Deletion of soluble epoxide hydrolase suppressed chronic kidney disease-related vascular calcification by restoring Sirtuin 3 expression

Regulation of soluble epoxide hydrolase in renal-associated diseases: insights from potential mechanisms to clinical researches

In recent years, numerous experimental studies have underscored the pivotal role of soluble epoxide hydrolase (sEH) in renal diseases, demonstrating the reno-protective effects of sEH inhibitors. The nexus between sEH and renal-associated diseases has garnered escalating attention. This review endeavors to elucidate the potential molecular mechanisms of sEH in renal diseases and emphasize the critical role of sEH inhibitors as a prospective treatment modality. Initially, we expound upon the correlation between sEH and Epoxyeicosatrienoic acids (EETs) and also addressing the impact of sEH on other epoxy fatty acids, delineate prevalent EPHX2 single nucleotide polymorphisms (SNPs) associated with renal diseases, and delve into sEH-mediated potential mechanisms, encompassing oxidative stress, inflammation, ER stress, and autophagy. Subsequently, we delineate clinical research pertaining to sEH inhibition or co-inhibition of sEH with other inhibitors for the regulation of renal-associated diseases, covering conditions such as acute kidney injury, chronic kidney diseases, diabetic nephropathy, and hypertension-induced renal injury. Our objective is to validate the potential role of sEH inhibitors in the treatment of renal injuries. We contend that a comprehensive comprehension of the salient attributes of sEH, coupled with insights from clinical experiments, provides invaluable guidance for clinicians and presents promising therapeutic avenues for patients suffering from renal diseases.

Association between dietary total choline and abdominal aorta calcification among older US adults: A cross-sectional study of the National Health and Nutrition Examination Survey

BACKGROUND

Numerous studies indicate a potential bidirectional association between dietary choline intake and its derivative, betaine, and subclinical atherosclerosis. However, little research has been conducted on the relationship between dietary choline and severe abdominal aortic calcification (SAAC).

METHODS

This cross-sectional study analyzed population-based data from the National Health and Nutrition Examination Survey (2013-2014). Choline intake and food sources were measured using two 24-h dietary-recall interviews. The abdominal aortic calcification score was measured using a dual-emission x-ray absorptiometry scan. To assess the relationship between choline intake and SAAC, the study utilized restricted cubic spline and a multivariable logistic regression model.

RESULTS

Among the 2640 individuals included in the study, 10.9% had SAAC. After adjusting for all selected covariates, compared with the lowest quartile of dietary choline, the odds ratios of SAAC for the second-quartile, third-quartile, and fourth-quartile dietary choline intake were 0.63 (95% confidence interval [CI], 0.43-0.93), 0.63 (95% CI, 0.42-0.94), and 0.77 (95% CI, 0.5-1.16), respectively. The study found an L-shaped relationship between dietary choline and SAAC in the dose-response analysis. Subgroup analyses did not demonstrate any statistically significant interaction effects for any subgroup.

CONCLUSION

The study found that a higher intake of dietary choline is associated with a lower prevalence of SAAC. The dose-response analysis revealed an L-shaped relationship between dietary choline and SAAC. However, further studies are warranted to investigate the direct role of choline in the development of SAAC.

Dietary antioxidants and vascular calcification: From pharmacological mechanisms to challenges

Vascular calcification (VC), an actively regulated process, has been recognized as an independent and strong predictor of cardiovascular disease (CVD) and mortality worldwide. Diet has been shown to have a major role in the progression of VC. Oxidative stress (OS), a common pro-calcification factor, is closely related to VC, and evidence strongly suggests that dietary antioxidants directly prevent VC. Herein, we provided an overview of OS and its key role in VC and underlined the mechanisms of harmful effects of OS on VC. Furthermore, we introduced dietary antioxidants, and discussed about surrounding the challenges of dietary antioxidants in VC management. This review will benefit future research about the effects of dietary antioxidants on cardiovascular health.

Vascular, valvular and kidney calcification manifested in mouse models of adenine-induced chronic kidney disease

BACKGROUND

Ectopic calcification (EC) involves multiple organ systems in chronic kidney disease (CKD). Previous CKD-animal models primarily focused on a certain histological abnormality but did not show the correlation with calcified development among various tissues. This study compared calcified deposition in various tissues during CKD progression in mice.

METHODS

Male 8-week-old C57BL/6J mice were randomly allocated to the seven groups: a basic, adenine, high-phosphorus, or adenine and high-phosphorus diet for 12-16 weeks (Ctl16, A12, P16, or AP16, respectively); an adenine diet for 4-6 weeks; and a high-phosphorus or adenine and high-phosphorus diet for 10-12 weeks (A6 + P10, A4 + P12, or A4 + AP12, respectively).

RESULTS

Compared to the Ctl16 mice, the P16 mice only displayed a slight abnormality in serum calcium and phosphorus; the A12 mice had the most serious kidney impairment; the A4 + P12 and A6 + P10 mice had similar conditions of CKD, mineral abnormalities, and mild calcification in the kidney and aortic valves; the A4 + AP12 and AP16 groups had severe kidney impairment, mineral abnormalities and calcification in the kidneys, aortic valves and aortas. Furthermore, calcium-phosphate particles were deposited not only in the tubulointerstitial compartment but in the glomerular and tubular basement membrane. The elemental composition of EC in various tissues matched the calcification of human cardiovascular tissue as determined by energy dispersive spectroscopy.

CONCLUSIONS

The severity of CKD was unparalleled with the progression of mineral metabolism disorder and EC. Calcification was closely related in different tissues and observed in the glomerular and tubular basement membranes.

Soluble epoxide hydrolase deficiency promotes liver regeneration and ameliorates liver injury in mice by regulating angiocrine factors and angiogenesis

BACKGROUND

Soluble epoxide hydrolase (sEH) is a key enzyme for the hydrolysis of epoxyeicosatrienoic acids (EETs) and has been implicated in the pathogenesis of hepatic inflammation, fibrosis, cancer, and nonalcoholic fatty liver disease. However, the role of sEH in liver regeneration and injury remains unclear.

METHODS

This study used sEH-deficient (sEH^-/-) mice and wild-type (WT) mice. Hepatocyte proliferation was assessed by immunohistochemical (IHC) staining for Ki67. Liver injury was evaluated by histological staining with hematoxylin and eosin (H&E), Masson's trichrome, and Sirius red, as well as IHC staining for α-SMA. Hepatic macrophage infiltration and angiogenesis were reflected by IHC staining for CD68 and CD31. Liver angiocrine levels were detected by ELISA. The mRNA levels of angiocrine or cell cycle-related genes were measured by quantitative real-time RT-PCR (qPCR). The protein levels of cell proliferation-related protein and phosphorylated signal transducer and activator of transcription 3 (STAT3) were detected by western blotting.

RESULTS

sEH mRNA and protein levels were significantly upregulated in mice after 2/3 partial hepatectomy (PHx). Compared with WT mice, sEH^-/- mice exhibited a higher liver/body weight ratio and more Ki67-positive cells on days 2 and 3 after PHx. The accelerated liver regeneration in sEH^-/- mice was attributed to angiogenesis and endothelial-derived angiocrine (HGF) production. Subsequently, hepatic protein expression of cyclinD1 (CYCD1) and the downstream direct targets of the STAT3 pathway, such as c-fos, c-jun, and c-myc, were also suppressed post-PHx in sEH^-/- compared to WT mice. Furthermore, sEH deficiency attenuated CCl₄-induced acute liver injury and reduced fibrosis in both CCl₄ and bile duct ligation (BDL)-induced liver fibrosis rodent models. Compared with WT mice, sEH^-/- mice had slightly decreased hepatic macrophage infiltration and angiogenesis. Meanwhile, sEH^-/- BDL mice had more Ki67-positive cells in the liver than WT BDL mice.

CONCLUSIONS

sEH deficiency alters the angiocrine profile of liver endothelial to accelerate hepatocyte proliferation and liver regeneration, and blunts acute liver injury and fibrosis by inhibiting inflammation and angiogenesis. sEH inhibition is a promising target for liver diseases to improve liver regeneration and damage.

Sirtuin-3-Mediated Cellular Metabolism Links Cardiovascular Remodeling with Hypertension

Hypertension can cause structural and functional abnormalities in the cardiovascular system, which can be attributed to both hemodynamic and nonhemodynamic factors. These alterations are linked with metabolic changes and are induced by pathological stressors. Sirtuins are enzymes that act as stress sensors and regulate metabolic adaptation by deacetylating proteins. Among them, mitochondrial SIRT3 performs a crucial role in maintaining metabolic homeostasis. Evidence from experimental and clinical studies has shown that hypertension-induced decreases in SIRT3 activity can lead to cellular metabolism reprogramming and, subsequently, increased susceptibility to endothelial dysfunction, myocardial hypertrophy, myocardial fibrosis, and heart failure. This review presents recent research advances in SIRT3-mediated metabolic adaptation in hypertensive cardiovascular remodeling.

The sirtuin family in health and disease

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

Intermedin Alleviates Vascular Calcification in CKD through Sirtuin 3-Mediated Inhibition of Mitochondrial Oxidative Stress

Vascular calcification (VC) is a common pathophysiological process of chronic kidney disease (CKD). Sirtuin 3 (Sirt3), a major NAD⁺-dependent protein deacetylase predominantly in mitochondria, is involved in the pathogenesis of VC. We previously reported that intermedin (IMD) could protect against VC. In this study, we investigated whether IMD attenuates VC by Sirt3-mediated inhibition of mitochondrial oxidative stress. A rat VC with CKD model was induced by the 5/6 nephrectomy plus vitamin D₃. Vascular smooth muscle cell (VSMC) calcification was induced by CaCl₂ and β-glycerophosphate. IMD_1-53 treatment attenuated VC in vitro and in vivo, rescued the depressed mitochondrial membrane potential (MMP) level and decreased mitochondrial ROS levels in calcified VSMCs. IMD_1-53 treatment recovered the reduced protein level of Sirt3 in calcified rat aortas and VSMCs. Inhibition of VSMC calcification by IMD_1-53 disappeared when the cells were Sirt3 absent or pretreated with the Sirt3 inhibitor 3-TYP. Furthermore, 3-TYP pretreatment blocked IMD_1-53-mediated restoration of the MMP level and inhibition of mitochondrial oxidative stress in calcified VSMCs. The attenuation of VSMC calcification by IMD_1-53 through upregulation of Sirt3 might be achieved through activation of the IMD receptor and post-receptor signaling pathway AMPK, as indicated by pretreatment with an IMD receptor antagonist or AMPK inhibitor blocking the inhibition of VSMC calcification and upregulation of Sirt3 by IMD_1-53. AMPK inhibitor treatment reversed the effects of IMD_1-53 on restoring the MMP level and inhibiting mitochondrial oxidative stress in calcified VSMCs. In conclusion, IMD attenuates VC by improving mitochondrial function and inhibiting mitochondrial oxidative stress through upregulating Sirt3.

Effect of C1q/TNF-Related Protein 9 on Coronary Artery Calcification: An Observational Study

Coronary artery calcification (CAC) increases the risk of acute coronary syndrome. This study examined the correlation between C1q/TNF-related protein 9 (CTRP9) and CAC and explored CTRP9 as a biomarker for prognosis. We divided 275 patients with coronary heart disease into four groups. In order to balance the baseline confounding factors, propensity score matching (PSM) was performed to match CAC patients with non-CAC patients in a 1:1 ratio. Optical coherence tomography (OCT) calcification scoring was performed in 126 patients with CAC. Moreover, 140 patients who underwent OCT were followed-up for 9 months for analysis of the correlation between CTRP9 levels and clinical prognosis. Based on OCT calcification scores, 126 patients with CAC were divided into the 0–2 and 3–4 groups. Plasma CTRP9 levels were significantly lower in the type 2 diabetes mellitus (T2DM), CAC and CAC with T2DM groups than in the control group. CTRP9 played roles as a protective factor and potential predictor in CAC severity. The AUC of the OCT calcification score 3–4 group predicted by the plasma CTRP9 level was 0.766. During the follow-up period, the cumulative event-free survival rate was significantly lower in the low-level CTRP9 (L-CTRP9) group than in the high-level (H-CTRP9) group, and the incidence of major endpoint events was significantly higher in the L-CTRP9 group than in the H-CTRP9 group. CTRP9 can be a valuable biomarker for CAC occurrence and severity and can predict patients’ clinical prognosis.

Role of Sirtuins in Diabetes and Age-Related Processes

The practice of intermittent fasting continues to grow as a widely practiced diet trend due to its feasibility and reported high success rate. By practicing intermittent fasting, levels of sirtuin proteins (SIRTs), also known as the longevity protein, rise in the body and bring numerous health benefits. Currently, seven SIRTs have been described in humans in different locations of the cell with a wide variety of corresponding functions including gene transcription, DNA repair, and protection against oxidative damage. SIRT activators, such as resveratrol found in red wine, are also commonly consumed to amplify the health benefits associated with protection against diabetes and age-related disease processes. The purpose of this review is to explore the interaction of intermittent fasting on SIRT levels and how the increase in these proteins impacts age-related disease processes. The understanding of SIRTs is continuously evolving as more interactions and SIRT-specific activators are being revealed. New discoveries are crucial for forming potential therapeutics that delay many common diseases and promote healthy living. 

Comprehensive Network-Based Analyses Reveal Novel Renal Function-Related Targets in Acute Kidney Injury

Background: Acute kidney injury (AKI) is a common clinical syndrome with limited methods of treatment and diagnosis. Although several molecules associated with AKI have been discovered, molecular mechanisms underlying AKI still remain unclear. Weighted gene co-expression network analysis (WGCNA) is a novel method to uncover the relationship between co-expression genes and clinical traits at the system level.

Methods: First, by employing WGCNA in transcriptional data on 30 patients with well/poor functioning kidney graft, we identified two co-expression modules that were significantly related to serum creatinine (SCr). Second, based on the modules, potential small molecular compound candidates for developing targeted therapeutics were obtained by connectivity map analysis. Furthermore, multiple validations of expression in space/time were carried out with two classical AKI models in vivo and other five databases of over 152 samples.

Results: Two of the 14 modules were found to be closely correlated with SCr. Function enrichment analysis illustrated that one module was enriched in the immune system, while the other was in the metabolic process. Six key renal function-related genes (RFRGs) were finally obtained. Such genes performed well in cisplatin-induced or cecal ligation and puncture-induced AKI mouse models.

Conclusion: The analysis suggests that WGCNA is a proper method to connect clinical traits with genome data to find novel targets in AKI. The kidney tissue with worse renal function tended to develop a “high immune but low metabolic activity” expression pattern. Also, ACSM2A, GLYAT, CORO1A, DPEP1, ALDH7A1, and EPHX2 are potential targets of molecular diagnosis and treatment in AKI.

The Role of Sirtuins in Osteogenic Differentiation of Vascular Smooth Muscle Cells and Vascular Calcification

Vascular calcification (VC) is a common pathological change in many chronic diseases, such as diabetes and chronic kidney disease. It is mainly deposited in the intima and media of vessels in the form of hydroxyapatite. Recently, a lot of research has been performed to show that VC is associated with various cellular stresses, such as hyperphosphate, hyperglycemia and oxidative stress. Unfortunately, our understanding of the pathogenesis of calcification is far from comprehensive. Sirtuins belong to a family of class III highly conserved deacetylases that are involved in the regulation of biological and cellular processes including mitochondrial biogenesis, metabolism, oxidative stress, inflammatory response, DNA repair, etc. Numerous studies have shown that sirtuins might play protective roles in VC, and restoring the activity of sirtuins may be a potentially effective treatment for VC. However, the exact mechanism of their vascular protection remains unclear. Here, we reviewed the roles of sirtuins in the osteogenic transformation of vascular smooth muscle cells and the development of VC. We also elucidated the applications of sirtuins agonists for the treatment of VC.

Mammalian Sirtuins and Their Relevance in Vascular Calcification

Cardiovascular diseases are a group of diseases with high morbidity and mortality that affect millions of people each year. Vascular calcification (VC) is an active process that involves the mineral deposition of calcium-phosphate complexes. VC is closely related to cardiovascular diseases, such as hypertension, heart failure, and calcific aortic stenosis, and is a type of ectopic calcification that occurs in the vessel walls. The sirtuins (silent mating-type information regulation 2; SIRTs), are a family of histone deacetylases whose function relies on nicotinamide adenine dinucleotide (NAD+). They have non-negligible functions in the regulation of energy metabolism, senescence, apoptosis, and other biological processes. Sirtuins have important effects on bone homeostasis and VC processes that share many similarities with bone formation. Sirtuins have been confirmed to deacetylate a variety of target proteins related to the occurrence and development of VC, thereby affecting the process of VC and providing new possibilities for the prevention and treatment of cardiovascular diseases. To facilitate the understanding of vascular calcification and accelerate the development of cardiovascular drugs, we reviewed and summarized recent research progress on the relationship between different types of sirtuins and VC.