Neurotransmitters in Type 2 Diabetes and the Control of Systemic and Central Energy Balance

Emerging biophysical techniques for probing synaptic transmission in neurodegenerative disorders

Plethora of research has shed light on the critical role of synaptic dysfunction in various neurodegenerative disorders (NDDs), including Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). Synapses, the fundamental units for neural communication in the brain, are highly vulnerable to pathological conditions and are central to the progression of neurological diseases. The presynaptic terminal, a key component of synapses responsible for neurotransmitter release and synaptic communication, undergoes structural and functional alterations in these disorders. Understanding synaptic transmission abnormalities is crucial for unravelling the pathophysiological mechanisms underlying neurodegeneration. In the quest to probe synaptic transmission in NDDs, emerging biophysical techniques play a pivotal role. These advanced methods offer insights into the structural and functional changes occurring at nerve terminals in conditions like AD, PD, HD & ALS. By investigating synaptic plasticity and alterations in neurotransmitter release dynamics, researchers can uncover valuable information about disease progression and potential therapeutic targets. The review articles highlighted provide a comprehensive overview of how synaptic vulnerability and pathology are shared mechanisms across a spectrum of neurological disorders. In major neurodegenerative diseases, synaptic dysfunction is a common thread linking these conditions. The intricate molecular machinery involved in neurotransmitter release, synaptic vesicle dynamics, and presynaptic protein regulation are key areas of focus for understanding synaptic alterations in neurodegenerative diseases.

Association between fasting blood glucose and psychotic symptoms in Chinese patients with first-episode drug-naïve major depressive disorder

INTRODUCTION

Psychotic depression (PD) is a highly debilitating disorder characterized by hallucinations and/or delusions accompanied by depression. A variety of neurotransmitters, hormones and corresponding receptors in the endocrine system are involved in the onset and progression of depression, and fasting blood glucose (FBG) can be an important indicator for monitoring the stability of the endocrine system. The aim of this study was to investigate the relationship between FBG and PD in a Chinese population with first-episode drug-naïve (FEDN) major depressive disorder (MDD).

METHODS

In this study, 1718 outpatient individuals diagnosed with first-episode drug-naïve major depressive disorder (FEDN MDD) were included. The association between PD and FBG levels was identified through multivariable binary logistic regression analysis. To investigate potential non-linear relationships, a two-piecewise linear regression model was utilized. Additionally, interaction and stratified analyses were performed based on gender, educational background, marital status, presence of comorbid anxiety, and history of suicide attempt.

RESULTS

Multivariate logistic regression analysis showed that FBG was positively associated with the risk of PD in FEDN MDD patients (OR = 1.68, 95% CI: 1.31 to 2.13; P < 0.05). Smoothed plots showed a non-linear relationship between FBG and PD, while the inflection point of FBG was calculated using a two-segmented logistic regression model to be 6.23 mmol/L. On the right side of the inflection point, the probability of PD increased substantially by 278% (OR = 3.78, 95% CI: 1.75 to 8.18, p < 0.001), while no significant association was observed on the left side of the inflection point (OR = 1.06, 95% CI: 0.73 to 1.52, p = 0.772).

CONCLUSIONS

Our investigation revealed a nonlinear relationship between FBG and PD in patients with FEDN MDD, thereby informing more effective intervention strategies for managing psychotic symptoms in individuals with depression.

Associations Between Diabetes Mellitus and Neurodegenerative Diseases

Diabetes mellitus (DM) and neurodegenerative diseases/disturbances are worldwide health problems. The most common chronic conditions diagnosed in persons 60 years and older are type 2 diabetes mellitus (T2DM) and cognitive impairment. It was found that diabetes mellitus is a major risk for cognitive decline, dementia, Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Different mechanisms of associations between these diseases and diabetes mellitus have been suggested. For example, it is postulated that an impaired intracellular insulin signaling pathway, together with hyperglycemia and hyperinsulinemia, may cause pathological changes, such as dysfunction of the mitochondria, oxidative stress inflammatory responses, etc. The association between diabetes mellitus and neurodegenerative diseases, as well as the mechanisms of these associations, needs further investigation. The aim of this review is to describe the associations between diabetes mellitus, especially type 1 (T1DM) and type 2 diabetes mellitus, and selected neurodegenerative diseases, i.e., Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. Suggested mechanisms of these associations are also described.

Genetic Nurture Effects on Type 2 Diabetes Among Chinese Han Adults: A Family-Based Design

Background/Objectives: Genes and environments were transmitted across generations. Parents' genetics influence the environments of their offspring; these two modes of inheritance can produce a genetic nurture effect, also known as indirect genetic effects. Such indirect effects may partly account for estimated genetic variance in T2D. However, the well-established specific genetic risk factors about genetic nurture effect for T2D are not fully understood. This study aimed to investigate the genetic nurture effect on type 2 diabetes and reveal the potential underlying mechanism using publicly available data. Methods: Whole-genome genotyping data of 881 offspring and/or their parents were collected. We assessed SNP-level, gene-based, and pathway-based associations for different types of genetic effects. Results: Rs3805116 (β: 0.54, p = 4.39 × 10-8) was significant for paternal genetic nurture effects. MRPS33 (p = 1.58 × 10-6), PIH1D2 (p = 6.76 × 10-7), and SD1HD (p = 2.67 × 10-6) revealed significantly positive paternal genetic nurture effects. Five ontologies were identified as enrichment in both direct and indirect genetic effects, including flavonoid metabolic process and antigen processing and presentation via the MHC class Ib pathway. Two pathways were only enriched in paternal genetic nurture effects, including the transforming growth factor beta pathway. Tissue enrichment of type 2 diabetes-associated genes on different genetic effect types was performed using publicly available gene expression data from the Human Protein Atlas database. We observed significant gene enrichment in paternal genetic nurture effects in the gallbladder, smooth muscle, and adrenal gland tissues. Conclusions: MRPS33, PIH1D2, and SD1HD are associated with increased T2D risk through the environment influenced by paternal genotype, suggesting a novel perspective on paternal contributions to the T2D predisposition.

Vasant Kusumakar Rasa Ameliorates Diabetic Encephalopathy by Reducing Oxidative Stress and Neuroinflammation and Improving Neurotransmitter Levels in Experimental Animals

PURPOSE

Diabetic encephalopathy (DE) is one of the complications of diabetes that affects the brain. In the Ayurveda system of medicine, Vasant Kusumakar Rasa (VKR) is cited as a classical herbo-mineral formulation for diabetes. However, the role of VKR in DE is still unclear.

METHODS

High-fat diet and streptozotocin (35 mg/kg, i.p.) were used to induce type 2 DE in Sprague Dawley rats. VKR at doses 28 mg/kg and 56 mg/kg was given via intragastric route to diabetic rats for 16 weeks. Estimation of plasma glucose, serum insulin, glycohemoglobin, and C-reactive protein (C-RP) was analyzed. Furthermore, the Morris water maze test was performed to assess cognitive behavior. Pro-inflammatory, such as TNF-α, IL-1β, and IL-6, were measured in brain tissue homogenate. Antioxidant enzyme assays were performed to estimate the levels of malondialdehyde, reduced glutathione, superoxide dismutase, and catalase in brain tissue. Histopathology of brain sections was performed using hematoxylin and eosin (H & E) staining. Neurotransmitters (viz., serotonin (5-HT), dopamine (DA), and norepinephrine (NE)) were estimated in the brain by high-performance liquid chromatography (HPLC). The data were analyzed by using ANOVA, followed by Dunnett's multiple comparison test.

RESULTS

VKR treatment, at a dose of 28 and 56 mg/kg, reduced the plasma glucose level significantly (236.7±17.08 and 221.8±17.50, respectively; p<0.001) when compared with diabetic control (461.7±13.03). The treatment also reduced serum insulin and glycated hemoglobin levels and improved the escape latency in VKR-treated animals as compared to diabetic animals. Brain tissue pro-inflammatory marker levels were reduced, and oxidative stress enzymes showed positive marks in diabetic rats treated with VKR. Histopathology of the brain demonstrated a reduction in neuronal damage in the VKR-treated diabetic animals. VKR treatment at doses of 28 and 56 mg/kg also improved the levels of 5-HT (1.78±0.11 and 1.72±0.18, respectively) when compared with diabetic control (0.91±0.08) significantly (p<0.01). DA levels were significantly (p<0.01) increased in VKR-treated animals when compared with diabetic animals. The treatment of VKR for 16 weeks also improved the NE levels significantly when compared with diabetic control animals.

CONCLUSION

The result of the study indicates that the treatment with VKR for 16 weeks has significant therapeutic potential in the management of type 2 DE.

Dietary Polyphenols and Gut Microbiota Cross-Talk: Molecular and Therapeutic Perspectives for Cardiometabolic Disease: A Narrative Review

The intricate interplay between the gut microbiota and polyphenols has emerged as a captivating frontier in understanding and potentially harnessing the therapeutic potential of these bioactive compounds. Phenolic compounds, renowned for their antioxidant, anti-inflammatory, antidiabetic, and anticancer properties, are subject to intricate transformations within the gut milieu, where the diverse microbial ecosystem exerts profound effects on their metabolism and bioavailability. Conversely, polyphenols exhibit a remarkable capacity to modulate the composition and activity of the gut microbiota, fostering a bidirectional relationship that extends beyond mere nutrient processing. This symbiotic interaction holds significant implications for human health, particularly in cardiometabolic diseases such as diabetes mellitus, metabolic-dysfunction-associated steatotic liver disease, and cardiovascular disease. Through a comprehensive exploration of molecular interactions, this narrative review elucidates the reciprocal dynamics between the gut microbiota and polyphenols, unveiling novel avenues for therapeutic intervention in cardiometabolic disorders. By unravelling the intricate cross-talk between these two entities, this review underscores the multifaceted roles of polyphenols in overall health and the pivotal role of gut microbiota modulation as a promising therapeutic strategy in mitigating the burden of cardiometabolic diseases.

Research on the mechanism of regulating spleen-deficient obesity in rats by bawei guben huashi jiangzhi decoction based on multi-omics analysis

ETHNOPHARMACOLOGY RELEVANCE

Bawei Guben Huashi Jiangzhi Decoction (BGHJ), a traditional Chinese compound formula, comprises eight Chinese medicinal herbs: Codonopsis Radix, Atractylodis Macrocephalae Rhizoma, Cassiae Semen, Lysimachiae Herba, Edgeworthiae Gardner Flos, Oryzae Semen cum Monasco, Nelumbinis Folium, and Alismatis Rhizoma. It has the therapeutic effects of improving digestive and absorptive functions of the gastrointestinal tract, reducing cholesterol levels, and helping to lose weight. Therefore, BGHJ is mainly used to treat spleen-deficient obesity (SDO) clinically.

AIM OF THE STUDY

This study aims to examine the efficacy and mechanism of BGHJ in a model of SDO in rats, as well as the potentially involved constituents entering the blood and differential metabolites.

METHODS

The SDO rat model was replicated utilizing a high-fat and high-sugar diet in conjunction with exhaustive swimming. Subsequently, the rats were subjected to a six-week intervention comprising varying dosages of BGHJ and a positive control, orlistat. To evaluate the efficacy of BGHJ on SDO model rats, we first measured the rats' body weight, body surface temperature, spleen index, as well as biochemical indicators in the serum and colon, and then assessed the pathological state of the colon and liver. Afterward, we analyzed the 16S rDNA gut microbiota, non-targeted serum metabolomics, and serum pharmacology to study the main active components of BGHJ and its action mechanism against SDO model rats. In addition, we constructed a network diagram for overall visualization and analysis, and experimentally verified the predicted results. Finally, we used quantitative polymerase chain reaction (qPCR) to detect the gene expression of proopiomelanocortin (POMC) and neuropeptide Y (NPY) indicators in rat hypothalamic neurons. We quantitatively targeted the detection of neurotransmitters dopamine (DA), acetylcholine (Ach), 5-hydroxytryptamine (5-HT), and noradrenaline (NA) in rat hypothalamus.

RESULTS

The results demonstrated that all dosage regimens of BGHJ exhibited the capacity to moderately modulate parameters including body weight, surface temperature, spleen index, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), 5-HT, interleukin 6 (IL-6) and interleukin 17 (IL-17), while concurrently reducing hepatic lipid droplet deposition and restoring intestinal integrity. Subsequent experimental results showed that we successfully identified 27 blood components of BGHJ and identified 52 differential metabolites in SDO model rats. At the same time, the experiment proved that BGHJ could effectively inhibit the metabolic pathway of arachidonic acid. In addition, BGHJ can also restore the intestinal microbiota composition of SDO model rats. Finally, we also found that BGHJ could regulate the expression of hypothalamic neurons and neurotransmitters.

CONCLUSIONS

The research revealed the main active ingredients of BGHJ and its mechanism against SDO model rats through gut microbiota, non-target serum metabolomics, and serum drug chemistry.

Epidemiological, Clinical and Biological Hemogram Features in a Cohort of Neuroendocrine Tumor Patients

We conducted a retrospective study based on 55 patients diagnosed with gastroenteropancreatic neuroendocrine tumors (GEP-NETs)-gastric (G-NET), small bowel (SB-NET) and colonic (C-NET), hospitalized and evaluated within the Surgical, Gastroenterology and Internal Medicine Clinics, in The Clinical Emergency County Hospital Craiova, between May 2016 and April 2024. We aimed in this study to analyze the epidemiological aspects and clinical characteristics of patients with GEP-NETs. In our study group, the patients' ages were between 39-82 years, with a mean of 66.40 (±12.46) years. The incidence of GEP-NETs cases in young patients was insignificant low-1 case. 45.46% of all patients lived in urban areas. 16.36% were G-NET, 14,54 were SB-NET and 69.09% were C-NET. The GEP-NETs diagnosis was established by immunohistochemistry features. Also, we observed that the most frequency localization was on the ascending colon, while the rarest on the colon it is located on the transverse colon and the rarest is on the small bowel, in spite of the generally literature data. From the C-NET group, 49.09% have been presented arterial hypertension probable explained by serotonin and dopamine secretion an inflammatory through phenotype expression and just one patient has been presented an erythematous psoriasis, which could be also explained by the same neurotransmitter's involvement as a possible purposed mechanism. The results obtained in our study demonstrate that could be a common profile of GEP-NETs patients through epidemiological general information and clinical characteristics. Also, we demonstrate that, in the last years, the incidence increased for the GEP-NETs.

Temporal associations of BMI and glucose parameters with depressive symptoms among US adults

As the prevalence of obesity, diabetes, and depression increases, it is important to examine how their associations are changing overtime. We investigated the temporal trends in the association between depressive symptoms, body mass index (BMI) and glucose profile parameters using data from 2005 to 2018 National Health and Nutrition Examination Survey. Depressive symptoms were assessed using the Patient Health Questionnaire. A total of 32,653 participants were included. Risk of depressive symptoms increased with higher BMI (aOR = 1.586, 95 % CI [1.364, 1.843]), insulin (aOR = 1.327, 95 % CI [1.159, 1.519]), HbA1c (aOR = 1.330, 95 % CI [1.116, 1.585]), or fasting glucose (aOR = 1.565, 95 % CI [1.247, 1.964]) levels compared to those with low levels. Sex differences were found, as overweight males had lower odds of depressive symptoms compared to healthy males, while overweight and obese females had higher odds compared to healthy females. High BMI and glucose parameters were consistently associated with higher depressive symptoms prevalence over time. Temporal variations were observed in the depressive symptoms-BMI and depressive symptoms-HbA1c associations, particularly at the 2007-2008 cycle. This study provides analytic insights into population level trends concerning physical and mental health problems.

Weight Loss Supplements

Being overweight or obese can predispose people to chronic diseases and metabolic disorders such as cardiovascular illnesses, diabetes, Alzheimer's disease, and cancer, which are costly public health problems and leading causes of mortality worldwide. Many people hope to solve this problem by using food supplements, as they can be self-prescribed, contain molecules of natural origin considered to be incapable of causing damage to health, and the only sacrifice they require is economic. The market offers supplements containing food plant-derived molecules (e.g., primary and secondary metabolites, vitamins, and fibers), microbes (probiotics), and microbial-derived fractions (postbiotics). They can control lipid and carbohydrate metabolism, reduce appetite (interacting with the central nervous system) and adipogenesis, influence intestinal microbiota activity, and increase energy expenditure. Unfortunately, the copious choice of products and different legislation on food supplements worldwide can confuse consumers. This review summarizes the activity and toxicity of dietary supplements for weight control to clarify their potentiality and adverse reactions. A lack of research regarding commercially available supplements has been noted. Supplements containing postbiotic moieties are of particular interest. They are easier to store and transport and are safe even for people with a deficient immune system.