OBJECTIVES

In Asia, younger individuals (below age 45) are diagnosed to have type 2 diabetes with increased rates of obesity defined by lower BMI yet with greater visceral adiposity (waist circumference and waisthip ratios). The prevalence data on type 1 diabetes is not well established, considered to be low, but is seen to be increasing as well. This changing phenotype therefore, presents a clinical dilemma in terms of correctly classifying diabetes and deciding on the consequent appropriate treatment. Distinguishing type 1 from type 2 diabetes has become more difficult with type 2 diabetes dramatically increasing in young adults and children. This study aims to define the characteristics of diabetes among young adults in the Philippines to provide a basis for appropriate management amidst changes in diabetes phenotypes seen globally.

METHODS

In this cross-sectional analytic study, we characterized the demographic, metabolic, and autoimmune features of diabetes among young adult Filipinos aged 18 to 45 years old consulting at a tertiary referral center in Manila, Philippines. Baseline serum A1c, FBS, 75-g oral glucose tolerance test, insulin, serum C-peptide, insulin autoantibodies, leptin, adiponectin, lipid profile, and thyroid function tests were obtained from the participants and analyzed. The homeostasis model assessment (HOMA) was used to estimate the insulin sensitivity.

RESULTS

A total of 348 patients with diabetes were included, with females comprising two-thirds of the participants. The mean age at diagnosis of diabetes was 35.9±7.22 years. The mean BMI was 28.12 kg/m2, with median waist to hip ratio (WHR) of 0·93. Metabolic syndrome was found in 60% of participants and 67.82% were obese by body mass index. The mean A1c was 9.07±2.52%. Good glucose control (A1c less than 7.0%) was seen in 23% of participants  while nearly half (48%) had HbA1c which was >9.0%. The median levels of fasting insulin and C-peptide were 12.62 (range 1.33–90.42) mIU/L and 0.78 ng/mL (range 0–16.2), respectively. 

Included participants were diagnosed with diabetes within a year and as such, majority did not have any micro- or macrovascular complications. The most common diabetes complication was sensory neuropathy detected by monofilament testing, which was found in 28% of participants, followed by non-proliferative diabetic retinopathy in 13%. A history of previous diabetic ketoacidosis was found in 10 patients (2.87%). Glutamic acid decarboxylase (GAD) and insulin auto-antibodies were found in 3.2% and 19.3% of participants, respectively. Approximately half (51.73%) of the participants were insulin resistant by HOMA-IR.

CONCLUSION

In contrast with Caucasians and other Asians, diabetes among young Filipino adults is associated with lower BMI but with a similarly high visceral adiposity as shown by an elevated WHR. Metabolic syndrome with insulin resistance as defined by a variety of indices is predominant. Type 1 diabetes with autoantibodies occur in only a small fraction of this population. Data derived from this work can provide a framework for cluster analysis towards personalized management specific to this population.

Human ; Acids ; Adiponectin ; Adiposity ; Adult ; Aged ; Antibodies ; Asia ; Asian ; Asian Continental Ancestry Group ; Autoantibodies ; Body Mass Index ; C-peptide ; Carboxy-lyases ; Child ; Cluster Analysis ; Demography ; Diabetes Complications ; Diabetes Mellitus ; Diabetes Mellitus, Type 1 ; Diabetes Mellitus, Type 2 ; Diabetic Ketoacidosis ; Diabetic Retinopathy ; Diagnosis ; Fasting ; Female ; Glucose ; Glucose Tolerance Test ; Glutamate Decarboxylase ; Glutamic Acid ; Insulin ; Insulin Resistance ; Ketosis ; Leptin ; Lipids ; Metabolic Syndrome ; Obesity ; Patients ; Peptides ; Phenotype ; Philippines ; Population ; Prevalence ; Serum ; Therapeutics ; Thyroid Gland ; Thyroid Function Tests ; Young Adult

Chronic visceral pain is a persistent and debilitating condition arising from dysfunction or sensitization of the visceral organs and their associated nervous pathways. Increasing evidence suggests that imbalances in central nervous system function play an essential role in the progression of visceral pain, but the exact mechanisms underlying the neural circuitry and molecular targets remain largely unexplored. In the present study, the ventral tegmental area (VTA) was shown to mediate visceral pain in mice. Visceral pain stimulation increased c-Fos expression and Ca²⁺ activity of glutamatergic VTA neurons, and optogenetic modulation of glutamatergic VTA neurons altered visceral pain. In particular, the upregulation of NMDA receptor 2A (NR2A) subunits within the VTA resulted in visceral pain in mice. Administration of a selective NR2A inhibitor decreased the number of visceral pain-induced c-Fos positive neurons and attenuated visceral pain. Pharmacology combined with chemogenetics further demonstrated that glutamatergic VTA neurons regulated visceral pain behaviors based on NR2A. In summary, our findings demonstrated that the upregulation of NR2A in glutamatergic VTA neurons plays a critical role in visceral pain. These insights provide a foundation for further comprehension of the neural circuits and molecular targets involved in chronic visceral pain and may pave the way for targeted therapies in chronic visceral pain.
Animals ; Male ; Visceral Pain/metabolism* ; Up-Regulation/physiology* ; Ventral Tegmental Area/metabolism* ; Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors* ; Neurons/drug effects* ; Mice, Inbred C57BL ; Mice ; Proto-Oncogene Proteins c-fos/metabolism* ; Chronic Pain/metabolism* ; Glutamic Acid/metabolism*

Sleep, an essential and evolutionarily conserved behavior, is regulated by numerous neurotransmitter systems. In mammals, glutamate serves as the wake-promoting signaling agent, whereas in Drosophila, it functions as the sleep-promoting signal. However, the precise molecular and cellular mechanisms through which glutamate promotes sleep remain elusive. Our study reveals that disruption of glutamate signaling significantly diminishes nocturnal sleep, and a neural cell-specific knockdown of the glutamate-gated chloride channel (GluClα) markedly reduces nocturnal sleep. We identified two pairs of neurons in the ventral nerve cord (VNC) that receive glutamate signaling input, and the GluClα derived from these neurons is crucial for sleep promotion. Furthermore, we demonstrated that GluClα mediates the glutamate-gated inhibitory input to these VNC neurons, thereby promoting sleep. Our findings elucidate that GluClα enhances nocturnal sleep by mediating the glutamate-gated inhibitory input to two pairs of VNC neurons, providing insights into the mechanism of sleep promotion in Drosophila.
Animals ; Sleep/physiology* ; Neurons/metabolism* ; Chloride Channels/genetics* ; Drosophila Proteins/genetics* ; Drosophila ; Glutamic Acid/metabolism* ; Animals, Genetically Modified

In this study, we systematically tested the hypothesis that during the critical developmental period of adolescence, on a macro scale, the concentrations of major excitatory and inhibitory neurotransmitters (glutamate/glutamine and γ‑aminobutyric acid [GABA]) in the dorsal and ventral lateral prefrontal cortex are associated with the brain's functional connectivity and an individual's psychopathology. Neurotransmitters were measured via magnetic resonance spectroscopy while functional connectivity was measured with resting-state fMRI (n = 121). Seed-based and network-based analyses revealed associations of neurotransmitter concentrations and functional connectivities between regions/networks that are connected to prefrontal cortices via structural connections that are thought to be under dynamic development during adolescence. These regions tend to be boundary areas between functional networks. Furthermore, several connectivities were found to be associated with individual's levels of internalizing psychopathology. These findings provide insights into specific neurochemical mechanisms underlying the brain's macroscale functional organization, its development during adolescence, and its potential associations with symptoms associated with internalizing psychopathology.
Humans ; Adolescent ; Glutamic Acid/metabolism* ; Prefrontal Cortex/diagnostic imaging* ; Male ; Glutamine/metabolism* ; Female ; gamma-Aminobutyric Acid/metabolism* ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Nerve Net/metabolism* ; Neural Pathways ; Connectome

Traumatic brain injury (TBI), as a significant central nervous system damage disease with high frequency in the world, leads to a huge number of patients with impaired health and lower quality of life every year. Lung injury is a common and dangerous consequence, which dramatically raises the mortality of patients. Discovering the pathophysiology of lung injury after TBI and discovering viable therapeutic targets has become an important need for clinical diagnosis and therapy. Neurotransmitters, as the fundamental chemical agents of the nervous system for signal transmission, not only govern neuronal activity and apoptosis in TBI but also significantly influence the pathophysiological mechanisms of lung injury subsequent to TBI. The imbalance is intricately linked to the onset and progression of lung damage. This paper systematically reviews the clinical characteristics and predominant pathogenesis of lung injury following TBI, emphasizing the role of key neurotransmitters, including glutamate (Glu), γ-aminobutyric acid (GABA), norepinephrine (NE), dopamine (DA), and acetylcholine (ACh), in lung injury post-TBI. It examines their influence on inflammatory response, vascular permeability, and pulmonary circulation function. Additionally, the paper evaluates the research advancements and potential applications of targeted therapeutic strategies for various neurotransmitter systems, such as receptor antagonists, transporter inhibitors, and neurotransmitter analogues. This research aims to offer a theoretical framework for clarifying the neural regulatory mechanisms of lung injury following TBI and to establish a basis for the development of novel therapeutic strategies and enhancement of the prognosis of the patients.
Humans ; Brain Injuries, Traumatic/metabolism* ; Neurotransmitter Agents/metabolism* ; Lung Injury/metabolism* ; gamma-Aminobutyric Acid/metabolism* ; Glutamic Acid/metabolism* ; Norepinephrine/metabolism* ; Dopamine/metabolism* ; Acetylcholine/metabolism*

The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics* ; Glutamic Acid/biosynthesis* ; Fermentation ; Metabolic Engineering ; Bacterial Proteins/metabolism* ; Bioreactors/microbiology* ; Gene Knockout Techniques

OBJECTIVES: To clarify the role of hippocampal glutamate system in regulating HPA axis in mediating the effect of electroacupuncture (EA) at the heart meridian for improving myocardial injury in rats with acute myocardial ischemia (AMI). METHODS: Male SD rats were randomized into sham-operated group, AMI group, EA group, and L-glutamic acid+EA group (n=9). Rat models of AMI were established by left descending coronary artery ligation, and EA was applied at the "Shenmen-Tongli" segment; the rats in L-glutamic acid+EA group were subjected to microinjection of L-glutamic acid into the bilateral hippocampus prior to AMI modeling and EA treatment. Cardiac functions of the rats were evaluated using echocardiography, and ECG and heart rate variation (HRV) were analyzed using PowerLab and LabChart. Pathological changes in the myocardial tissue was examined using HE staining, and serum levels of myocardial enzymes were detected with ELISA. Myocardial expressions of TH and GAP43 were detected with immunohistochemistry, and colocalization of VGLUT1, VGLUT2 and c-fos were observed using immunofluorescence staining; the expressions of VGLUT1, VGLUT2, NMDAR1 and NMDAR2B were detected using Western blotting. RESULTS: The rat models of AMI showed significantly decreased LVEF and LVFS and increased serum levels of myocardial enzymes in positive correlation with the HPA axis. Numerous TH- and GAP43-positive cells were observed in the hippocampus, where the expressions of NE and E, neurons colabeled with VGLUT1, VGLUT2 and c-fos, and expressions of VGLUT1, VGLUT2, NMDAR1, NMDAR2B and Glu increased significantly. All these changes were significantly improved by interventions with EA as compared with those in AMI and L-Glutamate+EA groups. CONCLUSIONS In rats with AMI, EA at the heart meridian can regulate excessive glutamate release in the hippocampus, thereby inhibiting HPA axis hyperactivity and reducing sympathetic nerve activity to protect the myocardial tissue.
Animals ; Electroacupuncture ; Male ; Rats, Sprague-Dawley ; Hippocampus/metabolism* ; Rats ; Glutamic Acid/metabolism* ; Myocardial Ischemia/physiopathology* ; Hypothalamo-Hypophyseal System/physiopathology* ; Pituitary-Adrenal System/physiopathology* ; Receptors, N-Methyl-D-Aspartate/metabolism*

OBJECTIVES: To investigate the therapeutic effect of Ziwuliuzhu acupuncture in a rat model of insomnia and its regulatory effect on the glutamic acid (Glu)/γ-aminobutyric acid (GABA)-glutamine (Gln) metabolic loop. METHODS: Forty male SD rats were randomly assigned to control group, model group, Najia group and Nazi group (n=10). In the latter 3 groups, rat models of insomnia were established by intraperitoneal injections of p-chlorophenylalanine and verified using a sodium pentobarbital-induced sleep test. After modeling, the rats in Najia and Nazi groups received acupuncture for 7 days at specifically chosen sets of acupoints based on the Ziwuliuzhu rationale in traditional Chinese medicine. Pathological changes in the hypothalamic tissue of the rats were examined with HE staining, and the levels of Glu and GABA in the hypothalamus were determined with high-performance liquid chromatography (HPLC)-mass spectrometry (MS)/MS. Immunohistochemistry was used to detect the expressions of GABAA receptors (GABAARs) in the hypothalamus, and the expression levels of glutamate decarboxylase (GAD65/67) and glutamine synthetase (GS) were determined with Western blotting. RESULTS: Compared with the model group, the rats in Najia and Nazi groups exhibited decreased Glu levels and GABAA receptor expression and increased GABA levels with a decreased Glu/GABA ratio in the hypothalamus. Ziwuliuzhu acupuncture significantly increased the protein expressions of GAD65 and GAD67 and lowered the expression of GS in the hypothalamus in the rat models of insomnia. CONCLUSIONS Ziwuliuzhu acupuncture produces sedative and hypnotic effects in rat models of insomnia possibly by regulating Glu and GABA-Gln metabolism to restore the excitatory/inhibitory balance between Glu and GABA.
Animals ; Rats, Sprague-Dawley ; Male ; Rats ; gamma-Aminobutyric Acid/metabolism* ; Sleep Initiation and Maintenance Disorders/therapy* ; Glutamine/metabolism* ; Glutamic Acid/metabolism* ; Acupuncture Therapy ; Hypothalamus/metabolism* ; Receptors, GABA-A/metabolism* ; Acupuncture Points

The functional role of glutamatergic (vGluT2) neurons in the pedunculopontine nucleus (PPN) in modulating motor activity remains controversial. Here, we demonstrated that the activity of vGluT2 neurons in the rostral PPN is correlated with locomotion and ipsilateral head-turning. Beyond these motor functions, we found that these rostral PPN-vGluT2 neurons remarkably respond to salient stimuli. Furthermore, we systematically traced the upstream and downstream projections of these neurons and identified two downstream projections from these neurons to the caudal pontine reticular nucleus/anterior gigantocellular reticular nucleus (PnC/GiA) and the zona incerta (ZI). Our findings indicate that the projections to the PnC/GiA inhibit movement, consistent with 'pause-and-play' behavior, whereas those to the ZI promote locomotion, and others respond to a new 'pause-switch-play' pattern. Collectively, these findings elucidate the multifaceted influence of the PPN on motor functions and provide a robust theoretical framework for understanding its physiological and potential therapeutic implications.
Pedunculopontine Tegmental Nucleus/physiology* ; Animals ; Neural Pathways/physiology* ; Vesicular Glutamate Transport Protein 2/metabolism* ; Locomotion/physiology* ; Glutamic Acid/metabolism* ; Neurons/physiology* ; Male ; Mice ; Motor Activity/physiology* ; Zona Incerta/physiology*

This study used m-chloropheniperazine(MCPP) and chronic unforeseeable mild stress(CUMS) to induce the rat models of anxiety and depression, respectively. The behaviors of rats were observed by the open field test(OFT), light-dark exploration test(LDE), tail suspension test(TST), and forced swimming test(FST), and the antidepressant and anxiolytic effects of agarwood essential oil(AEO), agarwood fragrant powder(AFP), and agarwood line incense(ALI) were explored. The enzyme-linked immunosorbent assay(ELISA) was used to determine the levels of 5-hydroxytryptamine(5-HT), glutamic acid(Glu), and γ-aminobutyric acid(GABA_A) in the hippocampal area. The Western blot assay was used to determine the protein expression levels of glutamate receptor 1(GluR1) and vesicular glutamate transporter type 1(VGluT1), exploring the anxiolytic and antidepressant mechanism of agarwood inhalation. The results showed that compared with the anxiety model group, the AEO, AFP, and ALI groups decreased the total distance(P<0.05), decreased the velocity of movements(P<0.05), prolonged the immobile time(P<0.05), and reduced the distance and velocity of the rat model of anxiety in the dark box(P<0.05). Compared with the depression model group, the AEO, AFP, and ALI groups increased the total distance and average velocity(P<0.05), reduced the immobile time(P<0.05), and reduced the forced swimming and tail suspension time(P<0.05). In terms of transmitter regulation, the AEO, AFP, and ALI groups decreased the level of Glu in the rat model of anxiety(P<0.05) and increased the levels of GABA_A and 5-HT(P<0.05), while the AEO, AFP, and ALI groups all increased the level of 5-HT in the rat model of depression(P<0.05) and decreased the levels of GABA_A and Glu(P<0.05). At the same time, the AEO, AFP, and ALI groups all increased the protein expression levels of GluR1 and VGluT1 in the hippocampus of the rat models of anxiety and depression(P<0.05). In conclusion, AEO, AFP, and ALI exert anxiolytic and antidepressant effects, and the mechanism might be related to the regulation of the neurotransmitter and the protein expression of GluR1 and VGluT1 in the hippocampus.
Animals ; Rats ; Anti-Anxiety Agents ; Serotonin ; alpha-Fetoproteins ; Antidepressive Agents ; Glutamic Acid ; gamma-Aminobutyric Acid