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Wang Z, do Carmo JM, da Silva AA, Fu Y, Jaynes LT, Sears J, Li X, Mouton AJ, Omoto ACM, Xu BP, Hall JE. Transient receptor potential cation channel 6 (TRPC6) deficiency leads to increased body weight and metabolic dysfunction. Am J Physiol Regul Integr Comp Physiol 2022; 323:R81-R97. [PMID: 35537100 DOI: 10.1152/ajpregu.00097.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
TRPC6, a member of the TRPC family, is expressed in the hypothalamus and modulates cell Ca2+ influx. However, the role of TRPC6 in controlling metabolic and cardiovascular functions under normal conditions has not been previously determined. Thus, the impacts of TRPC6 deletion on energy balance, metabolic and cardiovascular regulation as well as the anorexic responses to leptin and melanocortin 3/4 receptor (MC3/4R) activation were investigated in this study. Extensive cardiometabolic phenotyping was conducted in male and female TRPC6 knock out (KO) and control mice from 6 to 24 weeks of age to assess mechanisms by which TRPC6 influences regulation of energy balance and blood pressure (BP). We found that TRPC6 KO mice are heavier with greater adiposity, hyperphagic, and have reduced energy expenditure, impaired glucose tolerance, hyperinsulinemia, and increased liver fat compared to controls. TRPC6 KO mice also have smaller brains, reduced POMC mRNA levels in the hypothalamus, and impaired anorexic response to leptin but not to MC3/4R activation. BP and heart rate, assessed by telemetry, were similar in TRPC6 KO and control mice, and BP responses to air-jet stress were attenuated in TRPC6 KO mice despite increased body weight and metabolic disorders that normally raise BP and increase BP responses to stress. Our results provide evidence for a novel and important role of TRPC6 in controlling energy balance, adiposity, and glucose homeostasis, which suggests that normal TRPC6 function may be necessary to link weight gain and hyperleptinemia with BP responses to acute stress.
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Affiliation(s)
- Zhen Wang
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Yiling Fu
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Lance T Jaynes
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Jaylan Sears
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Xuan Li
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Alan J Mouton
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Ana C M Omoto
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - Brittney P Xu
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
| | - John E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, United States.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, United States
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2
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Abstract
PURPOSE OF REVIEW In this brief review, we highlight studies that have contributed to our current understanding of glucose homeostasis by the central nervous system (CNS) leptin-melanocortin system, particularly proopiomelanocortin neurons and melanocortin-4 receptors (MC4R). RECENT FINDINGS Leptin deficiency is associated with insulin resistance and impaired glucose metabolism whereas leptin administration improves tissue glucose uptake/oxidation and reduces hepatic glucose output. These antidiabetic effects of leptin have been demonstrated in experimental animals and humans, even when circulating insulin levels are barely detectable. Recent evidence suggests that these antidiabetic actions of leptin are mediated, in large part, by stimulation of leptin receptors (LRs) in the CNS and require activation of proopiomelanocortin (POMC) neurons and MC4R. These chronic antidiabetic effects of the CNS leptin-melanocortin system appear to be independent of autonomic nervous system and pituitary-thyroid-adrenal (PTA) axis mechanisms. The powerful antidiabetic actions of the CNS leptin-melanocortin system are capable of normalizing plasma glucose even in the absence of insulin and involve interactions of multiple neuronal populations and intracellular signaling pathways. Although the links between the CNS leptin-melanocortin system and its chronic effects on peripheral tissue glucose metabolism are still uncertain, they are independent of insulin action, activation of the autonomic nervous system, or the PTA axis. Unraveling the pathways that contribute to the powerful antidiabetic effects of the CNS leptin-melanocortin system may provide novel therapeutic approaches for diabetes mellitus.
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Affiliation(s)
- Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA.
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216-4505, USA
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3
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Abstract
The BBSome, a complex of 8 BBS (Bardet-Biedl syndrome) proteins known for its role in the control of cilia function and other cellular processes, has been implicated in blood pressure control, but the underlying mechanisms are not fully understood. Here, we show that neuronal BBSome plays an important role in blood pressure regulation. Targeted inactivation of the BBSome in the nervous system through Bbs1 gene deletion causes sympathetically mediated increase in blood pressure in mice. This phenotype is reproduced by selective ablation of the Bbs1 gene from the LRb (leptin receptor)-expressing neurons. Strikingly, the well-known role of the BBSome in the regulation of cilia formation and function is unlikely to account for the prohypertensive effect of BBSome inactivation as disruption of the IFT (intraflagellar transport) machinery required for ciliogenesis by deleting the Ift88 gene in LRb neurons had no effect on arterial pressure and sympathetic nerve activity. Furthermore, we found that Bbs1 gene deletion from AgRP (agouti-related protein) neurons or POMC (proopiomelanocortin) neurons increased renal and splanchnic sympathetic nerve activity without altering blood pressure. This lack of blood pressure increase despite the sympathetic overdrive may be explained by vascular adrenergic desensitization as indicated by the reduced vascular contractile response evoked by phenylephrine and the decreased expression of adrenergic receptors. Our results identify the neuronal BBSome as a new player in hemodynamic, sympathetic, and vascular regulation, in a manner independent of cilia.
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Affiliation(s)
- Deng-Fu Guo
- From the Department of Neuroscience and Pharmacology (D.-F.G., J.J.R., D.A.M., K.R.), University of Iowa Carver College of Medicine, Iowa City
| | - John J Reho
- From the Department of Neuroscience and Pharmacology (D.-F.G., J.J.R., D.A.M., K.R.), University of Iowa Carver College of Medicine, Iowa City
| | - Donald A Morgan
- From the Department of Neuroscience and Pharmacology (D.-F.G., J.J.R., D.A.M., K.R.), University of Iowa Carver College of Medicine, Iowa City
| | - Kamal Rahmouni
- From the Department of Neuroscience and Pharmacology (D.-F.G., J.J.R., D.A.M., K.R.), University of Iowa Carver College of Medicine, Iowa City.,Department of Internal Medicine (K.R.), University of Iowa Carver College of Medicine, Iowa City.,Obesity Research and Education Initiative (K.R.), University of Iowa Carver College of Medicine, Iowa City.,Fraternal Order of Eagles Diabetes Research Center (K.R.), University of Iowa Carver College of Medicine, Iowa City.,Iowa Neuroscience Institute (K.R.), University of Iowa Carver College of Medicine, Iowa City.,Veterans Affairs Health Care System, Iowa City (K.R.)
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4
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Hall JE, do Carmo JM, da Silva AA, Wang Z, Hall ME. Obesity, kidney dysfunction and hypertension: mechanistic links. Nat Rev Nephrol 2020; 15:367-385. [PMID: 31015582 DOI: 10.1038/s41581-019-0145-4] [Citation(s) in RCA: 298] [Impact Index Per Article: 74.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Excessive adiposity raises blood pressure and accounts for 65-75% of primary hypertension, which is a major driver of cardiovascular and kidney diseases. In obesity, abnormal kidney function and associated increases in tubular sodium reabsorption initiate hypertension, which is often mild before the development of target organ injury. Factors that contribute to increased sodium reabsorption in obesity include kidney compression by visceral, perirenal and renal sinus fat; increased renal sympathetic nerve activity (RSNA); increased levels of anti-natriuretic hormones, such as angiotensin II and aldosterone; and adipokines, particularly leptin. The renal and neurohormonal pathways of obesity and hypertension are intertwined. For example, leptin increases RSNA by stimulating the central nervous system proopiomelanocortin-melanocortin 4 receptor pathway, and kidney compression and RSNA contribute to renin-angiotensin-aldosterone system activation. Glucocorticoids and/or oxidative stress may also contribute to mineralocorticoid receptor activation in obesity. Prolonged obesity and progressive renal injury often lead to the development of treatment-resistant hypertension. Patient management therefore often requires multiple antihypertensive drugs and concurrent treatment of dyslipidaemia, insulin resistance, diabetes and inflammation. If more effective strategies for the prevention and control of obesity are not developed, cardiorenal, metabolic and other obesity-associated diseases could overwhelm health-care systems in the future.
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Affiliation(s)
- John E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA. .,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA.
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Zhen Wang
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA
| | - Michael E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA.,Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
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Chatmethakul T, Roghair RD. Risk of hypertension following perinatal adversity: IUGR and prematurity. J Endocrinol 2019; 242:T21-T32. [PMID: 30657741 PMCID: PMC6594910 DOI: 10.1530/joe-18-0687] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 01/18/2019] [Indexed: 12/12/2022]
Abstract
Consistent with the paradigm shifting observations of David Barker and colleagues that revealed a powerful relationship between decreased weight through 2 years of age and adult disease, intrauterine growth restriction (IUGR) and preterm birth are independent risk factors for the development of subsequent hypertension. Animal models have been indispensable in defining the mechanisms responsible for these associations and the potential targets for therapeutic intervention. Among the modifiable risk factors, micronutrient deficiency, physical immobility, exaggerated stress hormone exposure and deficient trophic hormone production are leading candidates for targeted therapies. With the strong inverse relationship seen between gestational age at delivery and the risk of hypertension in adulthood trumping all other major cardiovascular risk factors, improvements in neonatal care are required. Unfortunately, therapeutic breakthroughs have not kept pace with rapidly improving perinatal survival, and groundbreaking bench-to-bedside studies are urgently needed to mitigate and ultimately prevent the tsunami of prematurity-related adult cardiovascular disease that may be on the horizon. This review highlights our current understanding of the developmental origins of hypertension and draws attention to the importance of increasing the availability of lactation consultants, nutritionists, pharmacists and physical therapists as critical allies in the battle that IUGR or premature infants are waging not just for survival but also for their future cardiometabolic health.
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Affiliation(s)
- Trassanee Chatmethakul
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Robert D Roghair
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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6
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Pate AT, Schnell AL, Ennis TA, Samson WK, Yosten GLC. Expression and function of nesfatin-1 are altered by stage of the estrous cycle. Am J Physiol Regul Integr Comp Physiol 2019; 317:R328-R336. [PMID: 31141415 DOI: 10.1152/ajpregu.00249.2018] [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] [Indexed: 02/06/2023]
Abstract
Nesfatin-1 is a peptide derived from the nucleobindin 2 (Nucb2) precursor protein that has been shown to exert potent effects on appetite and cardiovascular function in male animals. Sex hormones modulate the expression of Nucb2 in several species, including goldfish, mouse, and rat, and human studies have revealed differential expression based on male or female sex. We therefore hypothesized that the ability of nesfatin-1 to increase mean arterial pressure (MAP) would be influenced by stage of the estrous cycle. Indeed, we found that in cycling female Sprague-Dawley rats, nesfatin-1 induced an increase in MAP on diestrus, when both estrogen and progesterone levels are low but not on proestrus or estrus. The effect of nesfatin-1 on MAP was dependent on functional central melanocortin receptors, because the nesfatin-1-induced increase in MAP was abolished by pretreatment with the melanocortin 3/4 receptor antagonist, SHU9119. We previously reported that nesfatin-1 inhibited angiotensin II-induced water drinking in male rats but found no effect of nesfatin-1 in females in diestrus. However, nesfatin-1 enhanced angiotensin II-induced elevations in MAP in females in diestrus but had no effect on males. Finally, in agreement with previous reports, the expression of Nucb2 mRNA in hypothalamus was significantly reduced in female rats in proestrus compared with rats in diestrus. From these data we conclude that the function and expression of nesfatin-1 are modulated by sex hormone status. Further studies are required to determine the contributions of chromosomal sex and individual sex hormones to the cardiovascular effects of nesfatin-1.
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Affiliation(s)
- Alicia T Pate
- Saint Louis College of Pharmacy, St. Louis, Missouri
| | - Abigayle L Schnell
- Department of Pharmacology and Physiology, St. Louis University School of Medicine, St. Louis, Missouri
| | - Teresa A Ennis
- Department of Pharmacology and Physiology, St. Louis University School of Medicine, St. Louis, Missouri
| | - Willis K Samson
- Department of Pharmacology and Physiology, St. Louis University School of Medicine, St. Louis, Missouri
| | - Gina L C Yosten
- Department of Pharmacology and Physiology, St. Louis University School of Medicine, St. Louis, Missouri
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7
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Wang Z, do Carmo JM, da Silva AA, Bailey KC, Aberdein N, Moak SP, Hall JE. Role of SOCS3 in POMC neurons in metabolic and cardiovascular regulation. Am J Physiol Regul Integr Comp Physiol 2019; 316:R338-R351. [PMID: 30673296 PMCID: PMC6483217 DOI: 10.1152/ajpregu.00163.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 02/08/2023]
Abstract
Suppressor of cytokine signaling 3 (SOCS3) is a negative regulator of leptin signaling. We previously showed that the chronic effects of leptin on blood pressure (BP) and glucose regulation are mediated by stimulation of proopiomelanocortin (POMC) neurons. In this study we examined the importance of endogenous SOCS3 in POMC neurons in control of metabolic and cardiovascular function and potential sex differences. Male and female SOCS3flox/flox/POMC-Cre mice in which SOCS3 was selectively deleted in POMC neurons and control SOCS3flox/flox mice were studied during a control diet (CD) or a high-fat diet (HFD) and during chronic leptin infusion. Body weight was lower in male and female SOCS3flox/flox/POMC-Cre than control mice fed the CD, despite similar food intake. Male SOCS3flox/flox/POMC-Cre mice exhibited increased energy expenditure. BP and heart rate were similar in male and female SOCS3flox/flox/POMC-Cre and control mice fed the CD. HFD-fed male and female SOCS3flox/flox/POMC-Cre mice showed attenuated weight gain. HFD-induced elevations in baseline BP and BP responses to an air-jet stress test were greater in female SOCS3flox/flox/POMC-Cre than control mice. Chronic leptin infusion produced similar responses for food intake, body weight, oxygen consumption, blood glucose, BP, and heart rate in all groups. Thus SOCS3 deficiency in POMC neurons influences body weight regulation in the setting of CD and HFD and differentially affects BP and energy balance in a sex-specific manner but does not amplify the dietary, glycemic, or cardiovascular effects of leptin.
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Affiliation(s)
- Zhen Wang
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
- Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
- Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
- Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Kandice C Bailey
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
- Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Nicola Aberdein
- Biomolecular Science Research Centre, Sheffield Hallam University , Sheffield , United Kingdom
| | - Sydney P Moak
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
- Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - John E Hall
- Department of Physiology and Biophysics, University of Mississippi Medical Center , Jackson, Mississippi
- Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
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8
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Aberdein N, Dambrino RJ, do Carmo JM, Wang Z, Mitchell LE, Drummond HA, Hall JE. Role of PTP1B in POMC neurons during chronic high-fat diet: sex differences in regulation of liver lipids and glucose tolerance. Am J Physiol Regul Integr Comp Physiol 2017; 314:R478-R488. [PMID: 29351427 DOI: 10.1152/ajpregu.00287.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of leptin receptor signaling and may contribute to leptin resistance in diet-induced obesity. Although PTP1B inhibition has been suggested as a potential weight loss therapy, the role of specific neuronal PTP1B signaling in cardiovascular and metabolic regulation and the importance of sex differences in this regulation are still unclear. In this study, we investigated the impact of proopiomelanocortin (POMC) neuronal PTP1B deficiency in cardiometabolic regulation in male and female mice fed a high-fat diet (HFD). When compared with control mice (PTP1B flox/flox), male and female mice deficient in POMC neuronal PTP1B (PTP1B flox/flox/POMC-Cre) had attenuated body weight gain (males: -18%; females: -16%) and fat mass (males: -33%; female: -29%) in response to HFD. Glucose tolerance was improved by 40%, and liver lipid accumulation was reduced by 40% in PTP1B/POMC-Cre males but not in females. When compared with control mice, deficiency of POMC neuronal PTP1B did not alter mean arterial pressure (MAP) in male or female mice (males: 112 ± 1 vs. 112 ± 1 mmHg in controls; females: 106 ± 3 vs. 109 ± 3 mmHg in controls). Deficiency of POMC neuronal PTP1B also did not alter MAP response to acute stress in males or females compared with control mice (males: Δ32 ± 0 vs. Δ29 ± 4 mmHg; females: Δ22 ± 2 vs. Δ27 ± 4 mmHg). These data demonstrate that POMC-specific PTP1B deficiency improved glucose tolerance and attenuated diet-induced fatty liver only in male mice and attenuated weight gain in males and females but did not enhance the MAP and HR responses to a HFD or to acute stress.
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Affiliation(s)
- Nicola Aberdein
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi.,Biomedical Research Center, Department of Health and Wellbeing, Sheffield Hallam University , Sheffield , United Kingdom
| | - Robert J Dambrino
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Zhen Wang
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Laura E Mitchell
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - Heather A Drummond
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center , Jackson, Mississippi
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9
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Stocker SD, Kinsman BJ, Sved AF. Recent Advances in Neurogenic Hypertension: Dietary Salt, Obesity, and Inflammation. Hypertension 2017; 70:HYPERTENSIONAHA.117.08936. [PMID: 28739972 PMCID: PMC5783795 DOI: 10.1161/hypertensionaha.117.08936] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neurally-mediated hypertension results from a dysregulation of sympathetic and/or neuroendocrine mechanisms to increase ABP. Multiple factors may exert multiple central effects to alter neural circuits and produce unique sympathetic signatures and elevate ABP. In this brief review, we have discussed novel observations regarding three contributing factors: dietary salt intake, obesity, and inflammation. However, the interaction among these and other factors is likely much more complex; recent studies suggest a prior exposure to one stimulus may sensitize the response to a subsequent hypertensive stimulus. Insight into the central mechanisms by which these factors selectively alter SNA or cooperatively interact to impact hypertension may represent a platform for novel therapeutic treatment strategies.
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Affiliation(s)
- Sean D Stocker
- From the Department of Medicine, Renal-Electrolyte Division (S.D.S., B.J.K.), Department of Neuroscience (A.F.S.), and University of Pittsburgh Hypertension Center (S.D.S.), University of Pittsburgh, PA.
| | - Brian J Kinsman
- From the Department of Medicine, Renal-Electrolyte Division (S.D.S., B.J.K.), Department of Neuroscience (A.F.S.), and University of Pittsburgh Hypertension Center (S.D.S.), University of Pittsburgh, PA
| | - Alan F Sved
- From the Department of Medicine, Renal-Electrolyte Division (S.D.S., B.J.K.), Department of Neuroscience (A.F.S.), and University of Pittsburgh Hypertension Center (S.D.S.), University of Pittsburgh, PA
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10
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Abstract
The objective of this review is to provide an in-depth evaluation of how renal nerves regulate renal and cardiovascular function with a focus on long-term control of arterial pressure. We begin by reviewing the anatomy of renal nerves and then briefly discuss how the activity of renal nerves affects renal function. Current methods for measurement and quantification of efferent renal-nerve activity (ERNA) in animals and humans are discussed. Acute regulation of ERNA by classical neural reflexes as well and hormonal inputs to the brain is reviewed. The role of renal nerves in long-term control of arterial pressure in normotensive and hypertensive animals (and humans) is then reviewed with a focus on studies utilizing continuous long-term monitoring of arterial pressure. This includes a review of the effect of renal-nerve ablation on long-term control of arterial pressure in experimental animals as well as humans with drug-resistant hypertension. The extent to which changes in arterial pressure are due to ablation of renal afferent or efferent nerves are reviewed. We conclude by discussing the importance of renal nerves, relative to sympathetic activity to other vascular beds, in long-term control of arterial pressure and hypertension and propose directions for future research in this field. © 2017 American Physiological Society. Compr Physiol 7:263-320, 2017.
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Affiliation(s)
- John W Osborn
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jason D Foss
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
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11
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do Carmo JM, da Silva AA, Romero DG, Hall JE. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin. FASEB J 2017; 31:2418-2428. [PMID: 28228474 DOI: 10.1096/fj.201601224r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 01/30/2017] [Indexed: 11/11/2022]
Abstract
Interactions of hypothalamic signaling pathways that control body temperature (BT), blood pressure (BP), and energy balance are poorly understood. We investigated whether the chronic BP and metabolic actions of leptin are differentially modulated by changes in ambient temperature (TA ). Mean arterial pressure (MAP), heart rate (HR), BT, motor activity (MA), and oxygen consumption (Vo2) were measured 24 h/d at normal laboratory TA (23°C), at thermoneutral zone (TNZ, 30°C) for mice or during cold exposure (15°C) in male wild-type mice. After control measurements, leptin (4 μg/kg/min) or saline vehicle was infused for 7 d. At TNZ, leptin reduced food intake (-11.0 ± 0.5 g cumulative deficit) and body weight by 6% but caused no changes in MAP or HR. At 15°C, leptin infusion did not alter food intake but increased MAP and HR (8 ± 1 mmHg and 33 ± 7 bpm), while Vo2 increased by ∼10%. Leptin reduced plasma glucose and insulin levels at 15°C but not at 30°C. These results demonstrate that the chronic anorexic effects of leptin are enhanced at TNZ, while its effects on insulin and glucose levels are attenuated and its effects on BP and HR are abolished. Conversely, cold TA caused resistance to leptin's anorexic effects but amplified its effects to raise BP and reduce insulin and glucose levels. Thus, the brain circuits by which leptin regulates food intake and cardiovascular function are differentially influenced by changes in TA -Do Carmo, J. M., da Silva, A. A., Romero, D. G., Hall, J. E. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin.
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Affiliation(s)
- Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi, USA;
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi, USA.,Centro Universitário Barão de Mauá, Ribeirão Preto, São Paulo, Brazil
| | - Damian G Romero
- Department of Biochemistry, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi, USA
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12
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Abstract
Hypertension and associated cardiovascular diseases represent the most common health complication of obesity and the leading cause of morbidity and mortality in overweight and obese patients. Emerging evidence suggests a critical role for the central nervous system particularly the brain action of the adipocyte-derived hormone leptin in linking obesity and hypertension. The preserved ability of leptin to cause cardiovascular sympathetic nerve activation despite the resistance to the metabolic actions of the hormone appears essential in this pathological process. This review describes the evidence supporting the neurogenic bases for obesity-associated hypertension with a particular focus on the neuronal and molecular signaling pathways underlying leptin's effects on sympathetic nerve activity and blood pressure.
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Affiliation(s)
- Balyssa B Bell
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA.
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13
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Steinbrekera B, Roghair R. Modeling the impact of growth and leptin deficits on the neuronal regulation of blood pressure. J Endocrinol 2016; 231:R47-R60. [PMID: 27613336 PMCID: PMC5148679 DOI: 10.1530/joe-16-0273] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/08/2016] [Indexed: 12/15/2022]
Abstract
The risk of hypertension is increased by intrauterine growth restriction (IUGR) and preterm birth. In the search for modifiable etiologies for this life-threatening cardiovascular morbidity, a number of pathways have been investigated, including excessive glucocorticoid exposure, nutritional deficiency and aberration in sex hormone levels. As a neurotrophic hormone that is intimately involved in the cardiovascular regulation and whose levels are influenced by glucocorticoids, nutritional status and sex hormones, leptin has emerged as a putative etiologic and thus a therapeutic agent. As a product of maternal and late fetal adipocytes and the placenta, circulating leptin typically surges late in gestation and declines after delivery until the infant consumes sufficient leptin-containing breast milk or accrues sufficient leptin-secreting adipose tissue to reestablish the circulating levels. The leptin deficiency seen in IUGR infants is a multifactorial manifestation of placental insufficiency, exaggerated glucocorticoid exposure and fetal adipose deficit. The preterm infant suffers from the same cascade of events, including separation from the placenta, antenatal steroid exposure and persistently underdeveloped adipose depots. Preterm infants remain leptin deficient beyond term gestation, rendering them susceptible to neurodevelopmental impairment and subsequent cardiovascular dysregulation. This pathologic pathway is efficiently modeled by placing neonatal mice into atypically large litters, thereby recapitulating the perinatal growth restriction-adult hypertension phenotype. In this model, neonatal leptin supplementation restores the physiologic leptin surge, attenuates the leptin-triggered sympathetic activation in adulthood and prevents leptin- or stress-evoked hypertension. Further pathway interrogation and clinical translation are needed to fully test the therapeutic potential of perinatal leptin supplementation.
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MESH Headings
- Adiposity
- Adult
- Animals
- Animals, Newborn
- Disease Models, Animal
- Female
- Fetal Growth Retardation/drug therapy
- Fetal Growth Retardation/metabolism
- Fetal Growth Retardation/physiopathology
- Hormone Replacement Therapy
- Humans
- Hypertension/etiology
- Hypertension/metabolism
- Hypertension/prevention & control
- Hypothalamus/metabolism
- Infant, Newborn
- Infant, Premature
- Infant, Premature, Diseases/drug therapy
- Infant, Premature, Diseases/metabolism
- Infant, Premature, Diseases/physiopathology
- Leptin/deficiency
- Leptin/genetics
- Leptin/metabolism
- Leptin/therapeutic use
- Male
- Mice
- Nerve Tissue Proteins/agonists
- Nerve Tissue Proteins/metabolism
- Neurodevelopmental Disorders/drug therapy
- Neurodevelopmental Disorders/metabolism
- Neurodevelopmental Disorders/physiopathology
- Pregnancy
- Receptors, Leptin/agonists
- Receptors, Leptin/metabolism
- Recombinant Proteins/metabolism
- Recombinant Proteins/therapeutic use
- Signal Transduction
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Affiliation(s)
- Baiba Steinbrekera
- Stead Family Department of PediatricsCarver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Robert Roghair
- Stead Family Department of PediatricsCarver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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14
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Ulyanova A, To XV, Asad ABMA, Han W, Chuang KH. MEMRI detects neuronal activity and connectivity in hypothalamic neural circuit responding to leptin. Neuroimage 2016; 147:904-915. [PMID: 27729278 DOI: 10.1016/j.neuroimage.2016.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 10/03/2016] [Accepted: 10/07/2016] [Indexed: 10/20/2022] Open
Abstract
Hypothalamus plays the central role in regulating energy homeostasis. To understand the hypothalamic neurocircuit in responding to leptin, Manganese-Enhanced MRI (MEMRI) was applied. Highly elevated signal could be mapped in major nuclei of the leptin signaling pathway, including the arcuate nucleus (ARC), paraventricular nucleus (PVN), ventromedial hypothalamus (VMH) and dorsomedial hypothalamus (DMH) in fasted mice and the enhancement was reduced by leptin administration. However, whether changes in MEMRI signal reflect Ca2+ channel activity, neuronal activation or connectivity in the leptin signaling pathway are not clear. By blocking L-type Ca2+ channels, the signal enhancement in the ARC, PVN and DMH, but not VMH, was reduced. By disrupting microtubule with colchicine, signal enhancement of the secondary neural areas like DMH and PVN was delayed which is consistent with the known projection density from ARC into these regions. Finally, strong correlation between c-fos expression and MEMRI signal increase rate was observed in the ARC, VMH and DMH. Together, we provide experimental evidence that MEMRI signal could represent activity and connectivity in certain hypothalamic nuclei and hence may be used for mapping activated neuronal pathway in vivo. This understanding would facilitate the application of MEMRI for evaluation of hypothalamic dysfunction in metabolic diseases.
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Affiliation(s)
- Anna Ulyanova
- Magnetic Resonance Imaging Group, Singapore Bioimaging Consortium, Agency for Science Technology and Research (A⁎STAR), Singapore; Department of Physiology, National University of Singapore, Singapore
| | - Xuan Vinh To
- Magnetic Resonance Imaging Group, Singapore Bioimaging Consortium, Agency for Science Technology and Research (A⁎STAR), Singapore
| | - A B M A Asad
- Magnetic Resonance Imaging Group, Singapore Bioimaging Consortium, Agency for Science Technology and Research (A⁎STAR), Singapore
| | - Weiping Han
- Lab of Metabolic Medicine, Singapore Bioimaging Consortium, A⁎STAR, Singapore
| | - Kai-Hsiang Chuang
- Magnetic Resonance Imaging Group, Singapore Bioimaging Consortium, Agency for Science Technology and Research (A⁎STAR), Singapore; Department of Physiology, National University of Singapore, Singapore.
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15
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Peotta V, Rahmouni K, Segar JL, Morgan DA, Pitz KM, Rice OM, Roghair RD. Neonatal growth restriction-related leptin deficiency enhances leptin-triggered sympathetic activation and central angiotensin II receptor-dependent stress-evoked hypertension. Pediatr Res 2016; 80:244-51. [PMID: 27049292 PMCID: PMC4990468 DOI: 10.1038/pr.2016.64] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/28/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND Neonatal growth restriction (nGR) leads to leptin deficiency and increases the risk of hypertension. Previous studies have shown nGR-related hypertension is normalized by neonatal leptin (nLep) and exacerbated by psychological stress. With recent studies linking leptin and angiotensin signaling, we hypothesized that nGR-induced nLep deficiency increases adult leptin sensitivity; leading to leptin- or stress-induced hypertension, through a pathway involving central angiotensin II type 1 receptors. METHODS We randomized mice with incipient nGR, by virtue of their presence in large litters, to vehicle or physiologic nLep supplementation (80 ng/g/d). Adult caloric intake and arterial pressure were monitored at baseline, during intracerebroventricular losartan infusion and during systemic leptin administration. RESULTS nGR increased leptin-triggered renal sympathetic activation and hypertension with increased leptin receptor expression in the arcuate nucleus of the hypothalamus; all of those nGR-associated phenotypes were normalized by nLep. nGR mice also had stress-related hyperphagia and hypertension, but only the stress hypertension was blocked by central losartan infusion. CONCLUSION nGR leads to stress hypertension through a pathway that involves central angiotensin II receptors, and nGR-associated leptin deficiency increases leptin-triggered hypertension in adulthood. These data suggest potential roles for preservation of neonatal growth and nLep supplementation in the prevention of nGR-related hypertension.
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Affiliation(s)
- Veronica Peotta
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Kamal Rahmouni
- Department of Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Jeffrey L. Segar
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Donald A. Morgan
- Department of Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Kate M. Pitz
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Olivia M. Rice
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Robert D. Roghair
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA
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16
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Bassi M, Furuya WI, Zoccal DB, Menani JV, Colombari DSA, Mulkey DK, Colombari E. Facilitation of breathing by leptin effects in the central nervous system. J Physiol 2016; 594:1617-25. [PMID: 26095748 PMCID: PMC4799963 DOI: 10.1113/jp270308] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 05/13/2015] [Indexed: 01/01/2023] Open
Abstract
With the global epidemic of obesity, breathing disorders associated with excess body weight have markedly increased. Respiratory dysfunctions caused by obesity were originally attributed to mechanical factors; however, recent studies have suggested a pathophysiological component that involves the central nervous system (CNS) and hormones such as leptin produced by adipocytes as well as other cells. Leptin is suggested to stimulate breathing and leptin deficiency causes an impairment of the chemoreflex, which can be reverted by leptin therapy. This facilitation of the chemoreflex may depend on the action of leptin in the hindbrain areas involved in the respiratory control such as the nucleus of the solitary tract (NTS), a site that receives chemosensory afferents, and the ventral surface of the medulla that includes the retrotrapezoid nucleus (RTN), a central chemosensitive area, and the rostral ventrolateral medulla (RVLM). Although the mechanisms and pathways activated by leptin to facilitate breathing are still not completely clear, evidence suggests that the facilitatory effects of leptin on breathing require the brain melanocortin system, including the POMC-MC4R pathway, a mechanism also activated by leptin to modulate blood pressure. The results of all the studies that have investigated the effect of leptin on breathing suggest that disruption of leptin signalling as caused by obesity-induced reduction of central leptin function (leptin resistance) is a relevant mechanism that may contribute to respiratory dysfunctions associated with obesity.
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Affiliation(s)
- M. Bassi
- Department of Physiology and Pathology, School of DentistrySão Paulo State University (UNESP)AraraquaraSPBrazil
| | - W. I. Furuya
- Department of Physiology and Pathology, School of DentistrySão Paulo State University (UNESP)AraraquaraSPBrazil
| | - D. B. Zoccal
- Department of Physiology and Pathology, School of DentistrySão Paulo State University (UNESP)AraraquaraSPBrazil
| | - J. V. Menani
- Department of Physiology and Pathology, School of DentistrySão Paulo State University (UNESP)AraraquaraSPBrazil
| | - D. S. A. Colombari
- Department of Physiology and Pathology, School of DentistrySão Paulo State University (UNESP)AraraquaraSPBrazil
| | - D. K. Mulkey
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsCTUSA
| | - E. Colombari
- Department of Physiology and Pathology, School of DentistrySão Paulo State University (UNESP)AraraquaraSPBrazil
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17
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do Carmo JM, da Silva AA, Wang Z, Freeman NJ, Alsheik AJ, Adi A, Hall JE. Regulation of Blood Pressure, Appetite, and Glucose by Leptin After Inactivation of Insulin Receptor Substrate 2 Signaling in the Entire Brain or in Proopiomelanocortin Neurons. Hypertension 2015; 67:378-86. [PMID: 26628674 DOI: 10.1161/hypertensionaha.115.06153] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 11/02/2015] [Indexed: 12/20/2022]
Abstract
Insulin receptor substrate 2 (IRS2) is one of the 3 major leptin receptor signaling pathways, but its role in mediating the chronic effects of leptin on blood pressure, food intake, and glucose regulation is unclear. We tested whether genetic inactivation of IRS2 in the entire brain (IRS2/Nestin-cre mice) or specifically in proopiomelanocortin (POMC) neurons (IRS2/POMC-cre mice) attenuates the chronic cardiovascular, metabolic, and antidiabetic effects of leptin. Mice were instrumented with telemetry probes for measurement of blood pressure and heart rate and with venous catheters for intravenous infusions. After a 5-day control period, mice received leptin infusion (2 μg/kg per minute) for 7 days. Compared with control IRS2(flox/flox) mice, IRS2/POMC-cre mice had similar body weight and food intake (33±1 versus 35±1 g and 3.6±0.5 versus 3.8±0.2 g per day) but higher mean arterial pressure (MAP) and heart rate (110±2 versus 102±2 mm Hg and 641±9 versus 616±5 bpm). IRS2/Nestin-cre mice were heavier (38±2 g), slightly hyperphagic (4.5±1.0 g per day), and had higher MAP and heart rate (108±2 mm Hg and 659±9 bpm) compared with control mice. Leptin infusion gradually increased MAP despite decreasing food intake by 31% in IRS2(flox/flox) and in Nestin-cre control mice. In contrast, leptin infusion did not change MAP in IRS2/Nestin-cre or IRS2/POMC-cre mice. The anorexic and antidiabetic effects of leptin, however, were similar in all 3 groups. These results indicate that IRS2 signaling in the central nervous system, and particularly in POMC neurons, is essential for the chronic actions of leptin to raise MAP but not for its anorexic or antidiabetic effects.
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Affiliation(s)
- Jussara M do Carmo
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson.
| | - Alexandre A da Silva
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson
| | - Zhen Wang
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson
| | - Nathan J Freeman
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson
| | - Ammar J Alsheik
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson
| | - Ahmad Adi
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson
| | - John E Hall
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson
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18
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Bruder-Nascimento T, Butler BR, Herren DJ, Brands MW, Bence KK, Belin de Chantemèle EJ. Deletion of protein tyrosine phosphatase 1b in proopiomelanocortin neurons reduces neurogenic control of blood pressure and protects mice from leptin- and sympatho-mediated hypertension. Pharmacol Res 2015; 102:235-44. [PMID: 26523876 DOI: 10.1016/j.phrs.2015.10.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 10/14/2015] [Accepted: 10/14/2015] [Indexed: 12/15/2022]
Abstract
Protein tyrosine phosphatase 1b (Ptp1b), which represses leptin signaling, is a promising therapeutic target for obesity. Genome wide deletion of Ptp1b, increases leptin sensitivity, protects mice from obesity and diabetes, but alters cardiovascular function by increasing blood pressure (BP). Leptin-control of metabolism is centrally mediated and involves proopiomelanocortin (POMC) neurons. Whether these neurons contribute to leptin-mediated increases in BP remain unclear. We hypothesized that increasing leptin signaling in POMC neurons with Ptp1b deletion will sensitize the cardiovascular system to leptin and enhance neurogenic control of BP. We analyzed the cardiovascular phenotype of Ptp1b+/+ and POMC-Ptp1b-/- mice, at baseline and after 7 days of leptin infusion or sympatho-activation with phenylephrine. POMCPtp1b deletion did not alter baseline cardiovascular hemodynamics (BP, heart rate) but reduced BP response to ganglionic blockade and plasma catecholamine levels that suggests a decreased neurogenic control of BP. In contrast, POMC-Ptp1b deletion increased vascular adrenergic reactivity and aortic α-adrenergic receptors expression. Chronic leptin treatment reduced vascular adrenergic reactivity and blunted diastolic and mean BP increases in POMC-Ptp1b-/- mice only. Similarly POMC-Ptp1b-/- mice exhibited a blunted increased in diastolic and mean BP accompanied by a gradual reduction in adrenergic reactivity in response to chronic vascular sympatho-activation with phenylephrine. Together these data rule out our hypothesis but suggest that deletion of Ptp1b in POMC neurons protects from leptin- and sympatho-mediated increases in BP. Vascular adrenergic desensitization appears as a protective mechanism against hypertension, and POMC-Ptp1b as a key therapeutic target for the treatment of metabolic and cardiovascular dysfunctions associated with obesity.
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Affiliation(s)
- Thiago Bruder-Nascimento
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - Benjamin R Butler
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - David J Herren
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - Michael W Brands
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States
| | - Kendra K Bence
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Eric J Belin de Chantemèle
- Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, GA, United States.
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19
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IL-10 gene transfer upregulates arcuate POMC and ameliorates hyperphagia, obesity and diabetes by substituting for leptin. Int J Obes (Lond) 2015; 40:425-33. [DOI: 10.1038/ijo.2015.201] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 08/25/2015] [Accepted: 08/30/2015] [Indexed: 11/08/2022]
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20
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Hall JE, do Carmo JM, da Silva AA, Wang Z, Hall ME. Obesity-induced hypertension: interaction of neurohumoral and renal mechanisms. Circ Res 2015; 116:991-1006. [PMID: 25767285 DOI: 10.1161/circresaha.116.305697] [Citation(s) in RCA: 697] [Impact Index Per Article: 77.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65% to 75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include (1) physical compression of the kidneys by fat in and around the kidneys, (2) activation of the renin-angiotensin-aldosterone system, and (3) increased sympathetic nervous system activity. Activation of the renin-angiotensin-aldosterone system is likely due, in part, to renal compression, as well as sympathetic nervous system activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for sympathetic nervous system activation in obesity have not been fully elucidated but may require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes mellitus, and inflammation. Unless effective antiobesity drugs are developed, the effect of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase.
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Affiliation(s)
- John E Hall
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson.
| | - Jussara M do Carmo
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| | - Alexandre A da Silva
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| | - Zhen Wang
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| | - Michael E Hall
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
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21
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do Carmo JM, da Silva AA, Ebaady SE, Sessums PO, Abraham RS, Elmquist JK, Lowell BB, Hall JE. Shp2 signaling in POMC neurons is important for leptin's actions on blood pressure, energy balance, and glucose regulation. Am J Physiol Regul Integr Comp Physiol 2014; 307:R1438-47. [PMID: 25339680 DOI: 10.1152/ajpregu.00131.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Previous studies showed that Src homology-2 tyrosine phosphatase (Shp2) is an important regulator of body weight. In this study, we examined the impact of Shp2 deficiency specifically in proopiomelanocortin (POMC) neurons on metabolic and cardiovascular function and on chronic blood pressure (BP) and metabolic responses to leptin. Mice with Shp2 deleted in POMC neurons (Shp2/Pomc-cre) and control mice (Shp2(flox/flox)) were implanted with telemetry probes and venous catheters for measurement of mean arterial pressure (MAP) and leptin infusion. After at least 5 days of stable control measurements, mice received leptin infusion (2 μg·kg(-1)·day(-1) iv) for 7 days. Compared with Shp2(flox/flox) controls, Shp2/Pomc-cre mice at 22 wk of age were slightly heavier (34 ± 1 vs. 31 ± 1 g) but consumed a similar amount of food (3.9 ± 0.3 vs. 3.8 ± 0.2 g/day). Leptin infusion reduced food intake in Shp2(flox/flox) mice (2.6 ± 0.5 g) and Shp2/Pomc-cre mice (3.2 ± 0.3 g). Despite decreasing food intake, leptin infusion increased MAP in control mice, whereas no significant change in MAP was observed in Shp2/Pomc-cre mice. Leptin infusion also decreased plasma glucose and insulin levels in controls (12 ± 1 to 6 ± 1 μU/ml and 142 ± 12 to 81 ± 8 mg/100 ml) but not in Shp2/Pomc-cre mice. Leptin increased V̇o2 by 16 ± 2% in controls and 7 ± 1% in Shp2/Pomc-cre mice. These results indicate that Shp2 signaling in POMC neurons contributes to the long-term BP and antidiabetic actions of leptin and may play a modest role in normal regulation of body weight.
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Affiliation(s)
- Jussara M do Carmo
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi;
| | - Alexandre A da Silva
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Sabira E Ebaady
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Price O Sessums
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Ralph S Abraham
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Joel K Elmquist
- Department of Pharmacology and Division of Hypothalamic Research, Department of Internal Medicine, Utah Southwestern Medical Center, Dallas, Texas; and
| | - Bradford B Lowell
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, and Cardiovascular-Renal Research Center, University of Mississippi Medical Center, Jackson, Mississippi
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22
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Samuelsson AM. New perspectives on the origin of hypertension; the role of the hypothalamic melanocortin system. Exp Physiol 2014; 99:1110-5. [PMID: 25210109 DOI: 10.1113/expphysiol.2014.080374] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Maternal obesity is a major public health problem. Pregnant obese women have increased risk of adverse outcomes for mother and child. Recent observational studies from mother-child cohort studies suggest that obesity during pregnancy is a risk factor for the development of cardiovascular diseases in the child later in life. We have previously shown that maternal obesity in rodents leads to sympathetically mediated hypertension in the juvenile offspring prior to obesity. This was associated with an exaggerated leptin surge in early postnatal life. Increased leptin during this critical period of development is likely to contribute to the onset of hypertension by altered leptin sensitivity and dysregulation of the normal neurotrophic action of leptin. Unpublished evidence also suggests that the central melanocortin system, including melanocortin 4 receptors, plays a key role in early origins of hypertension in offspring of obese rat dams. This review focuses on the role of the central leptin-melanocortin signalling pathways in the early origins of hypertension. The overall aim is to understand the central leptin-melanocortin system, with its multiple intracellular signalling pathways which differentially and independently regulate appetite, renal sympathetic nerve activity and blood pressure.
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Affiliation(s)
- Anne-Maj Samuelsson
- Division of Women's Health, Women's Health Academic Centre, King's College London and King's Health Partners, London, UK
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23
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Affiliation(s)
- Kamal Rahmouni
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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24
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Abstract
In addition to effects on appetite and metabolism, leptin influences many neuroendocrine and physiological systems, including the sympathetic nervous system. Building on my Carl Ludwig Lecture of the American Physiological Society, I review the sympathetic and cardiovascular actions of leptin. The review focuses on a critical analysis of the concept of selective leptin resistance (SLR) and the role of leptin in the pathogenesis of obesity-induced hypertension in both experimental animals and humans. We introduced the concept of SLR in 2002 to explain how leptin might increase blood pressure (BP) in obese states, such as diet-induced obesity (DIO), that are accompanied by partial leptin resistance. This concept, analogous to selective insulin resistance in the metabolic syndrome, holds that in several genetic and acquired models of obesity, there is preservation of the renal sympathetic and pressor actions of leptin despite attenuation of the appetite and weight-reducing actions. Two potential overlapping mechanisms of SLR are reviewed: 1) differential leptin molecular signaling pathways that mediate selective as opposed to universal leptin action and 2) brain site-specific leptin action and resistance. Although the phenomenon of SLR in DIO has so far focused on preservation of sympathetic and BP actions of leptin, consideration should be given to the possibility that this concept may extend to preservation of other actions of leptin. Finally, I review perplexing data on the effects of leptin on sympathetic activity and BP in humans and its role in human obesity-induced hypertension.
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Affiliation(s)
- Allyn L Mark
- Department of Internal Medicine and the Obesity Research and Education Initiative, University of Iowa Carver College of Medicine, Iowa City, Iowa
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do Carmo JM, da Silva AA, Dubinion J, Sessums PO, Ebaady SH, Wang Z, Hall JE. Control of metabolic and cardiovascular function by the leptin-brain melanocortin pathway. IUBMB Life 2013; 65:692-8. [PMID: 23847053 DOI: 10.1002/iub.1187] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/11/2013] [Indexed: 12/26/2022]
Abstract
Obesity is recognized as a major worldwide health problem. Excess weight gain is the most common cause of elevated blood pressure (BP) and markedly increases the risk of metabolic, cardiovascular and renal diseases. Although the mechanisms linking obesity with hypertension have not been fully elucidated, increased sympathetic nervous system (SNS) activity contributes to elevated BP in obese subjects. Recent evidence indicates that leptin and the central nervous system (CNS) melanocortin system, including melanocortin 4 receptors (MC4R), play a key role in linking obesity with increased SNS activity and hypertension. Leptin, a peptide-hormone produced by adipose tissue, crosses the blood-brain barrier and activates brain centers that control multiple metabolic functions as well as SNS activity and BP via the CNS melanocortin system. The crosstalk between peripheral signals (e.g., leptin) and activation of CNS pathways (e.g., MC4R) that regulate energy balance, SNS activity and BP represents an important target for treating obesity and its metabolic and cardiovascular consequences.
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Affiliation(s)
- Jussara M do Carmo
- Department of Physiology and Biophysics, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, MS 39216, USA.
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