Anti-Proliferative Effects of Lidocaine as an Autophagy Inducer in Bladder Cancer via Intravesical Instillation: In Vitro and Xenograft Mouse Model Experiments.

Lidocaine exerts potential anti-tumor effects on various cancer cell lines, and its intravesical instillation is considered safer than intravenous administration for bladder cancer. However, the mechanisms underlying its anti-tumor effects have not been fully elucidated. Here, we aimed to elucidate the anti-tumor molecular mechanisms of lidocaine in bladder cancer cells and a xenograft model to substantiate the efficacy of its intravesical administration. We investigated the anti-proliferative and autophagyinducing activities of lidocaine in Nara Bladder Tumor No. 2 (NBT-II) rat bladder carcinoma cells using cell viability, flow cytometry, a wound healing assay, and western blotting. We also established a xenograft mouse model of bladder cancer, and cancer growth was examined using in vivo bioluminescence imaging. Lidocaine decreased cell viability, induced G0/G1 phase cell cycle arrest, and inhibited cell migration partially via glycogen synthase kinase (GSK) 3ß phosphorylation. Moreover, a combination of lidocaine and SB216763 (a GSK3ß inhibitor) suppressed autophagy-related protein expression. Bafilomycin-A1 with lidocaine significantly enhanced microtubule-associated protein 1A/1B-light chain (LC3B) expression; however, it decreased LC3B expression in combination with 3-methyladenine compared to lidocaine alone. In the xenograft mouse model, the bladder cancer volume was reduced by lidocaine. Overall, lidocaine exerts anti-proliferative effects on bladder cancer via an autophagy-inducing mechanism.

Damage-associated molecular patterns as a mechanism of sevoflurane-induced neuroinflammation in neonatal rodents.

Background: General anesthesia is inevitable for pediatric patients undergoing surgery, though volatile anesthetic agents may cause neuroinflammation and neurodevelopmental impairment; however, the underlying pathophysiology remains unclear. We aimed to investigate the neuroinflammation mechanism in developing rat brains associated with sevoflurane exposure time, by identifying the specific damage-associated molecular patterns (DAMPs) pathway and evaluating the effects of non-steroidal anti-inflammatory drugs (NSAIDs) in alleviating neuroinflammation. Methods: A three-step experiment was conducted to investigate neuroinflammation induced by sevoflurane. First, the exposure time required for sevoflurane to cause neuroinflammation was determined. Next, the specific pathways of DAMPs involved in neuroinflammation by sevoflurane were identified. Finally, the effects of NSAIDs on sevoflurane-induced neuroinflammation were investigated. The expression of various molecules in the rat brain were assessed using immunohistochemistry (IHC), immunofluorescence (IF), quantitative real-time polymerase chain reaction (PCR), western blot analysis, and enzyme-linked immunosorbent assay (ELISA). Results: In total, 112 rats (aged 7 d) were used, of which six rats expired during the experiment (mortality rate, 5.3%). Expression of CD68, HMGB-1, galectin-3, TLR4, TLR9, and phosphorylated NF-κB was significantly increased upon 6 h of sevoflurane exposure. Conversely, transcriptional levels of TNF-α and IL-6 significantly increased and IFN-γ significantly decreased after 6 h of sevoflurane exposure. Co-administration of NSAIDs with sevoflurane anesthesia significantly attenuated TNF-α and IL-6 levels and restored IFN-γ levels. Conclusions: In conclusion, 6 h of sevoflurane exposure induces neuroinflammation through the DAMPs pathway, HMGB-1, and galectin-3. Co-administration of ibuprofen reduced sevoflurane-induced neuroinflammation.

Effect of high-dose vitamin C on renal ischemia-reperfusion injury.

Acute kidney injury frequently occurs after cardiac surgery, and is primarily attributed to renal ischemia-reperfusion (I/R) injury and inflammation from surgery and cardiopulmonary bypass. Vitamin C, an antioxidant that is often depleted in critically ill patients, could potentially mitigate I/R-induced oxidative stress at high doses. We investigated the effectiveness of high-dose vitamin C in preventing I/R-induced renal injury. The ideal time and optimal dosage for administration were determined in a two-phase experiment on Sprague-Dawley rats. The rats were assigned to four groups: sham, IRC (I/R + saline), and pre- and post-vitC (vitamin C before and after I/R, respectively), with vitamin C administered at 200 mg/kg. Additional groups were examined for dose modification based on the optimal timing determined: V100, V200, and V300 (100, 200, and 300 mg/kg, respectively). Renal I/R was achieved through 45 min of ischemia followed by 24 h of reperfusion. Vitamin C administration during reperfusion significantly reduced renal dysfunction and tubular damage, more than pre-ischemic administration. Doses of 100 and 200 mg/kg during reperfusion reduced oxidative stress markers, including myeloperoxidase and inflammatory responses by decreasing high mobility group box 1 release and nucleotide-binding and oligomerization domain-like receptor 3 inflammasome. Overall beneficial effect was most prominent with 200 mg/kg. The 300 mg/kg dose, however, showed no additional benefits over the IRC group regarding serum blood urea nitrogen and creatinine levels and histological evaluation. During reperfusion, high-dose vitamin C administration (200 mg/kg) significantly decreased renal I/R injury by effectively attenuating the major triggers of oxidative stress and inflammation.

Effects of dexmedetomidine on A549 non-small cell lung cancer growth in a clinically relevant surgical xenograft model.

The perioperative milieu following curative lung cancer surgery is accompanied by a stress response. Inflammasomes mediate inflammation resulting in the unfavorable immunomodulation of natural killer (NK) cell activity, thus promoting cancer progression. This study aimed to investigate the effects of dexmedetomidine (DEX) on the innate immune system, chronic inflammation, and lung cancer progression in a clinically relevant human-to-mouse xenograft model. The human lung cancer cell line A549-luc was subcutaneously injected into BALB/c nude mice. Saline or dexmedetomidine was administered for 2 weeks via an implanted osmotic minipump. After 4 weeks, the tumor size and weight were measured. NK cell activity, serum interferon-γ, interleukin (IL)-1ß and tumor necrosis factor (TNF)-α levels were also measured. IL-10, IL-18, and inflammasome expression levels were assessed in the tumor tissues. DEX caused a decrease in tumor size, tumor weight, and IL-1ß and TNF-α levels and an increase in NK cell activity and IFN-γ level. IL-10 and IL-18 expression was significantly decreased in the DEX-treated group. NLRP3, CTP1A, TXNIP, ASC, IL-1ß, and caspase-1 protein levels were decreased in the DEX-treated group. In conclusion, the use of DEX for 2 weeks inhibited lung cancer progression by suppressing inflammasome- and IL-1ß signaling-induced inflammation and enhancing NK cell activity.

Dexmedetomidine attenuates subarachnoid hemorrhage-induced acute lung injury through regulating autophagy and TLR/NFκB signaling pathway.

BACKGROUND: Acute lung injury (ALI) is the most serious complication of subarachnoid hemorrhage (SAH). We investigated role of autophagy and inflammatory signaling pathways in lung damage and therapeutic effects of dexmedetomidine (DEX). METHODS: Fifty male Wistar rats were randomly divided into five groups: sham, SAH, SAH+ DEX5, SAH+DEX25, and SAH+DEX50. SAH was induced using endovascular perforation technique. All rats received mechanical ventilation for 60 minutes. At 2 and 24 h of SAH induction, SAH+DEX groups were treated with 5, 25, and 50 µg/kg of DEX, respectively. Histological ALI score and pulmonary edema were assessed after 48 h. Lung expression of LC3B, ATG3, p62, TLR4, TLR9, and NFκB was assessed using western blotting and quantitative PCR. Blood levels of IL-6, IL-1ß, IFN-γ, and TNFα were also assessed. RESULTS: SAH induced ALI and pulmonary edema, which were attenuated in SAH+DEX5 (P < 0.001 for both) and SAH+DEX25 groups (P = 0.001 and P < 0.001 for ALI and edema, respectively). Lung expressions of LC3B and ATG3 were upregulated in SAH group, which was attenuated in SAH+DEX5 and SAH+DEX25 groups. Lung expressions of TLR4, TLR9, and NFκB were increased in SAH group, which was attenuated in SAH+DEX5 group. Blood IL-6 level was increased in SAH group and attenuated in SAH+DEX5 and SAH+DEX25 groups. Blood IFN-γ level was lower in SAH group than in sham group, and it was increased in SAH+DEX25 group. CONCLUSIONS: Low-dose DEX treatment after SAH may protect against ALI by disrupting pathological brain-lung crosstalk and alleviating autophagy flux and TLR-dependent inflammatory pathways.

Astrocytic urea cycle detoxifies Aß-derived ammonia while impairing memory in Alzheimer's disease.

Alzheimer's disease (AD) is one of the foremost neurodegenerative diseases, characterized by beta-amyloid (Aß) plaques and significant progressive memory loss. In AD, astrocytes are proposed to take up and clear Aß plaques. However, how Aß induces pathogenesis and memory impairment in AD remains elusive. We report that normal astrocytes show non-cyclic urea metabolism, whereas Aß-treated astrocytes show switched-on urea cycle with upregulated enzymes and accumulated entering-metabolite aspartate, starting-substrate ammonia, end-product urea, and side-product putrescine. Gene silencing of astrocytic ornithine decarboxylase-1 (ODC1), facilitating ornithine-to-putrescine conversion, boosts urea cycle and eliminates aberrant putrescine and its toxic byproducts ammonia and H2O2 and its end product GABA to recover from reactive astrogliosis and memory impairment in AD. Our findings implicate that astrocytic urea cycle exerts opposing roles of beneficial Aß detoxification and detrimental memory impairment in AD. We propose ODC1 inhibition as a promising therapeutic strategy for AD to facilitate removal of toxic molecules and prevent memory loss.

Changes in Hepcidin Levels in an Animal Model of Anemia of Chronic Inflammation: Mechanistic Insights Related to Iron Supplementation and Hepcidin Regulation.

We examined changes in hepcidin (closely associated with anemia of chronic inflammation (ACI)) and upstream regulatory pathways after intravenous (IV) iron supplementation in an ACI animal model. ACI was induced in male Sprague-Dawley rats by intraperitoneally administering complete Freund's adjuvant (CFA). Two weeks after starting CFA treatment, ACI rats received IV iron (CFA-iron) or vehicle (CFA-saline). Three days after IV iron treatment, iron profiles, hepcidin levels, and expression of proteins involved in the signaling pathways upstream of hepcidin transcription in the liver were measured. In CFA-treated rats, anemia with a concomitant increase in the levels of serum inflammatory cytokines and reactive oxygen species occurred. In CFA-iron rats, hemoglobin (Hb) concentration was still lower than that in control rats. In CFA-saline rats, hepatic hepcidin and ferritin levels increased compared with those in control rats and were further increased in CFA-iron rats. In CFA-saline rats, NADPH oxidase- (NOX-) 2, NOX-4, and superoxide dismutase levels in the liver were upregulated compared with those in control rats and their levels were further increased in CFA-iron rats. In CFA-saline rats, activities of the IL-6/STAT and BMP/SMAD pathways were enhanced in the liver compared with those in control rats and their levels were further increased in CFA-iron rats, whereas IL-6 expression remained unaffected after IV iron administration. In HepG2 cells, iron caused phosphorylation of STAT-3 and SMAD1/5 and knockdown of STAT-3 and SMAD1/5 using siRNAs reduced iron-induced hepcidin upregulation to levels similar to those in corresponding control cells. Renal erythropoietin expression and serum erythroferrone concentration were lower in CFA-iron rats than those in control rats. In ACI rats, IV iron supplementation did not recover Hb within three days despite an increase in hepatic ferritin levels, which might be attributable to an additional increase in hepcidin levels that was already upregulated under ACI conditions. Both STAT-3 phosphorylation and SMAD1/5 phosphorylation were associated with hepcidin upregulation after IV iron treatment, and this seems to be linked to iron-induced oxidative stress.

Effects of bisphenol A on the proliferation, migration, and tumor growth of colon cancer cells: In vitro and in vivo evaluation with mechanistic insights related to ERK and 5-HT3.

Bisphenol A (BPA) is a well-known endocrine-disrupting chemical related to the carcinogenesis of estrogen-responsive organs. Although human exposure to BPA mainly occurs via the oral route, its association with colon cancer has not been fully elucidated. We investigated the effects of BPA on the proliferation, migration, and tumor growth of colon cancer cells. BPA significantly promoted the proliferation of HT-29 human colon adenocarcinoma cells in a time- and dose-dependent manner. BPA also increased HT-29 cells migration. BPA increased the phosphorylation of extracellular signal-regulated kinase (ERK), and inhibition of the ERK pathway attenuated BPA-induced proliferation and migration. In addition, BPA reduced E-cadherin expression, a key factor impeding epithelial-to-mesenchymal transition, and increased 5-HT3 receptors expression, a major mitogenic factor. In xenograft models, tumor volume of the BPA-treated nude mice was 4.6 times that of the saline-treated group. Our findings provide primary evidence regarding the link between BPA and human colon cancer by demonstrating that BPA promotes the proliferation, migration, and tumor growth of colon cancer cells in both in vitro and in vivo models. In addition, we provided the mechanism of action of BPA, involved in the activation of the ERK pathway, the decrease in E-cadherin, and the increase in 5-HT3 receptors.

Identification for antitumor effects of tramadol in a xenograft mouse model using orthotopic breast cancer cells.

In our previous research showed that tramadol having potential anti-tumor effect was associated with enhancement of oncological prognosis in patients with breast cancer surgery. As these effects have not been confirmed by clinical dose-regulated animal or prospective human studies, we investigated the anti-tumor effect of tramadol in vivo. Female nude mice orthotopically inoculated with luciferase-expressing MCF-7 cells, were randomly divided into the control (saline), tramadol group 1 (1.5 mg kg-1 day-1), tramadol group 2 (3 mg kg-1 day-1), and morphine (0.5 mg kg-1 day-1) (n = 5/group). Bioluminescence signals after D-luciferin injection, tumor size, and tumor weight were compared among groups after 4 weeks. Estrogen receptor (ER), progesterone receptor (PR), and transient receptor potential vanilloid (TRPV)-1 expression, natural killer (NK) cell activity, and serum interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-6 were then examined. Tumour growth was attenuated in tramadol-treated groups (P < 0.05). NK cell activity was significantly decreased only in the morphine treated group not in sham, control, and tramadol groups. The expression levels of ERα, PRα and ß, and TRPV1 were decreased in tramadol group 2 compared with those in the morphine group, but not compared to the control group. Serum levels of IL-6 and TNFα were reduced in both tramadol-treated group 1 and 2 compared to the control group. Overall, clinical dose of tramadol has anti-tumour effects on MCF-7 cell-derived breast cancer in a xenograft mouse model.

Immunomodulatory Effects of Perioperative Dexmedetomidine in Ovarian Cancer: An In Vitro and Xenograft Mouse Model Study.

BACKGROUND: The surgical stress response (SSR) causes immunosuppression which may cause residual tumor growth and micrometastasis after cancer surgery. We investigated whether dexmedetomidine affects cancer cell behavior and immune function in an ovarian cancer xenograft mouse model. METHODS: The effect of dexmedetomidine on cell viability and cell cycle was assessed using SK-OV-3 cells at drug concentrations of 0.5, 0.1, 5, and 10 µg mL-1. BALB/c nude mice were used for the ovarian cancer model with the Dexmedetomidine group (n=6) undergoing surgery with dexmedetomidine infusion and the Control group (n=6) with saline infusion for 4 weeks. Natural killer (NK) cell activity, serum proinflammatory cytokines, and cortisol were measured at predetermined time points and tumor burden was assessed 4 weeks after surgery. RESULTS: Dexmedetomidine had no effect on cell viability or cell cycle. Following a sharp decrease on postoperative day (POD) 1, NK cell activity recovered faster in the Dexmedetomidine group with significant difference vs. the Control group on POD 3 (P=0.028). In the Dexmedetomidine group, cortisol levels were lower on POD 3 (P=0.004) and TNF-α levels were lower at 4 weeks after surgery (P<0.001) compared to the Control group. The Dexmedetomidine group showed lower tumor burden at 4 weeks vs. the Control group as observed by both tumor weight (P<0.001) and the in vivo imaging system (P=0.03). CONCLUSIONS: Dexmedetomidine infusion may improve ovarian cancer surgery outcome by suppressing the SSR and stress mediator release. Further studies are needed to elucidate the mechanisms by which dexmedetomidine acts on cancer and immune cells.

Isolation and characterization of dental follicle-derived Hertwig's epithelial root sheath cells.

OBJECTIVES: The aim of this study was the isolation and characterization of dental follicle-derived Hertwig's epithelial root sheath cells (DF-HERSCs). MATERIALS AND METHODS: DF-HERSCs were isolated from dental follicle (DF)-derived single-cell suspensions. Their epithelial phenotypes were analyzed by Western blotting, polymerase chain reaction (PCR), and quantitative polymerase chain reaction (qPCR). Epithelial-mesenchymal transition (EMT) was induced in DF-HERSCs by treatment with transforming growth factor-ß (TGF-ß) or fetal bovine serum (FBS)-added medium. Characteristics of DF-HERSCs were compared with normal human oral keratinocytes (NHOKs) and normal human epidermal keratinocytes (NHEKs). Osteogenic differentiation and mineralization of DF-HERSCs were analyzed by alkaline phosphatase (ALP) and Alizarin red staining. All experiments were conducted in triplicate. RESULTS: Primary DF-HERSCs were isolated from DF. Epithelial phenotypes of DF-HERSCs were confirmed by morphological and Western blot analysis. PCR results demonstrated that the origin of DF-HERSCs was neither endothelial nor hematopoietic. Enamel matrix derivative (EMD)-associated genes were not expressed in DF-HERSCs. Treatment with TGF-ß and FBS-added medium triggered the progression of EMT in DF-HERSCs. The acquired potency of differentiation and mineralization was shown in EMT-progressed DF-HERSCs. CONCLUSIONS: DF contains putative populations of HERSC, named DF-HERSC. DF-HERSCs shared common characteristics with NHOKs and NHEKs.

Deciphering Fatty Acid Synthase Inhibition-Triggered Metabolic Flexibility in Prostate Cancer Cells through Untargeted Metabolomics.

Fatty acid synthase (FAS) is a key enzyme involved in de novo lipogenesis that produces lipids that are necessary for cell growth and signal transduction, and it is known to be overexpressed, especially in cancer cells. Although lipid metabolism alteration is an important metabolic phenotype in cancer cells, the development of drugs targeting FAS to block lipid synthesis is hampered by the characteristics of cancer cells with metabolic flexibility leading to rapid adaptation and resistance. Therefore, to confirm the metabolic alterations at the cellular level during FAS inhibition, we treated LNCaP-LN3 prostate cancer cells with FAS inhibitors (Fasnall, GSK2194069, and TVB-3166). With untargeted metabolomics, we observed significant changes in a total of 56 metabolites in the drug-treated groups. Among the altered metabolites, 28 metabolites were significantly changed in all of the drug-treated groups. To our surprise, despite the inhibition of FAS, which is involved in palmitate production, the cells increase their fatty acids and glycerophospholipids contents endogenously. Also, some of the notable changes in the metabolic pathways include polyamine metabolism and energy metabolism. This is the first study to compare and elucidate the effect of FAS inhibition on cellular metabolic flexibility using three different FAS inhibitors through metabolomics. We believe that our results may provide key data for the development of future FAS-targeting drugs.

Astrocytes Control Sensory Acuity via Tonic Inhibition in the Thalamus.

Sensory discrimination is essential for survival. However, how sensory information is finely controlled in the brain is not well defined. Here, we show that astrocytes control tactile acuity via tonic inhibition in the thalamus. Mechanistically, diamine oxidase (DAO) and the subsequent aldehyde dehydrogenase 1a1 (Aldh1a1) convert putrescine into GABA, which is released via Best1. The GABA from astrocytes inhibits synaptically evoked firing at the lemniscal synapses to fine-tune the dynamic range of the stimulation-response relationship, the precision of spike timing, and tactile discrimination. Our findings reveal a novel role of astrocytes in the control of sensory acuity through tonic GABA release.

Anti-Tumor Potential of a 5-HT3 Receptor Antagonist as a Novel Autophagy Inducer in Lung Cancer: A Retrospective Clinical Study with In Vitro Confirmation.

Unlike 5-hydroxytryptamine (5-HT, serotonin) 1 and 5-HT2, the effect of 5-HT3 receptors on tumor cells is poorly understood. We conducted this study to determine whether the perioperative use of 5-HT3 receptor antagonists, which are widely used antiemetics, impacts the recurrence and mortality after lung cancer surgery and related anti-tumor mechanisms. From data on 411 patients, propensity score matching was used to produce 60 1:2 matched pairs of patients, and variables associated with the prognosis after open lung cancer surgery were analyzed. Additionally, the effects of 5-HT3 receptor antagonists were confirmed in vitro on A549 human lung adenocarcinoma cells. Cancer recurrence occurred in 10 (8.2%) and 14 (22.95%) patients (p = 0.005), treated or untreated, with palonosetron or ramosetron. Perioperative usage of palonosetron or ramosetron was also associated with lower recurrence rate after lung cancer surgery (hazard ratio (HR), 0.293; 95% confidence interval (CI) 0.110-0.780, p = 0.0141). Our in vitro experiments also showed that palonosetron and ramosetron inhibited cell proliferation and colony formation and reduced migration, which was associated with autophagic cell death via the extracellular signal-regulated kinase (ERK) pathway. Palonosetron and ramosetron may have anti-tumor potential against lung cancer cells, suggesting the need to consider these drugs as first-choice antiemetics in patients undergoing lung cancer surgery.

Direct differentiation of bone marrow mononucleated cells into insulin producing cells using pancreatic ß-cell-derived components.

Transplantation of stem cell-derived insulin producing cells (IPCs) has been proposed as an alternative to islet transplantation for the treatment of diabetes mellitus. However, current IPC differentiation protocols are focused on generating functional cells from the pluripotent stem cells and tend to rely on multistep, long-term exposure to various exogenous factors. In this study, we addressed the observation that under stress, pancreatic ß-cells release essential components that direct the differentiation of the bone marrow nucleated cells (BMNCs) into IPCs. Without any supplementation with known differentiation-inducing factors, IPCs can be generated from BMNCs by in vitro priming for 6 days with conditioned media (CM) from the ß-cells. In vitro primed BMNCs expressed the ß-cell-specific transcription factors, as well as insulin, and improved hyperglycemia and glucose intolerance after transplantation into the streptozotocin-induced diabetic mice. Furthermore, we have found that components of the CM which trigger the differentiation were enclosed by or integrated into micro particles (MPs), rather than being secreted as soluble factors. Identification of these differentiation-directing factors might enable us to develop novel technologies required for the production of clinically applicable IPCs.

Protective Effect of Ethyl Pyruvate against Myocardial Ischemia Reperfusion Injury through Regulations of ROS-Related NLRP3 Inflammasome Activation.

Emerging evidence indicates the pronounced role of inflammasome activation linked to reactive oxygen species (ROS) in the sterile inflammatory response triggered by ischemia/reperfusion (I/R) injury. Ethyl pyruvate (EP) is an antioxidant and conveys myocardial protection against I/R injury, while the exact mechanisms remain elusive. We aimed to investigate the effect of EP on myocardial I/R injury through mechanisms related to ROS and inflammasome regulation. The rats were randomly assigned to four groups: (1) sham, (2) I/R-control (IRC), (3) EP-pretreatment + I/R, and (4) I/R + EP-posttreatment. I/R was induced by a 30 min ligation of the left anterior descending artery followed by 4 h of reperfusion. EP (50 mg/kg) was administered intraperitoneally at 1 h before ischemia (pretreatment) or upon reperfusion (posttreatment). Both pre- and post-EP treatment resulted in significant reductions in myocardial infarct size (by 34% and 31%, respectively) and neutrophil infiltration. I/R-induced myocardial expressions of NADPH oxidase-4, carnitine palmitoyltransferase 1A, and thioredoxin-interacting protein (TXNIP) were mitigated by EP. EP treatment was associated with diminished inflammasome activation (NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like protein, and caspase-1) and interleukin-1ß induced by I/R. I/R-induced phosphorylation of ERK and p38 were also mitigated with EP treatments. In H9c2 cells, hypoxia-induced TXNIP and NLRP3 expressions were inhibited by EP and to a lesser degree by U0126 (MEK inhibitor) and SB203580 (p38 inhibitor) as well. EP's downstream protective mechanisms in myocardial I/R injury would include mitigation of ROS-mediated NLRP3 inflammasome upregulation and its associated pathways, partly via inhibition of hypoxia-induced phosphorylation of ERK and p38.

Dexmedetomidine restores autophagy and cardiac dysfunction in rats with streptozotocin-induced diabetes mellitus.

AIMS: Dexmedetomidine (DEX), a highly selective and potent α2-adrenergic receptor agonist, has anti-apoptotic, anti-inflammatory, and anti-oxidative stress effects in diabetes mellitus (DM) rats. The underlying molecular mechanisms and signaling pathways of diabetic cardiomyopathy remain poorly understood. This study aimed to elucidate the effect of DEX on cardiac function in DM rats. METHODS: Eight-week-old male Sprague Dawley rats were divided into three groups: control (n = 5), diabetes (DM, n = 7), and diabetes + DEX (DM + DEX, n = 10). DM was induced via intraperitoneal injection of streptozotocin (70 mg/kg); at 3 days later, DEX (1 µg/kg/h) was administered for 4 weeks. Cardiac function was evaluated using pressure-volume loop analysis and echocardiography. Left ventricular (LV) histological sections were used to analyze the interstitial collagen fraction. Using the LV samples, we performed a western blot analysis to evaluate signaling pathways and autophagic markers. RESULTS: The DM group had lower body weight and higher blood glucose level and heart weight/body weight ratio than the control group. However, metabolic changes did not differ between the DM and DM + DEX groups. Pressure-volume loop analysis and echocardiography showed impaired cardiac function, evidenced by a decrease in systolic and diastolic function, in both DM groups. DEX treatment in DM rats was associated with increased LV end-systolic pressure, LV contractility, cardiac output, and relaxed LV function compared with that in non-treated DM rats. LC3B and autophagy-related gene (ATG) proteins increased in the hearts of DM rats compared with the hearts of control rats. However, DEX reduced the expression of LC3B and ATG proteins in the hearts of DM rats. Increased p-ERK and decreased p-AKT were reduced in the hearts of DEX-treated DM rats. CONCLUSIONS: DEX reduces cardiac dysfunction and impaired autophagy in DM rats. This study reinforces our understanding of the potential anti-autophagic effect of DEX in patients with diabetic cardiomyopathy.

Renoprotective effects of dexmedetomidine against ischemia-reperfusion injury in streptozotocin-induced diabetic rats.

BACKGROUND: Diabetic patients are susceptible to renal ischemia-reperfusion injury, which leads to perioperative complications. Activation of NOD-like receptor protein 3 (NLRP3) inflammasome participates in the development of diabetes, and contributes to renal ischemia-reperfusion injury. Dexmedetomidine (DEX), a highly selective α2-adrenoreceptor agonist, shows renoprotective effects against ischemia-reperfusion injury. We aimed to elucidate the effects, underlying mechanisms, and optimal timing of DEX treatment in diabetic rats. METHODS: Male Sprague-Dawley rats (n = 12 per group) were randomly divided into normal-sham, diabetes-sham, diabetes-ischemia-reperfusion-control, diabetes-ischemia-reperfusion-DEX-pre-treatment, and diabetes-ischemia-reperfusion-DEX-post-treatment groups. Renal ischemia-reperfusion injury was induced in diabetic rats by occlusion of both renal arteries for 45 min, followed by reperfusion for 24 h. DEX (10 µg/kg) was administered intraperitoneally 1 h before ischemia (pre-treatment) or upon reperfusion (post-treatment). After reperfusion, renal tissue was biochemically and histopathologically evaluated. RESULTS: DEX treatment attenuated ischemia reperfusion-induced increase in NLRP3, caspase-1, IL-1ß, phospho-AKT, and phospho-ERK signaling. Moreover, oxidative stress injury, inflammatory reactions, apoptosis, and renal tubular damage were favorably modulated by DEX treatment. Furthermore, post-reperfusion treatment with DEX was significantly more effective than pre-treatment in modulating NLRP3 inflammasome, AKT and ERK signaling, and oxidative stress. CONCLUSIONS: This study shows that the protective effects of DEX in renal ischemia-reperfusion injury are preserved in diabetic conditions and may potentially provide a basis for the use of DEX in clinical treatment of renal ischemia-reperfusion injury.

In Vivo Differentiation of Therapeutic Insulin-Producing Cells from Bone Marrow Cells via Extracellular Vesicle-Mimetic Nanovesicles.

The current diabetes mellitus pandemic constitutes an important global health problem. Reductions in the mass and function of ß-cells contribute to most of the pathophysiology underlying diabetes. Thus, physiological control of blood glucose levels can be adequately restored by replacing functioning ß-cell mass. Sources of functional islets for transplantation are limited, resulting in great interest in the development of alternate sources, and recent progress regarding cell fate change via utilization of extracellular vesicles, also known as exosomes and microvesicles, is notable. Thus, this study investigated the therapeutic capacity of extracellular vesicle-mimetic nanovesicles (NVs) derived from a murine pancreatic ß-cell line. To differentiate insulin-producing cells effectively, a three-dimensional in vivo microenvironment was constructed in which extracellular vesicle-mimetic NVs were applied to subcutaneous Matrigel platforms containing bone marrow (BM) cells in diabetic immunocompromised mice. Long-term control of glucose levels was achieved over 60 days, and differentiation of donor BM cells into insulin-producing cells in the subcutaneous Matrigel platforms, which were composed of islet-like cell clusters with extensive capillary networks, was confirmed along with the expression of key pancreatic ß-cell markers. The resectioning of the subcutaneous Matrigel platforms caused a rebound in blood glucose levels and confirmed the source of functioning ß-cells. Thus, efficient differentiation of therapeutic insulin-producing cells was attained in vivo through the use of extracellular vesicle-mimetic NVs, which maintained physiological glucose levels.

Murine Sca1(+)Lin(-) bone marrow contains an endodermal precursor population that differentiates into hepatocytes.

The direct differentiation of hepatocytes from bone marrow cells remains controversial. Several mechanisms, including transdifferentiation and cell fusion, have been proposed for this phenomenon, although direct visualization of the process and the underlying mechanisms have not been reported. In this study, we established an efficient in vitro culture method for differentiation of functioning hepatocytes from murine lineage-negative bone marrow cells. These cells reduced liver damage and incorporated into hepatic parenchyma in two independent hepatic injury models. Our simple and efficient in vitro protocol for endodermal precursor cell survival and expansion enabled us to identify these cells as existing in Sca1(+) subpopulations of lineage-negative bone marrow cells. The endodermal precursor cells followed a sequential developmental pathway that included endodermal cells and hepatocyte precursor cells, which indicates that lineage-negative bone marrow cells contain more diverse multipotent stem cells than considered previously. The presence of equivalent endodermal precursor populations in human bone marrow would facilitate the development of these cells into an effective treatment modality for chronic liver diseases.