Ethanol at low concentration attenuates diabetes induced lung injury in rats model

TLR4 mediates glucolipotoxicity-induced mitochondrial dysfunction in osteoblasts by enhancing NLRP3-MAVS expression and interaction

Mitochondrial dysfunction is a critical mechanism underlying diabetic bone loss, which is driven by the inhibition of osteoblast differentiation due to glucolipotoxicity. The molecular mechanisms through which glucolipotoxicity induces mitochondrial dysfunction remain poorly understood. In this study, we observed an upregulation of Toll-like receptor 4 (TLR4) expression in osteoblasts subjected to glycolipotoxic conditions, which was associated with mitochondrial dysfunction. Proteomic analysis revealed that TLR4 plays a crucial role in glucolipotoxicity and is closely linked to mitochondrial function in osteoblasts. Knockdown of TLR4 was found to alleviate osteoblast differentiation disorders and mitochondrial dysfunction as well as mitochondria-mediated apoptosis induced by glucolipotoxicity. In contrast, overexpression of TLR4 exacerbated the detrimental effects of glucolipotoxicity. Mechanistically, glucolipotoxicity activates TLR4, resulting in increased expression of NLRP3 (NOD-like receptor protein 3) and MAVS (Mitochondrial antiviral signaling protein), which promotes the interaction between NLRP3 and MAVS. This cascade leads to increased intracellular reactive oxygen species, decreased ATP levels, elevated expression of Caspase-1, GSDMD, Bax, and reduced expression of the anti-apoptotic protein Bcl-2. Furthermore, TLR4 knockout was shown to mitigate bone loss in diabetic rats. Proteomic analysis revealed that the improvement in the expression of proteins related to mitochondrial function and osteogenic function in diabetic rats is associated with TLR4 knockout. Diabetic osteoporosis may be associated with increased TLR4 expression and disturbed oxidative phosphorylation. In conclusion, glucolipotoxicity activates TLR4, which subsequently induces the expression and interaction of NLRP3-MAVS, leading to mitochondrial dysfunction and inhibition of osteoblast differentiation. This process contributes to bone mass loss in diabetes.

Total flavonoids of Selaginella tamariscina (P. Beauv.) Spring ameliorates diabetes-induced acute lung injury via activating Nrf2/HO-1

Objectives

This investigation explored the mechanism by which the total flavonoids of Selaginella tamariscina (P.Beauv.) Spring (TFST) mitigate oxidative stress through the activation of the heme oxygenase-1 (HO-1) signaling pathway mediated by nuclear factor erythroid 2-related factor 2 (Nrf2), thereby ameliorating acute lung injury (ALI) induced by diabetes.

Materials and Methods

Male mice weighing 20-25 grams were divided into four groups: a control group, a diabetic group, a diabetic group treated with TFST, and a diabetic group treated with TFST and ML385. Various biological specimens were collected for analysis, including bronchoalveolar lavage fluid (BALF), blood, and tissue samples. These were subjected to a range of assessments covering hematological and BALF parameters tumor necrosis factor-alpha (TNF-α), interleukin-6 [IL-6]), biochemical markers (malondialdehyde [MDA], superoxide dismutase [SOD], glutathione peroxidase [GSH], Nrf2, and HO-1 levels), along with histopathological evaluations.

Results

Pre-treatment with TFST demonstrated a significant decrease in pulmonary tissue damage, evidenced by decreased wet-to-dry (W/D) lung ratios (P<0.001), reduced lung injury scores (P<0.0001), and lower levels of TNF-α, IL-6 (P<0.0001), as well as oxidative stress markers like MDA (P<0.05). Moreover, there was an elevation in the activity of anti-oxidative enzymes, specifically SOD and GSH (P<0.05), coupled with an enhanced expression of Nrf2 and HO-1 in the diabetic group (P<0.01).

Conclusion

The study findings demonstrate that TFST can suppress oxidative stress by modulating the Nrf2 pathway and up-regulating HO-1 activity, thereby ameliorating diabetes-induced acute lung injury.

Oleanolic acid and moderate drinking increase the pancreatic GLP-1R expression of the β-cell mass deficiency induced hyperglycemia

Background

Oleanolic acid (OA) and moderate drinking have been reported to attenuate diabetes. However, the underlying mechanism of OA and moderate drinking alone or in combination on the islet β-cell deficiency induced diabetes is not fully elucidated.

Methods

Male Sprague Dawley (SD) rats were intraperitoneally injected with 55 mg/kg streptozotocin (STZ) to induce β-cell deficiency. OA, 5% ethanol (EtOH), or a mixture of OA in 5% ethanol (OA+EtOH) were applied to three treatment groups of hyperglycemia rats for 6 weeks.

Results

STZ caused the increase of fast blood glucose (FBG) level.OA and EtOH treatment alone or in combination decreased the STZ increased FBG level during the 6 weeks of treatment. In addition, OA treatment also significantly increased the β-cell to total islet cell ratio. Both EtOH and OA+EtOH treatments promoted the increase of total islet cell number and α-cell to β-cell ratio when compared to OA group. STZ induced hyperglycemia dramatically reduced the glucagon-like peptide-1 receptor (GLP-1R) positive cells in islets, all the three treatments significantly increased the pancreatic GLP-1R positive cell number. In the meantime, STZ induced hyperglycemia suppressed the insulin mRNA expression and boosted the glucagon mRNA expression. EtOH and OA+EtOH treatments increased the insulin mRNA expression, but none of the 3 treatments altered the elevated glucagon level.

Conclusion

GLP-1R positive cell ratio in islets is crucial for the blood glucose level of diabetes. OA and 5% ethanol alone or in combination suppresses the blood glucose level of β-cell deficiency induced diabetes by increasing islet GLP-1R expression.

SARS-CoV-2 infection and diabetes: Pathophysiological mechanism of multi-system organ failure

Since the discovery of the coronavirus disease 2019 outbreak, a vast majority of studies have been carried out that confirmed the worst outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in people with preexisting health conditions, including diabetes, obesity, hypertension, cancer, and cardiovascular diseases. Likewise, diabetes itself is one of the leading causes of global public health concerns that impose a heavy global burden on public health as well as socio-economic development. Both diabetes and SARS-CoV-2 infection have their independent ability to induce the pathogenesis and severity of multi-system organ failure, while the co-existence of these two culprits can accelerate the rate of disease progression and magnify the severity of the disease. However, the exact pathophysiology of multi-system organ failure in diabetic patients after SARS-CoV-2 infection is still obscure. This review summarized the organ-specific possible molecular mechanisms of SARS-CoV-2 and diabetes-induced pathophysiology of several diseases of multiple organs, including the lungs, heart, kidneys, brain, eyes, gastrointestinal system, and bones, and sub-sequent manifestation of multi-system organ failure.

Type 2 Diabetes Induced by Changes in Proteomic Profiling of Zebrafish Chronically Exposed to a Mixture of Organochlorine Pesticides at Low Concentrations

Effect of organochlorine pesticides (OCPs) mixtures on development of type 2 diabetes mellitus (T2DM) and the underlying mechanism, especially at protein levels, are largely unknown. We exposed a mixture of five OCPs to zebrafish at concentrations of 0, 0.05, 0.25, 2.5, and 25 μg/L for 12 weeks. Differentially expressed proteins (DEPs) were quantitatively identified in female zebrafish livers, and its functional study was conducted. The significantly high glucose and low insulin levels were observed only at 0.05 μg/L, linking to the different pattern of DEPs than other concentrations. A total of 1082 proteins was quantified, of which 321 proteins formed 6 clusters in protein dynamics analysis. The enriched pathways in cluster 3 showing distinct pattern of DEPs could explain the nonlinear response at 0.05 μg/L, indicating that OCP mixtures adversely affected proteins associated with mitochondrial function and energy metabolism. We proposed a feasible mechanism that decrease in expression of aldehyde dehydrogenase led to abnormal accumulation of aldehydes, reducing expression of glyceraldehyde 3-phosphate dehydrogenase, and resulting in disruption of glucose homeostasis. Our findings help to better understand the causality of T2DM by exposure to OCP mixtures and to identify biomarkers in the protein expression level.

Pulmonary impairment in type 2 diabetic rats and its improvement by exercise

AIM

We aimed to evaluate whether the streptozotocin-induced diabetic model can generate lung functional, histological and biochemical impairments and whether moderate exercise can prevent these changes.

METHODS

Wistar rats were assigned to control (CTRL), exercise (EXE), diabetic (D) and diabetic with exercise (D+EXE) groups. We used the n5-STZ model of diabetes mellitus triggered by a single injection of streptozotocin (STZ, 120 mg/kg b.w., i.p.) in newborn rats on their 5th day of life. EXE and D+EXE rats were trained by running on a motorized treadmill, 5 days a week for 9 weeks. Blood glucose, body weight, food intake, exercise capacity, lung mechanics, morphology, and antioxidant enzymatic activity were analysed.

RESULTS

On the 14th week of life, diabetic rats exhibited a significant impairment in post-prandial glycaemia, glucose tolerance, body weight, food intake, lung function (tissue viscance, elastance, Newtonian resistance and hysteresis), morphological parameters, redox balance and exercise capacity. Physical training completely prevented the diabetes-induced alterations, except for those on fasting blood glucose, which nevertheless remained stable.

CONCLUSIONS

Mild diabetes in n5-STZ-treated rats jeopardized pulmonary mechanics, morphology and redox balance, which confirms the occurrence of diabetes-induced pneumopathy. Moreover, moderate exercise completely prevented all diabetes-induced respiratory alterations.

Fueling influenza and the immune response: Implications for metabolic reprogramming during influenza infection and immunometabolism

Recent studies support the notion that glycolysis and oxidative phosphorylation are rheostats in immune cells whose bioenergetics have functional outputs in terms of their biology. Specific intrinsic and extrinsic molecular factors function as molecular potentiometers to adjust and control glycolytic to respiratory power output. In many cases, these potentiometers are used by influenza viruses and immune cells to support pathogenesis and the host immune response, respectively. Influenza virus infects the respiratory tract, providing a specific environmental niche, while immune cells encounter variable nutrient concentrations as they migrate in response to infection. Immune cell subsets have distinct metabolic programs that adjust to meet energetic and biosynthetic requirements to support effector functions, differentiation, and longevity in their ever-changing microenvironments. This review details how influenza coopts the host cell for metabolic reprogramming and describes the overlap of these regulatory controls in immune cells whose function and fate are dictated by metabolism. These details are contextualized with emerging evidence of the consequences of influenza-induced changes in metabolic homeostasis on disease progression.

Effect of low-dose ethanol on NLRP3 inflammasome in diabetes-induced lung injury

To observe the changes in NLR family pyrin domain containing 3 (NLRP3) inflammasome in a rat model of diabetes-induced lung injury, and investigate the effect of low-dose ethanol on the production of NLRP3 inflammasome. The type I diabetic mellitus (DM) rat model was established, and the rats were divided into four groups: normal control group (CON group), low-dose ethanol group (EtOH group), diabetes group (DM group) and DM+EtOH group. The rats were fed for 6 and 12 weeks, respectively. The ratio of lung wet weight/body weight (lung/body coefficient) was calculated, and the changes of pulmonary morphology and fibrosis were observed by HE and Masson staining. The changes in pulmonary ultra-structure were examined by electron microscopy. The expressions of mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) and NLRP3 inflammasome key factors, NLRP3, ASC and caspase-1 proteins were detected by western blot. Compared with the CON group, the lung/body coefficient was increased (P<0.05), lung fibrosis occurred, ALDH2 protein expression was decreased, and NLRP3, ASC and caspase-1 protein expressions were increased in the DM rats (P<0.05). Compared with the DM group, the lung/body coefficient and fibrosis degree were decreased, ALDH2 protein expression was increased (P<0.05), and NLRP3, ASC and caspase-1 protein expressions were decreased in the DM+EtOH group (P<0.05). Hence, low-dose ethanol increased ALDH2 protein expression and alleviated diabetes-induced lung injury by inhibiting the production of NLRP3 inflammasome.

STAT3 and Nrf2 pathways modulate the protective effect of verapamil on lung injury of diabetic rats

OBJECTIVE

We aimed to assess the protective role of verapamil, L-type calcium channel blockers, against early lung damage in diabetic rats. Lung injury has recently been recognized as a consequent complication of diabetes mellitus. Hyperglycemia induces inflammatory changes in lung tissue early in the disease.

METHODS

Twenty four adult male rats were grouped into control, diabetic, diabetic treated with verapamil, and verapamil control. Streptozotocin (STZ) was used to induce diabetes. Oxidative parameters and antioxidative mechanisms were assessed in lung homogenate. Tumor necrosis factor alpha (TNFα) protein was measured as a pro-inflammatory mediator. Signal transducer and activator of transcription 3 (STAT3) gene expression and nuclear erythroid factor 2 (Nrf2) immunoexpression were screened.

RESULTS

The lung showed oxidative damage and inflammatory infiltration in STZ diabetic rats early at 2 weeks. The parameters significantly improved in lung tissue treated with verapamil. Histopathology of the lung tissue confirmed the results. Inhibition of STAT3/TNFα pathway was involved in the protection offered by verapamil. Activation of Nrf2 together with an increasing antioxidant capacity of diabetic lung significantly ameliorates the injury induced by diabetes.

CONCLUSIONS

Verapamil afforded protection in diabetic lung injury. The protection was mediated by the anti-inflammatory and antioxidant effects of verapamil.

Effects of Moderate Ethanol Consumption on Lipid Metabolism and Inflammation Through Regulation of Gene Expression in Rats

Aims

Epidemiological studies and experimental data from rodent models have reported a non-linear relationship between consumption of alcohol and cardiovascular disease (CVD) risk that suggests that light-to-moderate drinking as opposed to excessive consumption may provide some cardiovascular benefits. The present study examined potential mechanisms by which moderate alcohol consumption may provide a protective effect against CVD.

Short summary

Wistar rats exposed for 3 months to a 20% ethanol intermittent-access voluntary drinking paradigm displayed a reduction in epididymal fat, blood glucose and non-HDL and total cholesterol. These effects were accompanied by decreased expression of Hmgcr, Srebp-2, Cox-2 and RelA, indicating downregulation of genes involved in cholesterol synthesis and inflammation.

Methods

Twenty-four male Wistar rats voluntarily consumed a 20% v/v ethanol solution on alternate days for 13 weeks (ethanol-treated) or were given access to water alone (non-ethanol-exposed control).

Results

There was no difference in body weight gain between the two groups, however, epididymal fat weight was lower in ethanol-fed rats (P = 0.030). Blood glucose, total cholesterol, non-high-density lipoprotein (HDL) and oxidized low-density lipoprotein (LDL) levels were lower in the ethanol group compared to controls (P < 0.05). There was a significant reduction in the expression of hydroxymethylglutaryl-coenzyme A reductase and sterol regulatory element-binding protein-2 in ethanol-treated rats (P < 0.05), suggesting that ethanol may have lowered cholesterol levels via downregulation of genes involved in cholesterol synthesis. Paraoxonase-1, which is associated with inhibition of LDL cholesterol oxidation, was upregulated in the ethanol group (P = 0.029). Ethanol-treated rats exhibited significantly lower levels of high-mobility box group protein 1 (P ≤ 0.05). Cyclooxygenase-2 and RelA gene expression were significantly lower in ethanol-treated rats (P < 0.05), indicating possible anti-inflammatory effects.

Conclusions

These findings suggest that moderate ethanol consumption may potentially contribute to improved cardiovascular outcomes by reducing body fat, improving blood cholesterol and blood glucose, and modulation of gene expression involved in inflammation and/or cholesterol synthesis.

Inhibition of ALDH2 expression aggravates renal injury in a rat sepsis syndrome model

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is closely associated with organ injury. The aim of the present study was to investigate the change of ALDH2 expression in a rat model of sepsis-induced acute renal injury, and to observe the effect of ALDH2 inhibition on the kidney. A model of sepsis syndrome was established in Sprague-Dawley (SD) rats by cecal ligation and puncture (CLP). The rats were divided into sham, CLP and CLP + cyanamide (CYA, an ALDH2 inhibitor) groups. The hemodynamic parameters heart rate (HR) and mean arterial blood pressure (MABP) were measured. Plasma creatinine (CRE) and urea nitrogen (BUN) levels were measured using an automatic biochemical analyzer. Malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the kidney tissue were measured. Histological changes of the kidney tissue were observed using hematoxylin and eosin staining and NF-κB p65 expression was observed by an immunohistochemical staining method. The expression of renal ALDH2 at the mRNA and protein levels was detected by reverse transcription-polymerase chain reaction and western blotting. In the CLP compared with the sham group after 24 h, the MABP was decreased, plasma CRE and BUN levels were elevated, the renal MDA level was increased and SOD activity was decreased. In addition, glomerular atrophy occurred, the renal protein expression of NF-κB p65 was increased, and the mRNA and protein expression levels of ALDH2 were decreased. In contrast with the CLP group, in the CLP + CYA group, the MABP and ALDH2 expression were further decreased while glomerular atrophy was aggravated. Furthermore, CRE, BUN, MDA levels and NF-κB p65 expression were further increased and SOD activity was further reduced. In this rat model of sepsis syndrome, the reduction of renal ALDH2 expression was accompanied by kidney injury. Inhibition of ALDH2 with CYA aggravated the renal injury, and was associated with the overproduction of reactive oxygen species and inflammatory reaction.

Potential Biochemical Mechanisms of Lung Injury in Diabetes

Accumulating evidence has shown that the lung is one of the target organs for microangiopathy in patients with either type 1 or type 2 diabetes mellitus (DM). Diabetes is associated with physiological and structural abnormalities in the diabetic lung concurrent with attenuated lung function. Despite intensive investigations in recent years, the pathogenic mechanisms of diabetic lung injury remain largely elusive. In this review, we summarize currently postulated mechanisms of diabetic lung injury. We mainly focus on the pathogenesis of diabetic lung injury that implicates key pathways, including oxidative stress, non-enzymatic protein glycosylation, polyol pathway, NF-κB pathway, and protein kinase c pathway. We also highlight that while numerous studies have mainly focused on tissue or cell damage in the lung, studies focusing on mitochondrial dysfunction in the diabetic lung have remained sketchy. Hence, further understanding of mitochondrial mechanisms of diabetic lung injury should provide invaluable insights into future therapeutic approaches for diabetic lung injury.

Alcoholic Beverage Consumption and Chronic Diseases

Epidemiological and experimental studies have consistently linked alcoholic beverage consumption with the development of several chronic disorders, such as cancer, cardiovascular diseases, diabetes mellitus and obesity. The impact of drinking is usually dose-dependent, and light to moderate drinking tends to lower risks of certain diseases, while heavy drinking tends to increase the risks. Besides, other factors such as drinking frequency, genetic susceptibility, smoking, diet, and hormone status can modify the association. The amount of ethanol in alcoholic beverages is the determining factor in most cases, and beverage types could also make an influence. This review summarizes recent studies on alcoholic beverage consumption and several chronic diseases, trying to assess the effects of different drinking patterns, beverage types, interaction with other risk factors, and provide mechanistic explanations.

The Protective Effect of Low-Dose Ethanol on Myocardial Fibrosis through Downregulating the JNK Signaling Pathway in Diabetic Rats

Objective. To investigate the effects of low dose ethanol feeding in diabetic rats and analyze its underlying mechanisms. Methods. Male Sprague-Dawley rats were divided into 4 groups: control (Con), diabetes at 4 weeks (DM4W), diabetes at 8 weeks (DM8W), and EtOH + DM8W. After 8 weeks, hemodynamic parameters were recorded and heart weight/body weight (H/B) and hydroxyproline (Hp) content in myocardium were measured. Morphology of collagen in myocardial tissue was observed with Masson's trichrome staining method and collagen volume fraction (CVF) was analysed. The mRNA expression of ALDH2 was assessed with Real-Time PCR. The protein expressions of p-JNK and JNK were evaluated using western blot. Results. In contrast to Con group, there was no difference in hemodynamic parameters in DM4W group, but mean arterial pressure and heart rate were decreased in DM8W group, and the ratios of H/B, Hp, and CVF were markedly increased. ALDH2 mRNA expression was decreased, while the ratio of p-JNK/JNK were increased. Compared with DM8W group, the above indexes were improved in EtOH + DM8W group. Conclusion. With low dose ethanol intervention, enhanced ALDH2 expression can antagonize the happening of myocardial fibrosis in diabetic rats, which may be relevant with downregulating the JNK pathway.

Low Intensity Physical Exercise Attenuates Cardiac Remodeling and Myocardial Oxidative Stress and Dysfunction in Diabetic Rats

We evaluated the effects of a low intensity aerobic exercise protocol on cardiac remodeling and myocardial function in diabetic rats. Wistar rats were assigned into four groups: sedentary control (C-Sed), exercised control (C-Ex), sedentary diabetes (DM-Sed), and exercised diabetes (DM-Ex). Diabetes was induced by intraperitoneal injection of streptozotocin. Rats exercised for 9 weeks in treadmill at 11 m/min, 18 min/day. Myocardial function was evaluated in left ventricular (LV) papillary muscles and oxidative stress in LV tissue. Statistical analysis was given by ANOVA or Kruskal-Wallis. Echocardiogram showed diabetic groups with higher LV diastolic diameter-to-body weight ratio and lower posterior wall shortening velocity than controls. Left atrium diameter was lower in DM-Ex than DM-Sed (C-Sed: 5.73 ± 0.49; C-Ex: 5.67 ± 0.53; DM-Sed: 6.41 ± 0.54; DM-Ex: 5.81 ± 0.50 mm; P < 0.05 DM-Sed vs C-Sed and DM-Ex). Papillary muscle function was depressed in DM-Sed compared to C-Sed. Exercise attenuated this change in DM-Ex. Lipid hydroperoxide concentration was higher in DM-Sed than C-Sed and DM-Ex. Catalase and superoxide dismutase activities were lower in diabetics than controls and higher in DM-Ex than DM-Sed. Glutathione peroxidase activity was lower in DM-Sed than C-Sed and DM-Ex.

CONCLUSION

Low intensity exercise attenuates left atrium dilation and myocardial oxidative stress and dysfunction in type 1 diabetic rats.