Cardiometabolic Surgery for Treatment of Hypertension?

Adropin transgenesis improves recognition memory in diet-induced obese LDLR-deficient C57BL/6J mice

Obesity-related metabolic dysregulation causes mild cognitive impairment and increased risk for dementia. We used an LDLR-deficient C57BL/6J mouse model (LDLRKO) to investigate whether adropin, a neuropeptide linked to neurodegenerative diseases, improves cognitive function in situations of metabolic dysregulation. Adropin transgenic mice (AdrTG) were crossed with LDLRKO; male and female progeny were fed a high fat diet for 3-months. Male chow-fed wild type (WT) mice were used as controls. Diet-induced obesity and LDLR-deficiency caused severe dyslipidemia, irrespective of sex. The AdrTG prevented reduced adropin protein levels in LDLRKO cortex. In males, metabolic dysregulation and AdrTG genotype significantly and bi-directionally affected performance in the novel object recognition (NOR) test, a declarative hippocampal memory task (discrimination index mean ± SE for WT, 0.02 ± 0.088; LDLRKO, -0.115 ± 0.077; AdrTG;LDLRKO, 0.265 ± 0.078; genotype effect, p = 0.009; LDLRKO vs. AdrTG;LDLRKO, P < 0.05). A 2-way ANOVA (fixed variables: sex, AdrTG genotype) indicated a highly significant effect of AdrTG (P = 0.003). The impact of the diet-genotype interaction on the male mouse brain was investigated using RNA-seq. Gene-ontology analysis of transcripts showing fold-changes of>1.3 or <-1.3 (P < 0.05) indicated metabolic dysregulation affected gene networks involved in intercellular/neuronal signaling, immune processes, angiogenesis, and extracellular matrix organization. The AdrTG selectively attenuated the impact of metabolic dysregulation on intercellular/neuronal signaling pathways. Intercellular/neuronal signaling pathways were also the predominant processes overrepresented when directly comparing AdrTG;LDLRKO with LDRKO. In summary, adropin overexpression improves cognitive function in severe metabolic dysregulation through pathways related to cell-cell communication and neuronal processes, and independently of preventing inflammatory responses.

Obesity-Related Glomerulopathy: From Mechanism to Therapeutic Target

Obesity-related glomerulopathy (ORG) is a secondary glomerular disease caused by obesity, with clinical manifestations such as proteinuria and glomerulomegaly. Currently, the high incidence of obesity brings a change in the spectrum of kidney diseases across the globe, including China. ORG has become another important secondary nephropathy leading to end-stage renal disease (ESRD), and its incidence has increased significantly. This trend is bound to bring about a serious socioeconomic burden. Therefore, it is urgent to study its pathogenesis and intervention measures. Currently, the occurrence and development mechanisms in ORG are complicated by many factors, which are still unclear. In the past 20 years, with the continuous intensive research on mechanisms such as hypoxia in the metabolic process, immune inflammation, and pyroptosis, there have been new advances in the mechanism of ORG, especially the important role of inflammation in podocyte injury and its impact on the progress of ORG. Here, we briefly review the possible pathogenic role of the inflammasome in the podocyte damage in ORG and summarize the possible therapeutical strategies targeting inflammasome.

Obesity, kidney dysfunction, and inflammation: interactions in hypertension

Obesity contributes 65-75% of the risk for human primary (essential) hypertension (HT) which is a major driver of cardiovascular and kidney diseases. Kidney dysfunction, associated with increased renal sodium reabsorption and compensatory glomerular hyperfiltration, plays a key role in initiating obesity-HT and target organ injury. Mediators of kidney dysfunction and increased blood pressure include (i) elevated renal sympathetic nerve activity (RSNA); (ii) increased antinatriuretic hormones such as angiotensin II and aldosterone; (iii) relative deficiency of natriuretic hormones; (iv) renal compression by fat in and around the kidneys; and (v) activation of innate and adaptive immune cells that invade tissues throughout the body, producing inflammatory cytokines/chemokines that contribute to vascular and target organ injury, and exacerbate HT. These neurohormonal, renal, and inflammatory mechanisms of obesity-HT are interdependent. For example, excess adiposity increases the adipocyte-derived cytokine leptin which increases RSNA by stimulating the central nervous system proopiomelanocortin-melanocortin 4 receptor pathway. Excess visceral, perirenal and renal sinus fat compress the kidneys which, along with increased RSNA, contribute to renin-angiotensin-aldosterone system activation, although obesity may also activate mineralocorticoid receptors independent of aldosterone. Prolonged obesity, HT, metabolic abnormalities, and inflammation cause progressive renal injury, making HT more resistant to therapy and often requiring multiple antihypertensive drugs and concurrent treatment of dyslipidaemia, insulin resistance, diabetes, and inflammation. More effective anti-obesity drugs are needed to prevent the cascade of cardiorenal, metabolic, and immune disorders that threaten to overwhelm health care systems as obesity prevalence continues to increase.

High salt intake during puberty leads to cardiac remodelling and baroreflex impairment in lean and obese male Wistar rats

Modern lifestyle increases the prevalence of obesity and its co-morbidities in the young population. High-salt (HS) diets are associated with hypertension and cardiac remodelling. The present study evaluated the potential effects of cardiometabolic programming induced by HS intake during puberty in lean and obese rats. Additionally, we investigated whether HS could exacerbate the impairment of cardiovascular parameters in adult life due to postnatal early overnutrition (PO). At postnatal day 3 (PN3), twenty-four litters of Wistar rats were divided into two groups: normal litter (NL, nine pups/dam) and small litter (SL, three pups/dam) throughout the lactation period; weaning was at PN21. At PN30, the pups were subdivided into two more groups: NL plus HS (NLHS) and SL plus HS (SLHS). HS intake was from PN30 until PN60. Cardiovascular parameters were evaluated at PN120. SL rats became overweight at adulthood due to persistent hyperphagia; however, HS exposure during puberty reduced the weight gain and food intake of NLHS and SLHS. Both HS and obesity raised the blood pressure, impaired baro- and chemoreflex sensitivity and induced cardiac remodelling but no worsening was observed in the association of these factors, except a little reduction in the angiotensin type-2 receptor in the hearts from SLHS animals. Our results suggest that the response of newborn offspring to PO and juveniles to a HS diet leads to significant changes in cardiovascular parameters in adult rats. This damage may be accompanied by impairment of both angiotensin signalling and antioxidant defence in the heart.