High Glucose Concentrations Research Articles

Determination diabetes mellitus disease markers in tear fluid by photothermal AFM-IR analysis.

The tear fluids from three healthy individuals and three patients with diabetes mellitus were examined using atomic force microscopy-infrared spectroscopy (AFM-IR) and Fourier transform infrared spectroscopy (FTIR). The dried tear samples showed different surface morphologies: the control sample had a dense network of heart-shaped dendrites, while the diabetic sample had fern-shaped dendrites. By using the AFM-IR technique we identified spatial distribution of constituents, indicating how diabetes affects the structural characteristics of dried tears. FTIR showed that the dendritic structures gradually disappeared over time due to glucose-induced lysozyme damage. The tear fluid from diabetes mellitus patients has a higher concentration of glucose, which accelerates the breakdown of lysozyme and, as a result, the quick loss of the dendritic structure. Our study shows that analysis of dry tear fluid can be promising technique for the detection of glycated proteins that reveal long lasting hyperglycemia and diabetes mellitus.

Circulating insulin-like growth factor-1 and the risk of multiple sclerosis: a prospective cohort study.

Circulating insulin-like growth factor 1 (IGF-1) is positively associated with the risks of certain neurological disorders, including stroke, Alzheimer's disease, and Parkinson's disease. However, the association of IGF-1 with the risk of multiple sclerosis (MS) remains unclear. A total of 348,324 participants at baseline were included from the UK biobank in this prospective study. The association of circulating IGF-1 level with MS was analyzed by Cox proportional hazard models. Further, subgroup analyses were conducted to investigate the variables influencing these associations. Among 348,324 individuals, lower circulating IGF-1 concentrations were associated with a reduced risk of MS (95 % CI, 0.5930-0.9700; P value = 0.02763). The association between lower IGF-1 levels and reduced risk of MS remains robust in older and female participants. Moreover, risk of MS appeared to be lower in IGF-1-low individuals who never smoked, currently drinking alcohol, with higher body mass index, and higher glucose concentrations. Our findings indicate that a lower concentration of serum IGF-1 was associated with a reduced risk of MS. The results provide evidence that the circulating IGF-1 may play a significant role in the pathogenesis of MS.

Management of Neonatal Hyperglycaemia in Sweden-A Survey Study.

Neonatal hyperglycaemia is associated with a multitude of adverse outcomes, including mortality and impaired neurological development. The aim of this study was to characterise the current management of neonatal hyperglycaemia in Swedish neonatal units. A digital survey was sent to 27 Swedish neonatal units providing care to preterm infants born before 32 completed gestational weeks. Sixty-eight responses were collected from 21 different units. Thirty-two percent (22/68) of clinicians reported having a local treatment guideline for neonatal hyperglycaemia. Hyperglycaemia was defined as a glucose concentration above a value in the range of 8.0-10.0 mmol/L by 62.5% of clinicians, while 16.7% and 21.8% used a definition between 10.1 and 12.0 mmol/L and > 12 mmol/L, respectively. Intravenous glucose reduction was initiated at higher glucose concentrations by clinicians working at university hospital units (p = 0.006). Glucose concentration threshold for initiation of insulin treatment varied between 8 and 30 mmol/L. Three clinicians (3/35 (8.5%)) reported having experienced problems with frequent hypoglycaemia during ongoing insulin treatment. This study demonstrates extensive differences in clinical practice regarding neonatal hyperglycaemia both within and between neonatal units in Sweden. Randomised controlled trials are needed to provide evidence for clinical guidelines and to improve and standardise the care of these infants.

Enzymatic hydrolysis of pretreated lignocellulosic feedstocks improved by membrane separation

Enzymatic hydrolysis is crucial in processing lignocellulosic biomass into valuable products in biorefineries. Due to the synergistic action of used enzymes the cellulose and hemicelluloses chains are digested into fermentable monosaccharides. It is known that the process efficiency can be improved by the separation of reaction end-products being cellulases' inhibitors. The work aimed to investigate the efficiency of enzymatic hydrolysis of corn stover and poplar wood biomass in a stirred dead-end membrane bioreactor, enabling continuous separation of end-products. Four UF membranes with different molecular weight cut-offs were tested, and PES 5 kDa was chosen as the most suitable. To pretreat biomass before hydrolysis, soaking in aqueous ammonia (SAA) and liquid hot water (LHW) methods were compared. The LHW treatment allowed for obtaining relatively high glucose contents (up to 73.7%). In turn, the SAA method led to high xylose contents up to 23.5%. In general, remarkable improvements (up to 72.6%) in monosaccharides contents in hydrolyzates after membrane bioreactor were observed. Only in the case of corn stover after SAA pretreatment, the reaction efficiencies in the membrane bioreactor were similar to those obtained in a batch mode with an improvement of 4.3%.

Low-dose LPS and calorie restriction combined therapy for pancreatic ductal adenocarcinoma: an in vitro and in vivo study

Objective: This study aimed to evaluate the therapeutic effects of lipopolysaccharide (LPS) on Panc02 cells since LPS is an inflammatory agent with the potential to activate the immune system and reorganize the tumor microenvironment. Moreover, calorie restriction (CR) has been investigated in combination with LPS as a prospective adjuvant intervention for cancer therapy. Materials and Methods: Panc02 cells were cultured in two distinct media with low and high-glucose concentrations, and cell viability was investigated after applying varying doses of LPS to culture media. The in vivo effects of LPS and CR were investigated on the mice subcutaneous pancreatic ductal adenocarcinoma (PDAC) tumor model in terms of tumor mass, histological examination, mRNA expression profiles, and biochemical parameters. Results: The lowest cell count was detected in the cells treated with 10 μg/ml LPS in low-glucose environments in vivo. Tumor mass significantly decreased in the P+LPS+CR group in vivo. The mRNA expression analysis of tumor tissues indicated that P+LPS+CR acts through NF-κB, JNK, and IL-6 signaling pathways. Conclusion: Lipopolysaccharide alone is insufficient to show therapeutic effects, but it can inhibit tumor development by acting on NF-κB and JNK pathways when combined with CR. This study gives insight into developing new treatment options for PDAC.

P-40 A RARE PRESENTATION OF PROLONGED HYPOGLYCEMIA: CONGENITAL LEPTIN DEFICIENCY AND INSULIN INTOXICATION

Abstract Introduction Congenital leptin deficiency (CLD) is caused by mutations in the LEP gene with an incidence of 1 in 4.4 million, presenting with symptoms such as hyperphagia, obesity. Insulin intoxication is also a rare condition that usually occurs as a result of a suicide attempt or, a medication error. There is not an algorithm for the management of insulin intoxication. Here, we report the only case in the literature presenting with congenital leptin deficiency and insulin intoxication. Clinical Case A 33-year-old woman was admitted to the hospital with dizziness, nausea, and unconsciousness. She had applied nearly 300 IU insulin aspart of committing suicide. She had congenital leptin deficiency, hypothyroidism, and prediabetes. She had leptin replacement during 2020-2021 and didn’t have a replacement since then. Her body mass index was 62.2. Her blood pressure was 95/60 mm/Hg, Sp02 was 88 %, and heart rate was 120 per minute. Her blood glucose was 29 mg/dl, and there was respiratory acidosis. Liver and renal function tests, electrolytes, coagulation parameters, and thyroid hormones were normal. Chest x-ray and brain tomography were normal. Despite subsequent infusion of 20% dextrose solution via central catheter, serum glucose could only be kept at 70-80 mg/dl. In the following hours patient’s consciousness, pH level, and oxygen saturation returned to normal. We had to follow the patient with a high concentration of glucose (150-200cc/h %10 dextrose) for ten days because of reappearing hypoglycemia. On the 10th day of follow-up, we stopped IV glucose for a short time and measured the fasting hormones shown in Table 1. at 7.00 a.m. As there was hypocortisolemia, we applied 5mg prednisolone twice daily in the following days. Twenty-four hours after cortisol administration, we could easily stop the IV glucose. We followed the patient with 5mg prednisolone twice daily and oral carbohydrate intake for three days and didn’t observe hypoglycemia. Afterwards, we stopped prednisolone and the patient was normoglycemic for the following days. We again measured the fasting hormones shown in Table 2. At 7.00 a.m. three days after the last dose of prednisolone. The patient was not hypoglycemic or hypocortisolemic since then; vital parameters were all normal and we discharged the patient. Conclusion Prolonged hypoglycemia may have occurred in different mechanisms. Our patient had a thick subcutaneous fat tissue because of CLD; therefore, absorption of insulin may have increased and half life may be prolonged. Also, high dose exogenous insulin may have triggered the production of insulin antibodies causing prolonged duration of insulin action and hypoglycemia. Moreover, deep hypoglycemia may have affected the pituitary-adrenal cortisol axis causing relative adrenal insufficiency. The steroid decreased the insulin antibodies and also corrected the relative cortisol deficiency. More cases and data are needed to shed light on this subject.Table 1: Table 2:

Dose-Response Relationship of Phloretin Therapy on Water and Glucose Transport during Experimental Peritoneal Dialysis.

Water retention, ultrafiltration insufficiency, and metabolic complications due to abnormally high glucose concentrations are still common problems in patients treated with peritoneal dialysis. Phloretin, a nonselective inhibitor of facilitative glucose transporter channels (GLUT), has shown to improve water transport and lower glucose absorption in experimental peritoneal dialysis. However, the dose-response relationship remains unknown, and we therefore performed a dose-response study to elucidate the pharmacodynamic properties of intra-peritoneal phloretin therapy. Experimental peritoneal dialysis was performed in fifty healthy Sprague-Dawley rats, using glucose-based dialysis fluid containing five different concentrations of phloretin. We utilized radiolabeled 18F-deoxyglucose (18-FDG) to determine the plasma-to-dialysate transport. The data was then analyzed to determine the dose-response relationship of phloretin according to the Hill-model equation. Intraperitoneal phloretin therapy followed a dose-response relationship where higher concentrations of phloretin lowered the diffusion capacity of 18-FDG and conventional glucose, while enhancing ultrafiltration. Phloretin showed high potency for water removal and diffusion outcomes, requiring low concentrations to achieve substantial effects. Intraperitoneal phloretin therapy followed a distinct dose-response relationship, showing high potency in improving ultrafiltration and reducing glucose absorption in experimental PD. These findings support the therapeutic potential of GLUT-inhibitors like phloretin and support future clinical studies to evaluate efficacy and optimal dosing in patients undergoing PD.

Involvement of ADAM17-Klotho Crosstalk in High Glucose-Induced Alterations of Podocyte Function.

Microalbuminuria is the earliest clinical abnormality in diabetic kidney disease. High glucose (HG) concentrations are associated with the induction of oxidative stress in podocytes, leading to disruption of the glomerular filtration barrier. Our recent study revealed a significant decrease in the membrane-bound fraction of Klotho in podocytes that were cultured under HG conditions. Given that disintegrin and metalloproteinase 17 (ADAM17) is responsible for the shedding of Klotho from the cell membrane, the present study investigated the impact of HG on the interplay between ADAM17 and Klotho in human podocytes. We demonstrated that ADAM17 protein levels significantly increased in urine, renal tissue, and glomeruli from diabetic rats, with a concomitant increase in glomerular albumin permeability. High glucose increased ADAM17 extracellular activity, NADPH oxidase activity, and albumin permeability in podocytes. These effects were reversed after treatment with ADAM17 inhibitor, in cells with downregulated ADAM17 expression, or after the addition of Klotho. Additionally, elevations of extracellular ADAM17 activity were observed in podocytes with the downregulation of Klotho expression. Our data indicate a novel mechanism whereby hyperglycemia deteriorates podocyte function via ADAM17 activation. We also demonstrated the ability of Klotho to protect podocyte function under hyperglycemic conditions in an ADAM17-dependent manner.

Discovery and characterization of a new β-glucosidase from Wolfiporia cocos through RNA sequencing and heterologous expression in Escherichia coli.

De novo RNA-sequencing of Wolfiporia cocos mycelia cultured with filter paper composed of cellulose as the sole carbon source revealed a total of five expressed β-glucosidase genes. Among these, the β-glucosidase named Wcbg1B-1, which is composed of 539 amino acid residues and belongs to the GH1 family, had the highest mRNA abundance, accounting for 65% of the total mRNA of the five expressed β-glucosidases. The recombinant Wcbg1B-1 was successfully expressed in Escherichia coli, with an optimal pH of 6.0 and an optimal temperature of 40°C using p-nitrophenyl-β-d-glucopyranoside (pNPG) as the substrate. Recombinant Wcbg1B-1 has a Km value of 0.32mmol/L, a Vmax of 416μmol/min/mg and specific activity of 461.5U/mg. Recombinant Wcbg1B-1 has strict β-glycosidic bond specificity, the highest hydrolysis activity to cellobiose, followed by lactose, and the lowest hydrolysis activity to gentian. Recombinant Wcbg1B-1 exhibits hydrolytic activity towards macromolecular cellulose such as sodium carboxymethyl cellulose, microcrystalline cellulose and filter paper. Additionally, its high tolerance to high concentrations of glucose and salt makes it more practical for cellulose hydrolysis. Recombinant Wcbg1B-1 can hydrolyze lactose at low temperatures, indicating that it could also be a potential biocatalyst for lactose-reduced dairy industry.

Unlocking the power of empagliflozin: Rescuing inflammation in hyperglycaemia- exposed human cardiomyocytes through comprehensive multi-level analysis.

Hyperglycaemic conditions increase cardiac stress, a common phenomenon associated with inflammation, aging, and metabolic imbalance. Sodium-glucose cotransporter 2 inhibitors, a class of anti-diabetic drugs, showed to improve cardiovascular functions although their mechanism of action has not yet been fully established. This study investigated the effects of empagliflozin on cardiomyocytes following high glucose exposure, specifically focusing on inflammatory and metabolic responses. A three-part strategy was formulated: (i) a meta-analysis of selected randomized clinical trials was carried out to assess the anti-inflammatory effects of empagliflozin in diabetic patients; (ii) the impact of empagliflozin on human cardiomyocyte AC16 cells exposed to normal (5 mM) and high (33 mM) glucose concentrations for 2 and 7 days was explored by evaluating gene expression and protein levels of pivotal markers associated with cardiac inflammation, stress, endoplasmic reticulum damage, and calcium modulation; (iii) in silico data from bioinformatic analyses were exploited to construct an interaction map delineating the potential mechanism of action of empagliflozin on cardiac tissue. Empagliflozin reversed high-glucose mediated alterations at the transcriptional level, decreasing inflammatory, metabolic, and aging signatures. Specifically, in vitro experiments on human cardiomyocytes, meta-analyses of clinical data on inflammatory biomarkers from diabetic peripheral blood samples, and sequencing of pathological human heart tissues, all support that empagliflozin exerts anti-inflammatory effects both systemically and directly in cardiac tissue, on cardiomyocytes. Our study provides insights based on robust mechanistic data for optimizing heart failure management and highlights the intricate interplay between diabetes, inflammation, aging, and cardiovascular health.

The impact of tuberculosis-induced hyperglycemia on pulmonary microbiota and airway mucus secretion in individuals not previously diabetic: A systematic review and meta-analysis protocol.

The lung environment harbours a community of microbes that play a significant role in health and disease, including innate protection against pathogenic microorganisms. Infection with Mycobacterium tuberculosis, psychological stress associated with the tuberculosis (TB) disease, and the metabolites from the rifampicin treatment regimen have been reported to induce hyperglycemia and consequently type 2 diabetes mellitus (T2DM) in individuals not previously diabetic. The high glucose concentration is proposed to alter the composition of the lung microbiota and airway homeostasis, exerting an influence on TB disease and treatment outcomes. In this systematic review, we propose to synthesize literature on TB-induced hyperglycemia and its impact on lung microbiota and secretion of airway mucus in individuals not previously diabetic. A systematic search will be carried out on PubMed, EMBASE, MEDLINE, PROQUEST, Cochrane, SCOPUS, and manually on Google Scholar and references of relevant articles to identify other studies. We will review published articles that include studies on TB-induced hyperglycemia, pulmonary microbiome, mucin secretion, and (or) airway surface liquid upon TB diagnosis and during treatment. The quality of the study articles will be assessed using the modified Newcastle-Ottawa Scale (NOS). Meta-analysis will be conducted using random effect model for heterogeneity to pool estimates on microbial diversity. Egger's test will be performed to explore any selective reporting bias. The findings of the systematic review and the meta-analysis will be reported as per the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol guidelines. This protocol was developed and uploaded onto the International Prospective Register of Systematic Reviews (PROSPERO) database, registration number: CRD42024482248.

Productivity and properties of a Weizmannia coagulans strain capable of synthesizing L-lactic acid

Studies on the producers of L-lactic acid are highly relevant at the moment due to the broad scope of its applications. This study was aimed at selecting culture parameters for a milk-derived thermophilic strain of Weizmannia coagulans that is capable of producing L-lactic acid. It was found that the strain productivity depends on the culture temperature, stirring rate, medium pH, used neutralizing agent, and glucose concentration. The culture in flasks and a fermenter revealed that in 56 hours, the strain is capable of producing up to 80.4 g/L of lactic acid at a corresponding average productivity of 1.44 g/(L×h) with a conversion of about 99%. The most optimal parameters to achieve the highest indicators were a temperature of 50 °С, medium pH of 6.5, and a stirring rate of 150 rpm. This strain was shown to be uninhibited by high glucose concentrations; conversely, it exhibited higher productivity at glucose concentrations of 100–120 g/L in the medium. Among the neutralizing agents used for pH adjustment, the Ca(OH)2 agent was selected, which has the least effect on the size of producer cells during fermentation and whose by-products are the least toxic. The obtained results indicate that further studies on the metabolic properties and genetic modification of this strain are required in order to increase productivity, reduce the inhibitory effect of the target product on the metabolism of the producer, and obtain elevated lactic acid titers in a short fermentation time.

The Effect of Chlorogenic Acid Content in Coffee Can Reduce Malondialdehyde (MDA) and Increase Testosterone Hormone Levels in DM Conditions

Hyperglycemia is an uncontrolled condition of DM in the body, which causes a decrease in cell functions due to an increase in free radicals (ROS). This study explored the effects of Chlorogenic Acid found in coffee on mitigating MDA levels and augmenting testosterone in the context of Diabetes Mellitus (DM). Chlorogenic Acid, recognized for its substantial antioxidative properties, may ameliorate cellular impairments resulting from high glucose concentrations, consequently elevating Testosterone levels. The methodology employed was a Randomized Control Posttest Group Design involving 20 male Rattus norvegicus rats, aged 8-12 weeks, divided equally into four distinct groups. DM was simulated by administering 40mg/KgBB of streptozotocin and verifying the onset of Hyperglycemia through blood glucose evaluations three days post-administration. Following the confirmation of Hyperglycemia, a 14-day intervention with Robusta Coffee was initiated, with subsequent blood sampling on the fifteenth day to measure MDA and Testosterone concentrations. Results indicated that the groups KP, KP1, and KP2 exhibited notable variations in their responses when contrasted with KP, achieving statistical relevance Of ANOVA (p<0.05). However, no marked difference was observed in Testosterone levels between KP1 and KP2 (p>0.05). The investigation corroborated that Chlorogenic Acid in coffee plays a crucial role in reducing MDA and increasing testosterone hormone levels in DM conditions.

Roles for the long non-coding RNA Pax6os1/PAX6-AS1 in pancreatic beta cell function.

Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of beta cell function. Here, we show that an lncRNA-transcribed antisense to Pax6, annotated as Pax6os1/PAX6-AS1, was upregulated by high glucose concentrations in human as well as murine beta cell lines and islets. Elevated expression was also observed in islets from mice on a high-fat diet and patients with type 2 diabetes. Silencing Pax6os1/PAX6-AS1 in MIN6 or EndoC-βH1 cells increased several beta cell signature genes' expression. Pax6os1/PAX6-AS1 was shown to bind to EIF3D, indicating a role in translation of specific mRNAs, as well as histones H3 and H4, suggesting a role in histone modifications. Important interspecies differences were found, with a stronger phenotype in humans. Only female Pax6os1 null mice fed a high-fat diet showed slightly enhanced glucose clearance. In contrast, silencing PAX6-AS1 in human islets enhanced glucose-stimulated insulin secretion and increased calcium dynamics, whereas overexpression of the lncRNA resulted in the opposite phenotype.

Glucosamine Inhibits the Proliferation of Hepatocellular Carcinoma Cells by Eliciting Apoptosis, Autophagy, and the Anti-Warburg Effect.

Although glucosamine (GlcN) exhibits antitumor effects, its mechanism of action remains controversial. Additionally, its impact on hepatocellular carcinoma (HCC) is not well understood. This study aimed to investigate the antitumor effects of GlcN and its underlying mechanism in a mouse HCC cell line, Hepa1-6. GlcN treatment significantly inhibited Hepa1-6 cell proliferation. Gene expression analysis revealed that GlcN upregulated Chop and Bax while downregulating Bcl2, indicating the involvement of endoplasmic reticulum (ER) stress-induced apoptosis in the antiproliferative effects of GlcN. GlcN also increased the expression of FoxO1 and FoxO3, known tumor suppressors in various cancers. Furthermore, GlcN treatment elevated the levels of LC3II (an autophagy marker) and AMP-activated protein kinase activity, suggesting intracellular energy shortage. Indeed, GlcN treatment significantly suppressed glycolytic flux, lactate, and ATP production. Supplementing GlcN treatment with a high glucose concentration (20 mM) significantly attenuated its effect. We postulate that GlcN inhibits Hepa1-6 cell growth by inducing ER stress-induced apoptosis and autophagy and by inhibiting aerobic glycolysis (the Warburg effect), a key hallmark of cancer metabolism. Given that glucose transporter 2 (GLUT2), which is abundantly expressed in hepatocytes, has a high affinity for GlcN, these effects may result from GlcN competing with glucose for hepatocyte uptake by GLUT2. Our novel findings have potential implications for HCC treatment.

Molecular dynamics and solvation structures of the β-glucosidase from Humicola insolens (BGHI) in aqueous solutions containing glucose

The β-glucosidase enzyme is a glycosyl hydrolase that breaks down the β-1,4 linkage of cellobiose. It is inhibited by glucose at high concentrations due to competitive inhibition. However, at lower glucose concentrations, the glucose-tolerant β-glucosidase from Humicola insolens (BGHI) undergoes stimulation. Proteins, in aqueous sugar solutions, tend to be preferentially hydrated, which generally promotes their stabilization. Thus, solvation phenomena may contribute to both glucose tolerance and stimulation processes. We have performed atomistic classical Molecular Dynamics (MD) simulations of BGHI at different glucose concentrations to mimic the conditions found in the catalytic experiments. A detailed examination of the solvent environment through the calculation of minimum distance distribution functions (MDDFs) and Kirkwood-Buff (KB) integrals was performed. The enzyme is preferentially hydrated in the presence of glucose at all concentrations. Nevertheless, the hydration does not prevent the glucose from directly interacting with the BGHI surface or from entering the active site. Based on the obtained results, we hypothesize that preferential hydration is beneficial for enzyme activity. At the same time, product inhibition has little effect at lower concentrations of glucose, and at higher glucose concentrations, competition for the active site becomes predominant and the enzyme is primarily inhibited.

Preparation of blueberry blueberry muffins

Introduction: diabetes mellitus (DM) is a set of metabolic disorders, whose main common characteristic is the presence of high concentrations of blood glucose persistently or chronicly.Objective: prepare a blueberry muffins that allow expanding diabetic feed options.Method: a quantitative, experimental and transverse study was conducted, the study was conducted during the year 2020 at the Santo Domingo de Ecuador headquarters. A study sample of 100 cases was selected to whom the survey was applied and were selected by a simple random sampling. For data collection, a survey was applied under the quantitative approach, divided into three sections.Results: 62 % of the sample is male, 76 % have an age between 18 and 35 years, consume fresh water and natural water by 38 % and fruits and vegetables 46 %, 90 % of respondents would be arranged To consume cakes or muffins that is healthy, 30 % consider the difficult diets to make, it is evident that the % fat of the product is 3.02 %, which is beneficial for people suffering from diabetes.Conclusions: you can see in the study that people like fast food and that they would be willing to eat healthy muffins, appreciating that a healthy product can help change eating habits. It is considered that the most difficult aspect in the treatment of diabetes is to maintain an adequate diet.

Pituitary adenylate cyclase activating polypeptide counteracts high glucose‐induced inflammation in corneal epithelial cells

Aims/Purpose: The purpose of the current work was to evaluate the role of pituitary adenylate cyclase‐activating polypeptide (PACAP) to counteract inflammatory events characterizing diabetic keratopathy (DK).Methods: Rabbit corneal epithelial cells (SIRCs) were cultured in either normal glucose (5 mM) or high glucose (25 mM) ± PACAP (100 nM). The corneal epithelial barrier was assessed by measuring transepithelial electrical resistance (TEER). The inflammatory event was evaluated by analyzing the expression levels of tumor necrosis factor‐alpha (TNF‐α), interleukin (IL)‐1ß, and nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐kB), through western blot analysis, ELISA and immunofluorescence analysis.Results: In SIRCs, high glucose concentration led to the alteration of corneal epithelial barrier integrity and triggered the inflammatory events as demonstrated by the overexpression of TNF‐α and IL‐1β, and the activation of NF‐kB. The treatment with PACAP markedly restored corneal epithelial barrier integrity. Moreover, the treatment with the peptide significantly reduced the TNF‐α and IL‐1β cytokines expression and NF‐κB activation.Conclusions: Inflammation is enhanced in the diabetic cornea, and concurs with corneal epithelial barrier alteration. PACAP treatment has been shown to prevent high glucose‐induced inflammatory processes and maintain corneal epithelial barrier integrity. Therefore, PACAP therapy may represent a useful approach for the management of DK.Additional information: Study funded by MUR (PRIN PNRR P2022JRBMB).Reference Maugeri G et al. doi: 10.1016/j.peptides.2023.171107.

Supercooling tolerance in the Mexican lizard Barisia imbricata (Squamata: Anguidae).

Environmental temperature impacts the physiological processes of reptiles, determines their hours of activity per day, and may constrain their ability to meet critical ecological requirements. When environmental temperatures reach freezing, a few lizard species exhibit two mechanisms (supercooling and freezing tolerance) to survive freezing, and these two processes depend on cryoprotective molecules, such as glucose. Organisms produce high glucose concentrations to reach lower than normal crystallisation points, and this blood glucose concentration can double after freezing. The viviparous lizard Barisia imbricata lives along a wide elevational gradient (2100-4000m) at tropical latitudes in temperate and subtropical climates. Populations at extremely high elevations experience environmental temperatures at or below 0°C. We measured blood glucose concentrations in the lizard B. imbricata in different seasons and compared the values between seasons and between two populations occurring at the elevations of 2200 and 3700m. In addition, we froze lizards from the two populations and measured their blood glucose concentrations before and after freezing. We did not observe any differences in blood glucose concentrations between different seasons or the two populations. In addition, all lizards survived freezing; their mean crystallisation point was -4.13°C. Blood glucose concentration in the lizards increased after exposure to freezing temperatures during autumn and winter. Our results indicate that B. imbricata tolerates experimental freezing even in individuals not naturally exposed to subzero temperatures (i.e. populations at 2200m). Elevated blood glucose concentrations (present year-round) may help B. imbricata individuals survive at low temperatures.

Nitazoxanide controls virus viability through its impact on membrane bioenergetics

Viruses are dependent on cellular energy metabolism for their replication, and the drug nitazoxanide (Alinia) was shown to interfere with both processes. Nitazoxanide is an uncoupler of mitochondrial oxidative phosphorylation (OXPHOS). Our hypothesis was that mitochondrial uncoupling underlies the antiviral effects of nitazoxanide. Tizoxanide (the active metabolite of nitazoxanide), its derivative RM4848 and the uncoupler CCCP were applied to a virus-releasing cell line to obtain the same increasing levels of mitochondrial uncoupling, hence identical impact on OXPHOS. A decrease in infectious viral particle release was observed and reflected the intensity of impact on OXPHOS, irrespective of the nature of the drug. The antiviral effect was significant although the impact on OXPHOS was modest (≤ 25%), and disappeared when a high concentration (25 mM) of glucose was used to enhance glycolytic generation of ATP. Accordingly, the most likely explanation is that moderate interference with mitochondrial OXPHOS induced rearrangement of ATP use and acquisition of infective properties of the viral particles be highly sensitive to this rearrangement. The antiviral effect of nitazoxanide has been supported by clinical trials, and nitazoxanide is considered a safe drug. However, serious adverse effects of the uncoupler dinitrophenol occurred when used to increase significantly metabolic rate with the purpose of weight loss. Taken together, while impairment of mitochondrial bioenergetics is an unwanted drug effect, moderate interference should be considered as a basis for therapeutic efficacy.