Role of Nitric Oxide in Insulin Secretion and Glucose Metabolism

From lipids to glucose: Investigating the role of dyslipidemia in the risk of insulin resistance

Dyslipidemia is recognized as one of the most prevalent metabolic disorders and is frequently associated with other prevalent conditions, particularly diabetes mellitus. There appears to be a bidirectional connection between these two metabolic disorders. While considerable research has focused on how insulin resistance can lead to lipid abnormalities, the reverse relationship specifically, how dyslipidemia could assist in developing insulin resistance and diabetes mellitus has received relatively less attention. This review aims to comprehensively evaluate the mechanisms through which dyslipidemia can induce insulin resistance. Dyslipidemia is primarily classified into three main categories: hypercholesterolemia, hypertriglyceridemia, and low levels of HDL. These conditions may promote insulin resistance across multiple pathways, including the accumulation of lipid metabolites, dysfunction of pancreatic β-cells, increased reactive oxygen species, endoplasmic reticulum stress and inflammation, endothelial dysfunction, alterations in adiponectin levels, changes in bile acid composition and concentration, and dysbiosis of gut microbiota. However, further investigation is required to fully elucidate the cellular and molecular mechanisms underlying the relationship between lipid disorders and insulin resistance. Emphasizing such research could facilitate the development of therapeutic strategies targeting both conditions simultaneously.

A microfluidic wearable device for wound exudate management and analysis in human chronic wounds

Chronic wounds are a major global health challenge associated with substantial economic burden and a negative impact on patient quality of life. Real-time analysis of biomarkers like reactive oxygen and nitrogen species could guide treatment, but existing systems lack the capacity required for continuous monitoring. Wound exudate is secreted slowly and has a complex composition, making efficient fluid collection and real-time analysis challenging. To address these issues, we introduce iCares, a wearable device for wound exudate management and continuous in situ analysis of wound biomarkers. iCares contains a flexible nanoengineered sensor array that measures reactive species such as NO, H2O2, and O2, along with pH and temperature, providing multiparameter data to inform wound status. The device features pump-free triad microfluidic modules with a superhydrophobic-superhydrophilic Janus membrane, bioinspired wedge channels, and three-dimensional graded micropillars for efficient unidirectional exudate collection, transport, and refreshing. The sensors demonstrated a consistent response and analyte selectivity in vitro and in wound exudate. iCares was designed for rapid scalable manufacturing through advanced printing and laser patterning. Wireless connectivity supported long-term continuous monitoring in wounds. The iCares system real-time monitoring was tested in a murine model of diabetic skin wound during infection and antimicrobial treatment. Clinical wound evaluation was conducted in 20 patients with chronic wounds and in two patients before and after surgery. A machine learning analysis of the multiplexed data successfully classified wounds and healing times, indicating that wound exudate analysis by iCares could offer insight into chronic wound status to aid in treatment decisions.

GCH1 contributes to high-altitude adaptation in Tibetans by regulating blood nitric oxide

Nitric oxide (NO) is a key vasodilator that regulates vascular pressure and blood flow. Tibetans have developed a "blunted" mechanism for regulating NO levels at high altitude, with GTP cyclohydrolase 1 (GCH1) identified as a key candidate gene. Here, we present comprehensive genetic and functional analyses of GCH1, which exhibits strong Darwinian positive selection in Tibetans. We show that Tibetan-enriched GCH1 variants down-regulate its expression in the blood of Tibetans. Based on this observation, we generate the heterozygous Gch1 knockout (Gch1+/-) mouse model to simulate its downregulation in Tibetans. We find that under prolonged hypoxia, the Gch1+/- mice have relatively higher blood NO and blood oxygen saturation levels compared to the wild-type (WT) controls, providing better oxygen supplies to the cardiovascular and pulmonary systems. Markedly, hypoxia-induced cardiac hypertrophy and pulmonary remodeling are significantly attenuated in the Gch1+/- mice compared with the WT controls, likely due to the adaptive changes in molecular regulations related to metabolism, inflammation, circadian rhythm, extracellular matrix, and oxidative stress. This study sheds light on the role of GCH1 in regulating blood NO, contributing to the physiological adaptation of the cardiovascular and pulmonary systems in Tibetans at high altitude.

Mechanotransduction and Skeletal Muscle Atrophy: The Interplay Between Focal Adhesions and Oxidative Stress

Mechanical unloading leads to profound musculoskeletal degeneration, muscle wasting, and weakness. Understanding the specific signaling pathways involved is essential for uncovering effective interventions. This review provides new perspectives on mechanotransduction pathways, focusing on the critical roles of focal adhesions (FAs) and oxidative stress in skeletal muscle atrophy under mechanical unloading. As pivotal mechanosensors, FAs integrate mechanical and biochemical signals to sustain muscle structural integrity. When disrupted, these complexes impair force transmission, activating proteolytic pathways (e.g., ubiquitin-proteasome system) that accelerate atrophy. Oxidative stress, driven by mitochondrial dysfunction and NADPH oxidase-2 (NOX2) hyperactivation, exacerbates muscle degeneration through excessive reactive oxygen species (ROS) production, impaired repair mechanisms, and dysregulated redox signaling. The interplay between FA dysfunction and oxidative stress underscores the complexity of muscle atrophy pathogenesis: FA destabilization heightens oxidative damage, while ROS overproduction further disrupts FA integrity, creating a self-amplifying vicious cycle. Therapeutic strategies, such as NOX2 inhibitors, mitochondrial-targeted antioxidants, and FAK-activating compounds, promise to mitigate muscle atrophy by preserving mechanotransduction signaling and restoring redox balance. By elucidating these pathways, this review advances the understanding of muscle degeneration during unloading and identifies promising synergistic therapeutic targets, emphasizing the need for combinatorial approaches to disrupt the FA-ROS feedback loop.

Higher hemoglobin levels are associated with impaired left ventricular global strains in metabolic syndrome: a 3.0 T CMR feature tracking study

BACKGROUND

Metabolic syndrome (MetS) is a known contributor to increased cardiovascular risk and all-cause mortality. Recent literatures suggested that higher hemoglobin (Hb) levels were associated with Mets, left ventricular (LV) dysfunction and adverse events in general population. This study aimed to assess the associations between Hb levels and LV global strains in patients with MetS.

METHODS

A retrospective analysis included 254 patients with MetS and 78 sex-, age-, and Hb-matched controls. The MetS patients were stratified into five groups based on Hb levels: anemia, low-normal Hb, moderate-normal Hb, high-normal Hb, and high Hb. LV global radial, circumferential, and longitudinal strains (LVGRS, LVGCS, and LVGLS, respectively) were measured using the cardiac magnetic resonance feature tracking technique. Associations between Hb levels and LV global strains were evaluated using multiple linear regression, restricted cubic spline (RCS), and subgroup analyses.

RESULTS

After full adjustment, the LV global strains from three directions in the high Hb groups (LVGRS: β = -  4.943, 95% CI -  7.673 to - 2.213; LVGCS: β = -  2.341, 95% CI - 3.608 to - 1.074; LVGLS: β = -2.797, 95% CI - 4.049 to - 1.546, all p < 0.05) were significantly reduced than those in their respective moderate-normal Hb groups. Full adjusted RCS plots revealed inverted L-shaped associations between Hb levels and LV global strains, with significant reductions observed above 143 g/L (all p for nonlinearity < 0.05). Subgroup analyses indicated that the associations were more pronounced in MetS patients with obesity (LVGRS: β = -  0.005 [95% CI - 0.087 to 0.097] versus -0.087 [95% CI - 0.145 to - 0.030]; LVGCS: β = -0.006 [95% CI - 0.045 to 0.034] versus -0.048 [95% CI - 0.075 to - 0.021]; LVGLS: β = -0.011 [95% CI -  0.053 to 0.032] versus -0.063 [95% CI - 0.089 to - 0.036] for non-obese and obese patients; all p for interaction < 0.05).

CONCLUSIONS

Higher Hb levels are significantly associated with more severe LV dysfunction in MetS patients, particularly in those with obesity. Targeted monitoring and management of higher Hb levels in MetS patients may help mitigate further deterioration of cardiac function.

The association between oxidative balance score and gallstones in adults: a population-based study

PURPOSE

Oxidative stress is a significant contributor to the progression of gallstones. However, the combined or independent effects of dietary and lifestyle pro-antioxidants and antioxidants on gallstone formation remain unclear. Our study aims to investigate the potential link between the oxidative balance score (OBS) and the occurrence of gallstones.

PATIENTS AND METHODS

This study utilized data from the National Health and Nutrition Examination Survey (NHANES), conducted in the United States between 2017 and March 2020, identifying 750 gallstone cases among the 7,489 participants. Gallstone status was self-reported. The data in this study were analyzed using a range of statistical techniques, such as Multivariable logistic regression, restricted cubic spline curves (RCS), mediation effects analysis, subgroup analyses and sensitivity analysis.

RESULTS

Using fully adjusted multivariable logistic regression analysis, we identified a significant negative correlation between OBS and the occurrence of gallstones, with an odds ratio (OR) of 0.97 and a 95% confidence interval (CI) of 0.96 to 0.99. Furthermore, participants in the highest quartile of OBS exhibited a 41% reduced risk of gallstones compared to those in the lowest quartile, with an OR of 0.59 (95% CI: 0.45, 0.79) relative to the reference population. Additionally, a linear inverse association between OBS and gallstones was observed. Mediation analysis indicated that diabetes and cardiovascular diseases (CVD) mediated 3.5 and 4% of the association between OBS and gallstones, respectively.

CONCLUSION

This research suggests that lower OBS levels are associated with a higher susceptibility to gallstone formation, potentially offering a new perspective on clinical strategies for the management and prevention of gallstones.

Reassessing the role of nitric oxide in the pathogenesis of sphincter of Oddi dysfunction

The pathogenic mechanisms underlying sphincter of Oddi dysfunction (SOD) remain incompletely understood, and it often leads to severe symptoms encompassing nausea, vomiting, and abdominal pain. New evidence now suggests correlations between nitric oxide (NO) and SOD. In this review, we summarized the factors influencing SOD pathogenesis via NO and its derivative, the peroxynitrite anion. NO appears to enhance SOD progression by modulating sphincter of Oddi (SO) contractions via NO-sGC-cGMP signaling or inducing the apoptosis of enteric neurons, interstitial cells of Cajal, smooth muscle cells, and other cellular components via peroxynitrite anion-mediated organelle damage. Thus, a comprehensive understanding of SOD will provide a foundation for the identification of potential drugs and treatment approaches.

L-arginine administration exacerbates myocardial injury in diabetics via prooxidant and proinflammatory mechanisms along with myocardial structural disruption

BACKGROUND

L-arginine (L-Arg) is one of the most widely used amino acids in dietary and pharmacological products. However, the evidence on its usefulness and dose limitations, especially in diabetics is still controversial.

AIM

To investigate the effects of chronic administration of different doses of L-Arg on the cardiac muscle of type 2 diabetic rats.

METHODS

Of 96 male rats were divided into 8 groups as follows (n = 12): Control, 0.5 g/kg L-Arg, 1 g/kg L-Arg, 1.5 g/kg L-Arg, diabetic, diabetic + 0.5 g/kg L-Arg, diabetic + 1 g/kg L-Arg, and diabetic + 1.5 g/kg L-Arg; whereas L-Arg was orally administered for 3 months to all treated groups.

RESULTS

L-Arg produced a moderate upregulation of blood glucose levels to normal rats, but when given to diabetics a significant upregulation was observed, associated with increased nitric oxide, inflammatory cytokines, and malonaldehyde levels in diabetic rats treated with 1 g/kg L-Arg and 1.5 g/kg L-Arg. A substantial decrease in the antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione concentrations, and Nrf-2 tissue depletion were observed at 1 g/kg and 1.5 g/kg L-Arg diabetic treated groups, associated with myocardial injury, fibrosis, α-smooth muscle actin upregulation, and disruption of desmin cardiac myofilaments, and these effects were not noticeable at normal treated groups. On the other hand, L-Arg could significantly improve the lipid profile of diabetic rats and decrease their body weights.

CONCLUSION

L-Arg dose of 1 g/kg or more can exacerbates the diabetes injurious effects on the myocardium, while 0.5 g/kg dose can improve the lipid profile and decrease the body weight.

Brain glucose metabolism: Role of nitric oxide

One possible reason for failure in achieving optimal glycemic control in patients with type 2 diabetes (T2D) is that less attention has been paid to the brain, a fundamental player in glucose homeostasis, that consumes about 25% of total glucose utilization. In addition, animal and human studies indicate that nitric oxide (NO) is a critical player in glucose metabolism. NO synthesis from L-arginine is lower in patients with T2D, and endothelial NO synthase (eNOS)-derived NO bioavailability is lower in T2D. NO in the nervous system plays a role in neurovascular coupling (NVC) and the hypothalamic control of glucose sensing and energy homeostasis, influencing glucose utilization. This review explores NO's role in the brain's glucose metabolism. Literature indicates that glucose metabolism is different between neurons and astrocytes. Unlike neurons, astrocytes have a higher rate of glycolysis and a greater ability for lactate production. Astrocytes produce a greater amount of NO than neurons. NO inhibits mitochondrial respiration in both neurons and astrocytes and decreases intracellular ATP. NO-induced inhibition of mitochondrial respiration in neurons is not accompanied by compensatory glycolysis because phosphofructokinase 2.3 (PFK2.3), the most potent activator of PFK1 and thus glycolysis, is subjected to ubiquitylation and proteasomal degradation by cadherin-1 (Cdh1)-activated anaphase-promoting complex/cyclosome (APC/C), which leads to a low glycolytic rate in neurons. In astrocytes, NO inhibits mitochondrial respiration, but astrocytes display compensatory glycolysis by activating the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway.

AMPK-mediated regulation of cardiac energy metabolism: Implications for thermotolerance in Argopecten irradians irradians

AMPK is a key regulator of metabolism in eukaryotes across various pathways related to energy regulation. Although extensive investigations of AMPK have been conducted in mammals and some model organisms, research on AMPK in scallops is comparatively limited. In this study, three AMPK family genes (AiAMPKα, AiAMPKβ and AiAMPKγ) in scallop Argopecten irradians irradians were identified through genome scanning. Structure prediction and phylogenetic analyses of AiAMPKs were performed to determine their structural features and evolutionary relationships. Spatiotemporal expression patterns of AiAMPKs at different developmental stages and in healthy adult tissues were analyzed to elucidate the function of AiAMPKs in bay scallops' growth and development. The spatiotemporally specific expression of AiAMPKs implied their important roles in growth and development of bay scallops. Heat stress experiment was performed to determine the regulations of AiAMPKs in four kinds of thermosensitive tissues. Expression profiles revealed distinct molecular mechanisms of AiAMPKs in different tissues in response to heat stress: significant down-regulations in mobile hemocytes, but dominant up-regulations occurring in stationary gills, mantles and hearts. Functional verification including knock-down of AiAMPKα and inhibition of AiAMPK was separately conducted in the thermotolerant tissue heart at the post-transcription and translation levels. The thermotolerant index Arrhenius break temperature (ABT) showed a significant decrease and the rate-amplitude product (RAP) peaked earlier in the individuals after RNAi targeting AiAMPKα, displaying an earlier transition to anaerobic metabolism under heat stress, indicating an impairing ability of aerobic metabolism. After AiAMPK inhibition, widespread down-regulations of genes in key energy metabolism pathways, RNA polymerase II-mediated transcription, and aminoacyl-tRNA synthesis pathways were obviously observed, revealing the post-translational inhibition of AiAMPK hindered cardiac energy metabolism, basal transcription and translation. Overall, our findings provide evidences for exploring the molecular mechanisms of energy regulation in thermotolerant traits in bay scallops under ongoing global warming.

Diabetes and its Silent Partner: A Critical Review of Hyperinsulinemia and its Complications

In this complex realm of diabetes, hyperinsulinemia is no longer regarded as just a compensatory response to insulin resistance but rather has evolved into an integral feature. This comprehensive review provides a synthesis of the current literature, including various aspects associated with hyperinsulinemia in diabetic complications. Hyperinsulinemia has been shown to be more than just a compensatory mechanism, and the key findings demonstrate how hyperinsulinism affects the development of cardiovascular events as well as microvascular complications. Additionally, recognizing hyperinsulinemia as a modifiable factor, the diabetes management paradigm shifts towards cognitive ones that consider the use of lifestyle modifications in combination with newer pharmacotherapies and precision medicine approaches. These findings have crucial implications for the clinical work, requiring a careful appreciation of hyperinsulinemia's changing aspects as well as incorporation in personalized treatment protocol. In addition, the review focuses on bigger issues related to public health, showing that prevention and early diagnosis will help reduce the burden of complications. Research implications favor longitudinal studies, biomarker discovery, and the study of emerging treatment modalities; clinical practice should adopt global evaluations, patient education, and precision medicine adaptation. Finally, this critical review provides an overview of the underlying processes of hyperinsulinemia in diabetes and its overall health effects.

Responsive probes for in vivo magnetic resonance imaging of nitric oxide

Nitric oxide (NO), a pivotal signalling molecule, plays multifaceted roles in physiological and pathological processes, including cardiovascular and immune functions, neurotransmission and cancer progression. Nevertheless, measuring NO in vivo is challenging due to its transient nature and the complexity of the biological environment. Here we describe NO-responsive magnetic probes made of crosslinked superparamagnetic iron oxide nanoparticles tethered to a NO-sensitive cleavable linker for highly sensitive and selective NO magnetic resonance imaging in vivo. These probes enable the detection of NO at concentrations as low as 0.147 μM, allowing for the imaging and quantification of NO in mouse tumour models, studying its effects on tumour progression and immunity and assessing the response of tumour-associated macrophages to cancer immunotherapeutic agents. Additionally, they facilitate concurrent anatomical and molecular imaging of organs, helping to identify pathological alterations in the liver. Overall, these probes represent promising non-invasive tools for investigating the dose-dependent conflicting role of NO in physiological and pathophysiological processes.

Type 2 diabetes-related sarcopenia: role of nitric oxide

Sarcopenia, characterized by progressive and generalized loss of skeletal muscle (SkM) mass, strength, and physical performance, is a prevalent complication in type 2 diabetes (T2D). Nitric oxide (NO), a multifunctional gasotransmitter involved in whole-body glucose and insulin homeostasis, plays key roles in normal SkM physiology and function. Here, we highlight the role of NO in SkM mass maintenance and its potential contribution to the development of T2D-related sarcopenia. Physiologic NO level, primarily produced by sarcolemmal neuronal nitric oxide synthase (nNOSμ isoform), is involved in protein synthesis in muscle fibers and maintenance of SkM mass. The observed effect of nNOSμ on SkM mass is muscle-type specific and sex-dependent. Impaired NO homeostasis [due to a diminished nNOSμ-NO availability and excessive NO production through inducible NOS (iNOS) in response to atrophic stimuli, e.g., inflammatory cytokines] in SkM occurred during the development and progression of T2D, may cause sarcopenia. Theoretically, restoration of NO through nNOS overexpression, supplying NOS substrates (e.g., L-arginine and L-citrulline), phosphodiesterase (PDE) inhibition, and supplementation with NO donors (e.g., inorganic nitrate) may be potential therapeutic approaches to preserve SkM mass and prevents sarcopenia in T2D.

Singlet Oxygen-Triggered Release of Nitric Oxide in an Endoperoxide-Arginine Conjugate

Nitric oxide (NO) is an important signaling molecule in both healthy and pathological processes. In this work, we present the first example of a novel class of organic NO-donor compounds with minimal toxicity. The release is driven by the reaction of singlet oxygen spontaneously produced by the cycloreversion reaction of the endoperoxide. Cell culture and imaging data confirms the release of NO in this bimodular system.

Mitochondrial Function and Oxidative Stress Biomarkers in Diabetic Retinopathy Development: An Analytical Cross-Sectional Study

DR is a complex complication of DM with multiple biochemical pathways implicated in its genesis and progression. Circulating OS and mitochondrial function biomarkers represent potential candidates in the DR staging system. We conducted a comparative cross-sectional study comparing the OS biomarkers: TAC, GR, NOS, CARB, and hydroperoxydes, as well as mitochondrial function biomarkers: ATP synthase and ATPase activity in healthy volunteers, DM w/o DR, Moderate and Severe NPDR, and PDR. TAC is progressively diminished the more DR progresses to its proliferative stages. GR and NOS may function as biomarkers to differentiate the progression from S NPDR to PDR. CARB may correlate with the progression from M NPDR to S NPDR. Hydroperoxide levels were higher in patients with DR compared to DM w/o DR expressing OS in the early development of DR. ATPase activity is increasingly augmented the more DR progresses and may function as a biomarker that reflects the difference between N PDR and PDR, and ATP synthesis was lower the more DR progressed, being significantly lower compared to DM w/o DR. The behavior of OS and mitochondrial function in several stages of DR may aid in the staging and the prognosis of DR.

Maternal prediabetes as a risk factor of preeclampsia and placental dysfunction in pregnant female Sprague-Dawley rats

BACKGROUND

Prediabetes (PD) is associated with intermediate hyperglycaemia, dyslipidaemia, reduced nitric oxide (NO) bioavailability and moderate hypertension. All these factors are risk factor for preeclampsia (PE). However, the effects of the PD on placental function have not been shown. Accordingly, this study sought to investigate a possible link between maternal PD and the risk of developing PE.

METHODS

Pregnant female Sprague-Dawley rats (N = 18) were divided into normal, preeclamptic and prediabetic groups (n = 6 in each group) to study the effects of maternal PD on placenta function over the period of 19 days. Blood glucose and blood pressure were measured on gestational day (GND) 0, 9 and 18. Placental vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) mRNA expression were measured terminally. Data were analysed using ANOVA followed by the Tukey-Kramer post hoc test. Values of p < .05 were used to indicate statistical significance.

RESULTS

Maternal PD and PE significantly increased blood glucose, decrease NO concentration and increase in MAP by comparison to the normal pregnant control group. Maternal PD significantly decreased VEGF, PlGF mRNA expression with a slight increase in sFlt-1 mRNA expression comparison to the normal pregnant control group.

CONCLUSIONS

Maternal PD is associated with placental dysfunction due to impaired glucose handling, endothelial dysfunction and an imbalance in angiogenic and antiangiogenic factors. Therefore, maternal PD is a risk factor of PE.

Organic vs. inorganic nitrates: Metabolic and vascular outcomes in STZ-induced diabetes in mice

BACKGROUND

Diabetic animals often display dysregulated nitric oxide (NO) metabolism, contributing to vascular dysfunction. This study evaluates the metabolic and vascular effects of organic nitrate isosorbide mononitrate (ISMN) versus inorganic sodium nitrate (NaNO3) in mice with type 1 diabetes mellitus (T1DM) induced by streptozotocin (STZ).

EXPERIMENTAL APPROACH

T1DM was induced in male C57Bl6 mice with STZ ip and confirmed by fasting glucose. Mice were treated with ISMN (10 mg·kg-1) or NaNO3 (85 mg·L-1) for 14 days. A combination of in vivo, in vitro, and ex vivo studies assessed cardiometabolic benefits.

RESULTS

Both nitrates reduced blood and urinary hyperglycemia in T1DM mice, with ISMN exhibiting more significant reductions in blood glucose. ISMN and NaNO3 similarly reduced water and food intake, urinary volume, glucose intolerance, and insulin resistance while increasing insulin and nitrite levels in serum and urine. Both nitrates improved endothelium-independent vascular function and attenuated reactive oxygen species (ROS) while increasing NO levels in the aortic rings of T1DM mice. Furthermore, both nitrates similarly reduced mean arterial pressure in T1DM mice.

CONCLUSION AND IMPLICATIONS

ISMN and NaNO₃ have demonstrated comparable hypotensive and antioxidant effects, offering metabolic and vascular benefits in STZ-TDM1 mice. The more pronounced reduction in blood glucose with ISMN treatment compared to NaNO₃ is particularly promising. The antihyperglycemic effects of both nitrates were linked to increased serum insulin levels and enhanced insulin sensitivity. These results provide a foundation for future clinical studies to evaluate the potential of ISMN or NaNO3 as antidiabetogenic and antihypertensive adjuvant therapies in diabetic patients.

"NO" controversy?: A controversial role in insulin signaling of diabetic encephalopathy

Insulin, a critical hormone in the human body, exerts its effects by binding to insulin receptors and regulating various cellular processes. While nitric oxide (NO) plays an important role in insulin secretion and acts as a mediator in the signal transduction pathway between upstream molecules and downstream effectors, holds a significant position in the downstream signal network of insulin. Researches have shown that the insulin-NO system exhibits a dual regulatory effect within the central nervous system, which is crucial in the regulation of diabetic encephalopathy (DE). Understanding this system holds immense practical importance in comprehending the targets of existing drugs and the development of potential therapeutic interventions. This review extensively examines the characterization of insulin, NO, Nitric oxide synthase (NOS), specific NO pathway, their interconnections, and the mechanisms underlying their regulatory effects in DE, providing a reference for new therapeutic targets of DE.

Hyperglycemia-driven signaling bridges between diabetes and cancer

Growing epidemiological evidence indicates an association between obesity, type 2 diabetes, and certain cancers, suggesting the existence of common underlying mechanisms in these diseases. Frequent hyperglycemias in type 2 diabetes promote pro-inflammatory responses and stimulate intracellular metabolic flux which rewires signaling pathways and influences the onset and advancement of different types of cancers. Here, we review the provocative impact of hyperglycemia on a subset of interconnected signalling pathways that regulate (i) cell growth and survival, (ii) metabolism adjustments, (iii) protein function modulation in response to nutrient availability (iv) and cell fate and proliferation and which are driven respectively by PI3K (Phosphoinositide 3-kinase), AMPK (AMP-activated protein kinase), O-GlcNAc (O-linked N-acetylglucosamine) and Wnt/β-catenin. Specifically, we will elaborate on their involvement in glucose metabolism, inflammation, and cell proliferation, highlighting their interplay in the pathogenesis of diabetes and cancer. Furthermore, the influence of antineoplastic and antidiabetic drugs on the unbridled cellular pathways will be examined. This review aims to inspire the next molecular studies to understand how type 2 diabetes may lead to certain cancers. This will contribute to personalized medicine and direct better prevention strategies.

Association of Stress Hyperglycemia Ratio and in-Hospital Mortality in Patients with Sepsis: A Two Center Retrospective Cohort Study

Introduction

In critically ill patients, the stress hyperglycemia ratio (SHR) was significantly associated with mortality. However, the relationship between SHR and mortality in septic patients is still unclear.In this study, patients with sepsis from two Chinese academic centers were identified and divided into quartiles based on SHR levels.

Methods

Multivariable regression analysis will be used to determine associations between SHR and clinical outcomes in sepsis patients.The Kaplan-Meier curve was used to predict mortality in various groups of septic patients.

Results

A total of 1835 septic patients were included in the study.The in-hospital, 30-day, and 60-day mortality rates for all septic patients were 22.8%, 18.7%, and 21.7%, respectively. Increased SHR was significantly associated with hospital mortality in multivariate regression analysis.These results were further confirmed in the adjusted analysis, where the hospital mortality and the 60-day mortality of the highest SHR quartile were significantly increased compared to the lowest SHR quartile. However, the highest SHR quartile was not associated with 30-day mortality.In addition, the risk of in-hospital mortality, 30-day mortality and 60-day mortality showed a consistent upward trend with increasing SHR quartile. The survival curve showed that the worst prognosis was in the fourth SHR quartile.

Discussion

In conclusion, SHR was significantly associated with hospital mortality in patients with sepsis. This finding indicates that the SHR may be useful in identifying septic patients at higher risk of hospital mortality.

Association between stress hyperglycemia ratio index and all-cause mortality in critically ill patients with atrial fibrillation: a retrospective study using the MIMIC-IV database

BACKGROUND

The stress hyperglycemia ratio (SHR) was developed to mitigate the influence of long-term chronic glycemic factors on stress hyperglycemia levels, which are associated with adverse clinical events, particularly cardiovascular events. However, studies examining the SHR index and its prognostic significance in patients with atrial fibrillation (AF) are lacking. This study aims to evaluate the relationship between the SHR index and all-cause mortality in critically ill patients with AF upon Intensive Care Unit admission.

METHODS

The patients' data were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. All patients were categorized into four groups based on the SHR index. The outcomes include both primary and secondary endpoints, with the primary endpoints being 30-day and 365-day all-cause mortality, and the secondary endpoints being 90-day and 180-day all-cause mortality. The SHR index was analyzed using quartiles, and the Kaplan-Meier curve was employed to compare the outcomes across groups. Cox proportional-hazards regression and restricted cubic splines (RCS) were used to assess the relationship between the SHR index and the outcomes.

RESULTS

Out of a total of 1,685 participants, the average age was 63.12 years (range: 40.17 to 101.49), with 1,004 (59.58%) being male. Higher levels of the SHR index were associated with an increased risk of all-cause mortality at 30 days, 90 days, 180 days, and 365 days, as indicated by the Kaplan-Meier curves (log-rank P < 0.01). Additionally, Cox proportional-hazards regression analysis revealed that the risk of mortality at these time points was significantly higher in the highest quartile of the SHR index. Restricted cubic splines (RCS) analysis demonstrated U-shaped relationships between the SHR index and all-cause mortality, with inflection points at 0.73 for 30-day mortality and 0.76 for 365-day mortality. Compared to patients with SHR levels below these inflection points, those with higher levels had a 69.9% increased risk for 30-day all-cause mortality (hazard ratio [HR] 1.699; 95% confidence interval [CI] 1.336 to 2.159) and a 61.6% increased risk for 365-day all-cause mortality (HR 1.616; 95% CI 1.345 to 1.942).

CONCLUSION

In critically ill patients with AF, higher levels of the SHR index are significantly associated with an increased risk of all-cause mortality at 30 days, 90 days, 180 days, and 365 days. The SHR index may serve as a valid indicator for assessing the severity and guiding the treatment of AF patients in the ICU.

Association of stress hyperglycemia ratio and mortality in patients with sepsis: results from 13,199 patients

BACKGROUND

The stress hyperglycemia ratio (SHR), adjusted for average glycemic status, is suggested for assessing actual blood glucose levels. Its link with adverse outcomes is known in certain populations, yet its impact on sepsis patients' prognosis is unclear. This study explores the association between SHR and mortality in sepsis.

METHODS

We included 13,199 sepsis patients in this study and categorized SHR into distinct groups. Additionally, we utilized restricted cubic spline analysis to evaluate the correlation between SHR as a continuous variable and mortality. The primary outcome was 1-year all-cause mortality. Logistic regression and Cox proportional hazards models were employed to assess the associations between the SHR and both in-hospital mortality and 1-year mortality, respectively.

RESULTS

Among the study participants, 4,690 (35.5%) patients died during the 1-year follow-up. After adjusting for confounding variables, we identified a U-shaped correlation between SHR and 1-year mortality. Using an SHR of 0.99 as the reference point, the hazard ratio for predicted 1-year mortality increased by 1.17 (95% CI 1.08 to 1.27) per standard deviation above 0.99, whereas each standard deviation increase predicted the hazard ratio of 0.52 (95% CI 0.39 to 0.69) below 0.99. Furthermore, we found that SHR could enhance the predictive performance of conventional severity scores.

CONCLUSION

There exists a U shaped association between SHR and mortality in sepsis patients, where both low and high SHR values are associated with an increased risk of poor outcomes.

Impact of different hormones on the regulation of nitric oxide in diabetes

Polymetabolic syndrome achieved pandemic proportions and dramatically influenced public health systems functioning worldwide. Chronic vascular complications are the major contributors to increased morbidity, disability, and mortality rates in diabetes patients. Nitric oxide (NO) is among the most important vascular bed function regulators. However, NO homeostasis is significantly deranged in pathological conditions. Additionally, different hormones directly or indirectly affect NO production and activity and subsequently act on vascular physiology. In this paper, we summarize the recent literature data related to the effects of insulin, estradiol, insulin-like growth factor-1, ghrelin, angiotensin II and irisin on the NO regulation in physiological and diabetes circumstances.

Inspiratory muscle strength training to improve cardiometabolic health in patients with type 2 diabetes mellitus: protocol for the diabetes inspiratory training clinical trial

Type 2 diabetes mellitus (T2DM) is a complex, chronic metabolic disease that carries with it a high prevalence of comorbid conditions, making T2DM one of the leading causes of death in the U.S. Traditional lifestyle interventions (e.g., diet, exercise) can counter some adverse effects of T2DM, however, participation in these activities is low with reasons ranging from physical discomfort to lack of time. Thus, there is a critical need to develop novel management strategies that effectively reduce cardiometabolic disease risk and address barriers to adherence. High-resistance inspiratory muscle strength training (IMST) is a time-efficient and simple breathing exercise that significantly reduces systolic and diastolic BP and improves vascular endothelial function in adults with above-normal blood pressure. Herein we describe the study protocol for a randomized clinical trial to determine the effects of a 6-week IMST regimen on glycemic control and insulin sensitivity in adults with T2DM. Our primary outcome measures include fasting plasma glucose, fasting serum insulin, and insulin resistance utilizing homeostatic model assessment for insulin resistance (HOMA-IR). Secondary outcome measures include resting systolic BP and endothelium-dependent dilation. Further, we will collect plasma for exploratory proteomic analyses. This trial seeks to establish the cardiometabolic effects of 6 weeks of high-resistance IMST in patients with T2DM.

Aqueous extract of Peristrophe bivalvis (L.) Merr. leaf reversed the detrimental effects of nitric oxide synthase inhibitor on blood lipid profile and glucose level

There is evidence that nitric oxide (NO) modulates the metabolism of glucose and lipid, and some antihypertensive medications have been shown to affect glucose and lipid metabolism. Peristrophe bivalvis is a medicinal plant that has been shown to have antihypertensive properties. The study investigated the effect of aqueous extract of Peristrophe bivalvis leaf (APB) on fasting blood glucose level (FBG) and lipid profile in rats pretreated with nitro-L-arginine methyl ester (L-NAME). Male Wistar rats (150-170 g, n=30) were randomly divided into two groups: control (CT, n=5) and L-NAME pretreated (n=25). CT received 5 mL/kg of distilled water [DW]) while L-NAME pretreated group received 60 mg/kg of L-NAME (L-NAME60) for eight weeks. After eight weeks, the L-NAME pretreated group was randomly subdivided into L-NAME group (LN), L-NAME recovery group (LRE), L-NAME ramipril group (LRA), and L-NAME APB group (LAPB). The groups received L-NAME60+DW, DW, L-NAME60+10 mg/kg ramipril, and L-NAME60+APB (200 mg/kg), respectively, for five weeks. Serum NO, lipid profile, cyclic guanosine monophosphate (cGMP), and insulin were measured by spectrophotometry, assay kits, and ELISA, respectively. Data were analysed using ANOVA at p < 0.05. At the eighth week, a fall in FBG and an increase in triglyceride, total cholesterol, and low-density lipoprotein cholesterol were recorded in L8 compared to CT. The same effects were also noticed in the thirteenth week in LN. However, FBG was significantly increased and lipid levels were decreased in LAPB compared to LN. A significant increase was observed in cGMP level in LAPB compared to LN. The study showed that APB corrected the hyperlipidemia and hypoglycemia caused by L-NAME, and this effect might be via the activation of cGMP.

Nitrate: "the source makes the poison"

Interest in the role of dietary nitrate in human health and disease has grown exponentially in recent years. However, consensus is yet to be reached as to whether consuming nitrate from various food sources is beneficial or harmful to health. Global authorities continue to recommend an acceptable daily intake (ADI) of nitrate of 3.7 mg/kg-bw/day due to concerns over its carcinogenicity. This is despite evidence showing that nitrate consumption from vegetable sources, exceeding the ADI, is associated with decreased cancer prevalence and improvements in cardiovascular, oral, metabolic and neurocognitive health. This review examines the paradox between dietary nitrate and health and disease and highlights the key role of the dietary source and food matrix in moderating this interaction. We present mechanistic and epidemiological evidence to support the notion that consuming vegetable-derived nitrate promotes a beneficial increase in nitric oxide generation and limits toxic N-nitroso compound formation seen with high intakes of nitrate added during food processing or present in contaminated water. We demonstrate the need for a more pragmatic approach to nitrate-related nutritional research and guidelines. Ultimately, we provide an overview of our knowledge in this field to facilitate the various therapeutic applications of dietary nitrate, whilst maintaining population safety.

Nitric oxide in modulating oxidative stress mediated skeletal muscle insulin resistance

Insulin resistance (IR) being the major cause behind different metabolic disorders, has attracted a lot of attention. Epidemiological data shows marked rise in the cases over a period of time. Nitric oxide (NO), produced from nitric oxide synthases (NOS), is involved in a variety of biological functions, alteration in which causes various disorders like hypertension, atherosclerosis, and angiogenesis-associated disorders. IR has been found to be a contributing factor, which is associated with abnormal NO signalling. Skeletal muscle is essential for metabolism, both for its role in glucose uptake and its importance in metabolic disease. In this article, we give an overview of the significance of NO in oxidative stress (OS) mediated IR, describing its role in different conditions that are associated with skeletal muscle IR. NO is found to be involved in the activation of insulin receptor downstream pathway, which suggests absence of NO could lead to reduced glucose uptake, and may ultimately result in IR.

Central angiotensin-(1-7) attenuates hypoglycemia in sepsis-like conditions via reducing systemic and hepatic inflammation

Sepsis is understood as the result of initiating systemic inflammation derived from an inadequate host response against pathogens. In its acute phase, sepsis is marked by an exacerbated reaction to infection, tissue damage, organ failure, and metabolic dysfunction. Among these, hypoglycemia, characterized by disorders of the gluconeogenesis pathway, is related to one of the leading causes of mortality in septic patients. Recent research has investigated the involvement of sympathetic efferent neuroimmune pathways during systemic inflammation. These pathways can be stimulated by several centrally administered drugs, including Angiotensin-(1-7) (Ang-(1-7)). Therefore, the present study aims to evaluate the effects of central treatment with Ang-(1-7) on hypoglycemia during endotoxemia. For this, male Wistar Hannover rats underwent stereotaxic surgery for intracerebroventricular (i.c.v.) administration of Ang-(1-7) and cannulation of the jugular vein for lipopolysaccharide (LPS) injection. Our results demonstrate that LPS was capable of inducing hypoglycemia and that prior central treatment with Ang-(1-7) attenuated this effect. Our data also show that Ang-(1-7) reduced plasma concentrations of TNF-α, IL-1β, IL-6, and nitric oxide, in addition to the decrease and increase of hepatic IL-6 and IL-10 respectively, in animals subjected to systemic inflammation by LPS, resulting in the reduction of systemic and hepatic inflammation, thus attenuating the deleterious effects of LPS on phosphoenolpyruvate carboxykinase protein content. In summary, the data suggest that central treatment with Ang-(1-7) attenuates hypoglycemia induced by endotoxemia, probably through anti-inflammatory action, leading to reestablishing hepatic gluconeogenesis.

J-shaped relationship between stress hyperglycemia ratio and 90-day and 180-day mortality in patients with a first diagnosis of acute myocardial infarction: analysis of the MIMIC-IV database

AIMS

The Stress Hyperglycemia Ratio (SHR) potently predicts adverse outcomes in patients with cardiovascular and cerebrovascular diseases. However, the relationship between SHR and short-term mortality risk in patients with a first diagnosis of acute myocardial infarction (AMI) remains contentious. This study sought to understand better the relationship between SHR and short-term mortality risk in patients with a first diagnosis of AMI.

METHODS

We conducted a cohort study using data from 1961 patients with a first diagnosis of AMI from the MIMIC-IV (version 2.2) database. Patients were divided into three groups based on SHR tertiles. The Cox proportional hazards model and a two-segmented Cox proportional hazards model were used to elucidate the nonlinear relationship between SHR in patients with a first diagnosis of AMI and mortality.

RESULTS

Of the surveyed population, 175 patients (8.92%) died within 90 days, and 210 patients (10.71%) died within 180 days. After multivariate adjustments, elevated SHR levels were significantly and non-linearly associated with a higher risk of 90-day and 180-day mortality in patients with a first diagnosis of AMI, showing a J-shaped correlation with an inflection point at 0.9. Compared to participants with SHR levels below the inflection point, those with higher SHR levels had a fivefold increased risk of 90-day mortality (hazard ratio [HR] 5.74; 95% confidence interval [CI] 3.19, 10.33) and a fourfold increased risk of 180-day mortality (HR 4.56; 95% CI 2.62, 7.95). In the subgroup analysis, patients with pre-diabetes mellitus (pre-DM) and higher SHR levels had increased 90-day (HR 6.90; 95% CI  1.98, 24.02) and 180-day mortality risks (HR 5.30; 95% CI  1.96, 14.27).

CONCLUSION

In patients with a first diagnosis of AMI, there is a J-shaped correlation between SHR and 90-day and 180-day mortality, with an adverse prognostic inflection point of SHR at 0.9.

The cross-sectional correlation between the oxidative balance score and cardiometabolic risk factors and its potential correlation with longitudinal mortality in patients with cardiometabolic risk factors

BACKGROUND

This study analyzes the correlation between oxidative balance score (OBS), cardiometabolic risk factors (CMRFs), and mortality in individuals with CMRFs.

METHODS

Data were chosen from the National Health and Nutrition Examination Survey. The survey-weighted multivariable logistic regression models were implemented to explore the relationship between OBS and the risk of CMRFs. Then, Cox proportional hazard models were employed to estimate the impact of OBS on mortality in individuals with CMRFs.

RESULTS

Following multivariate adjustment, the subjects in the highest quartile exhibited a 46% reduction in the risk of CMRFs, a 33% reduction in the risk of diabetes, a 31% reduction in the risk of hypertension, and a 36% reduction in the risk of hyperlipidemia, compared with those in the lowest quartile. Furthermore, each 1-unit increase in OBS was remarkably negatively correlated with the prevalence of CMRFs, diabetes, hypertension, and hyperlipidemia. The correlation between OBS and CMFRs was found to be mediated by serum γ-glutamyltransferase (GGT) and white blood cells (WBC), and the mediation effect of GGT levels and WBC, accounting for 6.90% and 11.51%, respectively. Lastly, the multivariate Cox regression model revealed that elevated OBS, irrespective of whether it was treated as a categorical or continuous variable, exhibited a significant association with decreased mortality from all causes, cardiovascular disease, and cancer.

CONCLUSIONS

An increased OBS might reflect a lower risk of CMRFs and a favorable prognosis for individuals with CMRFs. Moreover, WBC and GGT may play a potential mediating role between OBS and CMRFs.

Exploring the metabolic and antioxidant potential of solergy: Implications for enhanced animal production

Cell models are indispensable tools in biotechnology when investigating the functional properties of organic compounds. The emergence of various additives designed to enhance animal production has introduced the need for in-depth evaluations, which are often hindered by the complexities of in vivo testing. In this study, we harnessed cell-based models to scrutinize the impact of Solergy as a regulator of cellular metabolism with a particular focus on its modulation of glycogen and antioxidant effects. Our experiment was designed to include assessments of the influence of Solergy on the viability of both terrestrial and aquatic vertebrate cell models, which revealed the benign nature of Solergy and its lack of adverse effects. Furthermore, we examined the capacity of Solergy to modulate intracellular ATP concentrations and enhance glycogen accumulation. Notably, the antioxidant potential of Solergy and its ability to mitigate cellular aging were evaluated within the same cellular frameworks. The outcomes of our investigation suggest that Solergy is a potent metabolic regulator that elevates cellular activity while exerting an antioxidant effect. Importantly, our study demonstrates that Solergy does not induce changes in membrane oxidation. These findings indicate the potential of using Solergy to regulate glycogen synthesis, intracellular ATP concentrations, and oxidative stress in production animals. The multifaceted effects of this additive, which acts as both a metabolism enhancer and an antioxidant, open doors to the creation of custom diets tailored to meet specific production needs while maintaining stable production parameters.

Adipose organ dysfunction and type 2 diabetes: Role of nitric oxide

Adipose organ, historically known as specialized lipid-handling tissue serving as the long-term fat depot, is now appreciated as the largest endocrine organ composed of two main compartments, i.e., subcutaneous and visceral adipose tissue (AT), madding up white and beige/brown adipocytes. Adipose organ dysfunction manifested as maldistribution of the compartments, hypertrophic, hypoxic, inflamed, and insulin-resistant AT, contributes to the development of type 2 diabetes (T2D). Here, we highlight the role of nitric oxide (NO·) in AT (dys)function in relation to developing T2D. The key aspects determining lipid and glucose homeostasis in AT depend on the physiological levels of the NO· produced via endothelial NO· synthases (eNOS). In addition to decreased NO· bioavailability (via decreased expression/activity of eNOS or scavenging NO·), excessive NO· produced by inducible NOS (iNOS) in response to hypoxia and AT inflammation may be a critical interfering factor diverting NO· signaling to the formation of reactive oxygen and nitrogen species, resulting in AT and whole-body metabolic dysfunction. Pharmacological approaches boosting AT-NO· availability at physiological levels (by increasing NO· production and its stability), as well as suppression of iNOS-NO· synthesis, are potential candidates for developing NO·-based therapeutics in T2D.

'NO-how' enzymatic S-nitrosylation controls insulin pathophysiology

Whether S-nitrosylation is the result of an unselective chemical process or enzymatically driven has been debated for years. A recent study by Zhou et al. identifies and characterizes the first S-nitroso-CoA (SNO-CoA)-assisted nitrosylase (SCAN) that catalyzes protein S-nitrosylation in mammals, including insulin receptor (INSR)/insulin receptor substrate 1 (IRS1), with implications for human metabolism.

Anti-obesity and anti-diabetic effects of L-citrulline are sex-dependent

AIMS

Anti-diabetic and anti-obesity effects of L-citrulline (Cit) have been reported in male rats. This study determined sex differences in response to Cit in Wistar rats.

MAIN METHODS

Type 2 diabetes (T2D) was induced using a high-fat diet followed by low-dose of streptozotocin (30 mg/kg) injection. Male and female Wistar rats were divided into 4 groups (n = 6/group): Control, control+Cit, T2D, and T2D + Cit. Cit (4 g/L in drinking water) was administered for 8 weeks. Obesity indices were recorded, serum fasting glucose and lipid profile were measured, and glucose and pyruvate tolerance tests were performed during the Cit intervention. White (WAT) and brown (BAT) adipose tissues were weighted, and the adiposity index was calculated at the end of the study.

KEY FINDINGS

Cit was more effective in decreasing fasting glucose (18 % vs. 11 %, P = 0.0100), triglyceride (20 % vs. 14 %, P = 0.0173), and total cholesterol (16 % vs. 11 %, P = 0.0200) as well as decreasing gluconeogenesis and improving glucose tolerance, in females compared to male rats with T2D. Following Cit administration, decreases in WAT weight (16 % vs. 14 % for gonadal, 21 % vs. 16 % for inguinal, and 18 % vs. 13 % for retroperitoneal weight, all P < 0.0001) and increases in BAT weight (58 % vs. 19 %, for interscapular and 10 % vs. 7 % for axillary, all P < 0.0001) were higher in females than male rats with T2D. The decrease in adiposity index was also higher (11 % vs. 9 %, P = 0.0007) in females.

SIGNIFICANCE

The anti-obesity and anti-diabetic effects of Cit in rats are sex-dependent, with Cit being more effective in female than male rats.

Enhancing immune regulation in vitro: the synergistic impact of 3'-sialyllactose and osteopontin in a nutrient blend following influenza virus infection

Natural components of breast milk, human milk oligosaccharides (HMOs) and osteopontin (OPN) have been shown to have a variety of functional activities and are widely used in infant formulas. However, the preventive and therapeutic effects of both on influenza viruses are not known. In this study, antiviral assays using a human laryngeal carcinoma cell line (HEP-2) showed that 3'-sialyllactose (3'-SL) and OPN had the best antiviral ability with IC50 values of 33.46 μM and 1.65 μM, respectively. 3'-SL (10 μM) and OPN (4 μM) were used in combination to achieve 75% inhibition. Further studies found that the combination of 200 μg/mL of 3'-SL with 500 μg/mL of OPN exerted the best antiviral ability. The reason for this was related to reduced levels of the cytokines TNF-α, IL-6, and iNOS in relation to mRNA expression. Plaque assay and TCID50 assay found the same results and verified synergistic effects. Our research indicates that a combination of 3'-SL and OPN can effectively reduce inflammatory storms and exhibit anti-influenza virus effects through synergistic action.

The genetic and dietary landscape of the muscle insulin signalling network

Metabolic disease is caused by a combination of genetic and environmental factors, yet few studies have examined how these factors influence signal transduction, a key mediator of metabolism. Using mass spectrometry-based phosphoproteomics, we quantified 23,126 phosphosites in skeletal muscle of five genetically distinct mouse strains in two dietary environments, with and without acute in vivo insulin stimulation. Almost half of the insulin-regulated phosphoproteome was modified by genetic background on an ordinary diet, and high-fat high-sugar feeding affected insulin signalling in a strain-dependent manner. Our data revealed coregulated subnetworks within the insulin signalling pathway, expanding our understanding of the pathway's organisation. Furthermore, associating diverse signalling responses with insulin-stimulated glucose uptake uncovered regulators of muscle insulin responsiveness, including the regulatory phosphosite S469 on Pfkfb2, a key activator of glycolysis. Finally, we confirmed the role of glycolysis in modulating insulin action in insulin resistance. Our results underscore the significance of genetics in shaping global signalling responses and their adaptability to environmental changes, emphasising the utility of studying biological diversity with phosphoproteomics to discover key regulatory mechanisms of complex traits.

Early Detection of Diabetic Peripheral Neuropathy in Diabetic Patients: A Cross-Sectional Study

BACKGROUND

Diabetic Peripheral Neuropathy (DPN) is a chronic complication in Type 2 Diabetes Mellitus (T2DM) patients and is characterized by paresthesia, pain, and hypoesthesia of the extremities. The Diabetic Neuropathy Symptom-Score (DNS) is a quick, inexpensive, and easy-to-perform tool to detect DPN in clinical practice. Biochemical markers like Nitric Oxide (NO) and Vascular Endothelial Growth Factor (VEGF) play a role in the early detection of DPN. This study aims to investigate the relationship between risk factors and these biomarkers. So, it is expected to improve the prevention and treatment of diabetic neuropathy more effectively.

METHOD

A cross-sectional method was used for this study. The sample size was 85 patients with T2DM who visited several primary healthcare in Medan, selected by consecutive sampling method based on eligibility criteria. Data collected included DNS, assessment of NO, VEGF, Glycated Hemoglobin (HbA1c), plasma blood glucose (PBG), and lipid profile. The collected data were analyzed using an independent T-test.

RESULT

The results showed that most T2DM patients, namely 73 people (85.9%), experienced DPN. From the bivariate analysis results, the risk factors associated with the prevalence of DPN in T2DM patients were found to be increased levels of total cholesterol, HbA1c, NO, and VEGF (p < 0.05). Meanwhile, blood pressure, fasting BGL, HDL-C, LDL-C, and triglycerides were not related to the occurrence of DPN in this study (p> 0.05).

CONCLUSION

DNS can be used as a quick and easy initial screening tool implemented in clinical practice for screening DPN. Diabetic patients with DPN tend to have lower NO and increased VEGF; besides, NO levels are also associated with the progression of DPN. Furthermore, education, blood sugar control, and physical exercise, especially leg exercises, can prevent progressive DPN.

Physicochemical Properties of Yanggaeng with Added Tempeh Powder

In this study, we investigated the physicochemical and antioxidative properties of the traditional Korean confectionery, Yanggaeng, when various amounts of tempeh powder (TP) were added. We replaced a portion of the white bean paste in Yanggaeng with TP at percentages of 0% (CON), 2% (TP2), 4% (TP4), and 6% (TP6) by total weight. The proximate composition results showed that TP6 exhibited the highest crude ash and crude protein contents, but its moisture content and carbohydrate content were the lowest compared to the CON. Tempeh addition altered the colorimetric properties by increasing the L* value, b* value, and browning index; however, tempeh addition did not alter the a* value. The results also showed that tempeh addition gradually decreased the pH of Yanggaeng. The Brix value was the highest in TP2; in TP4 and TP6, the Brix value gradually decreased, and these formulations exhibited lower Brix values than the CON. Furthermore, tempeh addition gradually induced antioxidative capacities, as evidenced by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities. The results of this study demonstrate that the addition of tempeh to Yanggaeng alters its physicochemical properties and antioxidative capacity.

The SLC6A15-SLC6A20 Neutral Amino Acid Transporter Subfamily: Functions, Diseases, and Their Therapeutic Relevance

The neutral amino acid transporter subfamily that consists of six members, consecutively SLC6A15-SLC620, also called orphan transporters, represents membrane, sodium-dependent symporter proteins that belong to the family of solute carrier 6 (SLC6). Primarily, they mediate the transport of neutral amino acids from the extracellular milieu toward cell or storage vesicles utilizing an electric membrane potential as the driving force. Orphan transporters are widely distributed throughout the body, covering many systems; for instance, the central nervous, renal, or intestinal system, supplying cells into molecules used in biochemical, signaling, and building pathways afterward. They are responsible for intestinal absorption and renal reabsorption of amino acids. In the central nervous system, orphan transporters constitute a significant medium for the provision of neurotransmitter precursors. Diseases related with aforementioned transporters highlight their significance; SLC6A19 mutations are associated with metabolic Hartnup disorder, whereas altered expression of SLC6A15 has been associated with a depression/stress-related disorders. Mutations of SLC6A18-SLCA20 cause iminoglycinuria and/or hyperglycinuria. SLC6A18-SLC6A20 to reach the cellular membrane require an ancillary unit ACE2 that is a molecular target for the spike protein of the SARS-CoV-2 virus. SLC6A19 has been proposed as a molecular target for the treatment of metabolic disorders resembling gastric surgery bypass. Inhibition of SLC6A15 appears to have a promising outcome in the treatment of psychiatric disorders. SLC6A19 and SLC6A20 have been suggested as potential targets in the treatment of COVID-19. In this review, we gathered recent advances on orphan transporters, their structure, functions, related disorders, and diseases, and in particular their relevance as therapeutic targets. SIGNIFICANCE STATEMENT: The following review systematizes current knowledge about the SLC6A15-SLCA20 neutral amino acid transporter subfamily and their therapeutic relevance in the treatment of different diseases.

Smart Magnetic Nanocarriers for Codelivery of Nitric Oxide and Doxorubicin for Enhanced Apoptosis in Cancer Cells

Extremely short half-life therapeutic molecule nitric oxide (NO) plays significant roles in the functioning of various physiological and pathological processes in the human body, whereas doxorubicin hydrochloride (DOX) is a clinically important anticancer drug widely used in cancer chemotherapy. Thus, the intracellular delivery of these therapeutic molecules is tremendously important to achieve their full potential. Herein, we report a novel approach for the development of highly water-dispersible magnetic nanocarriers for codelivery of NO and DOX. Primarily, bifunctional magnetic nanoparticles enriched with carboxyl and thiol groups were prepared by introducing cysteine onto the surface of citrate-functionalized Fe3O4 nanoparticles. DOX was electrostatically conjugated onto the surface of bifunctional nanoparticles via carboxyl moieties, whereas the thiol group was further nitrosated to provide NO-releasing molecules. The developed magnetic nanocarrier exhibited good aqueous colloidal stability, protein resistance behavior, and high encapsulation efficacy for NO (65.5%) and DOX (85%), as well as sustained release characteristics. Moreover, they showed superior cytotoxicity toward cancer (A549 and MCF-7) cells via apoptosis induction over normal (WI26VA4) cells. Specifically, we have developed magnetic nanocarriers having the capability of dual delivery of NO and DOX, which holds great potential for combinatorial cancer treatment.

Prognostic significance of the stress hyperglycemia ratio in critically ill patients

BACKGROUND

The stress hyperglycemia ratio (SHR) has demonstrated a noteworthy association with unfavorable cardiovascular clinical outcomes and heightened in-hospital mortality. Nonetheless, this relationship in critically ill patients remains uncertain. This study aims to elucidate the correlation between SHR and patient prognosis within the critical care setting.

METHODS

A total of 8978 patients admitted in intensive care unit (ICU) were included in this study. We categorized SHR into uniform groups and assessed its relationship with mortality using logistic or Cox regression analysis. Additionally, we employed the restricted cubic spline (RCS) analysis method to further evaluate the correlation between SHR as a continuous variable and mortality. The outcomes of interest in this study were in-hospital and 1-year all-cause mortality.

RESULTS

In this investigation, a total of 825 (9.2%) patients experienced in-hospital mortality, while 3,130 (34.9%) individuals died within the 1-year follow-up period. After adjusting for confounding variables, we identified a U-shaped correlation between SHR and both in-hospital and 1-year mortality. Specifically, within the SHR range of 0.75-0.99, the incidence of adverse events was minimized. For each 0.25 increase in the SHR level within this range, the risk of in-hospital mortality rose by 1.34-fold (odds ratio [OR]: 1.34, 95% CI: 1.25-1.44), while a 0.25 decrease in SHR within 0.75-0.99 range increased risk by 1.38-fold (OR: 1.38, 95% CI: 1.10-1.75).

CONCLUSION

There was a U-shaped association between SHR and short- and long-term mortality in critical ill patients, and the inflection point of SHR for poor prognosis was identified at an SHR value of 0.96.

From nitrate to NO: potential effects of nitrate-reducing bacteria on systemic health and disease

Current research has described improving multisystem disease and organ function through dietary nitrate (DN) supplementation. They have provided some evidence that these floras with nitrate (NO3-) reductase are mediators of the underlying mechanism. Symbiotic bacteria with nitrate reductase activity (NRA) are found in the human digestive tract, including the mouth, esophagus and gastrointestinal tract (GT). Nitrate in food can be converted to nitrite under the tongue or in the stomach by these symbiotic bacteria. Then, nitrite is transformed to nitric oxide (NO) by non-enzymatic synthesis. NO is currently recognized as a potent bioactive agent with biological activities, such as vasodilation, regulation of cardiomyocyte function, neurotransmission, suppression of platelet agglutination, and prevention of vascular smooth muscle cell proliferation. NO also can be produced through the conventional L-arginine-NO synthase (L-NOS) pathway, whereas endogenous NO production by L-arginine is inhibited under hypoxia-ischemia or disease conditions. In contrast, exogenous NO3-/NO2-/NO activity is enhanced and becomes a practical supplemental pathway for NO in the body, playing an essential role in various physiological activities. Moreover, many diseases (such as metabolic or geriatric diseases) are primarily associated with disorders of endogenous NO synthesis, and NO generation from the exogenous NO3-/NO2-/NO route can partially alleviate the disease progression. The imbalance of NO in the body may be one of the potential mechanisms of disease development. Therefore, the impact of these floras with nitrate reductase on host systemic health through exogenous NO3-/NO2-/NO pathway production of NO or direct regulation of floras ecological balance is essential (e.g., regulation of body homeostasis, amelioration of diseases, etc.). This review summarizes the bacteria with nitrate reductase in humans, emphasizing the relationship between the metabolic processes of this microflora and host systemic health and disease. The potential effects of nitrate reduction bacteria on human health and disease were also highlighted in disease models from different human systems, including digestive, cardiovascular, endocrine, nervous, respiratory, and urinary systems, providing innovative ideas for future disease diagnosis and treatment based on nitrate reduction bacteria.

Enhancing Muscle Intracellular Ca2+ Homeostasis and Glucose Uptake: Passive Pulsatile Shear Stress Treatment in Type 2 Diabetes

Type 2 diabetes mellitus (T2D) is a significant global public health problem that has seen a substantial increase in the number of affected individuals in recent decades. In a murine model of T2D (db/db), we found several abnormalities, including aberrant intracellular calcium concentration ([Ca2+]i), decreased glucose transport, increased production of reactive oxygen species (ROS), elevated levels of pro-inflammatory interleukins and creatine phosphokinase (CK), and muscle weakness. Previously, we demonstrated that passive pulsatile shear stress, generated by sinusoidal (headward-forward) motion, using a motion platform that provides periodic acceleration of the whole body in the Z plane (pGz), induces the synthesis of nitric oxide (NO) mediated by constitutive nitric oxide synthase (eNOS and nNOS). We investigated the effect of pGz on db/db a rodent model of T2D. The treatment of db/db mice with pGz resulted in several beneficial effects. It reduced [Ca2+]i overload; enhanced muscle glucose transport; and decreased ROS levels, interleukins, and CK. Furthermore, pGz treatment increased the expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), and neuronal nitric oxide synthase (nNOS); reduced inducible nitric oxide synthase (iNOS); and improved muscle strength. The cytoprotective effects of pGz appear to be mediated by NO, since pretreatment with L-NAME, a nonspecific NOS inhibitor, abolished the effects of pGz on [Ca2+]i and ROS production. Our findings suggest that a non-pharmacological strategy such as pGz has therapeutic potential as an adjunct treatment to T2D.

Nitric Oxide Function and Nitric Oxide Synthase Evolution in Aquatic Chordates

Nitric oxide (NO) is a key signaling molecule in almost all organisms and is active in a variety of physiological and pathological processes. Our understanding of the peculiarities and functions of this simple gas has increased considerably by extending studies to non-mammal vertebrates and invertebrates. In this review, we report the nitric oxide synthase (Nos) genes so far characterized in chordates and provide an extensive, detailed, and comparative analysis of the function of NO in the aquatic chordates tunicates, cephalochordates, teleost fishes, and amphibians. This comprehensive set of data adds new elements to our understanding of Nos evolution, from the single gene commonly found in invertebrates to the three genes present in vertebrates.

Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications

Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.

Pulegone Prevents Hypertension through Activation of Muscarinic Receptors and Cyclooxygenase Pathway in L-NAME-Induced Hypertensive Rats

The current study was designed to determine pulegone's antihypertensive and vasoprotective activity in L-NAME-induced hypertensive rats. Firstly, the hypotensive dose-response relationship of pulegone was evaluated in normotensive anesthetized rats using the invasive method. Secondly, the mechanism involved in hypotensive activity was determined in the presence of pharmacological drugs such as atropine/muscarinic receptor blocker (1 mg/kg), L-NAME/NOS inhibitor (20 mg/kg), and indomethacin/COX inhibitor (5 mg/kg) in anesthetized rats. Furthermore, studies were carried out to assess the preventive effect of pulegone in L-NAME-induced hypertensive rats. Hypertension was induced in rats by administering L-NAME (40 mg/kg) orally for 28 days. Rats were divided into six groups which were treated orally with tween 80 (placebo), captopril (10 mg/kg), and different doses of pulegone (20 mg/kg, 40 mg/kg, and 80 mg/kg). Blood pressure, urine volume, sodium, and body weight were monitored weekly. After 28 days, the effect of pulegone on lipid profile, hepatic markers, antioxidant enzymes, and nitric oxide was estimated from the serum of treated rats. Moreover, plasma mRNA expression of eNOS, ACE, ICAM1, and EDN1 was measured using real-time PCR. Results show that pulegone dose-dependently decreased blood pressure and heart rate in normotensive rats, with the highest effect at 30 mg/kg/i.v. The hypotensive effect of pulegone was reduced in the presence of atropine and indomethacin, whereas L-NAME did not change its hypotensive effect. Concurrent treatment with pulegone for four weeks in L-NAME-treated rats caused a reduction in both systolic blood pressure and heart rate, reversed the reduced levels of serum nitric oxide (NO), and ameliorated lipid profile and oxidative stress markers. Treatment with pulegone also improved the vascular response to acetylcholine. Plasma mRNA expression of eNOS was reduced, whereas ACE, ICAM1, and EDN1 levels were high in the L-NAME group, which was facilitated by pulegone treatment. To conclude, pulegone prevented L-NAME-induced hypertension by demonstrating a hypotensive effect through muscarinic receptors and cyclooxygenase pathway, indicating its use as a potential candidate in managing hypertension.

L-Arginine in diabetes: clinical and preclinical evidence

L-Arginine (L-Arg), is a semi-essential amino acid involved in the formation of nitric oxide. The functional relevance of L-Arg in diabetes mellitus has been evaluated both in animal models and in human subjects. In the literature there are several lines of evidence indicating that L-Arg has beneficial effects in diabetes and numerous studies advocate its administration to attenuate glucose intolerance in diabetic patients. Here we present a comprehensive overview of the main studies exploring the effects of L-Arg in diabetes, including preclinical and clinical reports on this topic.

Impaired insulin signaling at the bladder mucosa facilitates metabolic syndrome-associated bladder overactivity in rats with maternal and post-weaning fructose exposure

BACKGROUND/PURPOSE

Metabolic syndrome (MetS) and overactive bladder might share common pathophysiologies. Environmental fructose exposure during pre- and postnatal periods of rats may program MetS-associated bladder overactivity. We explored the dysregulated insulin signalling at bladder mucosa, as a common mechanism, in facilitating bladder overactivity in rats with MetS induced by maternal and post-weaning fructose diet.

METHODS

Male offspring of Sprague-Dawley rats were subject into 4 groups by maternal and post-weaning diets (i.e., Control/Control, Fructose/Control, Control/Fructose and Fructose/Fructose by diets). Micturition behavior was evaluated. Acidic ATP solution was used to elicit cystometric reflex along with insulin counteraction. Concentration-response curves to insulin were plotted. The canonical signalling pathway of insulin was evaluated in the bladder mucosal using Western blotting. Levels of detrusor cGMP and urinary NO₂ plus NO₃ were measured.

RESULTS

Male offspring with any fructose exposure presents traits of MetS and bladder overactivity. We observed all fructose exposure groups have the poor urodynamic response to insulin during ATP solution stimulation and poor insulin-activated detrusor relaxation in organ bath study. Compared to controls, the Control/Fructose and Fructose/Fructose groups showed the increased phosphorylation levels of IRS1 (Ser³⁰⁷) and IRS2 (Ser⁷³¹); thus, suppressed the downstream effectors and urinary NOx/detrusor cGMP levels. The Fructose/Control group showed the compensatory increase of phospho-AKT (Ser⁴⁷³) and phospho-eNOS/eNOS levels, but decreased in eNOS, phospho-eNOS, urinary NOx, and detrusor cGMP levels.

CONCLUSION

Our results show dysregulated insulin signalling at bladder mucosa should be a common mechanism of MetS-associated bladder overactivity programmed by pre-and postnatal fructose diet.

Metabolic effects of L-citrulline in type 2 diabetes

The prevalence of type 2 diabetes (T2D) is increasing worldwide. Decreased nitric oxide (NO) bioavailability is involved in the pathophysiology of T2D and its complications. L-citrulline (Cit), a precursor of NO production, has been suggested as a novel therapeutic agent for T2D. Available data from human and animal studies indicate that Cit supplementation in T2D increases circulating levels of Cit and L-arginine while decreasing circulating glucose and free fatty acids and improving dyslipidemia. The underlying mechanisms for these beneficial effects of Cit include increased insulin secretion from the pancreatic β cells, increased glucose uptake by the skeletal muscle, as well as increased lipolysis and β-oxidation, and decreased glyceroneogenesis in the adipose tissue. Thus, Cit has antihyperglycemic, antidyslipidemic, and antioxidant effects and has the potential to be used as a new therapeutic agent in the management of T2D. This review summarizes available literature from human and animal studies to explore the effects of Cit on metabolic parameters in T2D. It also discusses the possible mechanisms underlying Cit-induced improved metabolic parameters in T2D.