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Nature Communications Jun 2024Glucagon, a hormone released from pancreatic α-cells, is critical for maintaining euglycemia and plays a key role in the pathophysiology of diabetes. To stimulate the...
Glucagon, a hormone released from pancreatic α-cells, is critical for maintaining euglycemia and plays a key role in the pathophysiology of diabetes. To stimulate the development of new classes of therapeutic agents targeting glucagon release, key α-cell signaling pathways that regulate glucagon secretion need to be identified. Here, we focused on the potential importance of α-cell G signaling on modulating α-cell function. Studies with α-cell-specific mouse models showed that activation of α-cell G signaling causes a marked increase in glucagon secretion. We also found that intra-islet adenosine plays an unexpected autocrine/paracrine role in promoting glucagon release via activation of α-cell G-coupled A adenosine receptors. Studies with α-cell-specific Gα knockout mice showed that α-cell G also plays an essential role in stimulating the activity of the Gcg gene, thus ensuring proper islet glucagon content. Our data suggest that α-cell enriched G-coupled receptors represent potential targets for modulating α-cell function for therapeutic purposes.
Topics: Glucagon; Animals; Glucagon-Secreting Cells; Signal Transduction; Mice, Knockout; Mice; GTP-Binding Protein alpha Subunits, Gs; Adenosine; Receptor, Adenosine A2A; Male; Mice, Inbred C57BL; Islets of Langerhans
PubMed: 38879678
DOI: 10.1038/s41467-024-49537-x -
Metabolism: Clinical and Experimental Jun 2024Although it is well established that hormones like glucagon stimulates gluconeogenesis via the PKA-mediated phosphorylation of CREB and dephosphorylation of the...
BACKGROUND AND AIM
Although it is well established that hormones like glucagon stimulates gluconeogenesis via the PKA-mediated phosphorylation of CREB and dephosphorylation of the cAMP-regulated CREB coactivators CRTC2, the role of neural signals in the regulation of gluconeogenesis remains uncertain.
METHODS AND RESULTS
Here, we characterize the noradrenergic bundle architecture in mouse liver; we show that the sympathoexcitation induced by acute cold exposure promotes hyperglycemia and upregulation of gluconeogenesis via triggering of the CREB/CRTC2 pathway. Following its induction by dephosphorylation, CRTC2 translocates to the nucleus and drives the transcription of key gluconeogenic genes. Rodents submitted to different models of sympathectomy or knockout of CRTC2 do not activate gluconeogenesis in response to cold. Norepinephrine directly acts in hepatocytes mainly through a Ca-dependent pathway that stimulates CREB/CRTC2, leading to activation of the gluconeogenic program.
CONCLUSION
Our data demonstrate the importance of the CREB/CRTC2 pathway in mediating effects of hepatic sympathetic inputs on glucose homeostasis, providing new insights into the role of norepinephrine in health and disease.
PubMed: 38878857
DOI: 10.1016/j.metabol.2024.155940 -
Journal of Orthopaedic Surgery and... Jun 2024Facet joint degeneration (FJD) is a major cause of low back pain. Parathyroid hormone (PTH) (1-34) is commonly used to treat osteoporosis. However, little is known about...
PURPOSE
Facet joint degeneration (FJD) is a major cause of low back pain. Parathyroid hormone (PTH) (1-34) is commonly used to treat osteoporosis. However, little is known about its effects on FJD induced by estrogen deficiency. This study aims to investigate the effects of PTH (1-34) on FJD induced by estrogen deficiency and the underlying pathogenesis of the disease.
METHODS
Forty 3-month-old female Sprague-Dawley rats were randomly divided into four groups: 30 received bilateral ovariectomy (OVX) followed by 12 weeks of treatment with normal saline, PTH (1-34) or 17β-estradiol (E2), and 10 received sham surgery followed by administration of normal saline. Status and Wnt/β-catenin signaling activity in the cartilage and subchondral bone of the L4-L5 FJs and serum biomarkers were analyzed.
RESULTS
Administration of PTH (1-34) and E2 ameliorated cartilage lesions, and significantly decreased MMP-13 and caspase-3 levels and chondrocyte apoptosis. PTH (1-34) but not E2 significantly increased cartilage thickness, number of chondrocytes, and the expression of aggrecan. PTH (1-34) significantly improved microarchitecture parameters of subchondral bone, increased the expression of collagen I and osteocalcin, and decreased RANKL/OPG ratio. E2 treatment significantly increased the OPG level and decreased the RANKL/OPG ratio in the subchondral bone of ovariectomized rats, but it did not significantly improve the microarchitecture parameters of subchondral bone. Wnt3a and β-catenin expression was significantly reduced in the articular cartilage and subchondral bone in OVX rats, but PTH (1-34) could increase the expression of these proteins. E2 significantly increased the activity of Wnt/β-catenin pathway only in cartilage, but not in subchondral bone. The restoration of Wnt/β-catenin signaling had an obvious correlation with the improvement of some parameters associated with the FJs status.
CONCLUSION
Wnt/β-catenin signaling may be a potential therapeutic target for FJD induced by estrogen deficiency. PTH (1-34) is effective in treating this disease with better efficacy than 17β-estradiol, and the efficacy may be attributed to its restoration of Wnt/β-catenin signaling.
Topics: Animals; Female; Ovariectomy; Rats, Sprague-Dawley; Wnt Signaling Pathway; Parathyroid Hormone; Zygapophyseal Joint; Lumbar Vertebrae; Rats; Estradiol
PubMed: 38877549
DOI: 10.1186/s13018-024-04817-6 -
Scientific Reports Jun 2024Sodium-glucose cotransporter (SGLT) 2 inhibition is a well-known target for the treatment of type 2 diabetes, renal disease and chronic heart failure. The protein SGLT2... (Randomized Controlled Trial)
Randomized Controlled Trial
Sodium-glucose cotransporter (SGLT) 2 inhibition is a well-known target for the treatment of type 2 diabetes, renal disease and chronic heart failure. The protein SGLT2 is encoded by SLC5A2 (Solute Carrier Family 5 Member 2), which is highly expressed in renal cortex, but also in the testes where glucose uptake may be essential for spermatogenesis and androgen synthesis. We postulated that in healthy males, SGLT2 inhibitor therapy may affect gonadal function. We examined the impact on gonadal and steroid hormones in a post-hoc analysis of a double-blind, randomized, placebo-controlled research including 26 healthy males who were given either placebo or empagliflozin 10 mg once daily for four weeks. After one month of empagliflozin, there were no discernible changes in androgen, pituitary gonadotropin hormones, or inhibin B. Regardless of BMI category, the administration of empagliflozin, a highly selective SGLT2 inhibitor, did not alter serum androgen levels in men without diabetes. While SGLT2 is present in the testes, its inhibition does not seem to affect testosterone production in Leydig cells nor inhibin B secretion by the Sertoli cells.
Topics: Male; Humans; Benzhydryl Compounds; Glucosides; Adult; Sodium-Glucose Transporter 2 Inhibitors; Double-Blind Method; Testis; Testosterone; Inhibins; Middle Aged; Sodium-Glucose Transporter 2; Androgens; Leydig Cells; Sertoli Cells
PubMed: 38877312
DOI: 10.1038/s41598-024-64684-3 -
Scientific Reports Jun 2024Glucagon-like peptide 1 receptor (GLP-1R) agonist is an emerging anti-diabetic medication whose effects on the risk and progression of cholangiocarcinoma (CCA) are...
Glucagon-like peptide 1 receptor (GLP-1R) agonist is an emerging anti-diabetic medication whose effects on the risk and progression of cholangiocarcinoma (CCA) are controversial. This study aimed to elucidate the roles of GLP-1R and its agonists on intrahepatic CCA (iCCA) progression. Expressions of GLP-1R in iCCA tissues investigated by immunohistochemistry showed that GLP-1R expressions were significantly associated with poor histological grading (P = 0.027). iCCA cell lines, KKU-055 and KKU-213A, were treated with exendin-4 and liraglutide, GLP-1R agonists, and their effects on proliferation and migration were assessed. Exendin-4 and liraglutide did not affect CCA cell proliferation in vitro, but liraglutide significantly suppressed the migration of CCA cells, partly by inhibiting epithelial-mesenchymal transition. In contrast, liraglutide significantly reduced CCA tumor volumes and weights in xenografted mice (P = 0.046). GLP-1R appeared downregulated when CCA cells were treated with liraglutide in vitro and in vivo. In addition, liraglutide treatment significantly suppressed Akt and STAT3 signaling in CCA cells, by reducing their phosphorylation levels. These results suggested that liraglutide potentially slows down CCA progression, and further clinical investigation would benefit the treatment of CCA with diabetes mellitus.
Topics: Liraglutide; Cholangiocarcinoma; Humans; Animals; Cell Line, Tumor; Glucagon-Like Peptide-1 Receptor; Mice; Male; Bile Duct Neoplasms; Cell Proliferation; Epithelial-Mesenchymal Transition; Cell Movement; Female; Xenograft Model Antitumor Assays; Disease Progression; Middle Aged; Signal Transduction; Aged; Antineoplastic Agents; STAT3 Transcription Factor; Exenatide; Mice, Nude; Proto-Oncogene Proteins c-akt
PubMed: 38877189
DOI: 10.1038/s41598-024-64774-2 -
PloS One 2024The nerve growth factor (NGF) participates in cell survival and glucose-stimulated insulin secretion (GSIS) processes in rat adult beta cells. GSIS is a complex process...
The nerve growth factor (NGF) participates in cell survival and glucose-stimulated insulin secretion (GSIS) processes in rat adult beta cells. GSIS is a complex process in which metabolic events and ionic channel activity are finely coupled. GLUT2 and glucokinase (GK) play central roles in GSIS by regulating the rate of the glycolytic pathway. The biphasic release of insulin upon glucose stimulation characterizes mature adult beta cells. On the other hand, beta cells obtained from neonatal, suckling, and weaning rats are considered immature because they secrete low levels of insulin and do not increase insulin secretion in response to high glucose. The weaning of rats (at postnatal day 20 in laboratory conditions) involves a dietary transition from maternal milk to standard chow. It is characterized by increased basal plasma glucose levels and insulin levels, which we consider physiological insulin resistance. On the other hand, we have observed that incubating rat beta cells with NGF increases GSIS by increasing calcium currents in neonatal cells. In this work, we studied the effects of NGF on the regulation of cellular distribution and activity of GLUT2 and GK to explore its potential role in the maturation of GSIS in beta cells from P20 rats. Pancreatic islet cells from both adult and P20 rats were isolated and incubated with 5.6 mM or 15.6 mM glucose with and without NGF for 4 hours. Specific immunofluorescence assays were conducted following the incubation period to detect insulin and GLUT2. Additionally, we measured glucose uptake, glucokinase activity, and insulin secretion assays at 5.6 mM or 15.6 mM glucose concentrations. We observed an age-dependent variation in the distribution of GLUT2 in pancreatic beta cells and found that glucose plays a regulatory role in GLUT2 distribution independently of age. Moreover, NGF increases GLUT2 abundance, glucose uptake, and GSIS in P20 beta cells and GK activity in adult beta cells. Our results suggest that besides increasing calcium currents, NGF regulates metabolic components of the GSIS, thereby contributing to the maturation process of pancreatic beta cells.
Topics: Animals; Glucose Transporter Type 2; Glucokinase; Insulin-Secreting Cells; Rats; Nerve Growth Factor; Glucose; Insulin; Rats, Wistar; Male; Insulin Secretion; Cells, Cultured
PubMed: 38875221
DOI: 10.1371/journal.pone.0303934 -
Frontiers in Immunology 2024About 10-20% of pancreas allografts are still lost in the early postoperative period despite the identification of numerous detrimental risk factors that correlate with...
BACKGROUND
About 10-20% of pancreas allografts are still lost in the early postoperative period despite the identification of numerous detrimental risk factors that correlate with graft thrombosis.
METHODS
We conducted a multicenter study including 899 pancreas transplant recipients between 2000 and 2018. Early pancreas failure due to complete thrombosis, long-term pancreas, kidney and patient survivals were analyzed and adjusted to donor, recipient and perioperative variables using a multivariate cause-specific Cox model stratified to transplant centers.
RESULTS
Pancreas from donors with history of hypertension (6.7%), as well as with high body mass index (BMI), were independently associated with an increased risk of pancreas failure within the first 30 post-operative days (respectively, HR= 2.57, 95% CI from 1.35 to 4.89 and HR= 1.11, 95% CI from 1.04 to 1.19). Interaction term between hypertension and BMI was negative. Donor hypertension also impacted long-term pancreas survival (HR= 1.88, 95% CI from 1.13 to 3.12). However, when pancreas survival was calculated after the postoperative day 30, donor hypertension was no longer a significant risk factor (HR= 1.22, 95% CI from 0.47 to 3.15). A lower pancreas survival was observed in patients receiving a pancreas from a hypertensive donor without RAAS (Renin Angiotensin Aldosterone System) blockers compared to others (50% vs 14%, p < 0.001). Pancreas survival was similar among non-hypertensive donors and hypertensive ones under RAAS blockers.
CONCLUSION
Donor hypertension was a significant and independent risk factor of pancreas failure. The well-known pathogenic role of renin-angiotensin-aldosterone system seems to be involved in the genesis of this immediate graft failure.
Topics: Humans; Pancreas Transplantation; Male; Female; Hypertension; Middle Aged; Adult; Thrombosis; Tissue Donors; Angiotensin II; Risk Factors; Graft Survival; Allografts; Retrospective Studies; Graft Rejection
PubMed: 38873595
DOI: 10.3389/fimmu.2024.1359381 -
Frontiers in Pharmacology 2024Dilated cardiomyopathy (DCM) is a fatal myocardial condition with ventricular structural changes and functional deficits, leading to systolic dysfunction and heart...
Dilated cardiomyopathy (DCM) is a fatal myocardial condition with ventricular structural changes and functional deficits, leading to systolic dysfunction and heart failure (HF). DCM is a frequent complication in oncologic patients receiving Doxorubicin (Dox). Dox is a highly cardiotoxic drug, whereas its damaging spectrum affects most of the organs by multiple pathogenic cascades. Experimentally reproduced DCM/HF through Dox administrations has shed light on the pathogenic drivers of cardiotoxicity. Growth hormone (GH) releasing peptide 6 (GHRP-6) is a GH secretagogue with expanding and promising cardioprotective pharmacological properties. Here we examined whether GHRP-6 administration concomitant to Dox prevented the onset of DCM/HF and multiple organs damages in otherwise healthy rats. Myocardial changes were sequentially evaluated by transthoracic echocardiography. Autopsy was conducted at the end of the administration period when ventricular dilation was established. Semiquantitative histopathologic study included heart and other internal organs samples. Myocardial tissue fragments were also addressed for electron microscopy study, and characterization of the transcriptional expression ratio between Bcl-2 and Bax. Serum samples were destined for REDOX system balance assessment. GHRP-6 administration in parallel to Dox prevented myocardial fibers consumption and ventricular dilation, accounting for an effective preservation of the LV systolic function. GHRP-6 also attenuated extracardiac toxicity preserving epithelial organs integrity, inhibiting interstitial fibrosis, and ultimately reducing morbidity and mortality. Mechanistically, GHRP-6 proved to sustain cellular antioxidant defense, upregulate prosurvival gene Bcl-2, and preserve cardiomyocyte mitochondrial integrity. These evidences contribute to pave potential avenues for the clinical use of GHRP-6 in Dox-treated subjects.
PubMed: 38873418
DOI: 10.3389/fphar.2024.1402138 -
Frontiers in Endocrinology 2024Previous observational epidemiological studies have suggested a potential association between thyroid function and inflammatory bowel disease (IBD). However, the...
BACKGROUND
Previous observational epidemiological studies have suggested a potential association between thyroid function and inflammatory bowel disease (IBD). However, the findings remain inconclusive, and whether this association is causal remains uncertain. The objective of this study is to investigate the causal association between thyroid function and IBD.
METHODS
Genome-wide association studies (GWAS) involving seven indicators of thyroid function, IBD, and 41 cytokines were analyzed. Bidirectional two-sample Mendelian randomization (MR) and multivariable MR were conducted to examine the causal relationship between thyroid function and IBD and to explore the potential mechanisms underlying the associations.
RESULTS
Genetically determined hypothyroidism significantly reduced the risk of CD (odds ratio [OR] = 0.761, 95% CI: 0.655-0.882, < 0.001). Genetically determined reference-range TSH was found to have a suggestive causal effect on IBD (OR = 0.931, 95% CI: 0.888-0.976, = 0.003), (Crohn disease) CD (OR = 0.915, 95% CI: 0.857-0.977, = 0.008), and ulcerative colitis (UC) (OR =0.910, 95% CI: 0.830-0.997, = 0.043). In reverse MR analysis, both IBD and CD appeared to have a suggestive causal effect on the fT3/fT4 ratio (OR = 1.002, = 0.013 and OR = 1.001, = 0.015, respectively). Among 41 cytokines, hypothyroidism had a significant impact on interferon-inducible protein-10 (IP-10) (OR = 1.465, 95% CI: 1.094-1.962, = 0.010). The results of multivariable MR showed that IP-10 may mediate the causal effects of hypothyroidism with CD.
CONCLUSION
Our results suggest that an elevated TSH level reduces the risk of CD, with IP-10 potentially mediating this association. This highlights the pituitary-thyroid axis could serve as a potential therapeutic strategy for CD.
Topics: Humans; Genome-Wide Association Study; Cytokines; Inflammatory Bowel Diseases; Thyroid Gland; Hypothyroidism; Mendelian Randomization Analysis; Thyroid Function Tests; Polymorphism, Single Nucleotide; Thyrotropin; Male
PubMed: 38872961
DOI: 10.3389/fendo.2024.1376139 -
Health and Quality of Life Outcomes Jun 2024Compared with multiple daily insulin injections (MDI), continuous subcutaneous insulin infusion (CSII) is significantly more expensive and has not been widely used in... (Comparative Study)
Comparative Study
BACKGROUND
Compared with multiple daily insulin injections (MDI), continuous subcutaneous insulin infusion (CSII) is significantly more expensive and has not been widely used in Chinese type 1 diabetes mellitus (T1DM) patients. So there are still significant knowledge gaps regarding clinical and patient-reported outcomes in China.
AIMS
This study aims to compare the glycated hemoglobin (HbA), insulin therapy related quality of life (ITR-QOL), fear of hypoglycemia (FOH) of adult T1DM patients treated with MDI and CSII based on propensity score matching in real-world conditions in China.
METHODS
Four hundred twenty adult T1DM patients who were treated with MDI or CSII continuously for more than 12 months in a national metabolic center from June 2021 to June 2023 were selected as the study subjects. Their QOL and FOH were evaluated with Insulin Therapy Related Quality of Life Measure Questionnaire-Chinese version (ITR-QOL-CV) and the Chinese Version Hypoglycemia Fear Survey-Worry Scale (CHFSII-WS), and their HbA were collected at the same time. Potential confounding variables between the two groups were matched using propensity score matching.
RESULTS
Of the 420 patients included in the study, 315 were in MDI group and 105 were in CSII group. 102 pairs were successfully matched. After matching, the total score of ITR-QOL-CV scale in CSII group was significantly higher than that in MDI group (87.08 ± 13.53 vs. 80.66 ± 19.25, P = 0.006). Among them, the dimensions of daily life, social life, and psychological state were all statistically different (P < 0.05). The scores of CHFSII-WS (8.33 ± 3.49 vs. 11.77 ± 5.27, P = 0.003) and HbA (7.19 ± 1.33% vs. 7.71 ± 1.93%, P = 0.045) in CSII group were lower than those in MDI group.
CONCLUSIONS
25.0% of T1DM adults are treated with CSII. Compared with adult T1DM patients treated with MDI, those treated with CSII have higher ITR-QOL, less FoH, and better control of HbA in real-world conditions in China. Therefore, regardless of economic factors, CSII is recommended for adult T1DM patients to optimize the therapeutic effect and outcomes.
Topics: Humans; Diabetes Mellitus, Type 1; Male; Female; Propensity Score; China; Adult; Quality of Life; Insulin; Glycated Hemoglobin; Insulin Infusion Systems; Middle Aged; Hypoglycemic Agents; Hypoglycemia; Surveys and Questionnaires
PubMed: 38872219
DOI: 10.1186/s12955-024-02263-w