro-inflammatory cytokines including interleukin-1ß (IL-1ß), IL-6, IL-18, and IL-23 as well as increased expressions of some tight junction proteins in the colon following SG, suggesting an improvement of pro-inflammatory status. This was accompanied by changing populations of the gut microbiota such as increased richness of Lactobacillus subspecies following SG. Importantly, oral administrations of broad-spectrum antibiotics to delete most intestinal bacteria abrogated surgical effects to relieve colonic pro-inflammation. This was further confirmed by transcriptional analysis of colon indicating that SG regulated inflammation related pathways in a manner that was gut microbiota relevant. Conclusion: These results support that SG decreases obesity related colonic pro-inflammatory status through the gut microbial alterations.

Sleeve gastrectomy improved microvascular phenotypes from obesity cohort, detected with optical coherence tomography angiography.

AIMS: To examine how metabolic status is associated with microvascular phenotype and to identify variables associated with vascular remodeling after bariatric surgery, using noninvasive optical coherence tomography angiography (OCTA). METHODS: The study included 136 obese subjects scheduled for bariatric surgery and 52 normal-weight controls. Patients with obesity were divided into metabolically healthy obesity (MHO) and metabolic syndrome (MetS) groups according to the diagnosis criteria of the Chinese Diabetes Society. Retinal microvascular parameters were measured by OCTA, including superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel densities. Follow-ups were performed at the baseline and 6 months after bariatric surgery. RESULTS: Fovea SCP, average DCP, fovea DCP, parafovea DCP, and perifovea DCP vessel densities were significantly lower in the MetS group, compared to controls (19.91% vs. 22.49%, 51.60% vs. 54.20%, 36.64% vs. 39.14%, 56.24% vs. 57.65% and 52.59% vs. 55.58%, respectively, all p < .05). Parafovea SCP, average DCP, parafovea DCP, and perifovea DCP vessel densities significantly improved in patients with obesity 6 months after surgery, compared to baseline (54.21% vs. 52.97%, 54.43% vs. 50.95%, 58.29% vs. 55.54% and 55.76% vs. 51.82%, respectively, all p < .05). Multivariable analyses showed that baseline blood pressure and insulin were independent predictors of vessel density changes 6 months after surgery. CONCLUSIONS: Retinal microvascular impairment occurred mainly in MetS rather than MHO patients. Retinal microvascular phenotype improved 6 months after bariatric surgery and baseline blood pressure and insulin status may be key determinants. OCTA may be a reliable method to evaluate the microvascular complications associated with obesity.

Lipid Profiling Reveals Lipidomic Signatures of Weight Loss Interventions.

Obesity is an epidemic all around the world. Weight loss interventions that are effective differ from each other with regard to various lipidomic responses. Here, we aimed to find lipidomic biomarkers that are related to beneficial changes in weight loss. We adopted an untargeted liquid chromatography with tandem mass spectrometry (LC-MS/MS) method to measure 953 lipid species for Exercise (exercise intervention cohort, N = 25), 1388 lipid species for LSG (laparoscopic sleeve gastrectomy cohort, N = 36), and 886 lipid species for Cushing (surgical removal of the ACTH-secreting pituitary adenomas cohort, N = 25). Overall, the total diacylglycerol (DG), triacylglycerol (TG), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), and sphingomyelin (SM) levels were associated with changes in BMI, glycated hemoglobin (HbA1c), triglyceride, and total cholesterol according to weight loss interventions. We found that 73 lipid species changed among the three weight loss interventions. We screened 13 lipid species with better predictive accuracy in diagnosing weight loss situations in either Exercise, LSG, or Cushing cohorts (AUROC > 0.7). More importantly, we identified three phosphatidylcholine (PC) lipid species, PC (14:0_18:3), PC (31:1), and PC (32:2) that were significantly associated with weight change in three studies. Our results highlight potential lipidomic biomarkers that, in the future, could be used in personalized approaches involving weight loss interventions.

A parabrachial-hypothalamic parallel circuit governs cold defense in mice.

Thermal homeostasis is vital for mammals and is controlled by brain neurocircuits. Yet, the neural pathways responsible for cold defense regulation are still unclear. Here, we found that a pathway from the lateral parabrachial nucleus (LPB) to the dorsomedial hypothalamus (DMH), which runs parallel to the canonical LPB to preoptic area (POA) pathway, is also crucial for cold defense. Together, these pathways make an equivalent and cumulative contribution, forming a parallel circuit. Specifically, activation of the LPB → DMH pathway induced strong cold-defense responses, including increases in thermogenesis of brown adipose tissue (BAT), muscle shivering, heart rate, and locomotion. Further, we identified somatostatin neurons in the LPB that target DMH to promote BAT thermogenesis. Therefore, we reveal a parallel circuit governing cold defense in mice, which enables resilience to hypothermia and provides a scalable and robust network in heat production, reshaping our understanding of neural circuit regulation of homeostatic behaviors.

Hypothalamic warm-sensitive neurons require TRPC4 channel for detecting internal warmth and regulating body temperature in mice.

Precise monitoring of internal temperature is vital for thermal homeostasis in mammals. For decades, warm-sensitive neurons (WSNs) within the preoptic area (POA) were thought to sense internal warmth, using this information as feedback to regulate body temperature (Tcore). However, the cellular and molecular mechanisms by which WSNs measure temperature remain largely undefined. Via a pilot genetic screen, we found that silencing the TRPC4 channel in mice substantially attenuated hypothermia induced by light-mediated heating of the POA. Loss-of-function studies of TRPC4 confirmed its role in warm sensing in GABAergic WSNs, causing additional defects in basal temperature setting, warm defense, and fever responses. Furthermore, TRPC4 antagonists and agonists bidirectionally regulated Tcore. Thus, our data indicate that TRPC4 is essential for sensing internal warmth and that TRPC4-expressing GABAergic WSNs function as a novel cellular sensor for preventing Tcore from exceeding set-point temperatures. TRPC4 may represent a potential therapeutic target for managing Tcore.

Remote firing propagation in the neural network of C. elegans.

Understanding the mechanisms of firing propagation in brain networks has been a long-standing problem in the fields of nonlinear dynamics and network science. In general, it is believed that a specific firing in a brain network may be gradually propagated from a source node to its neighbors and then to the neighbors' neighbors and so on. Here, we explore firing propagation in the neural network of Caenorhabditis elegans and surprisingly find an abnormal phenomenon, i.e., remote firing propagation between two distant and indirectly connected nodes with the intermediate nodes being inactivated. This finding is robust to source nodes but depends on the topology of network such as the unidirectional couplings and heterogeneity of network. Further, a brief theoretical analysis is provided to explain its mechanism and a principle for remote firing propagation is figured out. This finding provides insights for us to understand how those cognitive subnetworks emerge in a brain network.

Sufficient nitrogen promoted high phosphorus tolerance and phosphorus-accumulating capability of Polygonum hydropiper in relation to changes of phytohormones and phenols.

Nitrogen (N) application is efficient to enhance phosphorus (P)-phytoextraction efficiency of P-accumulating plants. However, there is little available information on growth, P uptake and physiological changes of P-accumulating plants in high P media with different N application, and that whether the improved growth or P uptake is related with changes of phytohormones and phenols. This study investigated growth, P-accumulating capability, phytohormones and phenols of a mining ecotype (ME) and a non-mining ecotype (NME) of Polygonum hydropiper in high P media (400 mg L-1) with sufficient N (SN, 50 mg L-1) and low N (LN, 12.5 mg L-1) supply. SN supply greatly increased tissue biomass, P-accumulating capability of P. hydropiper in high P media, and the ME showed higher P bioaccumulation coefficient, and tissue P accumulation than the NME. The greatest tissue biomass and P accumulation was found at 5 weeks. At 5 weeks, SN supply greatly decreased concentrations of indole-3-acetic acid (IAA), zeatin, abscisic acid (ABA), total phenolic and flavonoid in tissues of P. hydropiper, compared with LN supply. The ME produced lower concentrations of IAA, zeatin, ABA, total phenolic and flavonoid than the NME in leaf and stem in high P media with N supply. Significantly negative correlations were found between IAA, zeatin, ABA, flavonoid concentrations and biomass as well as P accumulation in leaf. Thus, SN supply promoted high P tolerance and P-accumulating capability of the ME in relation to modulating phytohormones and phenols to suitable concentrations, ultimately improving P-phytoextraction ability.

Sleeve gastrectomy ameliorated high-fat diet (HFD)-induced non-alcoholic fatty liver disease and upregulated the nicotinamide adenine dinucleotide +/ Sirtuin-1 pathway in mice.

BACKGROUND: /Objective: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, and effective treatments are lacking. Bariatric surgery, including sleeve gastrectomy (SG), is a potential therapeutic strategy for NAFLD, but the molecular mechanisms underlying its effects are not fully understood. In this study, the effects of SG and the underlying mechanisms were evaluated in a mouse model of high-fat diet (HFD)-induced NAFLD. METHODS: C57BL/6 mice were randomly divided into three groups: normal diet with sham operation (NC-Sham group), HFD with sham operation (HFD-Sham group), and HFD with sleeve gastrectomy (HFD-SG group). Glucose metabolism and fat accumulation in the body and liver were analyzed before and after SG. Lipid metabolism and inflammation in the liver were evaluated. Nicotinamide adenine dinucleotide (NAD+) levels as well as nicotinamide riboside kinase (NRK1) and Sirtuin-1 (SIRT1) expression levels were evaluated. RESULTS: SG attenuated the HFD-induced increases in glucose and insulin levels, fat accumulation, and lipid droplet accumulation. Fatty acid biosynthesis, the expression of the metabolism-related genes ACC1, FASN, SCD1, and DGAT1, and the levels of inflammatory factors were higher in HFD mice than in NC mice and decreased after SG. NAD + concentrations were 54.9 ± 13.4 µmol/mg in NC-Sham mice, 37.6 ± 8.1 µmol/mg in HFD-Sham mice, and 79.9 ± 13.0 µmol/mg in HFD-SG mice (p < 0.05). NRK1 and SIRT1 expression increased dramatically after SG at both the RNA and protein levels. CONCLUSION: SG significantly alleviated NAFLD in HFD-induced obese mice with increasing the hepatic NAD + levels and upregulating the NRK1/NAD+/SIRT1 pathway.

Hepatokine Pregnancy Zone Protein Governs the Diet-Induced Thermogenesis Through Activating Brown Adipose Tissue.

Intermittent fasting (IF), as a dietary intervention for weight loss, takes effects primarily through increasing energy expenditure. However, whether inter-organ systems play a key role in IF remains unclear. Here, a novel hepatokine, pregnancy zone protein (PZP) is identified, which has significant induction during the refeeding stage of IF. Further, loss of function studies and protein therapeutic experiment in mice revealed that PZP promotes diet-induced thermogenesis through activating brown adipose tissue (BAT). Mechanistically, circulating PZP can bind to cell surface glucose-regulated protein of 78 kDa (GRP78) to promote uncoupling protein 1 (UCP1) expression via a p38 MAPK-ATF2 signaling pathway in BAT. These studies illuminate a systemic regulation in which the IF promotes BAT thermogenesis through the endocrinal system and provide a novel potential target for treating obesity and related disorders.

PS-341 alleviates chronic low-grade inflammation and improves insulin sensitivity through the inhibition of TM4 (UBAC2) degradation.

BACKGROUND: The TM4 (UBAC2) protein, which contains 4 transmembrane domains and one ubiquitin binding domain, is mainly expressed in cell and nuclear membranes. The current research aimed to explore the role of TM4 in metabolic inflammation and to examine whether the ubiquitin-proteasome inhibitor PS-341 could regulate the function of TM4. METHODS: The metabolic phenotypes of TM4 knockout (KO) mice were studied. We next explored the association between the polymorphisms of TM4 and obesity in a Chinese Han population. TM4 expression in the visceral fat of obese patients who underwent laparoscopic cholecystectomy was also analysed. Finally, the effect of PS-341 on the degradation and function of the TM4 protein was investigated in vivo and in vitro. RESULTS: TM4 KO mice developed obesity, hepatosteatosis, hypertension, and glucose intolerance under a high-fat diet. TM4 counterregulated Nur77, IKKß, and NF-kB both in vivo and in vitro. The TM4 SNP rs147851454 is significantly associated with obesity after adjusting for age and sex (OR 1.606, 95% CI 1.065-2.422 P = 0.023) in 3394 non-diabetic and 1862 type 2 diabetic adults of Han Chinese. TM4 was significantly downregulated in the visceral fat of obese patients. PS-341 induced TM4 expression through inhibition of TM4 degradation in vitro. In db/db mice, PS-341 administration led to downregulation of Nur77/IKKß/NF-κB expression in visceral fat and liver, and alleviation of hyperglycaemia, hypertension, and glucose intolerance. The hyperinsulinaemic-euglycaemic clamp demonstrated that PS-341 improved the glucose infusion rate and alleviated insulin resistance in db/db mice. CONCLUSIONS: PS-341 alleviates chronic low-grade inflammation and improves insulin sensitivity through inhibition of TM4 degradation.

A Qualitative Exploration of Patients' Experiences with Lifestyle Changes After Sleeve Gastrectomy in China.

PURPOSE: Sleeve gastrectomy (SG) is the most widely used surgical treatment for severe obesity worldwide. Individuals who have undergone SG usually need to change lifestyle behaviors as a response to the anatomical changes imposed by SG, and patients need to sustain lifestyle changes for long-term surgical success. Little is known about how patients experience and manage lifestyle changes following SG. In China, where SG comprises over 70% of bariatric surgical procedures, there have been no reports addressing this issue. This study aimed to describe individuals' experiences related to lifestyle changes after SG in China. MATERIALS AND METHODS: Semi-structured interviews were conducted at the Shanghai Huashan Hospital in China with adults who had undergone SG between 2012 and 2018. Two independent researchers used an interpretive thematic approach to analyze transcripts for themes and sub-themes. RESULTS: Interviews (N = 15) revealed three major themes of participants' experiences with postoperative lifestyle changes: advantages outweigh disadvantages; developing self-management strategies (i.e., adopting new behaviors and developing habits, continuing self-monitoring, focusing on health over weight, staying determined); and experiencing culture-specific difficulties in adherence to follow-up visits and lifestyle recommendations. CONCLUSION: The data from this study provided a rich description of the postoperative experiences of patients in China. Participants reported that surgical benefits supersede the surgery-related side effects, and participants were able to develop self-management strategies in order to achieve success. However, personal and social barriers, such as the challenges of applying postoperative dietary guidelines into daily practice, may impede patients making and sustaining recommended behavioral changes.

Cold-Inducible Klf9 Regulates Thermogenesis of Brown and Beige Fat.

Promoting development and function of brown and beige fat may represent an attractive treatment of obesity. In the current study, we show that fat Klf9 expression is markedly induced by cold exposure and a ß-adrenergic agonist. Moreover, Klf9 expression levels in human white adipose tissue (WAT) are inversely correlated with adiposity, and Klf9 overexpression in primary fat cells stimulates cellular thermogenesis, which is Ucp1 dependent. Fat-specific Klf9 transgenic mice gain less weight and have smaller fat pads due to increased thermogenesis of brown and beige fat. Moreover, Klf9 transgenic mice displayed lower fasting blood glucose levels and improved glucose tolerance and insulin sensitivity under the high-fat diet condition. Conversely, Klf9 mutation in brown adipocytes reduces the expression of thermogenic genes, causing a reduction in cellular respiration. Klf9-mutant mice exhibited obesity and cold sensitivity due to impairments in the thermogenic function of fat. Finally, fat Klf9 deletion inhibits the ß3 agonist-mediated induction of WAT browning and brown adipose tissue thermogenesis. Mechanistically, cold-inducible Klf9 stimulates expression of Pgc1α, a master regulator of fat thermogenesis, by a direct binding to its gene promoter region, subsequently promoting energy expenditure. The current study reveals a critical role for KLF9 in mediating thermogenesis of brown and beige fat.

Prevalence and risk factors for symptoms suggestive of hypoglycemia and early dumping syndrome after sleeve gastrectomy.

BACKGROUND: Postprandial hypoglycemia and early dumping syndrome are common complications after bariatric surgery. Although sleeve gastrectomy (SG) has become a primary option for many bariatric surgeons, limited information was available for the prevalence and risk factors of the complications. OBJECTIVE: To assess the prevalence and possible risk factors for postprandial hypoglycemia and early dumping syndrome based on self-reported symptoms of SG patients. SETTING: The study was conducted at a bariatric surgery center in a university hospital. METHODS: In this study, all patients who underwent an SG (n = 222) between December 2011 and May 2018 in our center were invited to participate in a questionnaire survey. The Edinburgh Hypoglycemia Scoring System and the Dumping Symptom Rating Scale were used to evaluate symptoms, and clinical data of the patients were collected. The median follow-up time was 1.1 years. RESULTS: The questionnaire was completed and returned by 54.95% (122/222) of the patients and 62.30% (76/122) of the responders were women. The prevalence rates of mild and moderate symptoms suggestive of hypoglycemia were 65.57% (80/122) and .82%, respectively. An associated risk factor was younger age (adjusted for sex, body mass index, and waist circumference at baseline: odds ratio 3.69; 95% confidence interval [1.22-11.21]), but this association disappeared after further adjustment of low-density protein cholesterol (LDL-C) (odds ratio 6.42; 95% confidence interval [.38-108],;P > .05). The prevalence rate of mild symptoms suggestive of early dumping was 40.98% (50/122), associated risk factor was lower LDL-C. CONCLUSION: Mild-to-moderate symptoms suggestive of hypoglycemia and early dumping syndrome were common in patients after SG, with the prevalence rates of 66.39% (81/122) and 40.98% (50/122), respectively. Patients with both symptoms suggestive of early dumping syndrome and hypoglycemia accounted for 33.61% (41/122) of all patients. Younger age indicated higher risk of hypoglycemia after SG and lower LDL-C may play an important role in this relationship. Lower LDL-C was associated with higher risk of early dumping syndrome after SG.

Pb exposure reduces the expression of SNX6 and Homer1 in offspring rats and PC12 cells.

Lead (Pb) is a widespread environmental heavy metal toxicant and chronic Pb exposure can have irreversible effects on memory and cognitive function, which is closely related to dendritic spines. Studies have shown that SNX6 and Homer1 can regulate the growth of dendritic spines. We aimed to investigate the effect of Pb exposure on the dendritic spines in hippocampus, the expression of SNX6 and Homer1 in rats and PC12 cells. The animals were randomly divided to three groups: control group, low lead group and high lead group. PC12 cells were divided into 3 groups: 0 µM, 1 µM and 100 µM Pb acetate. The results showed that the Pb levels in blood and hippocampus of all exposure groups were significantly higher than that of the control group. The morphology of dendritic spines in hippocampus after Pb treatment was changed and the density of dendritic spines was reduced. The expression of SNX6 and Homer1 was decreased in Pb exposed groups compared with the control group. Furthermore, up-regulation of SNX6 expression could reverse the down-regulation of Pb exposure on Homer1. These results indicate that Pb exposure can reduce the expression of SNX6 and lead to a decrease in Homer1 expression, which affects the changes in dendritic spines causing learning and memory impairment.

Effects of sleeve gastrectomy on the composition and diurnal oscillation of gut microbiota related to the metabolic improvements.

BACKGROUND: Disruptions of the composition and diurnal oscillation of gut microbiota are involved in metabolic disorders. OBJECTIVES: To identify alterations in both the composition and diurnal oscillation of gut microbiota after high-fat diet (HFD) feeding and sleeve gastrectomy (SG) related to host metabolic status. SETTING: University laboratories. METHODS: Twenty-one 6-week-old male C57 BL/6 J mice were randomized on an HFD (n = 14) or normal chow (NC, n = 7). After 14 weeks of feeding, HFD-induced obese mice were randomized to receive either SG or sham surgery (n = 7 in each group). Fecal samples were collected every 6 hours over a 24-hour period at 14 weeks of NC or HFD feeding and subsequently 8 weeks after surgery. The composition and diurnal oscillation of gut microbiota were characterized using next-generation Illumina sequencing of 16 S rDNA. RESULTS: HFD feeding led to adiposity, disrupted composition, and impaired diurnal oscillation of gut microbiota relative to NC. After surgery, SG mice had considerable weight loss, improved glucose tolerance, and insulin sensitivity compared with sham mice. SG restored the reduced richness and disruptions in the composition of gut microbiota. The diminished diurnal oscillation of gut microbiota was improved after SG. CONCLUSION: SG not only changed the disrupted composition of gut microbiota toward that of NC feeding, but also improved the dampened diurnal oscillation of gut microbiota due to HFD feeding.

The effects of lead exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells.

Lead (Pb) is an environmental neurotoxic metal. Chronic exposure to Pb causes deficits of learning and memory in children and spatial learning deficits in developing rats. In this study we investigated the effects of Pb exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells. The animals were randomly divided to three groups: control group; low lead exposure group; high lead exposure group; PC12 cells were divided into 3 groups: 0 µM (control group), 1 µM and 100 µM Pb acetate. The results showed that Pb levels in blood and brain of Pb exposed groups were significantly higher than that of the control group (p < 0.05). The expression of HMGB1 and HO-1 were increased in Pb exposed groups than that of the control group (p < 0.05). Moreover, we found that the up-regulation of HO-1 in Pb exposure environment inhibited the expression of HMGB1.

MiR-145 improves macrophage-mediated inflammation through targeting Arf6.

PURPOSE: To explore the relationship between miR-145 and ADP ribosylation factor 6 (Arf6) in regulating macrophage-mediated inflammation. METHODS: THP-1 cells were induced by 160 nM of phorbol 12-myristate 13-acetate (PMA) for 48 h to differentiate to macrophages and then were treated with LPS (100 ng/ml) for 8 h to simulate chronic metabolic inflammation in vitro. Dual-luciferase reporter assay was performed. MiR-145 siRNA and LV-ARF6-RNAi were used to up or down regulate miR-145 and Arf6 expression in THP-1 cells, respectively. Omental adipose tissue from patients in surgical ward were collected to detect the expression of miR-145, Arf6 and production of proinflammatory cytokines. Patients were divided into three groups according to their body mass index and history of diabetes. RESULTS: Dual-luciferase reporter assays showed the direct down-regulation of Arf6 by miR-145. Forty-eight-hour-transfection of miR-145 inhibitor resulted in significant increase of Arf6, IL-1beta, TNF-alpha and IL-6 as well as phosphorylation of p65 in NF-kappaB pathway in THP-1 cells, which, inversely, were reversed by overexpressing miR-145. In addition, down-regulation of Arf6 in macrophages reduced expression and secretion of cytokines. Expression of miR-145 was found to be attenuated in the omental adipose tissue of obese patients and diabetics with greater Arf6 expression, confirming the role of miR-145 in regulating macrophage-mediated inflammation targeting Arf6. CONCLUSIONS: By means of reducing the expression of Arf6 and subsequent signal transduction via NF-kappaB, miR-145 plays a role in inhibiting the secretion of inflammatory factors and then improving the inflammatory status. MiR-145 might be one of the candidates for anti-inflammatory treatment for metabolic diseases.