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Samario-Román J, Velasco M, Larqué C, Cárdenas-Vázquez R, Ortiz-Huidobro RI, Hiriart M. NGF effects promote the maturation of rat pancreatic beta cells by regulating GLUT2 levels and distribution, and glucokinase activity. PLoS One 2024; 19:e0303934. [PMID: 38875221 PMCID: PMC11178159 DOI: 10.1371/journal.pone.0303934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/02/2024] [Indexed: 06/16/2024] Open
Abstract
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.
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Affiliation(s)
- Jazmín Samario-Román
- Neuroscience Division, Cognitive Neuroscience Department, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Myrian Velasco
- Neuroscience Division, Cognitive Neuroscience Department, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Carlos Larqué
- Department of Embryology and Genetics, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - René Cárdenas-Vázquez
- Laboratory of Experimental Animal Biology, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Rosa Isela Ortiz-Huidobro
- Department of Genomic Medicine and Environmental Toxicology, Instituto de Investigaciones Biomédicas, Ciudad de México, Mexico
| | - Marcia Hiriart
- Neuroscience Division, Cognitive Neuroscience Department, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Subbamanda YD, Bhargava A. Intercommunication between Voltage-Gated Calcium Channels and Estrogen Receptor/Estrogen Signaling: Insights into Physiological and Pathological Conditions. Cells 2022; 11:cells11233850. [PMID: 36497108 PMCID: PMC9739980 DOI: 10.3390/cells11233850] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Voltage-gated calcium channels (VGCCs) and estrogen receptors are important cellular proteins that have been shown to interact with each other across varied cells and tissues. Estrogen hormone, the ligand for estrogen receptors, can also exert its effects independent of estrogen receptors that collectively constitute non-genomic mechanisms. Here, we provide insights into the VGCC regulation by estrogen and the possible mechanisms involved therein across several cell types. Notably, most of the interaction is described in neuronal and cardiovascular tissues given the importance of VGCCs in these electrically excitable tissues. We describe the modulation of various VGCCs by estrogen known so far in physiological conditions and pathological conditions. We observed that in most in vitro studies higher concentrations of estrogen were used while a handful of in vivo studies used meager concentrations resulting in inhibition or upregulation of VGCCs, respectively. There is a need for more relevant physiological assays to study the regulation of VGCCs by estrogen. Additionally, other interacting receptors and partners need to be identified that may be involved in exerting estrogen receptor-independent effects of estrogen.
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Ortiz-Huidobro RI, Larqué C, Velasco M, Chávez-Maldonado JP, Sabido J, Sanchez-Zamora YI, Hiriart M. Sexual dimorphism in the molecular mechanisms of insulin resistance during a critical developmental window in Wistar rats. Cell Commun Signal 2022; 20:154. [PMID: 36224569 PMCID: PMC9554987 DOI: 10.1186/s12964-022-00965-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/17/2022] [Indexed: 11/23/2022] Open
Abstract
Background Insulin resistance (IR) is a condition in which the response of organs to insulin is impaired. IR is an early marker of metabolic dysfunction. However, IR also appears in physiological contexts during critical developmental windows. The molecular mechanisms of physiological IR are largely unknown in both sexes. Sexual dimorphism in insulin sensitivity is observed since early stages of development. We propose that during periods of accelerated growth, such as around weaning, at postnatal day 20 (p20) in rats, the kinase S6K1 is overactivated and induces impairment of insulin signaling in its target organs. This work aimed to characterize IR at p20, determine its underlying mechanisms, and identify whether sexual dimorphism in physiological IR occurs during this stage.
Methods We determined systemic insulin sensitivity through insulin tolerance tests, glucose tolerance tests, and blood glucose and insulin levels under fasting and fed conditions at p20 and adult male and female Wistar rats. Furthermore, we quantified levels of S6K1 phosphorylated at threonine 389 (T389) (active form) and its target IRS1 phosphorylated at serine 1101 (S1101) (inhibited form). In addition, we assessed insulin signal transduction by measuring levels of Akt phosphorylated at serine 473 (S473) (active form) in white adipose tissue and skeletal muscle through western blot. Finally, we determined the presence and function of GLUT4 in the plasma membrane by measuring the glucose uptake of adipocytes. Results were compared using two-way ANOVA (With age and sex as factors) and one-way ANOVA with post hoc Tukey’s tests or t-student test in each corresponding case. Statistical significance was considered for P values < 0.05. Results We found that both male and female p20 rats have elevated levels of glucose and insulin, low systemic insulin sensitivity, and glucose intolerance. We identified sex- and tissue-related differences in the activation of insulin signaling proteins in p20 rats compared to adult rats. Conclusions Male and female p20 rats present physiological insulin resistance with differences in the protein activation of insulin signaling. This suggests that S6K1 overactivation and the resulting IRS1 inhibition by phosphorylation at S1101 may modulate to insulin sensitivity in a sex- and tissue-specific manner. Video Abstract
Supplementary Information The online version contains supplementary material available at 10.1186/s12964-022-00965-6. Insulin regulates the synthesis of carbohydrates, lipids and proteins differently between males, and females. One of its primary functions is maintaining adequate blood glucose levels favoring glucose entry in muscle and adipose tissue after food consumption. Insulin resistance (IR) is a condition in which the response of organs to insulin is impaired. IR is frequently associated with metabolic dysfunction such as inflammation, obesity, or type 2 diabetes. However, physiological IR develops in healthy individuals during periods of rapid growth, pregnancy, or aging by mechanisms not fully understood. We studied the postnatal development, specifically around weaning at postnatal day 20 (p20) of Wistar rats. In previous works, we identified insulin resistance during this period in male rats. This work aimed to characterize IR at p20, determine its underlying mechanisms, and identify whether sexual dimorphism in physiological IR occurs during this stage. We found that p20 rats of both sexes have elevated blood glucose and insulin levels, low systemic insulin sensitivity, and glucose intolerance. We identified differences in insulin-regulated protein activation (S6K1, IRS1, Akt, and GLUT4) between sexes in different tissues and adipose tissue depots. Studying these mechanisms and their differences between males and females is essential to understanding insulin actions and their relationship with the possible development of metabolic diseases in both sexes.
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Affiliation(s)
- Rosa Isela Ortiz-Huidobro
- Neurosciences Division, Department of Cognitive Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Carlos Larqué
- Department of Embryology, and Genetics, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Myrian Velasco
- Neurosciences Division, Department of Cognitive Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Juan Pablo Chávez-Maldonado
- Neurosciences Division, Department of Cognitive Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Jean Sabido
- Neurosciences Division, Department of Cognitive Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Yuriko Itzel Sanchez-Zamora
- Neurosciences Division, Department of Cognitive Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marcia Hiriart
- Neurosciences Division, Department of Cognitive Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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Membrane polarization in non-neuronal cells as a potential mechanism of metabolic disruption by depolarizing insecticides. Food Chem Toxicol 2022; 160:112804. [PMID: 34990786 DOI: 10.1016/j.fct.2021.112804] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/22/2021] [Accepted: 12/31/2021] [Indexed: 01/01/2023]
Abstract
A significant rise in the incidence of obesity and type 2 diabetes has occurred worldwide in the last two decades. Concurrently, a growing body of evidence suggests a connection between exposure to environmental pollutants, particularly insecticides, and the development of obesity and type 2 diabetes. This review summarizes key evidence of (1) the presence of different types of neuronal receptors - target sites for neurotoxic insecticides - in non-neuronal cells, (2) the activation of these receptors in non-neuronal cells by membrane-depolarizing insecticides, and (3) changes in metabolic functions, including lipid and glucose accumulation, associated with changes in membrane potential. Based on these findings, we propose that changes in membrane potential (Vmem) by certain insecticides serve as a novel regulator of lipid and glucose metabolism in non-excitable cells associated with obesity and type 2 diabetes.
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Smita RM, Shuvo APR, Raihan S, Jahan R, Simin FA, Rahman A, Biswas S, Salem L, Sagor MAT. The Role of Mineral Deficiencies in Insulin Resistance and Obesity. Curr Diabetes Rev 2022; 18:e171121197987. [PMID: 34789132 DOI: 10.2174/1573399818666211117104626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/06/2021] [Accepted: 07/02/2021] [Indexed: 11/22/2022]
Abstract
Minerals are critical for maintaining overall health. These tiny chemical compounds are responsible for enzymatic activation, maintaining healthy teeth and bones, regulating energy metabolism, enhancing immunity, and aiding muscle and brain function. However, mineral deficiency in the form of inadequate or under nourished intake affects millions of people throughout the world, with well-documented adverse health consequences of malnutrition. Conversely, mineral deficiency may also be a risk factor for Insulin Resistance (IR) and obesity. This review focuses on another, more "less discussed" form of malnutrition, namely mineral deficiency and its contribution to metabolic disorders. At the cellular level, minerals maintain not only molecular communication but also trigger several key biochemical pathways. Disturbances in these processes due to mineral insufficiency may gradually lead to metabolic disorders such as insulin resistance, pre-diabetes, and central obesity, which might lead to renal failure, cardiac arrest, hepatic carcinoma, and various neurodegenerative diseases. Here we discuss the burden of disease promoted by mineral deficiencies and the medical, social, and economic consequences. Mineral deficiency-mediated IR and obesity have a considerable negative impact on individual well-being, physical consideration, and economic productivity. We discuss possible molecular mechanisms of mineral deficiency that may lead to IR and obesity and suggest strategies to counter these metabolic disorders. To protect mankind from mineral nutrient deficiencies, the key is to take a variety of foods in reasonable quantities, such as organic and pasture-raised eggs, low fat dairy, and grass-fed and finished meats, insecticide, and pesticide-free vegetables and fruits.
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Affiliation(s)
| | | | - Sabbir Raihan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Rajib Jahan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Faria Anjum Simin
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Ashiqur Rahman
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Soumick Biswas
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Liyad Salem
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Md Abu Taher Sagor
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
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6
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Monica Shih MC, Huang CCJ, Chu HP, Hsu NC, Chung BC. Embryonic Steroids Control Developmental Programming of Energy Balance. Endocrinology 2021; 162:6380292. [PMID: 34599818 DOI: 10.1210/endocr/bqab196] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Indexed: 12/25/2022]
Abstract
Glucose is a major energy source for growth. At birth, neonates must change their energy source from maternal supply to its own glucose production. The mechanism of this transition has not been clearly elucidated. To evaluate the possible roles of steroids in this transition, here we examine the defects associated with energy production of a mouse line that cannot synthesize steroids de novo due to the disruption of its Cyp11a1 (cytochrome P450 family 11 subfamily A member 1) gene. The Cyp11a1 null embryos had insufficient blood insulin and failed to store glycogen in the liver since embryonic day 16.5. Their blood glucose dropped soon after maternal deprivation, and the expression of hepatic gluconeogenic and glycogenic genes were reduced. Insulin was synthesized in the mutant fetal pancreas but failed to be secreted. Maternal glucocorticoid supply rescued the amounts of blood glucose, insulin, and liver glycogen in the fetus but did not restore expression of genes for glycogen synthesis, indicating the requirement of de novo glucocorticoid synthesis for glycogen storage. Thus, our investigation of Cyp11a1 null embryos reveals that the energy homeostasis is established before birth, and fetal steroids are required for the regulation of glycogen synthesis, hepatic gluconeogenesis, and insulin secretion at the fetal stage.
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Affiliation(s)
- Meng-Chun Monica Shih
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- National Laboratory Animal Center, National Applied Research Laboratories, Taipei, Taiwan
| | - Chen-Che Jeff Huang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Hsueh-Ping Chu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Institute of Molecular and Cell Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Nai-Chi Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Bon-Chu Chung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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7
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Zhou X, Heiranian M, Yang M, Epsztein R, Gong K, White CE, Hu S, Kim JH, Elimelech M. Selective Fluoride Transport in Subnanometer TiO 2 Pores. ACS NANO 2021; 15:16828-16838. [PMID: 34637268 DOI: 10.1021/acsnano.1c07210] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Synthesizing nanopores which mimic the functionality of ion-selective biological channels has been a challenging yet promising approach to advance technologies for precise ion-ion separations. Inspired by the facilitated fluoride (F-) permeation in the biological fluoride channel, we designed a highly fluoride-selective TiO2 film using the atomic layer deposition (ALD) technique. The subnanometer voids within the fabricated TiO2 film (4 Å < d < 12 Å, with two distinct peaks at 5.5 and 6.5 Å), created by the hindered diffusion of ALD precursors (d = 7 Å), resulted in more than eight times faster permeation of sodium fluoride compared to other sodium halides. We show that the specific Ti-F interactions compensate for the energy penalty of F- dehydration during the partitioning of F- ions into the pore and allow for an intrapore accumulation of F- ions. Concomitantly, the accumulation of F- ions on the pore walls also enhances the transport of sodium (Na+) cations due to electrostatic interactions. Molecular dynamics simulations probing the ion concentration and mobility within the TiO2 pore further support our proposed mechanisms for the selective F- transport and enhanced Na+ permeation in the TiO2 film. Overall, our work provides insights toward the design of ion-selective nanopores using the ALD technique.
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Affiliation(s)
- Xuechen Zhou
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Mohammad Heiranian
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Meiqi Yang
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Razi Epsztein
- Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Kai Gong
- Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544, United States
| | - Claire E White
- Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544, United States
| | - Shu Hu
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Jae-Hong Kim
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Menachem Elimelech
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
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Barragán-Álvarez CP, Padilla-Camberos E, Díaz NF, Cota-Coronado A, Hernández-Jiménez C, Bravo-Reyna CC, Díaz-Martínez NE. Loss of Znt8 function in diabetes mellitus: risk or benefit? Mol Cell Biochem 2021; 476:2703-2718. [PMID: 33666829 DOI: 10.1007/s11010-021-04114-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/18/2021] [Indexed: 12/13/2022]
Abstract
The zinc transporter 8 (ZnT8) plays an essential role in zinc homeostasis inside pancreatic β cells, its function is related to the stabilization of insulin hexameric form. Genome-wide association studies (GWAS) have established a positive and negative relationship of ZnT8 variants with type 2 diabetes mellitus (T2DM), exposing a dual and controversial role. The first hypotheses about its role in T2DM indicated a higher risk of developing T2DM for loss of function; nevertheless, recent GWAS of ZnT8 loss-of-function mutations in humans have shown protection against T2DM. With regard to the ZnT8 role in T2DM, most studies have focused on rodent models and common high-risk variants; however, considerable differences between human and rodent models have been found and the new approaches have included lower-frequency variants as a tool to clarify gene functions, allowing a better understanding of the disease and offering possible therapeutic targets. Therefore, this review will discuss the physiological effects of the ZnT8 variants associated with a major and lower risk of T2DM, emphasizing the low- and rare-frequency variants.
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Affiliation(s)
- Carla P Barragán-Álvarez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico
| | - Eduardo Padilla-Camberos
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico
| | - Nestor F Díaz
- Departamento de Fisiología y Desarrollo Celular, Instituto Nacional de Perinatología, Mexico City, Mexico
| | - Agustín Cota-Coronado
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico
| | - Claudia Hernández-Jiménez
- Departamento de Cirugía Experimental, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - Carlos C Bravo-Reyna
- Departamento de Cirugía Experimental, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Nestor E Díaz-Martínez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Guadalajara, Mexico.
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Heterogeneous expression of CFTR in insulin-secreting β-cells of the normal human islet. PLoS One 2020; 15:e0242749. [PMID: 33264332 PMCID: PMC7710116 DOI: 10.1371/journal.pone.0242749] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is due to mutations in the CF-transmembrane conductance regulator (CFTR) and CF-related diabetes (CFRD) is its most common co-morbidity, affecting ~50% of all CF patients, significantly influencing pulmonary function and longevity. Yet, the complex pathogenesis of CFRD remains unclear. Two non-mutually exclusive underlying mechanisms have been proposed in CFRD: i) damage of the endocrine cells secondary to the severe exocrine pancreatic pathology and ii) intrinsic β-cell impairment of the secretory response in combination with other factors. The later has proven difficult to determine due to low expression of CFTR in β-cells, which results in the general perception that this Cl−channel does not participate in the modulation of insulin secretion or the development of CFRD. The objective of the present work is to demonstrate CFTR expression at the molecular and functional levels in insulin-secreting β-cells in normal human islets, where it seems to play a role. Towards this end, we have used immunofluorescence confocal and immunofluorescence microscopy, immunohistochemistry, RT-qPCR, Western blotting, pharmacology, electrophysiology and insulin secretory studies in normal human, rat and mouse islets. Our results demonstrate heterogeneous CFTR expression in human, mouse and rat β-cells and provide evidence that pharmacological inhibition of CFTR influences basal and stimulated insulin secretion in normal mouse islets but not in islets lacking this channel, despite being detected by electrophysiological means in ~30% of β-cells. Therefore, our results demonstrate a potential role for CFTR in the pancreatic β-cell secretory response suggesting that intrinsic β-cell dysfunction may also participate in the pathogenesis of CFRD.
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Baspinar B, Güldaş M. Traditional plain yogurt: a therapeutic food for metabolic syndrome? Crit Rev Food Sci Nutr 2020; 61:3129-3143. [PMID: 32746616 DOI: 10.1080/10408398.2020.1799931] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Dairy products have an important role in a healthy diet due to their high-quality protein and rich micronutrients. Yogurt, a fermented milk product, has a similar composition to milk but is a more concentrated product in terms of group B vitamins, minerals, and proteins. It is known that bioactive metabolites and live enzymes that occur by fermentation and digestion, affect the health positively by improving gut microbiota. In recent years, the prevalence of metabolic syndrome, which threatens public health, is increasing rapidly. As with other noninfectious diseases, the diet has an important effect on the prevention and treatment of metabolic syndrome. It has been demonstrated that yogurt has a high-quality amino acid pattern, reduces energy intake by stimulating satiety, and regulates blood glucose level. In addition to the rich protein variety, yogurt also contains peptides that positively affect blood pressure. Unlike milk, increased acidity during the fermentation of yogurt positively affects calcium absorption. Calcium plays an important role in the control of blood glucose and energy metabolism through insulin-dependent and non-insulin-dependent routes. In addition to reducing inflammation, calcium has a positive effect on the regulation of the blood lipid profile by increasing fecal fat excretion. There are many lipid and lipoid nutrients such as saturated fatty acids, phospholipids, sphingolipids, and conjugated linoleic acid that may affect the blood lipid profile in yogurt positively or negatively. There are seen very few randomized controlled studies that are focused on the relationship between yogurt and metabolic syndrome, and these are based on contradictory results. In this review, based on the clinical studies conducted to date, and the nutrient content of yogurt, possible mechanisms of these contradictory results are investigated.
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Affiliation(s)
- Busra Baspinar
- Nutrition and Dietetics, Ankara Universitesi, Ankara, Turkey
| | - Metin Güldaş
- Nutrition and Dietetics, Uludag University, Görükle, Bursa, Turkey
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11
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Enhanced expression of β cell Ca V3.1 channels impairs insulin release and glucose homeostasis. Proc Natl Acad Sci U S A 2019; 117:448-453. [PMID: 31871187 PMCID: PMC6955371 DOI: 10.1073/pnas.1908691117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We reveal that increased expression of CaV3.1 channels in rat islets selectively impairs first-phase glucose-stimulated insulin secretion. This deterioration is recapitulated in human islets. Its causal role in diabetes development is clearly manifested in an in vivo diabetic model. Mechanistically, this is due to reduction of phosphorylated FoxO1 in the cytoplasm, elevated FoxO1 nuclear retention, and decreased syntaxin 1A, SNAP-25, and synaptotagmin III in a CaV3.1 channel- and calcineurin-dependent manner. Our findings suggest that elevated expression of CaV3.1 channels in pancreatic islets drives FoxO1-mediated down-regulation of exocytotic proteins resulting in the diabetic phenotypes of impaired insulin secretion and aberrant glucose homeostasis. This causal connection pinpoints β cell CaV3.1 channels as a potential druggable target for antidiabetes therapy. Voltage-gated calcium 3.1 (CaV3.1) channels are absent in healthy mouse β cells and mediate minor T-type Ca2+ currents in healthy rat and human β cells but become evident under diabetic conditions. Whether more active CaV3.1 channels affect insulin secretion and glucose homeostasis remains enigmatic. We addressed this question by enhancing de novo expression of β cell CaV3.1 channels and exploring the consequent impacts on dynamic insulin secretion and glucose homeostasis as well as underlying molecular mechanisms with a series of in vitro and in vivo approaches. We now demonstrate that a recombinant adenovirus encoding enhanced green fluorescent protein–CaV3.1 subunit (Ad-EGFP-CaV3.1) efficiently transduced rat and human islets as well as dispersed islet cells. The resulting CaV3.1 channels conducted typical T-type Ca2+ currents, leading to an enhanced basal cytosolic-free Ca2+ concentration ([Ca2+]i). Ad-EGFP-CaV3.1-transduced islets released significantly less insulin under both the basal and first phases following glucose stimulation and could no longer normalize hyperglycemia in recipient rats rendered diabetic by streptozotocin treatment. Furthermore, Ad-EGFP-CaV3.1 transduction reduced phosphorylated FoxO1 in the cytoplasm of INS-1E cells, elevated FoxO1 nuclear retention, and decreased syntaxin 1A, SNAP-25, and synaptotagmin III. These effects were prevented by inhibiting CaV3.1 channels or the Ca2+-dependent phosphatase calcineurin. Enhanced expression of β cell CaV3.1 channels therefore impairs insulin release and glucose homeostasis by means of initial excessive Ca2+ influx, subsequent activation of calcineurin, consequent dephosphorylation and nuclear retention of FoxO1, and eventual FoxO1-mediated down-regulation of β cell exocytotic proteins. The present work thus suggests an elevated expression of CaV3.1 channels plays a significant role in diabetes pathogenesis.
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Jurkovicova-Tarabova B, Cmarko L, Rehak R, Zamponi GW, Lacinova L, Weiss N. Identification of a molecular gating determinant within the carboxy terminal region of Ca v3.3 T-type channels. Mol Brain 2019; 12:34. [PMID: 30961646 PMCID: PMC6454634 DOI: 10.1186/s13041-019-0457-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 04/01/2019] [Indexed: 01/02/2023] Open
Abstract
The physiological functions controlled by T-type channels are intrinsically dependent on their gating properties, and alteration of T-type channel activity is linked to several human disorders. Therefore, it is essential to develop a clear understanding of the structural determinants responsible for the unique gating features of T-type channels. Here, we have investigated the specific role of the carboxy terminal region by creating a series a deletion constructs expressed in tsA-201 cells and analyzing them by patch clamp electrophysiology. Our data reveal that the proximal region of the carboxy terminus contains a structural determinant essential for shaping several gating aspects of Cav3.3 channels, including voltage-dependence of activation and inactivation, inactivation kinetics, and coupling between the voltage sensing and the pore opening of the channel. Altogether, our data are consistent with a model in which the carboxy terminus stabilizes the channel in a closed state.
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Affiliation(s)
| | - Leos Cmarko
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
| | - Renata Rehak
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Gerald W. Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Lubica Lacinova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Academy of Sciences, Bratislava, Slovakia
| | - Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, 16610 Prague, Czech Republic
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13
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Zhao D, Cao Y, Yu CG, Yuan SS, Zhang N, Zhang YY, Staessen JA, Feng YM. The association of calcium channel blockers with β-cell function in type 2 diabetic patients: A cross-sectional study. J Clin Hypertens (Greenwich) 2019; 21:638-647. [PMID: 30900372 DOI: 10.1111/jch.13517] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/14/2019] [Accepted: 02/20/2019] [Indexed: 12/20/2022]
Abstract
Type 2 diabetes mellitus (T2DM) patients are often accompanied with hypertension. However, the association of antihypertensive drugs with β-cell function has not been well studied. To investigate this question, the authors performed a cross-sectional study involving 882 hypertensive T2DM patients. To assess β-cell function, patients were given 75g glucose orally and C-peptide levels before and 1, 2, and 3 hours after glucose intake were measured. Homa-β was computed by Homeostasis Model Assessment model to evaluate β-cell function using fasting C-peptide and glucose levels in the plasma. Multivariable-adjusted analysis was performed to evaluate the association of antihypertensive drugs with C-peptide levels, HbA1c, and Homa-β. Among 882 hypertensive patients, 547 (62.0%) received antihypertensive treatment. Multivariate-adjusted analysis demonstrated that use of calcium channel blockers (CCBs) was negatively associated with HbA1c levels (CCBs: 0.95 [95% CI: 0.92-0.98], P = 0.002). Our data further illustrated that the C-peptide levels before and 1, 2, and 3 hours of OGTT were 1.10-, 1.18-, 1.19-, and 1.15-fold increase in T2DM patients taking CCBs (P = 0.084 for fasting C-peptide levels; P ≤ 0.024 for C-peptide levels at 1, 2, and 3 hours after OGTT) in comparison with non-CCB users. Nevertheless, usage of any other antihypertensive drugs did neither associated with HbA1c nor associated with C-peptide levels (P ≥ 0.11). In conclusion, CCB treatment was negatively associated with HbA1c levels but positively associated with β-cell function in hypertensive T2DM patients, implying that CCBs could be considered to treat hypertensive T2DM patients with reduced β-cell function.
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Affiliation(s)
- Dong Zhao
- Beijing Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Capital Medical University, Beijing Luhe hospital, Beijing, China
| | - Yu Cao
- Center for Evidence-Based Medicine, Beijing Luhe Hospital, Capital Medical University, Beijing, China
| | - Cai-Guo Yu
- Beijing Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Capital Medical University, Beijing Luhe hospital, Beijing, China
| | - Sha-Sha Yuan
- Beijing Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Capital Medical University, Beijing Luhe hospital, Beijing, China
| | - Ning Zhang
- Beijing Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Capital Medical University, Beijing Luhe hospital, Beijing, China
| | - Yuan-Yuan Zhang
- Beijing Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Capital Medical University, Beijing Luhe hospital, Beijing, China
| | - Jan A Staessen
- Department of Cardiovascular Sciences, Research Unit Hypertension and Cardiovascular Epidemiology, University of Leuven, Leuven, Belgium.,Cardiovascular Research Institute, Maastricht University, Maastricht, The Netherlands
| | - Ying-Mei Feng
- Beijing Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Capital Medical University, Beijing Luhe hospital, Beijing, China.,Center for Evidence-Based Medicine, Beijing Luhe Hospital, Capital Medical University, Beijing, China
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14
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Hou Y, Fan W, Yang W, Samdani AQ, Jackson AO, Qu S. Farnesoid X receptor: An important factor in blood glucose regulation. Clin Chim Acta 2019; 495:29-34. [PMID: 30910597 DOI: 10.1016/j.cca.2019.03.1626] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 03/13/2019] [Accepted: 03/21/2019] [Indexed: 12/12/2022]
Abstract
Farnesoid X receptor (FXR) is a transcription factor that can be activated by bile acid as well as influenced bile acid metabolism. β-cell bile acid metabolism is mediated by FXR and closely related to the regulation of blood glucose (BG). FXR can regulate BG through multiple pathways. This review summarises recent studies on FXR regulation of BG balance via bile acid regulation, lowering glucagon-like peptide-1 (GLP-1), inhibiting gluconeogenesis, increasing insulin secretion and enhancing insulin sensitivity. In addition, the current review provides additional insight into the relationship between FXR and BG which may provide a new theoretical basis for further study on the role of FXR.
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Affiliation(s)
- Yangfeng Hou
- Clinic Medicine Department, Hengyang Medical School, University of South China, Hengyang City, Hunan Province 421001, PR China
| | - Wenjing Fan
- Pathophysiology Department, University of South China, Hengyang City, Hunan Province 421001, PR China; Emergency Department, The Second Affiliated Hospital, University of South China, Hengyang City, Hunan Province 421001, PR China
| | - Wenling Yang
- Clinic Medicine Department, Hengyang Medical School, University of South China, Hengyang City, Hunan Province 421001, PR China
| | - Abdul Qadir Samdani
- Spinal Surgery Department, The First Affiliated Hospital, University of South China, Hengyang City, Hunan Province 421001, PR China
| | - Ampadu Okyere Jackson
- International College, Hengyang Medical School, University of South China, Hengyang City, Hunan Province 421001, PR China
| | - Shunlin Qu
- Pathophysiology Department, University of South China, Hengyang City, Hunan Province 421001, PR China.
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