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1.
Article in English | MEDLINE | ID: mdl-39024357

ABSTRACT

Diabetes mellitus is one of the leading causes of chronic kidney disease and its progression to end-stage kidney disease. Diabetic kidney disease (DKD) is characterized by glomerular hypertrophy, hyperfiltration, inflammation and the onset of albuminuria, together with a progressive reduction in glomerular filtration rate. This progression is further accompanied by tubulointerstitial inflammation and fibrosis. Factors such as genetic predisposition, epigenetic modifications, metabolic derangements, hemodynamic alterations, inflammation, and inappropriate renin-angiotensin-aldosterone system (RAAS) activity contribute to the onset and progression of DKD. In this context, decades of work have focused on glycemic and blood pressure reduction strategies, especially targeting the RAAS to slow disease progression. While much of the work has focused on targeting angiotensin II, emerging data support that the mineralocorticoid receptor (MR) is integral in the development and progression of DKD. Molecular mechanisms linked to the underlying pathophysiological changes derived from MR activation include vascular endothelial, as well as epithelial cell responses, to oxidative stress and inflammation. These responses lead to alterations in the microcirculatory environment, the abnormal release of extracellular vesicles, gut dysbiosis, epithelial-mesenchymal transition, and kidney fibrosis. Herein we present recent experimental and clinical evidence on the MR in DKD onset and progress along with new MR based strategies for the treatment and prevention of DKD.

2.
Article in English | MEDLINE | ID: mdl-38621759

ABSTRACT

Adsorption-based extracorporeal therapies have been subject to technical developments and clinical application for close to five decades. More recently, new technological developments in membrane and sorbent manipulation have made it possible to deliver more biocompatible extracorporeal adsorption therapies to patients with a variety of conditions. There are several key rationales based on physicochemical principles and clinical considerations that justify the application and investigation of such therapies as evidenced by multiple ex-vivo, experimental, and clinical observations. Accordingly, unspecific adsorptive extracorporeal therapies have now been applied to the treatment of a wide array of conditions from poisoning to drug overdoses, to inflammatory states and sepsis, and acute or chronic liver and kidney failure. In response to the rapidly expanding knowledge base and increased clinical evidence, we convened an Acute Disease Quality Initiative (ADQI) consensus conference dedicated to such treatment. The data show that hemoadsorption has clinically acceptable short-term biocompatibility and safety, technical feasibility, and experimental demonstration of specified target molecule removal. Pilot studies demonstrate potentially beneficial effects on physiology and larger studies of endotoxin-based hemoadsorption have identified possible target phenotypes for larger randomized controlled trials (RCTs). Moreover, in a variety of endogenous and exogenous intoxications, removal of target molecules has been confirmed in vivo. However, some studies have raised concerns about harm or failed to deliver benefits. Thus, despite many achievements, modern hemoadsorption remains a novel and experimental intervention with limited data, and a large research agenda.

3.
Am J Physiol Regul Integr Comp Physiol ; 324(1): R90-R101, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36440901

ABSTRACT

Widespread consumption of diets high in fat and fructose (Western diet, WD) has led to increased prevalence of obesity and diastolic dysfunction (DD). DD is a prominent feature of heart failure with preserved ejection fraction (HFpEF). However, the underlying mechanisms of DD are poorly understood, and treatment options are still limited. We have previously shown that deletion of the cell-specific mineralocorticoid receptor in endothelial cells (ECMR) abrogates DD induced by WD feeding in female mice. However, the specific role of ECMR activation in the pathogenesis of DD in male mice has not been clarified. Therefore, we fed 4-wk-old ECMR knockout (ECMRKO) male mice and littermates (LM) with either a WD or chow diet (CD) for 16 wk. WD feeding resulted in DD characterized by increased left ventricle (LV) filling pressure (E/e') and diastolic stiffness [E/e'/LV inner diameter at end diastole (LVIDd)]. Compared with CD, WD in LM resulted in increased myocardial macrophage infiltration, oxidative stress, and increased myocardial phosphorylation of Akt, in concert with decreased phospholamban phosphorylation. WD also resulted in focal cardiomyocyte remodeling, characterized by areas of sarcomeric disorganization, loss of mitochondrial electron density, and mitochondrial fragmentation. Conversely, WD-induced DD and associated biochemical and structural abnormalities were prevented by ECMR deletion. In contrast with our previously reported observations in females, WD-fed male mice exhibited enhanced Akt signaling and a lower magnitude of cardiac injury. Collectively, our data support a critical role for ECMR in obesity-induced DD and suggest critical mechanistic differences in the genesis of DD between males and females.


Subject(s)
Cardiomyopathies , Heart Failure , Female , Male , Animals , Mice , Endothelial Cells/pathology , Heart Failure/complications , Receptors, Mineralocorticoid/genetics , Mice, Obese , Proto-Oncogene Proteins c-akt , Stroke Volume , Cardiomyopathies/etiology , Cardiomyopathies/prevention & control , Diet, Western , Obesity/etiology
4.
J Mol Cell Cardiol ; 167: 32-39, 2022 06.
Article in English | MEDLINE | ID: mdl-35331697

ABSTRACT

Sphingomyelinases ensure ceramide production and play an integral role in cell turnover, inward budding of vesicles and outward release of exosomes. Recent data indicate a unique role for neutral sphingomyelinase (nSMase) in the control of ceramide-dependent exosome release and inflammatory pathways. Further, while inhibition of nSMase in vascular tissue attenuates the progression of atherosclerosis, little is known regarding its role on metabolic signaling and arterial vasomotor function. Accordingly, we hypothesized that nSMase inhibition with GW4869, would attenuate Western diet (WD) - induced increases in aortic stiffness through alterations in pathways which lead to oxidative stress, inflammation and vascular remodeling. Six week-old female C57BL/6L mice were fed either a WD containing excess fat (46%) and fructose (17.5%) for 16 weeks or a standard chow diet (CD). Mice were variably treated with GW4869 (2.0 µg/g body weight, intraperitoneal injection every 48 h for 12 weeks). WD feeding increased nSMase2 expression and activation while causing aortic stiffening and impaired vasorelaxation as determined by pulse wave velocity (PWV) and wire myography, respectively. Moreover, these functional abnormalities were associated with aortic remodeling and attenuated AMP-activated protein kinase, Sirtuin 1, and endothelial nitric oxide synthase activation. GW4869 treatment prevented the WD-induced increases in nSMase activation, PWV, and impaired endothelium dependent/independent vascular relaxation. GW4869 also inhibited WD-induced aortic CD36 expression, lipid accumulation, oxidative stress, inflammatory responses, as well as aortic remodeling. These findings indicate that targeting nSMase prevents diet - induced aortic stiffening and impaired vascular relaxation by attenuating oxidative stress, inflammation and adverse vascular remodeling.


Subject(s)
Vascular Stiffness , Animals , Ceramides , Diet, Western/adverse effects , Female , Inflammation/metabolism , Mice , Mice, Inbred C57BL , Pulse Wave Analysis , Sphingomyelin Phosphodiesterase , Vascular Remodeling
5.
Am J Physiol Heart Circ Physiol ; 322(2): H167-H180, 2022 02 01.
Article in English | MEDLINE | ID: mdl-34890280

ABSTRACT

Consumption of diets high in fat, sugar, and salt (Western diet, WD) is associated with accelerated arterial stiffening, a major independent risk factor for cardiovascular disease (CVD). Women with obesity are more prone to develop arterial stiffening leading to more frequent and severe CVD compared with men. As tissue transglutaminase (TG2) has been implicated in vascular stiffening, our goal herein was to determine the efficacy of cystamine, a nonspecific TG2 inhibitor, at reducing vascular stiffness in female mice chronically fed a WD. Three experimental groups of female mice were created. One was fed regular chow diet (CD) for 43 wk starting at 4 wk of age. The second was fed a WD for the same 43 wk, whereas a third cohort was fed WD, but also received cystamine (216 mg/kg/day) in the drinking water during the last 8 wk on the diet (WD + C). All vascular stiffness parameters assessed, including aortic pulse wave velocity and the incremental modulus of elasticity of isolated femoral and mesenteric arteries, were significantly increased in WD- versus CD-fed mice, and reduced in WD + C versus WD-fed mice. These changes coincided with respectively augmented and diminished vascular wall collagen and F-actin content, with no associated effect in blood pressure. In cultured human vascular smooth muscle cells, cystamine reduced TG2 activity, F-actin:G-actin ratio, collagen compaction capacity, and cellular stiffness. We conclude that cystamine treatment represents an effective approach to reduce vascular stiffness in female mice in the setting of WD consumption, likely because of its TG2 inhibitory capacity.NEW & NOTEWORTHY This study evaluates the novel role of transglutaminase 2 (TG2) inhibition to directly treat vascular stiffness. Our data demonstrate that cystamine, a nonspecific TG2 inhibitor, improves vascular stiffness induced by a diet rich in fat, fructose, and salt. This research suggests that TG2 inhibition might bear therapeutic potential to reduce the disproportionate burden of cardiovascular disease in females in conditions of chronic overnutrition.


Subject(s)
Cystamine/pharmacology , Diet, Western/adverse effects , Enzyme Inhibitors/pharmacology , Protein Glutamine gamma Glutamyltransferase 2/antagonists & inhibitors , Vascular Stiffness/drug effects , Actins/metabolism , Animals , Aorta/metabolism , Aorta/physiology , Cells, Cultured , Collagen/metabolism , Elasticity , Female , Humans , Mesenteric Arteries/metabolism , Mesenteric Arteries/physiology , Mice , Mice, Inbred C57BL , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/physiology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/physiology , Pulse Wave Analysis
6.
Am J Physiol Regul Integr Comp Physiol ; 322(3): R253-R262, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35107025

ABSTRACT

Mineralocorticoid receptor (MR) activation plays an important role in hepatic insulin resistance. However, the precise mechanisms by which MR activation promotes hepatic insulin resistance remains unclear. Therefore, we sought to investigate the roles and mechanisms by which MR activation promotes Western diet (WD)-induced hepatic steatosis and insulin resistance. Six-week-old C57BL6J mice were fed either mouse chow or a WD, high in saturated fat and refined carbohydrates, with or without the MR antagonist spironolactone (1 mg/kg/day) for 16 wk. WD feeding resulted in systemic insulin resistance at 8 and 16 wk. WD also induced impaired hepatic insulin metabolic signaling via phosphoinositide 3-kinases/protein kinase B pathways, which was associated with increased hepatic CD36, fatty acid transport proteins, fatty acid-binding protein-1, and hepatic steatosis. Meanwhile, consumption of a WD-induced hepatic mitochondria dysfunction, oxidative stress, and inflammatory responses. These abnormalities occurring in response to WD feeding were blunted with spironolactone treatment. Moreover, spironolactone promoted white adipose tissue browning and hepatic glucose transporter type 4 expression. These data suggest that enhanced hepatic MR signaling mediates diet-induced hepatic steatosis and dysregulation of adipose tissue browning, and subsequent hepatic mitochondria dysfunction, oxidative stress, inflammation, as well as hepatic insulin resistance.


Subject(s)
Fatty Liver , Insulin Resistance , Animals , Diet, High-Fat , Diet, Western/adverse effects , Fatty Liver/etiology , Fatty Liver/metabolism , Insulin/metabolism , Insulin Resistance/physiology , Liver/metabolism , Mice , Mice, Inbred C57BL , Receptors, Mineralocorticoid/metabolism , Spironolactone/metabolism , Spironolactone/pharmacology
7.
Am J Physiol Renal Physiol ; 320(3): F505-F517, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33522410

ABSTRACT

Recent evidence suggests that dipeptidyl peptidase-4 (DPP4) inhibition with saxagliptin (Saxa) is renoprotective under comorbid conditions associated with activation of the renin-angiotensin-aldosterone system (RAAS), such as diabetes, obesity, and hypertension, which confer a high cardiovascular risk. Immune system activation is now recognized as a contributor to RAAS-mediated tissue injury, and, importantly, immunomodulatory effects of DPP4 have been reported. Accordingly, we examined the hypothesis that DPP4 inhibition with Saxa attenuates angiotensin II (ANG II)-induced kidney injury and albuminuria via attenuation of immune activation in the kidney. To this end, male mice were infused with either vehicle or ANG II (1,000 ng/kg/min, s.c.) for 3 wk and received either placebo or Saxa (10 mg/kg/day, p.o.) during the final 2 wk. ANG II infusion increased kidney, but not plasma, DPP4 activity in vivo as well as DPP4 activity in cultured proximal tubule cells. The latter was prevented by angiotensin receptor blockade with olmesartan. Further, ANG II induced hypertension and kidney injury characterized by mesangial expansion, mitochondrial damage, reduced brush border megalin expression, and albuminuria. Saxa inhibited DPP4 activity ∼50% in vivo and attenuated ANG II-mediated kidney injury, independent of blood pressure. Further mechanistic experiments revealed mitigation by Saxa of proinflammatory and profibrotic mediators activated by ANG II in the kidney, including CD8+ T cells, resident macrophages (CD11bhiF4/80loLy6C-), and neutrophils. In addition, Saxa improved ANG II suppressed anti-inflammatory regulatory T cell and T helper 2 lymphocyte activity. Taken together, these results demonstrate, for the first time, blood pressure-independent involvement of renal DPP4 activation contributing to RAAS-dependent kidney injury and immune activation.NEW & NOTEWORTHY This work highlights the role of dipeptidyl peptidase-4 (DPP4) in promoting ANG II-mediated kidney inflammation and injury. Specifically, ANG II infusion in mice led to increases in blood pressure and kidney DPP4 activity, which then led to activation of CD8+ T cells, Ly6C- macrophages, and neutrophils and suppression of anti-inflammatory T helper 2 lymphocytes and regulatory T cells. Collectively, this led to kidney injury, characterized by mesangial expansion, mitochondrial damage, and albuminuria, which were mitigated by DPP4 inhibition independent of blood pressure reduction.


Subject(s)
Dipeptidyl Peptidase 4/metabolism , Hypoglycemic Agents/pharmacology , Macrophages/metabolism , Angiotensin II/pharmacology , Animals , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Hypertension/drug therapy , Hypertension/physiopathology , Kidney/drug effects , Kidney/metabolism , Kidney Tubules, Proximal/drug effects , Kidney Tubules, Proximal/metabolism , Macrophages/drug effects , Male , Mice
8.
Am J Physiol Renal Physiol ; 318(5): F1220-F1228, 2020 05 01.
Article in English | MEDLINE | ID: mdl-32281419

ABSTRACT

Consumption of a Western diet (WD) induces central aortic stiffening that contributes to the transmittance of pulsatile blood flow to end organs, including the kidney. Our recent work supports that endothelial epithelial Na+ channel (EnNaC) expression and activation enhances aortic endothelial cell stiffening through reductions in endothelial nitric oxide (NO) synthase (eNOS) and bioavailable NO that result in inflammatory and oxidant responses and perivascular fibrosis. However, the role that EnNaC activation has on endothelial responses in the renal circulation remains unknown. We hypothesized that cell-specific deletion of the α-subunit of EnNaC would prevent WD-induced central aortic stiffness and protect the kidney from endothelial dysfunction and vascular stiffening. Twenty-eight-week-old female αEnNaC knockout and wild-type mice were fed either mouse chow or WD containing excess fat (46%), sucrose, and fructose (17.5% each). WD feeding increased fat mass, indexes of vascular stiffening in the aorta and renal artery (in vivo pulse wave velocity and ultrasound), and renal endothelial cell stiffening (ex vivo atomic force microscopy). WD further impaired aortic endothelium-dependent relaxation and renal artery compliance (pressure myography) without changes in blood pressure. WD-induced renal arterial stiffening occurred in parallel to attenuated eNOS activation, increased oxidative stress, and aortic and renal perivascular fibrosis. αEnNaC deletion prevented these abnormalities and support a novel mechanism by which WD contributes to renal arterial stiffening that is endothelium and Na+ channel dependent. These results demonstrate that cell-specific EnNaC is important in propagating pulsatility into the renal circulation, generating oxidant stress, reduced bioavailable NO, and renal vessel wall fibrosis and stiffening.


Subject(s)
Aorta/metabolism , Diet, Western/adverse effects , Epithelial Sodium Channels/metabolism , Renal Artery/physiopathology , Vascular Diseases/metabolism , Vascular Stiffness , Animals , Aorta/pathology , Aorta/physiopathology , Elasticity , Epithelial Sodium Channels/deficiency , Epithelial Sodium Channels/genetics , Female , Fibrosis , Mice, Inbred C57BL , Mice, Knockout , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/metabolism , Oxidative Stress , Renal Artery/pathology , Signal Transduction , Vascular Diseases/genetics , Vascular Diseases/pathology , Vascular Diseases/physiopathology , Vascular Remodeling
9.
Arterioscler Thromb Vasc Biol ; 39(2): 212-223, 2019 02.
Article in English | MEDLINE | ID: mdl-30580570

ABSTRACT

Objective- Abdominal aortic aneurysm is caused by the accumulation of inflammatory cells in the aortic wall. Our recent studies demonstrated that inhibition of Notch signaling attenuates abdominal aortic aneurysm formation by shifting the macrophage balance towards anti-inflammatory (M2) phenotype. Using IL12p40-/- (interleukin 12 p40) mice, we investigated the effects of M2-predominant macrophages on the development of abdominal aortic aneurysm. Approach and Results- Male (8-10 week-old) wild-type and IL12p40-/- mice (n=15) on C57BL/6 background were infused with Ang II (angiotensin II, 1000 ng/kg per minute) by implanting osmotic pumps subcutaneously for 28 days. In the IL12p40-/- mice, Ang II significantly increased the maximal intraluminal diameter (9/15) as determined by transabdominal ultrasound imaging. In addition, IL12p40-deletion significantly increased aortic stiffness in response to Ang II as measured by pulse wave velocity and atomic force microscopy. Histologically, IL12p40-/- mice exhibited increased maximal external diameter of aorta and aortic lesions associated with collagen deposition and increased elastin fragmentation compared with wild-type mice infused with Ang II. Mechanistically, IL12p40 deficiency by siRNA (small interfering RNA) augmented the Tgfß2-mediated Mmp2 expression in wild-type bone marrow-derived macrophages without affecting the expression of Mmp9. No such effects of IL12p40 deficiency on MMP2/MMP9 was observed in human aortic smooth muscle cells or fibroblasts. Depletion of macrophages in IL12p40-/- mice by clodronate liposomes significantly decreased the maximal external diameter of aorta and aortic stiffness in response to Ang II as determined by imaging and atomic force microscopy. Conclusions- IL12p40 depletion promotes the development of abdominal aortic aneurysm, in part, by facilitating recruitment of M2-like macrophages and potentiating aortic stiffness and fibrosis mediated by Tgfß2.


Subject(s)
Angiotensin II/pharmacology , Aortic Aneurysm, Abdominal/chemically induced , Interleukin-12 Subunit p40/physiology , Animals , Collagen/metabolism , Interleukin-12 Subunit p40/deficiency , Macrophages/physiology , Male , Matrix Metalloproteinase 2/metabolism , Mice , Mice, Inbred C57BL , Transforming Growth Factor beta2/physiology , Vascular Stiffness
10.
Diabetologia ; 61(1): 21-28, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28776083

ABSTRACT

Diabetic cardiomyopathy is characterised in its early stages by diastolic relaxation abnormalities and later by clinical heart failure in the absence of dyslipidaemia, hypertension and coronary artery disease. Insulin resistance, hyperinsulinaemia and hyperglycaemia are each independent risk factors for the development of diabetic cardiomyopathy. The pathophysiological factors in diabetes that drive the development of cardiomyopathy include systemic metabolic disorders, inappropriate activation of the renin-angiotensin-aldosterone system, subcellular component abnormalities, oxidative stress, inflammation and dysfunctional immune modulation. These abnormalities collectively promote cardiac tissue interstitial fibrosis, cardiac stiffness/diastolic dysfunction and, later, systolic dysfunction, precipitating the syndrome of clinical heart failure. Recent evidence has revealed that dysregulation of coronary endothelial cells and exosomes also contributes to the pathology behind diabetic cardiomyopathy. Herein, we review the relationships among insulin resistance/hyperinsulinaemia, hyperglycaemia and the development of cardiac dysfunction. We summarise the current understanding of the pathophysiological mechanisms in diabetic cardiomyopathy and explore potential preventative and therapeutic strategies.


Subject(s)
Diabetic Cardiomyopathies/blood , Diabetic Cardiomyopathies/physiopathology , Hyperglycemia/blood , Hyperglycemia/physiopathology , Animals , Heart Diseases/blood , Heart Diseases/physiopathology , Humans , Insulin Resistance/physiology
11.
Curr Hypertens Rep ; 20(8): 72, 2018 07 04.
Article in English | MEDLINE | ID: mdl-29974262

ABSTRACT

PURPOSE OF REVIEW: To update and review novel insights into the mechanisms, measurements, and therapeutic approaches to arterial stiffness. RECENT FINDINGS: Arterial (e.g., vascular) stiffness has been shown over time to prognosticate for cardiovascular and kidney outcomes. In this context, there has been increased interest behind the mechanisms that drive arterial stiffness beyond aging and interest in how to apply newer technologies in measurement of arterial stiffness. Pulse wave velocity has been the gold standard for measurement but industry has been innovating to improve measurement with use of single-point PWV as well as pharmacologic approaches with anti-hypertensives and oral hypoglycemic agents. Emerging data on the role of the mineralocorticoid receptor, the endothelial sodium channel (EnNaC), and uric acid in arterial stiffness are promising a number of potential therapies. Newer techniques of measuring PWV for arterial stiffness and novel therapies may soon lead to better outcomes from hypertension complications.


Subject(s)
Antihypertensive Agents/pharmacology , Hypertension , Vascular Stiffness , Humans , Hypertension/metabolism , Hypertension/physiopathology , Hypertension/therapy , Pulse Wave Analysis/methods , Therapies, Investigational , Uric Acid/metabolism , Vascular Stiffness/drug effects , Vascular Stiffness/physiology
12.
Kidney Int ; 92(2): 313-323, 2017 08.
Article in English | MEDLINE | ID: mdl-28341271

ABSTRACT

The global burden of kidney disease is increasing strikingly in parallel with increases in obesity and diabetes. Indeed, chronic kidney disease (CKD) and end-stage renal disease (ESRD) coupled with comorbidities such as obesity, diabetes, and hypertension cost the health care system hundreds of billions of dollars in the US alone. The progression to ESRD in patients with obesity and diabetes continues despite widespread use of inhibitors of the renin-angiotensin-aldosterone system (RAAS) along with aggressive blood pressure and glycemic control in these high-risk populations. Thereby, it is increasingly important to better understand the underlying mechanisms involved in obesity-related CKD in order to develop new strategies that prevent or interrupt the progression of this costly disease. In this context, a key mechanism that drives development and progression of kidney disease in obesity is endothelial dysfunction and associated tubulointerstitial fibrosis. However, the precise interactive mechanisms in the development of aortic and kidney endothelial dysfunction and tubulointerstitial fibrosis remain unclear. Further, strategies specifically targeting kidney fibrosis have yielded inconclusive benefits in human studies. While clinical data support the benefits derived from inhibition of the RAAS, there is a tremendous amount of residual risk for the progression of kidney disease in individuals with obesity and diabetes. There is promising experimental data to suggest that exercise, targeting inflammation and oxidative stress, lowering uric acid, and targeting the mineralocorticoid receptor signaling and/or sodium channel inhibition could improve tubulointerstitial fibrosis and mitigate progression of kidney disease in persons with obesity and diabetes.


Subject(s)
Kidney Failure, Chronic/etiology , Kidney/physiopathology , Obesity/complications , Obesity/physiopathology , Aldosterone/metabolism , Animals , Humans , Insulin Resistance , Obesity/metabolism , Receptors, Mineralocorticoid/metabolism , Renal Circulation , Renin-Angiotensin System
13.
Cardiovasc Diabetol ; 16(1): 9, 2017 01 13.
Article in English | MEDLINE | ID: mdl-28086951

ABSTRACT

Obese and diabetic individuals are at increased risk for impairments in diastolic relaxation and heart failure with preserved ejection fraction. The impairments in diastolic relaxation are especially pronounced in obese and diabetic women and predict future cardiovascular disease (CVD) events in this population. Recent clinical data suggest sodium glucose transporter-2 (SGLT2) inhibition reduces CVD events in diabetic individuals, but the mechanisms of this CVD protection are unknown. To determine whether targeting SGLT2 improves diastolic relaxation, we utilized empagliflozin (EMPA) in female db/db mice. Eleven week old female db/db mice were fed normal mouse chow, with or without EMPA, for 5 weeks. Blood pressure (BP), HbA1c and fasting glucose were significantly increased in untreated db/db mice (DbC) (P < 0.01). EMPA treatment (DbE) improved glycemic indices (P < 0.05), but not BP (P > 0.05). At baseline, DbC and DbE had already established impaired diastolic relaxation as indicated by impaired septal wall motion (>tissue Doppler derived E'/A' ratio) and increased left ventricular (LV) filling pressure (

Subject(s)
Benzhydryl Compounds/therapeutic use , Blood Pressure/drug effects , Diabetes Mellitus, Type 2/drug therapy , Disease Models, Animal , Glucosides/therapeutic use , Sodium-Glucose Transporter 2 Inhibitors , Ventricular Function, Left/drug effects , Animals , Benzhydryl Compounds/pharmacology , Blood Pressure/physiology , Diabetes Mellitus, Type 2/physiopathology , Diastole/drug effects , Diastole/physiology , Female , Glucosides/pharmacology , Glycemic Index/drug effects , Glycemic Index/physiology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Sodium-Glucose Transporter 2/physiology , Ventricular Function, Left/physiology
14.
Cardiovasc Diabetol ; 16(1): 61, 2017 05 05.
Article in English | MEDLINE | ID: mdl-28476142

ABSTRACT

BACKGROUND: Diastolic dysfunction (DD), a hallmark of obesity and primary defect in heart failure with preserved ejection fraction, is a predictor of future cardiovascular events. We previously reported that linagliptin, a dipeptidyl peptidase-4 inhibitor, improved DD in Zucker Obese rats, a genetic model of obesity and hypertension. Here we investigated the cardioprotective effects of linagliptin on development of DD in western diet (WD)-fed mice, a clinically relevant model of overnutrition and activation of the renin-angiotensin-aldosterone system. METHODS: Female C56Bl/6 J mice were fed an obesogenic WD high in fat and simple sugars, and supplemented or not with linagliptin for 16 weeks. RESULTS: WD induced oxidative stress, inflammation, upregulation of Angiotensin II type 1 receptor and mineralocorticoid receptor (MR) expression, interstitial fibrosis, ultrastructural abnormalities and DD. Linagliptin inhibited cardiac DPP-4 activity and prevented molecular impairments and associated functional and structural abnormalities. Further, WD upregulated the expression of TRAF3IP2, a cytoplasmic adapter molecule and a regulator of multiple inflammatory mediators. Linagliptin inhibited its expression, activation of its downstream signaling intermediates NF-κB, AP-1 and p38-MAPK, and induction of multiple inflammatory mediators and growth factors that are known to contribute to development and progression of hypertrophy, fibrosis and contractile dysfunction. Linagliptin also inhibited WD-induced collagens I and III expression. Supporting these in vivo observations, linagliptin inhibited aldosterone-mediated MR-dependent oxidative stress, upregulation of TRAF3IP2, proinflammatory cytokine, and growth factor expression, and collagen induction in cultured primary cardiac fibroblasts. More importantly, linagliptin inhibited aldosterone-induced fibroblast activation and migration. CONCLUSIONS: Together, these in vivo and in vitro results suggest that inhibition of DPP-4 activity by linagliptin reverses WD-induced DD, possibly by targeting TRAF3IP2 expression and its downstream inflammatory signaling.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cardiomyopathies/prevention & control , Diet, Western/adverse effects , Dipeptidyl Peptidase 4/metabolism , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Linagliptin/pharmacology , Myocarditis/prevention & control , Myocardium/enzymology , Adaptor Proteins, Signal Transducing/genetics , Animals , Cardiomyopathies/enzymology , Cardiomyopathies/etiology , Cardiomyopathies/physiopathology , Cells, Cultured , Diastole , Disease Models, Animal , Down-Regulation , Female , Fibrosis , Mice, Inbred C57BL , Myocarditis/enzymology , Myocarditis/etiology , Myocarditis/physiopathology , Myocardium/ultrastructure , NF-kappa B/metabolism , Nitrosative Stress/drug effects , Obesity/etiology , Oxidative Stress/drug effects , Recovery of Function , Signal Transduction/drug effects , Time Factors , Transcription Factor AP-1/metabolism , Ventricular Dysfunction, Left/enzymology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/prevention & control , Ventricular Function, Left/drug effects , p38 Mitogen-Activated Protein Kinases/metabolism
15.
Int J Mol Sci ; 17(5)2016 May 20.
Article in English | MEDLINE | ID: mdl-27213360

ABSTRACT

Proteinuria is a marker of incipient kidney injury in many disorders, including obesity. Previously, we demonstrated that megalin, a receptor endocytotic protein in the proximal tubule, is downregulated in obese mice, which was prevented by inhibition of dipeptidyl protease 4 (DPP4). Obesity is thought to be associated with upregulation of intra-renal angiotensin II (Ang II) signaling via the Ang II Type 1 receptor (AT1R) and Ang II suppresses megalin expression in proximal tubule cells in vitro. Therefore, we tested the hypothesis that Ang II will suppress megalin protein via activation of DPP4. We used Ang II (200 ng/kg/min) infusion in mice and Ang II (10(-8) M) treatment of T35OK-AT1R proximal tubule cells to test our hypothesis. Ang II-infused mouse kidneys displayed increases in DPP4 activity and decreases in megalin. In proximal tubule cells, Ang II stimulated DPP4 activity concurrent with suppression of megalin. MK0626, a DPP4 inhibitor, partially restored megalin expression similar to U0126, a mitogen activated protein kinase (MAPK)/extracellular regulated kinase (ERK) kinase kinase (MEK) 1/2 inhibitor and AG1478, an epidermal growth factor receptor (EGFR) inhibitor. Similarly, Ang II-induced ERK phosphorylation was suppressed with MK0626 and Ang II-induced DPP4 activity was suppressed by U0126. Therefore, our study reveals a cross talk between AT1R signaling and DPP4 activation in the regulation of megalin and underscores the significance of targeting DPP4 in the prevention of obesity related kidney injury progression.


Subject(s)
Angiotensin II/metabolism , Dipeptidyl Peptidase 4/metabolism , Gene Expression Regulation , Kidney Tubules, Proximal/metabolism , Low Density Lipoprotein Receptor-Related Protein-2/biosynthesis , MAP Kinase Signaling System , Angiotensin II/pharmacology , Animals , Cell Line , Enzyme Inhibitors/pharmacology , Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors , Extracellular Signal-Regulated MAP Kinases/metabolism , Male , Mice , Mice, Obese , Obesity/complications , Obesity/metabolism , Renal Insufficiency/etiology , Renal Insufficiency/metabolism
16.
Diabetes Spectr ; 28(3): 175-80, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26300610

ABSTRACT

IN BRIEF Hypertension is prevalent in most individuals with diabetic kidney disease (DKD). Failure to treat hypertension appropriately in this subgroup of patients results in an increased risk of cardiovascular morbidity and mortality, as well as a faster progression of kidney disease. The current guidance for appropriate treatment of hypertension in this high-risk population provides an opportunity to improve both kidney and cardiovascular outcomes. This review discusses the current state of evidence-based hypertension management in patients with DKD.

17.
Kidney Int ; 85(3): 686-92, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24067435

ABSTRACT

Preparation for end-stage renal disease (ESRD) is widely acknowledged to be suboptimal in the United States. We sought to determine whether participation in a kidney disease screening and education program resulted in improved ESRD preparation and survival in 595 adults who developed ESRD after participating in the National Kidney Foundation Kidney Early Evaluation Program (KEEP), a community-based screening and education program. Non-KEEP patients were selected from a national ESRD registry and matched to KEEP participants based on demographic and clinical characteristics. The main outcomes were pre-ESRD nephrologist care, placement of permanent vascular access, use of peritoneal dialysis, pre-emptive transplant wait listing, transplantation, and mortality after ESRD. Participation in KEEP was associated with significantly higher rates of pre-ESRD nephrologist care (76.0% vs. 69.3%), peritoneal dialysis (10.3% vs. 6.4%), pre-emptive transplant wait listing (24.2% vs. 17.1%), and transplantation (9.7% vs. 6.4%) but not with higher rates of permanent vascular access (23.4% vs. 20.1%). Participation in KEEP was associated with a lower risk for mortality (hazard ratio 0.80), but this was not statistically significant after adjusting for ESRD preparation. Thus, participation in a voluntary community kidney disease screening and education program was associated with higher rates of ESRD preparation and survival.


Subject(s)
Patient Education as Topic , Renal Dialysis , Renal Insufficiency, Chronic/therapy , Aged , Female , Humans , Male , Middle Aged , Renal Insufficiency, Chronic/mortality
18.
Am J Kidney Dis ; 64(4): 510-33, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25257325

ABSTRACT

The incidence and prevalence of diabetes mellitus have grown significantly throughout the world, due primarily to the increase in type 2 diabetes. This overall increase in the number of people with diabetes has had a major impact on development of diabetic kidney disease (DKD), one of the most frequent complications of both types of diabetes. DKD is the leading cause of end-stage renal disease (ESRD), accounting for approximately 50% of cases in the developed world. Although incidence rates for ESRD attributable to DKD have recently stabilized, these rates continue to rise in high-risk groups such as middle-aged African Americans, Native Americans, and Hispanics. The costs of care for people with DKD are extraordinarily high. In the Medicare population alone, DKD-related expenditures among this mostly older group were nearly $25 billion in 2011. Due to the high human and societal costs, the Consensus Conference on Chronic Kidney Disease and Diabetes was convened by the American Diabetes Association in collaboration with the American Society of Nephrology and the National Kidney Foundation to appraise issues regarding patient management, highlighting current practices and new directions. Major topic areas in DKD included (1) identification and monitoring, (2) cardiovascular disease and management of dyslipidemia, (3) hypertension and use of renin-angiotensin-aldosterone system blockade and mineralocorticoid receptor blockade, (4) glycemia measurement, hypoglycemia, and drug therapies, (5) nutrition and general care in advanced-stage chronic kidney disease, (6) children and adolescents, and (7) multidisciplinary approaches and medical home models for health care delivery. This current state summary and research recommendations are designed to guide advances in care and the generation of new knowledge that will meaningfully improve life for people with DKD.


Subject(s)
Diabetes Mellitus, Type 1 , Diabetes Mellitus, Type 2 , Diabetic Nephropathies , Disease Management , Adolescent , Adult , Clinical Trials as Topic , Comorbidity , Delivery of Health Care , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/therapy , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/therapy , Diabetic Nephropathies/diagnosis , Diabetic Nephropathies/epidemiology , Diabetic Nephropathies/therapy , Ethnicity , Humans , Hypoglycemic Agents/classification , Hypoglycemic Agents/therapeutic use , Kidney Function Tests/methods , Monitoring, Physiologic/methods , Practice Guidelines as Topic , Prevalence , Risk Factors
19.
Curr Hypertens Rep ; 16(6): 434, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24760443

ABSTRACT

Population level data support that consumption of fructose and fructose-based sweeteners has dramatically increased and suggest that high dietary intake of fructose is an important factor in the development of the cardiorenal metabolic syndrome (CRS). The CRS is a constellation of cardiac, kidney and metabolic disorders including insulin resistance, obesity, metabolic dyslipidemia, high blood pressure, and evidence of early cardiac and kidney disease. The consequences of fructose metabolism may result in intracellular ATP depletion, increased uric acid production, oxidative stress, inflammation, and increased lipogenesis, which are associated with endothelial dysfunction. Endothelial dysfunction is an early manifestation of vascular disease and a driver for the development of CRS. A better understanding of fructose overconsumption in the development of CRS may provide new insights into pathogenesis and future therapeutic strategies.


Subject(s)
Cardio-Renal Syndrome/etiology , Endothelium, Vascular/physiopathology , Fructose/metabolism , Metabolic Syndrome/etiology , Uric Acid/metabolism , Cardio-Renal Syndrome/physiopathology , Endothelium, Vascular/metabolism , Female , Fructose/adverse effects , Humans , Insulin Resistance/physiology , Male , Metabolic Syndrome/physiopathology , Risk Assessment , Sensitivity and Specificity , Sweetening Agents/adverse effects , Uric Acid/adverse effects
20.
Cardiorenal Med ; 14(1): 129-135, 2024.
Article in English | MEDLINE | ID: mdl-38342088

ABSTRACT

BACKGROUND: The vascular endothelium serves as a semi-selective permeable barrier as a conduit for transport of fluid, solutes, and various cell populations between the vessel lumen and tissues. The endothelium thus has a dynamic role in the regulation of coagulation, immune system, lipid and electrolyte transport, as well as neurohumoral influences on vascular tone and end-organ injury to tissues such as the heart and kidney. SUMMARY: Within this framework, pharmacologic strategies for heart and kidney diseases including blood pressure, glycemic control, and lipid reduction provide significant risk reduction, yet certain populations are at risk for substantial residual risk for disease progression and treatment resistance and often have unwanted off-target effects leaving the need for adjunct, alternative targeted therapies. Recent advances in techniques in sequencing and spatial transcriptomics have paved the way for the development of new therapies for targeting heart and kidney disease that include various gene, cell, and nano-based therapies. Cell-specific endothelium-specific targeting of viral vectors will enable their use for the treatment of heart and kidney diseases with gene therapy that can avoid unwanted off-target effects, improve treatment resistance, and reduce residual risk for disease progression. KEY MESSAGES: The vascular endothelium is an important therapeutic target for chronic kidney and cardiovascular diseases. Developing endothelial-specific gene therapies can benefit patients who develop resistance to current treatments.


Subject(s)
Cardio-Renal Syndrome , Endothelium, Vascular , Humans , Cardio-Renal Syndrome/physiopathology , Cardio-Renal Syndrome/metabolism , Endothelium, Vascular/physiopathology , Endothelium, Vascular/metabolism , Genetic Therapy/methods , Animals
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