Hypoxia-induced acute lung injury is aggravated in Streptozotocin diabetic mice

Atractylenolide-I Alleviates Hyperglycemia-Induced Heart Developmental Malformations through Direct and Indirect Modulation of the STAT3 Pathway

BACKGROUND

Gestational diabetes could elevate the risk of congenital heart defects (CHD) in infants, and effective preventive and therapeutic medications are currently lacking. Atractylenolide-I (AT-I) is the active ingredient of Atractylodes Macrocephala Koidz (known as Baizhu in China), which is a traditional pregnancy-supporting Chinese herb.

PURPOSE

In this study, we investigated the protective effect of AT-I on the development of CHD in embryos exposed to high glucose (HG).

STUDY DESIGN AND METHODS

First, systematic review search results revealed associations between gestational diabetes mellitus (GDM) and cardiovascular malformations. Subsequently, a second systematic review indicated that heart malformations were consistently associated with oxidative stress and cell apoptosis. We assessed the cytotoxic impacts of Atractylenolide compounds (AT-I, AT-II, and AT-III) on H9c2 cells and chick embryos, determining an optimal concentration of AT-I for further investigation. Second, immunofluorescence, western blot, Polymerase Chain Reaction (PCR), and flow cytometry were utilized to delve into the mechanisms through which AT-I mitigates oxidative stress and apoptosis in cardiac cells. Molecular docking was employed to investigate whether AT-I exerts cardioprotective effects via the STAT3 pathway. Then, we developed a streptozotocin-induced diabetes mellitus (PGDM) mouse model to evaluate AT-I's protective efficacy in mammals. Finally, we explored how AT-I protects hyperglycemia-induced abnormal fetal heart development through microbiota analysis and untargeted metabolomics analysis.

RESULTS

The study showed the protective effect of AT-I on embryonic development using a chick embryo model which rescued the increase in the reactive oxygen species (ROS) and decrease in cell survival induced by HG. We also provided evidence suggesting that AT-I might directly interact with STAT3, inhibiting its phosphorylation. Further, in the PGDM mouse model, we observed that AT-I not only partially alleviated PGDM-related blood glucose issues and complications but also mitigated hyperglycemia-induced abnormal fetal heart development in pregnant mice. This effect is hypothesized to be mediated through alterations in gut microbiota composition. We proposed that dysregulation in microbiota metabolism could influence the downstream STAT3 signaling pathway via EGFR, consequently impacting cardiac development and formation.

CONCLUSIONS

This study marks the first documented instance of AT-I's effectiveness in reducing the risk of early cardiac developmental anomalies in fetuses affected by gestational diabetes. AT-I achieves this by inhibiting the STAT3 pathway activated by ROS during gestational diabetes, significantly reducing the risk of fetal cardiac abnormalities. Notably, AT-I also indirectly safeguards normal fetal cardiac development by influencing the maternal gut microbiota and suppressing the EGFR/STAT3 pathway.

The involvement of oxidative stress and the TLR4/NF-κB/NLRP3 pathway in acute lung injury induced by high-altitude hypoxia

OBJECTIVE

This study investigated the effect of oxidative stress and the TLR4/NF-κB/NLRP3 pathway on the pathogenesis of acute lung injury (ALI) induced by high-altitude hypoxia.

METHODS

Rats were placed in an animal hyperbaric oxygen chamber to establish a rat model of ALI induced by high-altitude hypoxia after treatment with N-acetylcysteine (NAC; a reactive oxygen species [ROS] inhibitor) or/and MCC950 (an NLPR3 inflammasome inhibitor). After modeling, the wet-to-dry weight ratio (W/D) of rat lung tissues was calculated. In lung tissues, ROS levels were detected with immunofluorescence, the enzyme activity was tested with the kit, and the expression of TLR4/NF-κB/NLRP3 pathway-related genes and proteins was measured with western blotting and qRT-PCR. The levels of inflammatory factors in the serum were quantified with ELISA.

RESULTS

After modeling, rats showed significantly increased W/D, ROS levels, and Malondialdehyde (MDA) concentrations and markedly diminished Superoxide dismutase (SOD) and Glutathione (GSH) concentrations in lung tissues (all P < 0.01), accompanied by substantially enhanced serum levels of TNF-α, IL-6, and IL-1β, significantly reduced serum levels of IL-10, and remarkably augmented TLR4, NLRP3, p-NF-κB p65, NF-κB p65 mRNA, and Caspase-1 expression in lung tissues (all P < 0.01). Furthermore, treatment with NAC or MCC950 alone or in combination prominently lowered the W/D of lung tissues (P < 0.01), serum levels of TNF-α (P < 0.05), IL-6 (P < 0.05), and IL-1β (P < 0.01), and NF-κB p65 expression and phosphorylation (P < 0.05, P < 0.01) while significantly increasing SOD and GSH concentrations (P < 0.05, P < 0.01) and serum levels of IL-10 (P < 0.01) in modeled rats. Meanwhile, treatment of NAC alone or combined with MCC950 significantly reduced MDA concentration and ROS levels (P < 0.05, P < 0.01) in modeled rats, and treatment of MCC950 alone or combined with NAC considerably declined TLR4, NLRP3, and Caspase-1 expression in modeled rats (P < 0.05, P < 0.01).

CONCLUSION

Inhibition of oxidative stress and the TLR4/NF-κB/NLRP3 pathway can ameliorate ALI in rats exposed to high-altitude hypoxia.

Montelukast Influence on Lung in Experimental Diabetes

Background and Objectives: The influence of montelukast (MK), an antagonist of cysLT1 leukotriene receptors, on lung lesions caused by experimental diabetes was studied. Materials and Methods: The study was conducted on four groups of six adult male Wistar rats. Diabetes was produced by administration of streptozotocin 65 mg/kg ip. in a single dose. Before the administration of streptozotocin, after 72 h, and after 8 weeks, the serum values of glucose, SOD, MDA, and total antioxidant capacity (TAS) were determined. After 8 weeks, the animals were anesthetized and sacrificed, and the lungs were harvested and examined by optical microscopy. Pulmonary fibrosis, the extent of lung lesions, and the lung wet-weight/dry-weight ratio were evaluated. Results: The obtained results showed that MK significantly reduced pulmonary fibrosis (3.34 ± 0.41 in the STZ group vs. 1.73 ± 0.24 in the STZ+MK group p < 0.01) and lung lesion scores and also decreased the lung wet-weight/dry-weight (W/D) ratio. SOD and TAS values increased significantly when MK was administered to animals with diabetes (77.2 ± 11 U/mL in the STZ group vs. 95.7 ± 13.3 U/mL in the STZ+MK group, p < 0.05, and 25.52 ± 2.09 Trolox units in the STZ group vs. 33.29 ± 1.64 Trolox units in the STZ+MK group, respectively, p < 0.01), and MDA values decreased. MK administered alone did not significantly alter any of these parameters in normal animals. Conclusions: The obtained data showed that by blocking the action of peptide leukotrienes on cysLT1 receptors, montelukast significantly reduced the lung lesions caused by diabetes. The involvement of these leukotrienes in the pathogenesis of fibrosis and other lung diabetic lesions was also demonstrated.

Persistent Hyperglycemia Worsens the Oleic Acid Induced Acute Lung Injury in Rat Model of Type II Diabetes Mellitus

Aim

This research aimed to study the impacts of persistent hyperglycemia on oleic acid (OA)-induced acute lung injury (ALI) in a rat model of type II diabetes mellitus.

Materials and Methods

Healthy adult male albino rats that weigh 150 to 180 g were divided into four groups (n = 6). Group I-saline (75 μL i.v.) was injected and served as a control; group II-OA (75 μL i.v.) was injected to induce ALI. Group III-pretreated with a high-fat diet and streptozotocin (35 mg/kg), was injected with saline, and served as a control for group IV. Group IV was pretreated with a high-fat diet, and streptozotocin (35 mg/kg) was injected with OA (75 μL i.v). Urethane was used to anesthetize the animal. The jugular venous cannulation was done for drug/saline administration, carotid artery cannulation was done to record blood pressure, and the tracheal cannulation was done to maintain the respiratory tract's patent. Heart rate, mean arterial pressure, and respiratory frequency were recorded on a computerized chart recorder; an arterial blood sample was collected to measure PaO2/FiO2. Additionally, the pulmonary water content and lung histology were examined.

Result

Hyperglycemic rats showed no significant change in the cardio-respiratory parameter. Histology of the lungs shows fibroblastic proliferation; however, rats survived throughout the observation period. There was an early deterioration of all the cardio-respiratory parameters in hyperglycemic rats when induced ALI (OA- induced), and survival time was significantly less compared to nonhyperglycemic rats.

Conclusion

Persistent hyperglycemia may cause morphological changes in the lungs, which worsens the outcome of acute lung injury.

Effects of aerobic exercise on lipopolysaccharide-induced experimental acute lung injury in the animal model of type 1 diabetes mellitus

NEW FINDINGS

What is the central question of this study? We evaluated the effects of diabetes and exercise on lipopolysaccharide-induced acute lung injury. By providing a comprehensive analysis of redox status, blood gases and histological parameters, we aimed to contribute to the ongoing debate in the literature. What are the main findings and its importance? We demonstrated the preventive effect of exercise, but diabetes did not alter the severity of acute lung injury.

ABSTRACT

Acute lung injury (ALI) is a life-threatening respiratory condition. Diabetes (DM) is a metabolic disease characterized by hyperglycaemia. There is an ongoing debate concerning whether there is a protective effect of diabetes in ALI. Exercise is a special type of physical activity that has numerous beneficial effects. The aim of our study was to investigate the effects of diabetes and exercise on the prognosis of ALI. Male Wistar albino rats were divided into two groups (sedentary and exercise). Both groups were divided into four subgroups: Control, ALI, DM, DM+ALI (n = 6 each). Diabetes was induced by injection of streptozotocin (50 mg/kg i.p.). The maximal exercise capacity was determined with the incremental load test. Animals were exercised on a treadmill for 45 min at 70% of maximal exercise capacity, 5 days a week for 12 weeks. Acute lung injury was induced by intratracheal injection of lipopolysaccharide (100 μg/100 g body weight) 24 h before the end of the experiment. We performed arterial blood gas analysis. Redox status was measured in both plasma and lung tissue. Malondialdehyde and 8-hydroxy-2'-deoxyguanosine levels were measured in lung tissue. Lung tissue was evaluated histologically. Acute lung injury caused significant damage in the lung tissue, which was verified histologically, with an increase in oxidative stress parameters. Exercise prevented the lung damage induced by ALI and reduced oxidative stress in the lung tissue. Diabetes did not alter the magnitude of damage done by ALI. Exercise showed a protective effect against DM and ALI in rats. The effect of DM was insignificant for the prognosis of ALI.

Exercise training ameliorates early diabetic kidney injury by regulating the H2 S/SIRT1/p53 pathway

Exercise training exerts protective effects against diabetic nephropathy. This study aimed to investigate whether exercise training could attenuate diabetic renal injury via regulating endogenous hydrogen sulfide (H₂ S) production. First, C57BL/6 mice were allocated into the control, diabetes, exercise, and diabetes + exercise groups. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ). Treadmill exercise continued for four weeks. Second, mice was allocated into the control, diabetes, H₂ S and diabetes + H₂ S groups. H₂ S donor sodium hydrosulfide (NaHS) was intraperitoneally injected once daily for four weeks. STZ-induced diabetic mice exhibited glomerular hypertrophy, tissue fibrosis and increased urine albumin levels, urine protein- and albumin-to-creatinine ratios, which were relieved by exercise training. Diabetic renal injury was associated with apoptotic cell death, as evidenced by the enhanced caspase-3 activity, the increased TdT-mediated dUTP nick-end labeling -positive cells and the reduced expression of anti-apoptotic proteins, all of which were attenuated by exercise training. Exercise training enhanced renal sirtuin 1 (SIRT1) expression in diabetic mice, accompanied by an inhibition of the p53-#ediated pro-apoptotic pathway. Furthermore, exercise training restored the STZ-mediated downregulation of cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) and the reduced renal H₂ S production. NaHS treatment restored SIRT1 expression, inhibited the p53-mediated pro-apoptotic pathway and attenuated diabetes-associated apoptosis and renal injury. In high glucose-treated MPC5 podocytes, NaHS treatment inhibited the p53-mediated pro-apoptotic pathway and podocyte apoptosis in a SIRT1-dependent manner. Collectively, exercise training upregulated CBS/CSE expression and enhanced the endogenous H₂ S production in renal tissues, thereby contributing to the modulation of the SIRT1/p53 apoptosis pathway and improvement of diabetic nephropathy.

Gut-Lung Dysbiosis Accompanied by Diabetes Mellitus Leads to Pulmonary Fibrotic Change through the NF-κB Signaling Pathway

Growing evidence shows that the lungs are an unavoidable target organ of diabetic complications. However, the pathologic mechanisms of diabetic lung injury are still controversial. This study demonstrated the dysbiosis of the gut and lung microbiome, pulmonary alveolar wall thickening, and fibrotic change in streptozotocin-induced diabetic mice and antibiotic-induced gut dysbiosis mice compared with controls. In both animal models, the NF-κB signaling pathway was activated in the lungs. Enhanced pulmonary alveolar well thickening and fibrotic change appeared in the lungs of transgenic mice expressing a constitutively active NF-κB mutant compared with wild type. When lincomycin hydrochloride-induced gut dysbiosis was ameliorated by fecal microbiota transplant, enhanced inflammatory response in the intestine and pulmonary fibrotic change in the lungs were significantly decreased compared with lincomycin hydrochloride-treated mice. Furthermore, the application of fecal microbiota transplant and baicalin could also redress the microbial dysbiosis of the gut and lungs in streptozotocin-induced diabetic mice. Taken together, these data suggest that multiple as yet undefined factors related to microbial dysbiosis of gut and lungs cause pulmonary fibrogenesis associated with diabetes mellitus through an NF-κB signaling pathway.

A novel role of kallikrein-related peptidase 8 in the pathogenesis of diabetic cardiac fibrosis

Rationale: Among all the diabetic complications, diabetic cardiomyopathy, which is characterized by myocyte loss and myocardial fibrosis, is the leading cause of mortality and morbidity in diabetic patients. Tissue kallikrein-related peptidases (KLKs) are secreted serine proteases, that have distinct and overlapping roles in the pathogenesis of cardiovascular diseases. However, whether KLKs are involved in the development of diabetic cardiomyopathy remains unknown.The present study aimed to determine the role of a specific KLK in the initiation of endothelial-to-mesenchymal transition (EndMT) during the pathogenesis of diabetic cardiomyopathy.

Methods and Results-By screening gene expression profiles of KLKs, it was found that KLK8 was highly induced in the myocardium of mice with streptozotocin-induced diabetes. KLK8 deficiency attenuated diabetic cardiac fibrosis, and rescued the impaired cardiac function in diabetic mice. Small interfering RNA (siRNA)-mediated KLK8 knockdown significantly attenuated high glucose-induced endothelial damage and EndMT in human coronary artery endothelial cells (HCAECs). Diabetes-induced endothelial injury and cardiac EndMT were significantly alleviated in KLK8-deficient mice. In addition, transgenic overexpression of KLK8 led to interstitial and perivascular cardiac fibrosis, endothelial injury and EndMT in the heart. Adenovirus-mediated overexpression of KLK8 (Ad-KLK8) resulted in increases in endothelial cell damage, permeability and transforming growth factor (TGF)-β1 release in HCAECs. KLK8 overexpression also induced EndMT in HCAECs, which was alleviated by a TGF-β1-neutralizing antibody. A specificity protein-1 (Sp-1) consensus site was identified in the human KLK8 promoter and was found to mediate the high glucose-induced KLK8 expression. Mechanistically, it was identified that the vascular endothelial (VE)-cadherin/plakoglobin complex may associate with KLK8 in HCAECs. KLK8 cleaved the VE-cadherin extracellular domain, thus promoting plakoglobin nuclear translocation. Plakoglobin was required for KLK8-induced EndMT by cooperating with p53. KLK8 overexpression led to plakoglobin-dependent association of p53 with hypoxia inducible factor (HIF)-1α, which further enhanced the transactivation effect of HIF-1α on the TGF-β1 promoter. KLK8 also induced the binding of p53 with Smad3, subsequently promoting pro-EndMT reprogramming via the TGF-β1/Smad signaling pathway in HCAECs. The in vitro and in vivo findings further demonstrated that high glucose may promote plakoglobin-dependent cooperation of p53 with HIF-1α and Smad3, subsequently increasing the expression of TGF-β1 and the pro-EndMT target genes of the TGF-β1/Smad signaling pathway in a KLK8-dependent manner.

Conclusions: The present findings uncovered a novel pro-EndMT mechanism during the pathogenesis of diabetic cardiac fibrosis via the upregulation of KLK8, and may contribute to the development of future KLK8-based therapeutic strategies for diabetic cardiomyopathy.

The Role of Oxymatrine in Amelioration of Acute Lung Injury Subjected to Myocardial I/R by Inhibiting Endoplasmic Reticulum Stress in Diabetic Rats

Background

Oxymatrine (OMT) is the primary pharmacological component of Sophora flavescens Aiton., which has been shown to possess potent antifibrotic, antioxidant, and anti-inflammatory activities. The aim of the present study was to clarify the protective mechanism of OMT on acute lung injury (ALI) subjected to myocardial ischemia/reperfusion (I/R).

Methods

A myocardial I/R-induced ALI model was achieved in diabetic rats by occluding the left anterior descending coronary artery for 1 h, followed by reperfusion for 1 h. The levels of inflammatory factors (tumor necrosis factor-α, interleukin- (IL-) 6, and IL-17) in bronchoalveolar lavage fluid were assessed using commercially available kits. The index of myocardial injury, including the detection of cardiac troponin I (cTnI), cardiac troponin T (cTnT), lactate dehydrogenase (LDH), and creatine kinase-MB (CK-MB), was also determined using commercially available kits. Hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling were used to identify histological changes. The expression levels of endoplasmic reticulum chaperone BiP (GRP78), DNA damage-inducible transcript 3 protein (CHOP), eukaryotic translation initiation factor 2-alpha kinase 3 (PERK), inositol dependent enzyme 1α (IRE1α), ATF6, caspase-3, -9, and-12, Bcl-2, and Bax were determined by Western blotting. The mRNA expression levels of GRP78 and CHOP were detected by reverse transcription-quantitative PCR.

Results

Myocardial I/R increased the levels of cTnI, cTnT, LDH, and CK-MB in diabetic rats. Damaged and irregularly arranged myocardial cells were also observed, as well as more serious ALI with higher lung injury scores and WET/DRY ratios and lower PaO₂. Moreover, the expression of key proteins of endoplasmic reticulum stress (ERS) was increased by I/R injury, including phosphorylated- (p-) PERK, p-IRE1ɑ, and ATF6, as well as decreased levels of apoptosis. These effects were all significantly reversed by OMT treatment.

Conclusions

OMT protects against ALI subjected to myocardial I/R by inhibiting ERS in diabetic rats.

NLRP3 inflammasome-dependent pyroptosis and apoptosis in hippocampus neurons mediates depressive-like behavior in diabetic mice

A relatively large number of diabetic patients risk complications of clinical depression that lead to poorer quality of life, however the precise mechanisms for diabetes-associated depression are not fully understood. Links between hyperglycemia-induced oxidative stress and NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome activation have been reported in the pathogenesis of diabetes. The present study aimed to elucidate the contribution of NLRP3-mediated apoptotic/pyroptotic neuronal cell death to diabetes-associated depression. We found that depressive-like behavior in streptozotocin (STZ)-induced diabetic mice was associated with hippocampal NLRP3 inflammasome activation. Hyperglycemia increased reactive oxygen species (ROS) production, thus leading to NLRP3 inflammasome activation in hippocampal neurons. It was found that STZ treatment induced apoptotic and pyroptotic cell death in the hippocampus as evidenced by increases of cleaved caspase 3 positive hippocampal neurons, TUNEL-positive cells, protein levels of p53, Bax, Puma, and the cleaved GSDMD N-terminal fragment, all of which were decreased in NLRP3 deficient mice. Using murine hippocampal neuronal cell line HT22, we found that high glucose induced apoptotic and pyroptotic cell death in a NLRP3 inflammasome-dependent manner in vitro. In addition, NLRP3 deficiency alleviated depressive-like behavior in STZ-induced diabetic mice. Our results suggest that hyperglycemia results in apoptosis and pyroptosis of hippocampal neuron cells in a NLRP3-dependent manner, which was associated with the depressive phenotypes evoked by STZ-induced diabetes. The study identifies a novel function of NLRP3 activation in high glucose-induced neuronal cell death, which sheds further light on the pathogenesis and new therapeutic targets of diabetes-associated depression.

Expression and regulation of tumor necrosis factor-α-induced protein-8-like 2 is associated with acute lung injury induced by myocardial ischemia reperfusion in diabetic rats

AIMS

The purpose of the present study was to investigate the possible role of TIPE2 on acute lung injury (ALI) induced by myocardial ischemia/reperfusion (MIR) in diabetic rats.

METHODS

Sprague-Dawley (SD) rats were randomly separated into four groups: control+sham (C + sham); control+MIR (C + MIR); diabetes+sham (D + sham); diabetes+MIR (D + MIR). Diabetes was induced using streptozotocin. Eight weeks after diabetes induction, MIR was conducted. At 2 h after MIR, myocardial injury indices were assessed; arterial blood, bronchoalveolar lavage fluid (BALF) and lung tissues were collected for corresponding detection.

RESULTS

Rats subjected to MIR showed serious ALI (estimated via pathological changes, lung injury score and Wet/Dry weight ratio), lung inflammation and pulmonary cell apoptosis compared with sham groups, especially in D + MIR group. Evaluation of protein expression in lung tissues showed that p-JNK and nuclear NF-κB p65 protein levels were higher in D + MIR group as compared with C + MIR group. Besides, either hyperglycemia or MIR can significantly upregulate TIPE2 protein levels.

CONCLUSIONS

In conclusion, diabetic lungs are more susceptible to MIR. TIPE2 may involve in this pathological process, possibly through regulation of inflammation, oxidative stress and apoptosis.

Hypoxic pulmonary vasoconstriction is lacking in rats with type 1 diabetes

Hypoxic pulmonary vasoconstriction (HPV) is the most important feature of intact lung circulation that matches local blood perfusion to ventilation. The main goal of this work was to study the effects of diabetes on the development of HPV in rats. The experimental design comprised diabetes mellitus induction by streptozotocin, video-morphometric measurements of the lumen area of intrapulmonary arteries (iPAs) using perfused lung tissue slices and patch-clamp techniques. It was shown that iPA lumen size was significantly reduced under physical and chemical hypoxia (7-10 mm Hg) in normal iPA, but, on the contrary, it clearly increased in diabetic lung slices. The amplitude of the outward K⁺ current in diabetic iPAs smooth muscle cells (SMCs) was two-fold greater than that seen in healthy cells. Chemical hypoxia led to significant decrease in the amplitude of the K⁺ outward current in healthy iPA SMCs while it was without effect in diabetic cells. The data obtained clearly indicate a significant dysregulation of vascular tone in pulmonary circulation under diabetes, ie diabetes damages the adaptive mechanism for regulating blood flow from poorly ventilated to better ventilated regions of the lung under hypoxia. This effect could be clinically important for patients with diabetes who have acute or chronic lung diseases associated with the lack of blood oxygenation.

The Roles of Autophagy in Acute Lung Injury Induced by Myocardial Ischemia Reperfusion in Diabetic Rats

Patients with diabetes are vulnerable to myocardial ischemia reperfusion (IR) injury, which may also induce acute lung injury (ALI) due to overaccumulation of reactive oxygen species (ROS) and inflammation cytokine in circulation. Despite autophagy plays a significant role in diabetes and pulmonary IR injury, the role of autophagy in ALI secondary to myocardial IR in diabetes remains largely elusive. We aimed to investigate pulmonary autophagy status and its roles in oxidative stress and inflammation reaction in lung tissues from diabetic rats subjected to myocardial IR. Control or diabetic rats were either treated with or without autophagy inducer rapamycin (Rap) or autophagy inhibitor 3-methyladenine (3-MA) before myocardial IR, which was achieved by occluding the left anterior descending coronary artery for 30 min and followed by reperfusion for 120 min. Diabetic rats subjected to myocardial IR showed more serious ALI with higher lung injury score and WET/DRY ratio and lower PaO₂ as compared with control rats, accompanied with impaired autophagy indicated by reduced LC-3II/LC-3I ratio and Beclin-1 expression, decreased superoxide dismutase (SOD) activity, and increased 15-F2t-Isoprostane formation in lung tissues, as well as increased levels of leukocyte count and proinflammatory cytokines in BAL fluid. Improving autophagy with Rap significantly attenuated all these changes, but the autophagy inhibitor 3-MA exhibited adverse or opposite effects as Rap. In conclusion, diabetic lungs are more vulnerable to myocardial IR, which are involved in impaired autophagy. Improving autophagy could attenuate ALI induced by myocardial IR in diabetic rats, possibly through inhibiting inflammatory reaction and oxidative stress.

Nuciferine downregulates Per-Arnt-Sim kinase expression during its alleviation of lipogenesis and inflammation on oleic acid-induced hepatic steatosis in HepG2 cells

Non-alcoholic fatty liver disease (NAFLD) is a prevalent liver disease associated with lipotoxicity, lipid peroxidation, oxidative stress, and inflammation. Nuciferine, an active ingredient extracted from the natural lotus leaf, has been reported to be effective for the prevention and treatment of NAFLD. Per-Arnt-Sim kinase (PASK) is a nutrient responsive protein kinase that regulates lipid and glucose metabolism, mitochondrial respiration, and gene expression. The aim of the present study was to investigate the protective effect of nuciferine against NAFLD and its inhibitory effect on PASK, exploring the possible underlying mechanism of nuciferine-mediated inhibition on NAFLD. Relevant biochemical parameters (lipid accumulation, extent of oxidative stress and release of inflammation cytokines) in oleic acid (OA)-induced HepG₂ cells that mimicked steatosis in vitro were measured and compared with the control. It was found that nuciferine and silenced-PASK (siRNA PASK) both inhibited triglyceride (TG) accumulation and was effective in decreasing fatty acid (FFAs). The content of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) were increased respectively by nuciferine and siRNA PASK without increase in glutathione (GSH). Malondialdehyde (MDA) was decreased respectively by nuciferine and siRNA PASK. In addition, nuciferine decreased TNF-a, IL-6 and IL-8 as well as the siRNA PASK group. IL-10 was increased by nuciferine and siRNA PASK respectively. Further investigation revealed that nuciferine and siRNA PASK could respectively regulate the expression of target genes involved in lipogenesis and inflammation, suggesting that nuciferine may be a potential therapeutic treatment for NAFLD. Furthermore, the modulated effect of nuciferine on (OA)-induced HepG₂ cells lipogenesis and inflammation, which was accompanied with PASK inhibition, was also consistent with siRNA PASK, implying that PASK might play a role in nuciferine-mediated regulation on NAFLD.