1
|
Brito R, Sapunar J, Aguilar-Farías N, Navarro-Riquelme J, Pavez M, Hirata MH, Cerda A. Influence of Seropositivity against Adenovirus-36 on the Risk of Obesity and Insulin Resistance in the Child Population of Southern Chile. Viruses 2024; 16:995. [PMID: 38932286 PMCID: PMC11209367 DOI: 10.3390/v16060995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Background: Previous infection with Adenovirus-36 (HAdv-D36) has been associated with adipogenesis and glycemic regulation in cell culture and animal models. In humans, HAdv-D36 antibodies correlate with increased obesity risk yet paradoxically enhance glycemic control across various demographics. This study assesses the association of HAdv-D36 seropositivity with obesity, lipid, and glycemic profiles among school-aged children. Methods: We evaluated 208 children aged 9-13, categorized by BMI z-scores into normal weight (-1 to +1), overweight (+1 to +2), and obese (>+3). Assessments included anthropometry, Tanner stage for pubertal development, and biochemical tests (relating to lipids, glucose, and insulin), alongside HAdv-D36 seropositivity checked via ELISA. Insulin resistance was gauged using Chilean pediatric criteria. Results: The cohort displayed a high prevalence of overweight/obesity. HAdv-D36 seropositivity was 5.4%, showing no correlation with nutritional status. Additionally, no link between HAdv-D36 seropositivity and lipid levels was observed. Notably, insulin levels and HOMA-RI were significantly lower in HAdv-D36 positive children (p < 0.001). No cases of insulin resistance were reported in the HAdv-D36 (+) group in our population. Conclusions: HAdv-D36 seropositivity appears to decrease insulin secretion and resistance, aligning with earlier findings. However, no association with obesity development was found in the child population of southern Chile.
Collapse
Affiliation(s)
- Roberto Brito
- Center of Excellence in Translational Medicine CEMT-BIOREN, Universidad de La Frontera, Temuco 4810296, Chile; (R.B.); (J.S.); (M.P.)
| | - Jorge Sapunar
- Center of Excellence in Translational Medicine CEMT-BIOREN, Universidad de La Frontera, Temuco 4810296, Chile; (R.B.); (J.S.); (M.P.)
- Department of Internal Medicine, Universidad de La Frontera, Temuco 4781176, Chile
| | - Nicolás Aguilar-Farías
- Department of Physical Education, Sports and Recreation, Universidad de La Frontera, Temuco 4811230, Chile;
| | - Juan Navarro-Riquelme
- Department of Pediatrics and Children’s Surgery, Universidad de La Frontera, Temuco 4781176, Chile;
| | - Monica Pavez
- Center of Excellence in Translational Medicine CEMT-BIOREN, Universidad de La Frontera, Temuco 4810296, Chile; (R.B.); (J.S.); (M.P.)
- Department of Internal Medicine, Universidad de La Frontera, Temuco 4781176, Chile
| | - Mario Hiroyuki Hirata
- School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo 05508-060, Brazil;
| | - Alvaro Cerda
- Center of Excellence in Translational Medicine CEMT-BIOREN, Universidad de La Frontera, Temuco 4810296, Chile; (R.B.); (J.S.); (M.P.)
- Department of Basic Sciences, Universidad de La Frontera, Temuco 4811230, Chile
| |
Collapse
|
2
|
Manríquez V, Brito R, Pavez M, Sapunar J, Fonseca L, Molina V, Ortiz E, Baeza R, Reimer C, Charles M, Schneider C, Hirata MH, Hirata RDC, Cerda A. Adenovirus 36 seropositivity is related to the expression of anti-adipogenic lncRNAs GAS5 and MEG3 in adipose tissue obtained from subjects with obesity. Int J Obes (Lond) 2024:10.1038/s41366-024-01555-x. [PMID: 38898229 DOI: 10.1038/s41366-024-01555-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 04/29/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND Human Adenovirus D-36 (HAdV-D36) promotes adipogenesis in cellular and animal models and may contribute to the development of human obesity. Induction of PPARγ by HAdV-D36 seems to have a central role in the maintenance of adipogenic status. There is limited information about epigenetic mechanisms contributing to this process in human adipose tissue. This study evaluated the expression of lncRNAs (ADINR, GAS5 and MEG3) and miRNAs (miR-18a and miR-140) involved in the adipogenic process in visceral adipose tissue (VAT) of subjects with obesity with previous HAdV-D36 infection (seropositive) and unexposed (seronegative) subjects with obesity. METHODS Individuals with obesity were grouped according to the presence of antibodies against HAdV-D36 (Seropositive: HAdV-D36[+], n = 29; and Seronegative: HAdV-D36[-], n = 28). Additionally, a group of individuals without obesity (n = 17) was selected as a control group. The HAdV-D36 serology was carried out by ELISA. Biopsies of VAT were obtained during an elective and clinically indicated surgery (bariatric or cholecystectomy). RNA extraction from VAT was performed and the expression of PPARG and non-coding RNAs was evaluated by qPCR. RESULTS HAdV-D36[+] individuals had lower expression of anti-adipogenic lncRNAs GAS5 (p = 0.016) and MEG3 (p = 0.035) compared with HAdV-D36[-] subjects with obesity. HAdV-D36[+] subjects also presented increased expression of the adipogenic miRNA miR-18a (p = 0.042), which has been reported to be modulated by GAS5 through a RNA sponging mechanism during adipogenic differentiation. Additionally, an inverse correlation of GAS5 with PPARG expression was observed (r = -0.917, p = 0.01). CONCLUSION Our results suggest that HAdV-D36 is related to non-coding RNAs implicated in adipogenesis, representing a potential mechanism by which previous HAdV-D36 infection could be associated with the long-term maintenance of adipogenic status, probably through the GAS5/miR-18a axis.
Collapse
Affiliation(s)
- Víctor Manríquez
- Center of Excellence in Translational Medicine, CEMT-BIOREN, Universidad de La Frontera, Temuco, Chile
| | - Roberto Brito
- Center of Excellence in Translational Medicine, CEMT-BIOREN, Universidad de La Frontera, Temuco, Chile
| | - Monica Pavez
- Center of Excellence in Translational Medicine, CEMT-BIOREN, Universidad de La Frontera, Temuco, Chile
- Department of Internal Medicine, Universidad de La Frontera, Temuco, Chile
| | - Jorge Sapunar
- Center of Excellence in Translational Medicine, CEMT-BIOREN, Universidad de La Frontera, Temuco, Chile
- Department of Internal Medicine, Universidad de La Frontera, Temuco, Chile
- Centro de Investigación en Epidemiología Cardiovascular y Nutricional, EPICYN, Universidad de La Frontera, Temuco, Chile
| | - Luis Fonseca
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Víctor Molina
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Eugenia Ortiz
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Romilio Baeza
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Camila Reimer
- Department of Internal Medicine, Universidad de La Frontera, Temuco, Chile
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Maria Charles
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Constance Schneider
- Centro de Tratamiento de la Obesidad, Clínica Alemana de Temuco, Temuco, Chile
| | - Mario Hiroyuki Hirata
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Rosario Dominguez Crespo Hirata
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Alvaro Cerda
- Center of Excellence in Translational Medicine, CEMT-BIOREN, Universidad de La Frontera, Temuco, Chile.
- Centro de Investigación en Epidemiología Cardiovascular y Nutricional, EPICYN, Universidad de La Frontera, Temuco, Chile.
- Department of Basic Sciences, Universidad de La Frontera, Temuco, Chile.
| |
Collapse
|
3
|
Yu X, Zoh RS, Fluharty DA, Mestre LM, Valdez D, Tekwe CD, Vorland CJ, Jamshidi-Naeini Y, Chiou SH, Lartey ST, Allison DB. Misstatements, misperceptions, and mistakes in controlling for covariates in observational research. eLife 2024; 13:e82268. [PMID: 38752987 PMCID: PMC11098558 DOI: 10.7554/elife.82268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 04/02/2024] [Indexed: 05/18/2024] Open
Abstract
We discuss 12 misperceptions, misstatements, or mistakes concerning the use of covariates in observational or nonrandomized research. Additionally, we offer advice to help investigators, editors, reviewers, and readers make more informed decisions about conducting and interpreting research where the influence of covariates may be at issue. We primarily address misperceptions in the context of statistical management of the covariates through various forms of modeling, although we also emphasize design and model or variable selection. Other approaches to addressing the effects of covariates, including matching, have logical extensions from what we discuss here but are not dwelled upon heavily. The misperceptions, misstatements, or mistakes we discuss include accurate representation of covariates, effects of measurement error, overreliance on covariate categorization, underestimation of power loss when controlling for covariates, misinterpretation of significance in statistical models, and misconceptions about confounding variables, selecting on a collider, and p value interpretations in covariate-inclusive analyses. This condensed overview serves to correct common errors and improve research quality in general and in nutrition research specifically.
Collapse
Affiliation(s)
- Xiaoxin Yu
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Roger S Zoh
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - David A Fluharty
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Luis M Mestre
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Danny Valdez
- Department of Applied Health Science, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Carmen D Tekwe
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Colby J Vorland
- Department of Applied Health Science, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Yasaman Jamshidi-Naeini
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| | - Sy Han Chiou
- Department of Statistics and Data Science, Southern Methodist UniversityDallasUnited States
| | - Stella T Lartey
- University of Memphis, School of Public HealthMemphisUnited Kingdom
| | - David B Allison
- Department of Epidemiology and Biostatistics, Indiana University School of Public Health-BloomingtonBloomingtonUnited States
| |
Collapse
|
4
|
Association between Pediatric Adenovirus Infection and Type 1 Diabetes. CHILDREN 2022; 9:children9101494. [PMID: 36291430 PMCID: PMC9600003 DOI: 10.3390/children9101494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/16/2022] [Accepted: 09/23/2022] [Indexed: 12/05/2022]
Abstract
Background: Viruses are among the inducers of type 1 diabetes (T1D) as they are implicated in the initiation of β-cell destruction. This study aimed to explore the link between adenoviruses’ infection, inflammatory biomarkers, and the development of T1D. Methods: The study population included 80 children with T1D and 40 healthy controls (2–16 years old). The T1D group was further clustered into two groups according to time of T1D diagnosis: a group of children who were diagnosed during the first year of life and a second group who were diagnosed after the first year of life. Adenovirus DNA, anti-adenovirus IgG, cytokines, and lipid profiles were screened in the different groups. The results were statistically assessed using one-way analysis of variance (ANOVA) and LSD t-test. Results: Positive adenovirus PCR was detected in 2.5% and 20% of normal and T1D children, respectively. Moreover, the positive PCR results for adenovirus were found significantly higher in the T1D group, who were diagnosed during the first year of life (33.4%), in comparison to those diagnosed after the first year of life (12%). Anti-adenoviruses IgG was found in 12.5% and 40% of healthy controls and diabetic children, respectively. Seropositive results were found to be higher in newly diagnosed children (46.7%) in comparison to those previously diagnosed with T1D (36%). Body mass index (BMI), IFN-γ, IL-15, adiponectin, lipid profile, and microalbuminuria were significantly increased in T1D adenoviruses-positive children compared to children who were negative for adenoviruses. Conclusions: Adenovirus infection could be among the contributing risk factors and may play a role in the induction of T1D in children.
Collapse
|
5
|
Konicek C, Heenemann K, Cramer K, Vahlenkamp TW, Schmidt V. Case Series of Disseminated Xanthogranulomatosis in Red-crowned Parakeets (Cyanoramphus novaezelandiae) with Detection of Psittacine Adenovirus 2 (PsAdV-2). Animals (Basel) 2022; 12:ani12182316. [PMID: 36139176 PMCID: PMC9495053 DOI: 10.3390/ani12182316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/03/2022] [Accepted: 09/04/2022] [Indexed: 12/25/2022] Open
Abstract
Simple Summary Lipometabolic disorders, such as xanthogranulomatosis, are common diseases in avian medicine. Various manifestations of lipometabolic disorders and risk factors for acquiring lipometabolic diseases have been described in the past years. Xanthogranulomas are usually limited to the skin and supposed to be associated with traumatic or inflammatory injuries in that area. Disseminated xanthogranulomatosis, appearing simultaneously in several internal organs, has been recently described in psittacine birds, the cause of the diseases was not known. Here, we describe a case series of disseminated xanthogranulomatosis in another psittacine species, the Red-crowned Parakeet (Cyanoramphus novaezelandiae) and a possible association with a concurrent psittacine adenovirus 2 (PsAdV-2) infection. Viral infections that trigger lipometabolic diseases have been described in human medicine in some species of small animals and in chickens. PsAdV-2- infections are widely distributed in avian species. A possible association between PsAdV-2- infections and lipometabolic diseases in the Red-crowned Parakeet should be considered. Individual birds and flocks with both or either of these diseases should be carefully examined and monitored. Abstract Xanthogranulomatosis is a common dermatological disease in birds. This form of inflammation, possibly associated with lipometabolic disorders, can also be seen in visceral organs, which as yet has only rarely been described in avian medicine. In general, diseases related to impaired lipid metabolism are frequently reported in avian medicine, with hepatic steatosis and atherosclerosis being the most common. In human medicine, infectious agents—especially some strains of adenovirus—were implicated in contributing to lipometabolic disorders; this has also been described for chicken. Here, a case series of six Red-crowned Parakeets (Cyanoramphus novaezelandiae) is presented, all cases being characterized by psittacine adenovirus 2 (PsAdV-2) infection with or without disseminated xanthogranulomatosis. The affected individuals were examined alive by clinical examination. Total body radiographs were taken of two birds, haematology and blood biochemistry results were achieved in one bird. The birds either died immediately after clinical presentation or within two days, two individuals were euthanized due to worsening of their clinical condition. All birds underwent a post-mortem examination. While four birds were finally diagnosed with disseminated xanthogranulomatosis, all six individuals had large eosinophilic intranuclear inclusion bodies in the epithelial cells of the collecting ducts of the kidney and tested positive for PsAdV-2. Further examinations are needed to clarify to what extent PsAdV-2 might elicit lipometabolic disease in birds, or psittacines in general, and, in particular, the Red-crowned Parakeet.
Collapse
Affiliation(s)
- Cornelia Konicek
- Service for Birds and Reptiles, Clinic for Small Animal Internal Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Wien, Austria
| | - Kristin Heenemann
- Institute of Virology, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 29, 04103 Leipzig, Germany
| | - Kerstin Cramer
- Clinic for Birds and Reptiles, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany
| | - Thomas W. Vahlenkamp
- Institute of Virology, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 29, 04103 Leipzig, Germany
| | - Volker Schmidt
- Clinic for Birds and Reptiles, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany
- Correspondence:
| |
Collapse
|
6
|
Tsilingiris D, Vallianou NG, Karampela I, Muscogiuri G, Dalamaga M. Use of adenovirus type-5 vector vaccines in COVID-19: potential implications for metabolic health? Minerva Endocrinol (Torino) 2022; 47:264-269. [PMID: 35621112 DOI: 10.23736/s2724-6507.22.03797-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Dimitrios Tsilingiris
- First Department of Propedeutic Internal Medicine, School of Medicine, Laiko General Hospital, National and Kapodistrian University of Athens, Athens, Greece -
| | - Natalia G Vallianou
- First Department of Internal Medicine, Evangelismos General Hospital, Athens, Greece
| | - Irene Karampela
- Second Department of Critical Care, Medical School, Attikon General University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Giovanna Muscogiuri
- Unit of Endocrinology, Department of Clinical Medicine and Surgery, School of Medicine, University of Naples Federico II, Naples, Italy.,Unit of Endocrinology, Department of Clinical Medicine and Surgery, School of Medicine, Centro Italiano per la Cura e il Benessere del Patiente con Obesità (CIBO), University of Naples Federico II, Naples, Italy
| | - Maria Dalamaga
- Department of Biological Chemistry, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
7
|
E4orf1 Prevents Progression of Fatty Liver Disease in Mice on High Fat Diet. Int J Mol Sci 2022; 23:ijms23169286. [PMID: 36012550 PMCID: PMC9409018 DOI: 10.3390/ijms23169286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/05/2022] [Accepted: 08/14/2022] [Indexed: 11/21/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) covers a broad spectrum of liver diseases ranging from steatosis to cirrhosis. There are limited data on prevention of hepatic steatosis or its progression to liver disease. Here, we tested if either transgenic (Tg) doxycycline-induced expression in adipose tissue of E4orf1 (E4), an adenoviral protein, or dietary fat restriction attenuated hepatic steatosis or its progression in mice. Twelve to fourteen-week-old TgE4 mice (E4 group) and control mice were exposed to a 60% (Kcal) high fat diet (HFD) for 20 weeks, while another group of mice on HFD for 10 weeks were switched to a chow diet (chow group) for another 10 weeks. Glycemic control was determined at weeks 10 and 20. Tissues were collected for gene and protein analysis at sacrifice. Compared to control, diet reversal significantly reduced body weight in the chow group, whereas E4 expression attenuated weight gain, despite HFD. E4 mice evinced significantly improved glucose clearance, lower endogenous insulin secretion, reduced serum triglycerides, attenuated hepatic steatosis and inflammation. Interestingly, in spite of weight loss and lower liver fat, chow mice showed significant upregulation of hepatic genes involved in lipid metabolism. Despite HFD, E4 prevents hepatic lipid accumulation and progression of hepatic steatosis, while diet reversal maintains hepatic health, but is unable to improve molecular changes.
Collapse
|
8
|
Dhurandhar NV, Petersen KS, Webster C. Key Causes and Contributors of Obesity: A Perspective. Nurs Clin North Am 2021; 56:449-464. [PMID: 34749887 DOI: 10.1016/j.cnur.2021.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Obesity is a disease with several potential causes and contributors. This article provides a focused overview of key known causes of obesity and factors that contribute to obesity. Obesity ultimately results from impaired energy storage mechanisms, such as dysregulation of hunger, satiety, digestion, fat storage, and metabolic rate. In addition, myriad contributors promote its expression, including dietary factors, sleep quality and duration, psychological health and well-being, and tobacco cessation, among others. This article concludes with a discussion of the clinical relevance of causes and contributors in obesity prevention and treatment, which is paramount to providing effective, individualized clinical management.
Collapse
Affiliation(s)
- Nikhil V Dhurandhar
- Department of Nutritional Sciences, Texas Tech University, 1301 Akron Avenue, P.O. Box 41270, Lubbock, TX 79409, USA.
| | - Kristina S Petersen
- Department of Nutritional Sciences, Texas Tech University, 1301 Akron Avenue, P.O. Box 41270, Lubbock, TX 79409, USA
| | - Chelsi Webster
- Department of Nutritional Sciences, Texas Tech University, 1301 Akron Avenue, P.O. Box 41270, Lubbock, TX 79409, USA
| |
Collapse
|
9
|
da Silva Fernandes J, Schuelter-Trevisol F, Cancelier ACL, Gonçalves e Silva HC, de Sousa DG, Atkinson RL, Trevisol DJ. Adenovirus 36 prevalence and association with human obesity: a systematic review. Int J Obes (Lond) 2021; 45:1342-1356. [PMID: 33753885 PMCID: PMC7983349 DOI: 10.1038/s41366-021-00805-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 02/01/2021] [Accepted: 03/04/2021] [Indexed: 01/31/2023]
Abstract
INTRODUCTION Obesity has numerous etiologies and includes biological factors. Studies have demonstrated that the human adenovirus subtype 36 (Adv36) is an adipogenic agent and causes metabolic alterations. Study results on the prevalence of Adv36 and clinical effects in humans vary substantially. This was a systematic review to summarize the studies on the prevalence of Adv36 infection and its association with human obesity. METHODS A systematic literature review was conducted using the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Observational or experimental studies found in the Medline, Embase, LILACS, Science Direct and SciELO databases that presented results on the prevalence of Adv36 in humans were included. RESULTS Thirty-seven studies were screened. A total of 10,300 adults aged 18-70 years and 4585 children and adolescents aged 3-18 years were assessed. The average prevalence of Adv36 among adults was 22.9%, ranging from 5.5% to 49.8%. Among children and adolescents, the average prevalence of Adv36 was 28.9%, ranging from 7.5% to 73.9%. There was a positive statistical relationship between Adv36 and weight gain, obesity, or metabolic changes in 31 studies. However, in four studies there was no association with obesity, and in one, no association was described. One of the studies showed an inverse correlation, i.e., Adv36 was a protective factor against obesity. CONCLUSION Strong evidence suggested a positive association between viral infection and obesity. However, due to the multi-causality of obesity and heterogeneity of studies, diagnostic tests should be standardized and easily accessible by the population to estimate the overall prevalence of Adv36 infection and its association with obesity.
Collapse
Affiliation(s)
- Jaime da Silva Fernandes
- grid.412297.b0000 0001 0648 9933Postgraduate Program in Health Sciences at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil ,grid.412297.b0000 0001 0648 9933Medical School at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil
| | - Fabiana Schuelter-Trevisol
- grid.412297.b0000 0001 0648 9933Postgraduate Program in Health Sciences at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil ,grid.412297.b0000 0001 0648 9933Medical School at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil ,Clinical Research Center of Hospital Nossa Senhora da Conceição, Tubarão, Santa Catarina Brazil
| | - Ana Carolina Lobor Cancelier
- grid.412297.b0000 0001 0648 9933Postgraduate Program in Health Sciences at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil ,grid.412297.b0000 0001 0648 9933Medical School at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil
| | - Helena Caetano Gonçalves e Silva
- grid.412297.b0000 0001 0648 9933Postgraduate Program in Health Sciences at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil ,grid.412297.b0000 0001 0648 9933Medical School at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil
| | - Daiana Gomes de Sousa
- grid.412297.b0000 0001 0648 9933Medical School at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil
| | - Richard L. Atkinson
- grid.224260.00000 0004 0458 8737Virginia Commonwealth University, School of Medicine, Richmond, VA USA
| | - Daisson José Trevisol
- grid.412297.b0000 0001 0648 9933Postgraduate Program in Health Sciences at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil ,grid.412297.b0000 0001 0648 9933Medical School at University of Southern Santa Catarina (UNISUL), Tubarão, Brazil
| |
Collapse
|
10
|
Barrera-Alcocer J, García-Benavides L, Muñoz-Valle JF, de la Cruz-Mosso U, González RA, Luquín S, Alarcón-Romero LDC, Marino-Ortega LA, Matia-Garcia I, Parra-Rojas I. Presence of Adenovirus-36 DNA in Adipose Tissue of Women: Relationship with Adipocyte Morphology and the Expression of C/EBPβ and HIF-1α. Diabetes Metab Syndr Obes 2021; 14:477-486. [PMID: 33568924 PMCID: PMC7868284 DOI: 10.2147/dmso.s285341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/26/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Human adenovirus 36 (HAd36) infection has been associated with obesity. Experiments using 3T3-L1 adipocyte cultured cells and human adipose stem cells (hASCc) have shown that HAd36 stimulates the expression of genes implicated in cell differentiation and increased lipid accumulation. The presence of HAd36 in adipose tissue of overweight and obese women has also been confirmed. This study aims to analyze the presence of HAd36 DNA in the adipose tissue of women undergoing surgery for weight reduction and its relationship with obesity through changes in adipocyte morphology as well as the expression of C/EBPβ and HIF-1α. METHODS Fifty-two subcutaneous adipose tissue biopsies were collected. The anthropometric parameters measured were weight, height, skin folds, body circumferences, and body fat percentage. Biochemical measures were performed for glucose, cholesterol, triglycerides, cholesterol HDL-c, and LDL-c. The presence of HAd36 DNA was performed by conventional PCR. Adipocyte morphology was analyzed in H&E-stained sections using ImageJ/Fiji software. The expression of genes C/EBPβ, HIF-1α and β-actin was determined using TaqMan probes. RESULTS HAd36 DNA was detected in 31% of adipose tissue samples. The presence of viral DNA was not significantly associated with anthropometric, clinical, or metabolic measurements, or with changes in adipose tissue morphology. The levels of mRNA expression for C/EBPβ and HIF-1α did not show significant differences between positive and negative samples for HAd36 (p>0.05). CONCLUSION The presence of HAd36 DNA in adipose tissue was identified, but it was not related to morphological changes of adipocytes, or the expression of C/EBPβ and HIF-1α. Further studies are needed to confirm these findings.
Collapse
Affiliation(s)
- Jorge Barrera-Alcocer
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Leonel García-Benavides
- Instituto de Terapéutica Experimental y Clínica, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - José F Muñoz-Valle
- Instituto de Investigación en Ciencias Biomédicas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Ulises de la Cruz-Mosso
- Instituto de Investigación en Ciencias Biomédicas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Ramón A González
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Sonia Luquín
- Departamento de Neurociencias, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Luz del C Alarcón-Romero
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Linda A Marino-Ortega
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Ines Matia-Garcia
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
| | - Isela Parra-Rojas
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, México
- Correspondence: Isela Parra-Rojas Laboratorio de Investigación en Obesidady Diabetes, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Avenida Lázaro Cárdenas S/N, Ciudad Universitaria, Chilpancingo, Guerrero, 39090, MéxicoTel/Fax +52 7474719310 Email
| |
Collapse
|
11
|
Hegde V, Dhurandhar NV, Reddy PH. Hyperinsulinemia or Insulin Resistance: What Impacts the Progression of Alzheimer's Disease? J Alzheimers Dis 2020; 72:S71-S79. [PMID: 31744006 DOI: 10.3233/jad-190808] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes mellitus (T2D), which is often accompanied by hyperinsulinemia and insulin resistance, is associated with an increased risk for developing mild cognitive impairment and Alzheimer's disease (AD); however, the underlying mechanisms for this association are still unclear. Recent findings have shown that hyperinsulinemia and insulin resistance can coexist or be independent events. This makes it imperative to determine the contribution of these individual conditions in impacting AD. This literature review highlights the recent developments of hyperinsulinemia and insulin resistance involvement in the progression and pathogenesis of AD.
Collapse
Affiliation(s)
- Vijay Hegde
- Obesity and Metabolic Health Laboratory, Department of Nutritional Sciences Texas Tech University, Lubbock, TX, USA
| | - Nikhil V Dhurandhar
- Obesity and Metabolic Health Laboratory, Department of Nutritional Sciences Texas Tech University, Lubbock, TX, USA
| | - P Hemachandra Reddy
- Internal Medicine, Cell Biology and Biochemistry, Neuroscience/Pharmacology and Neurology, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| |
Collapse
|
12
|
Characterization of the adipogenic protein E4orf1 from adenovirus 36 through an in silico approach. J Mol Model 2020; 26:285. [PMID: 32978703 DOI: 10.1007/s00894-020-04531-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
Adenovirus 36 (Ad-36) is related to human obesity due to its adipogenic activity mediated by the early 4 open reading frame 1 (E4orf1) protein. Mechanisms underlying the adipogenic effect of E4orf1 are not completely understood; however, the proliferation and differentiation of fat cells are increased through the activation of the phosphatidyl inositol 3 kinase pathway by binding proteins containing PDZ domain. This study characterized E4orf1 tridimensional structure and analyzed its interactions with PDZ domain-containing proteins in order to provide new information about the behavior of this viral protein and its targets, which could provide an interesting druggable target for obesity-related cardiometabolic alterations. In silico strategies such as homology modeling, docking, and molecular dynamics (MD) were used to study the interaction of E4orf1 with five PDZ domains of disk large homolog 1 (PDZ-1 and PDZ-2), membrane-associated guanylate kinase 1 (PDZ-3), and multi-PDZ domain protein 1 (PDZ-7 and PDZ-10). Mutagenesis analysis of selected residues was performed to evaluate their effects on the stabilization of E4orf1:PDZ complexes. MD simulations showed that the E4orf1:PDZ10 complex was more stable than the others ones. The highly hydrophobic residues at the C-terminal region (114-125) of the E4orf1 are essential in the initial phase stabilization of the complexes. Moreover, the residues 80-85 in the core region contribute to longer stabilization of the E4orf1:PDZ10 complex, a result that was confirmed by in silico mutagenesis. In conclusion, E4orf1 forms a stable complex with PDZ10 domain, and the residues 80-85 are of particular importance. The characterization of E4orf1 interactions with PDZ domains provides an initial approach to discover druggable targets for Ad-36-induced obesity.
Collapse
|
13
|
Lessan N, Saradalekshmi KR, Alkaf B, Majeed M, Barakat MT, Lee ZPL, Atkinson RL. Obesity and Diabetes in an Arab population: Role of Adenovirus 36 Infection. Sci Rep 2020; 10:8107. [PMID: 32415247 PMCID: PMC7229214 DOI: 10.1038/s41598-020-65008-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 04/16/2020] [Indexed: 11/16/2022] Open
Abstract
Prior infection with adenovirus 36 (Adv36) has been associated with increased adiposity, improved insulin sensitivity, and a lower prevalence of diabetes. This study investigated the prevalence of Adv36 seropositivity and its association with obesity and diabetes among adults attending a diabetes centre in the UAE.Participants (N = 973) with different weight and glucose tolerance categories were recruited. Adv36 seropositivity (Adv36 + ) was assessed using ELISA. Differences among groups were analyzed using statistical tests as appropriate to the data. Prevalence of Adv36+ in the study population was 47%, with no significant difference in obese and non-obese subgroups (42.5% vs 49.6% respectively; p=non-significant). Females were more likely to be Adv36+ compared to males (odds ratio 1.78; 95% CI 1.36–2.32, p < 0.001). We found no significant association between Adv36 seropositivity and different BMI categories, or glucose tolerance status. In our population, the effect of Adv36 infection on lipid profile varied between healthy individuals and individuals with obesity. Adv36 infection is more prevalent in the UAE than in other countries but has no association with obesity. Our study found that females were more likely to be Adv36 positive regardless of weight or diabetes status.
Collapse
Affiliation(s)
- Nader Lessan
- Imperial College London Diabetes Centre, Abu Dhabi, UAE.
| | | | - Budour Alkaf
- Imperial College London Diabetes Centre, Abu Dhabi, UAE
| | - Maria Majeed
- Imperial College London Diabetes Centre, Abu Dhabi, UAE
| | | | | | - Richard L Atkinson
- Virginia Commonwealth University, Richmond, VA, USA.,Obetech Obesity Research Center, Richmond, VA, USA
| |
Collapse
|
14
|
Shirani F, Teimoori A, McAinch AJ, Rashno M, Latifi SM, Karandish M. Human adenovirus 36 improves insulin sensitivity and lipid profiles and increases inflammatory markers in Wistar rats. J Investig Med 2020; 68:980-984. [PMID: 32303633 DOI: 10.1136/jim-2019-001165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2020] [Indexed: 12/15/2022]
Abstract
Human adenovirus 36 (Ad-36) causes obesity with increased adiposity, in contrast, Ad-36 infection reduces glucose and lipid metabolism; the results, however, are not consistent. In the current study, the effects of Ad-36 infection on glucose and lipid profile and inflammatory markers in Wistar rats were investigated. Sixty male Wistar rats were randomly divided into infected and control groups. Ad-36 virus suspension was injected in the experimental group rats. Blood samples were collected in the beginning and after 12 weeks in both groups. After 12 weeks, a significant improvement was observed in fasting blood glucose, fasting serum insulin, insulin sensitivity, serum triglycerides and total cholesterol in the infected group compared with the non-infected groups. There were no significant differences in inflammatory biomarkers including tumor necrosis factor-α, interleukin 6 and monocyte chemoattractant protein-1 levels between infected and control groups. This study showed that Ad-36 had favorable effects on glycemic and lipid control in infected rats, but inflammatory biomarker levels were similar for 2 groups. Ad-36 infections could potentially be a new way to develop novel antidiabetic and antihyperlipidemic therapeutic agents.
Collapse
Affiliation(s)
- Fatemeh Shirani
- Department of Nutrition, School of Allied Medical Sciences, and Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Teimoori
- School of Medicine, Health Research Institute, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Andrew J McAinch
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia.,Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, Melbourne, Victoria, Australia
| | - Mohammad Rashno
- Department of Immunology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Seyed Mahmoud Latifi
- Diabetes Research Center and Department of Statistics and Epidemiology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Karandish
- Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| |
Collapse
|
15
|
Reducing endogenous insulin is linked with protection against hepatic steatosis in mice. Nutr Diabetes 2020; 10:11. [PMID: 32286259 PMCID: PMC7156670 DOI: 10.1038/s41387-020-0114-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/06/2020] [Accepted: 03/18/2020] [Indexed: 12/13/2022] Open
Abstract
Background Obesity and type 2 diabetes (T2D) are closely associated with hepatic steatosis (HS), which if untreated can advance to serious liver conditions. Since insulin promotes hepatic lipogenesis, reducing hyperinsulinemia may help in treating HS. E4orf1 is an adenovirus-derived protein that improves glucose clearance independent of insulin, lowers insulin amount required for glucose disposal, and reduces HS. As a next step, we evaluated the mechanism for E4orf1-induced reduction in HS and tested that E4orf1 does not induce hypoglycemia, an important attribute for its application as a potential anti-diabetic agent. Methods C57Bl/6J mice that transgenically express E4orf1 in adipose tissue (E4orf-Tg) and wild-type (WT) mice received a chow diet for 6 weeks, followed by a high-fat (HF) diet for additional 10 weeks. Body composition, blood glucose, and serum insulin levels upon glucose load were measured at 0, 6, 7, and 16 weeks. Serum free fatty acid (FFA), triglyceride (TG), and hepatic TG were measured at study termination. We compared histology and the mRNA/protein markers of hepatic and adipose tissue lipid metabolism between the two groups of mice. Results On chow diet, both groups remained normoglycemic, but E4orf1 expression reduced insulin response. On HF diet, glycemic control in WT deteriorated, whereas E4orf1 significantly enhanced glycemic control, lowered insulin response, reduced hepatic triglycerides, and serum FFA. Overall, a comparison of hepatic mRNA and/or protein expression suggested that E4orf1 expression significantly decreased de novo lipogenesis (DNL) and intracellular lipid transport and increased fat oxidation and TG export. Adipose tissue mRNA and protein markers suggested that E4orf1 expression lowered DNL and increased lipolysis. Conclusion Considering that E4orf1 is not secreted in circulation, we postulate that reduced endogenous insulin in E4orf1 mice indirectly contributes to reduce HS by altering hepatic lipid metabolism, including lipogenesis. This study underscores the possibility of indirectly impacting HS by manipulating adipose tissue metabolism.
Collapse
|
16
|
Hegde V, Vijayan M, Kumar S, Akheruzzaman M, Sawant N, Dhurandhar NV, Reddy PH. Adenovirus 36 improves glycemic control and markers of Alzheimer's disease pathogenesis. Biochim Biophys Acta Mol Basis Dis 2019; 1865:165531. [PMID: 31398466 DOI: 10.1016/j.bbadis.2019.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/30/2019] [Accepted: 08/05/2019] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide. While the causes of AD are unclear, several risk factors have been identified, including impaired glycemic control, which significantly increases the risk of cognitive decline and AD. In vitro and in vivo studies show that human adenovirus 36 (Ad36) improves glycemic control by increasing cellular glucose uptake in cells, experimental animal models and in humans who are naturally exposed to the virus. This study, tested improvement in glycemic control by Ad36 and delay in onset of cognitive decline in APPswe transgenic mice (Tg2576 line), a model of genetic predisposition to impaired glycemic control and AD. Three-month old APPswe mice were divided into Ad36 infected (Ad36) or mock infected (control) groups and baseline glycemic control measured by glucose tolerance test (GTT) prior to infection. Changes in glycemic control were determined 10- and 24-week post infection. Serum insulin was also measured during GTT. Cognition was determined by Y-maze test, while motor coordination and skill acquisition by rotarod test. Glycemic control as determined by GTT showed less deterioration in Ad36 infected mice over time, accompanied by a significant attenuation of cognitive decline. Analysis of brain tissue lysate showed significantly reduced levels of amyloid beta 42 in Ad36 mice relative to control mice. Golgi-Cox staining analysis also revealed reduced dendritic spines and synaptic gene expression in control mice compared to Ad36 infected mice. This proof of concept study shows that in a mouse model of AD, Ad36 improves glycemic control and ameliorates cognitive decline.
Collapse
Affiliation(s)
- V Hegde
- Obesity and Metabolic Health Laboratory, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX 79409, USA.
| | - M Vijayan
- Internal Medicine, Cell Biology and Biochemistry, Neuroscience/Pharmacology and Neurology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - S Kumar
- Internal Medicine, Cell Biology and Biochemistry, Neuroscience/Pharmacology and Neurology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Md Akheruzzaman
- Obesity and Metabolic Health Laboratory, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - N Sawant
- Internal Medicine, Cell Biology and Biochemistry, Neuroscience/Pharmacology and Neurology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - N V Dhurandhar
- Obesity and Metabolic Health Laboratory, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - P H Reddy
- Internal Medicine, Cell Biology and Biochemistry, Neuroscience/Pharmacology and Neurology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| |
Collapse
|
17
|
E4orf1 protein reduces the need for endogenous insulin. Nutr Diabetes 2019; 9:17. [PMID: 31127081 PMCID: PMC6534626 DOI: 10.1038/s41387-019-0085-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/30/2019] [Accepted: 05/08/2019] [Indexed: 11/11/2022] Open
Abstract
Background E4orf1 protein derived from adenovirus-36 reduces glucose excursion in mice, and lowers endogenous insulin response, suggesting a reduced need for insulin. We tested if the E4orf1-mediated lowering of insulin response is due to increased tissue sensitivity to insulin, reduced ability to produce or release insulin, or a reduced need for insulin release. Methods Experiment 1: hyperinsulinemic–euglycemic clamps (HEC) and glucose tolerance test (GTT) were performed in high fat fed transgenic mice expressing E4orf1 or non-transgenic littermates (n = 12 each), for 4 weeks. Experiments 2, 3, and 4: E4orf1 or null vectors were expressed in rat-pancreatic β-cell line (INS-1) for 72 h, and cells were exposed to varying levels of glucose. Cell lysates and media were collected. Experiment 5: 3T3L1-preadipocytes that express E4orf1 upon doxycycline induction, or null vector were induced with doxycycline and then exposed to protein transport inhibitor. Supernatant and cell lysate were collected. Experiment 6: 3T3L1-preadipocytes that express E4orf1 upon doxycycline induction, or null vector were co-cultured with INS-1 cells for 24 h. Media was collected. Results Experiment 1: E4orf1 transgenic mice cleared glucose faster compared to non-transgenic mice during GTT. HEC showed that E4orf1 did not alter tissue sensitivity to exogenous insulin in mice. Experiments 2, 3, and 4: in INS1 cells, E4orf1 did not alter Glut2 abundance or Akt activation, suggesting no reduction in glucose sensing or insulin synthesis, respectively. E4orf1 did not influence glucose-stimulated insulin secretion in media by INS1 cells. Experiment 5: E4orf1 was present in cell lysate, but not in media, indicating it is not a secretory protein. Experiment 6: INS1 cells released less insulin in media when co-cultured in the presence of E4orf1-expressing 3T3-L1 cells. Conclusions Our studies support the working hypothesis that the E4orf1-mediated lowering of insulin response is not due to increased tissue sensitivity to insulin, or reduced ability to produce or release insulin, but likely to be due to a reduced need for insulin release.
Collapse
|