Versican accumulation drives Nos2 induction and aortic disease in Marfan syndrome via Akt activation.

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening condition associated with Marfan syndrome (MFS), a disease caused by fibrillin-1 gene mutations. While various conditions causing TAAD exhibit aortic accumulation of the proteoglycans versican (Vcan) and aggrecan (Acan), it is unclear whether these ECM proteins are involved in aortic disease. Here, we find that Vcan, but not Acan, accumulated in Fbn1C1041G/+ aortas, a mouse model of MFS. Vcan haploinsufficiency protected MFS mice against aortic dilation, and its silencing reverted aortic disease by reducing Nos2 protein expression. Our results suggest that Acan is not an essential contributor to MFS aortopathy. We further demonstrate that Vcan triggers Akt activation and that pharmacological Akt pathway inhibition rapidly regresses aortic dilation and Nos2 expression in MFS mice. Analysis of aortic tissue from MFS human patients revealed accumulation of VCAN and elevated pAKT-S473 staining. Together, these findings reveal that Vcan plays a causative role in MFS aortic disease in vivo by inducing Nos2 via Akt activation and identify Akt signaling pathway components as candidate therapeutic targets.

Protective effect of microbiota-derived short chain fatty acids on vascular dysfunction in mice with systemic lupus erythematosus induced by toll like receptor 7 activation.

Our objective was to investigate whether short-chain fatty acids (SCFAs), specifically acetate and butyrate, could prevent vascular dysfunction and elevated blood pressure (BP) in mice with systemic lupus erythematosus (SLE) induced by TLR7 activation using imiquimod (IMQ). Treatment with both SCFAs and dietary fibers rich in resistant starch (RS) or inulin-type fructans (ITF) effectively prevented the development of hypertension and cardiac hypertrophy. Additionally, these treatments improved aortic relaxation induced by acetylcholine and mitigated vascular oxidative stress. Acetate and butyrate treatments also contributed to the maintenance of colonic integrity, reduced endotoxemia, and decreased the proportion of helper T (Th)17 cells in mesenteric lymph nodes (MLNs), blood, and aorta in TLR7-induced SLE mice. The observed changes in MLNs were correlated with increased levels of GPR43 mRNA in mice treated with acetate and increased GPR41 levels along with decreased histone deacetylase (HDAC)- 3 levels in mice treated with butyrate. Notably, the effects attributed to acetate, but not butyrate, were nullified when co-administered with the GPR43 antagonist GLPG-0974. T cell priming and differentiation into Th17 cells in MLNs, as well as increased Th17 cell infiltration, were linked to aortic endothelial dysfunction and hypertension subsequent to the transfer of faecal microbiota from IMQ-treated mice to germ-free (GF) mice. These effects were counteracted in GF mice through treatment with either acetate or butyrate. To conclude, these findings underscore the potential of SCFA consumption in averting hypertension by restoring balance to the interplay between the gut, immune system, and vascular wall in SLE induced by TLR7 activation.

Targeting the gut microbiota with dietary fibers: a novel approach to prevent the development cardiovascular complications linked to systemic lupus erythematosus in a preclinical study.

This study is to investigate whether dietary fiber intake prevents vascular and renal damage in a genetic mouse model of systemic lupus erythematosus (SLE), and the contribution of gut microbiota in the protective effects. Female NZBWF1 (SLE) mice were treated with resistant-starch (RS) or inulin-type fructans (ITF). In addition, inoculation of fecal microbiota from these experimental groups to recipient normotensive female C57Bl/6J germ-free (GF) mice was performed. Both fiber treatments, especially RS, prevented the development of hypertension, renal injury, improved the aortic relaxation induced by acetylcholine, and the vascular oxidative stress. RS and ITF treatments increased the proportion of acetate- and butyrate-producing bacteria, respectively, improved colonic inflammation and integrity, endotoxemia, and decreased helper T (Th)17 proportion in mesenteric lymph nodes (MLNs), blood, and aorta in SLE mice. However, disease activity (splenomegaly and anti-ds-DNA) was unaffected by both fibers. T cell priming and Th17 differentiation in MLNs and increased Th17 infiltration was linked to aortic endothelial dysfunction and hypertension after inoculation of fecal microbiota from SLE mice to GF mice, without changes in proteinuria and autoimmunity. All these effects were lower in GF mice after fecal inoculation from fiber-treated SLE mice. In conclusion, these findings support that fiber consumption prevented the development of hypertension by rebalancing of dysfunctional gut-immune system-vascular wall axis in SLE.

Mineralocorticoid receptor blockade improved gut microbiota dysbiosis by reducing gut sympathetic tone in spontaneously hypertensive rats.

Microbiota has a crucial role in the host blood pressure (BP) regulation. The present study analyzes whether the mineralocorticoid receptor antagonist spironolactone ameliorates the dysbiosic state in a genetic model of neurogenic hypertension. Twenty-week-old male Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were randomly allocated into three groups: untreated WKY, untreated SHR, and SHR treated with spironolactone for 5 weeks. Spironolactone restored the Firmicutes/Bacteroidetes proportion, and acetate-producing bacteria populations to WKY levels. Spironolactone reduced the percentage of intestinal aerobic bacteria. The amelioration of gut dysbiosis was linked to a reduction in the gut pathology, an enhanced colonic integrity, a reduced gut permeability and an attenuated sympathetic drive in the gut. Spironolactone was unable to reduce neuroinflammation and oxidative stress in the paraventricular nuclei in the hypothalamus. Spironolactone reduced the higher Th17 cells proportion in mesenteric lymph nodes and Th17 infiltration in aorta, improved aortic endothelial function and reduced systolic BP. This study demonstrates for the first time that spironolactone reduces gut dysbiosis in SHR. This effect could be related to its capability to improve gut integrity and pathology due to reduced sympathetic drive in the gut.

The melatonergic agonist agomelatine ameliorates high fat diet-induced obesity in mice through the modulation of the gut microbiome.

BACKGROUND AND PURPOSE: Melatonin has shown beneficial effects on obesity, both in humans and experimental models, via regulating the altered circadian rhythm and thus ameliorating the gut dysbiosis associated with this metabolic condition. However, its clinical use is limited, mostly due to its short half-life. Agomelatine is an agonist of the melatonin receptors that could be used to manage obesity and offer a better profile than melatonin. EXPERIMENTAL APPROACH: Male C57BL/6 mice were fed a high fat diet and orally treated for five weeks with agomelatine, or melatonin or metformin, used as control drugs. Metabolic profile, inflammatory status, vascular dysfunction and intestinal microbiota composition were assessed. KEY RESULTS: Agomelatine lessened body weight gain, enhanced glucose and lipid metabolisms, and improved insulin resistance. It also reduced the obesity-associated inflammatory status and endothelial dysfunction, probably linked to its effect on gut dysbiosis, consisting of the restoration of bacterial populations with key functions, such as short chain fatty acid production. CONCLUSIONS AND IMPLICATIONS: Agomelatine can be considered as a novel therapeutic tool for the management of human obesity and its associated comorbidities.

The NO signalling pathway in aortic aneurysm and dissection.

Recent studies have shown that NO is a central mediator in diseases associated with thoracic aortic aneurysm, such as Marfan syndrome. The progressive dilation of the aorta in thoracic aortic aneurysm ultimately leads to aortic dissection. Unfortunately, current medical treatments have neither halt aortic enlargement nor prevented rupture, leaving surgical repair as the only effective treatment. There is therefore a pressing need for effective therapies to delay or even avoid the need for surgical repair in thoracic aortic aneurysm patients. Here, we summarize the mechanisms through which NO signalling dysregulation causes thoracic aortic aneurysm, particularly in Marfan syndrome. We discuss recent advances based on the identification of new Marfan syndrome mediators related to pathway overactivation that represent potential disease biomarkers. Likewise, we propose iNOS, sGC and PRKG1, whose pharmacological inhibition reverses aortopathy in Marfan syndrome mice, as targets for therapeutic intervention in thoracic aortic aneurysm and are candidates for clinical trials.

Gut Microbiota Has a Crucial Role in the Development of Hypertension and Vascular Dysfunction in Toll-like Receptor 7-Driven Lupus Autoimmunity.

Our group has investigated the involvement of gut microbiota in hypertension in a murine model of systemic lupus erythematosus induced by Toll-like receptor (TLR)-7 activation. Female BALB/c mice were randomly assigned to four experimental groups: an untreated control (CTR), a group treated with the TLR7 agonist imiquimod (IMQ), IMQ-treated with vancomycin, and IMQ-treated with a cocktail of broad-spectrum antibiotics. We carried out faecal microbiota transplant (FMT) from donor CTR or IMQ mice to recipient IMQ or CTR animals, respectively. Vancomycin inhibited the increase in blood pressure; improved kidney injury, endothelial function, and oxidative stress; and reduced T helper (Th)17 infiltration in aortas from IMQ-treated mice. The rise in blood pressure and vascular complications present in IMQ mice were also observed in the CTR mice recipients of IMQ microbiota. Reduced relative populations of Sutterella and Anaerovibrio were associated with high blood pressure in our animals, which were increased after stool transplantation of healthy microbiota to IMQ mice. The reduced endothelium-dependent vasodilator responses to acetylcholine induced by IMQ microbiota were normalized after interleukin-17 neutralization. In conclusion, gut microbiota plays a role in the TLR7-driven increase in Th17 cell, endothelial dysfunction, vascular inflammation, and hypertension. The vascular changes induced by IMQ microbiota were initiated by Th17 infiltrating the vasculature.

Changes in Gut Microbiota Induced by Doxycycline Influence in Vascular Function and Development of Hypertension in DOCA-Salt Rats.

Previous experiments in animals and humans show that shifts in microbiota and its metabolites are linked to hypertension. The present study investigates whether doxycycline (DOX, a broad-spectrum tetracycline antibiotic) improves dysbiosis, prevent cardiovascular pathology and attenuate hypertension in deoxycorticosterone acetate (DOCA)-salt rats, a renin-independent model of hypertension. Male Wistar rats were randomly assigned to three groups: control, DOCA-salt hypertensive rats, DOCA-salt treated with DOX for 4 weeks. DOX decreased systolic blood pressure, improving endothelial dysfunction and reducing aortic oxidative stress and inflammation. DOX decreased lactate-producing bacterial population and plasma lactate levels, improved gut barrier integrity, normalized endotoxemia, plasma noradrenaline levels and restored the Treg content in aorta. These data demonstrate that DOX through direct effects on gut microbiota and its non-microbial effects (anti-inflammatory and immunomodulatory) reduces endothelial dysfunction and the increase in blood pressure in this low-renin form of hypertension.

Allium-Derived Compound Propyl Propane Thiosulfonate (PTSO) Attenuates Metabolic Alterations in Mice Fed a High-Fat Diet through Its Anti-Inflammatory and Prebiotic Properties.

BACKGROUND: Propyl propane thiosulfonate (PTSO) is an organosulfur compound from Allium spp. that has shown interesting antimicrobial properties and immunomodulatory effects in different experimental models. In this sense, our aim was to evaluate its effect on an experimental model of obesity, focusing on inflammatory and metabolic markers and the gut microbiota. METHODS AND RESULTS: Mice were fed a high-fat diet and orally treated with different doses of PTSO (0.1, 0.5 and 1 mg/kg/day) for 5 weeks. PTSO lessened the weight gain and improved the plasma markers associated with glucose and lipid metabolisms. PTSO also attenuated obesity-associated systemic inflammation, reducing the immune cell infiltration and, thus, the expression of pro-inflammatory cytokines in adipose and hepatic tissues (Il-1ẞ, Il-6, Tnf-α, Mcp-1, Jnk-1, Jnk-2, Leptin, Leptin R, Adiponectin, Ampk, Ppar-α, Ppar-γ, Glut-4 and Tlr-4) and improving the expression of different key elements for gut barrier integrity (Muc-2, Muc-3, Occludin, Zo-1 and Tff-3). Additionally, these effects were connected to a regulation of the gut microbiome, which was altered by the high-fat diet. CONCLUSION: Allium-derived PTSO can be considered a potential new tool for the treatment of metabolic syndrome.

Probiotics Prevent Hypertension in a Murine Model of Systemic Lupus Erythematosus Induced by Toll-Like Receptor 7 Activation.

Our group tested the effects of Lactobacillus fermentum CECT5716 (LC40) and/or Bifidobacterium breve CECT7263 (BFM) in the prevention of gut dysbiosis, hypertension and endothelial dysfunction in a pharmacologically-induced model of systemic lupus erythematosus (SLE). We treated eight-week-old BALB/cByJRj mice without (Ctrl) or with the agonist of TLR-7 Imiquimod (IMQ) for 8 weeks. Concomitantly, LC40 (109 CFU/mL) and BFM (109 CFU/mL) were administered through oral gavage once a day. IMQ induced intestinal dysbiosis consisting of a decrease in the α-diversity measured with Chao-richness and numbers of species. LC40 and BFM did not restore these parameters. The three-dimensional principal component analysis of bacterial taxa in stool samples presented perfect clustering between Ctrl and IMQ groups. Clusters corresponding to LC40 and BFM were more akin to IMQ. BFM and LC40 were detected colonizing the gut microbiota of mice treated respectively. LC40 and BFM decreased plasma double-stranded DNA autoantibodies, and B cells in spleen, which were increased in the IMQ group. Also, LC40 and BFM treatments activated TLR9, reduced T cells activation, and Th17 polarization in mesenteric lymph nodes. Aortae from IMQ mice displayed a decreased endothelium-dependent vasodilator response to acetylcholine linked to pro-inflammatory and pro-oxidative status, which were normalized by both BFM and LC40. In conclusion, we demonstrate for the first time that the chronic treatment with LC40 or BFM prevented hypertension and endothelial dysfunction in a mouse lupus model induced by TLR-7 activation.

Gut microbiota contributes to the development of hypertension in a genetic mouse model of systemic lupus erythematosus.

BACKGROUND AND PURPOSE: Hypertension is an important cardiovascular risk factor that is prevalent in the systemic lupus erythematosus patient population. Here, we have investigated whether intestinal microbiota is involved in hypertension in a genetic mouse model of systemic lupus erythematosus. EXPERIMENTAL APPROACH: Twenty-six-week-old female NZW/LacJ (control) and NZBWF1 (F1 hybrid of New Zealand Black and New Zealand White strains; systemic lupus erythematosus) mice were treated for 6 weeks with a broad-spectrum antibiotic mixture or with vancomycin. Faecal microbiota transplantation was performed from donor systemic lupus erythematosus group to recipient to germ-depleted or germ-free mice. KEY RESULTS: Antibiotic treatment inhibited the development of hypertension and renal injury, improved endothelial dysfunction and vascular oxidative stress, and decreased aortic Th17 infiltration in NZBWF1 mice. High BP and vascular complications found in systemic lupus erythematosus mice, but not autoimmunity, kidney inflammation and endotoxemia, were reproduced by the transfer of gut microbiota from systemic lupus erythematosus donors to germ-free or germ-depleted mice. Increased proportions of Bacteroides were linked with high BP in these mice. The reduced endothelium-dependent vasodilator responses to acetylcholine and the high BP induced by microbiota from hypertensive systemic lupus erythematosus mice were inhibited after IL-17 neutralization. CONCLUSION AND IMPLICATIONS: Changes in T-cell populations, endothelial function, vascular inflammation and hypertension driven by a genetic systemic lupus erythematosus background can be modified by antibiotic-induced changes in gut microbiota. The vascular changes induced by hypertensive systemic lupus erythematosus microbiota were mediated by Th17 infiltration in the vasculature.

Aortic disease in Marfan syndrome is caused by overactivation of sGC-PRKG signaling by NO.

Thoracic aortic aneurysm, as occurs in Marfan syndrome, is generally asymptomatic until dissection or rupture, requiring surgical intervention as the only available treatment. Here, we show that nitric oxide (NO) signaling dysregulates actin cytoskeleton dynamics in Marfan Syndrome smooth muscle cells and that NO-donors induce Marfan-like aortopathy in wild-type mice, indicating that a marked increase in NO suffices to induce aortopathy. Levels of nitrated proteins are higher in plasma from Marfan patients and mice and in aortic tissue from Marfan mice than in control samples, indicating elevated circulating and tissue NO. Soluble guanylate cyclase and cGMP-dependent protein kinase are both activated in Marfan patients and mice and in wild-type mice treated with NO-donors, as shown by increased plasma cGMP and pVASP-S239 staining in aortic tissue. Marfan aortopathy in mice is reverted by pharmacological inhibition of soluble guanylate cyclase and cGMP-dependent protein kinase and lentiviral-mediated Prkg1 silencing. These findings identify potential biomarkers for monitoring Marfan Syndrome in patients and urge evaluation of cGMP-dependent protein kinase and soluble guanylate cyclase as therapeutic targets.

Mycophenolate mediated remodeling of gut microbiota and improvement of gut-brain axis in spontaneously hypertensive rats.

Microbiota has a role in the host blood pressure (BP) regulation. The immunosuppressive drug mofetil mycophenolate (MMF) ameliorates hypertension. The present study analyzes whether MMF improves dysbiosis in a genetic model of hypertension. Twenty weeks old male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were randomly divided into three groups: untreated WKY, untreated SHR, and SHR treated with MMF for 5 weeks. MMF treatment restored gut bacteria from the phyla Firmicutes and Bacteroidetes, and acetate- and lactate-producing bacteria to levels similar to those found in WKY, increasing butyrate-producing bacteria. MMF increased the percentage of anaerobic bacteria in the gut. The improvement of gut dysbiosis was associated with an enhanced colonic integrity and a decreased sympathetic drive in the gut. MMF inhibited neuroinflammation in the paraventricular nuclei in the hypothalamus. MMF increased the lower regulatory T cells proportion in mesenteric lymph nodes and Th17 and Th1 infiltration in aorta, improved aortic endothelial function and reduced systolic BP. This study demonstrates for the first time that MMF reduces gut dysbiosis in SHR. This effect could be related to its capability to improve gut integrity due to reduced sympathetic drive in the gut associated to the reduced brain neuroinflammation.

Mycophenolate Improves Brain-Gut Axis Inducing Remodeling of Gut Microbiota in DOCA-Salt Hypertensive Rats.

Microbiota is involved in the host blood pressure (BP) regulation. The immunosuppressive drug mofetil mycophenolate (MMF) ameliorates hypertension. The present study analyzed whether MMF improves dysbiosis in mineralocorticoid-induced hypertension. Male Wistar rats were assigned to three groups: untreated (CTR), deoxycorticosterone acetate (DOCA)-salt, and DOCA treated with MMF for 4 weeks. MMF treatment reduced systolic BP, improved endothelial dysfunction, and reduced oxidative stress and inflammation in aorta. A clear separation in the gut bacterial community between CTR and DOCA groups was found, whereas the cluster belonging to DOCA-MMF group was found to be intermixed. No changes were found at the phylum level among all experimental groups. MMF restored the elevation in lactate-producing bacteria found in DOCA-salt joined to an increase in the acetate-producing bacteria. MMF restored the percentage of anaerobic bacteria in the DOCA-salt group to values similar to control rats. The improvement of gut dysbiosis was associated with an enhanced colonic integrity and a decreased sympathetic drive in the gut. MMF inhibited neuroinflammation in the paraventricular nuclei in the hypothalamus. This study demonstrates for the first time that MMF reduces gut dysbiosis in DOCA-salt hypertension models. This effect seems to be related to its capacity to improve gut integrity due to reduced sympathetic drive in the gut associated with reduced brain neuroinflammation.

Probiotic Bifidobacterium breve prevents DOCA-salt hypertension.

Many probiotics that affect gut microbial ecology have been shown to produce beneficial effects on renin-angiotensin-dependent rodent models and human hypertension. We hypothesized that Bifidobacterium breve CECT7263 (BFM) would attenuate hypertension in deoxycorticosterone acetate (DOCA)-salt rats, a renin-independent model of hypertension. Rats were randomly divided into five groups: control, DOCA-salt, treated DOCA-salt-BFM, treated DOCA-salt-butyrate, and treated DOCA-salt-acetate, for 5 weeks. BFM prevented the increase in systolic blood pressure, cardiac weight, and renal damage induced by DOCA-salt. BFM increased acetate-producing bacterial population and gut acetate levels, improved colonic integrity, normalized endotoxemia, plasma trimethylamine (TMA) levels, and restored the Th17 and Treg content in mesenteric lymph nodes and aorta. Furthermore, BFM improved nitric oxide-dependent vasorelaxation induced by acetylcholine in aortic rings and reduced NADPH oxidase activity in DOCA-salt animals. These protective effects were mimicked by acetate, but not by butyrate supplementation. These data demonstrate that BFM induces changes in gut microbiota linked with attenuation of endothelial dysfunction and increase in blood pressure in this low-renin form of hypertension. These beneficial effects seem to be mediated by increased acetate and reduced TMA production by gut microbiota, thus, improving gut integrity and restoring Th17/Tregs polarization and endotoxemia.

Microbiota and Hypertension: Role of the Sympathetic Nervous System and the Immune System.

There are numerous studies indicating a direct association between hypertension and gut microbiota in both animal models and humans. In this review, we focused on the imbalance in the gut microbiota composition relative to healthy state or homeostasis, termed dysbiosis, associated with hypertension and discuss the current knowledge regarding how microbiota regulates blood pressure (BP), involving the sympathetic nervous system and the immune system. The profile of ecological parameters and bacterial genera composition of gut dysbiosis in hypertension varies according to the experimental model of hypertension. Recent evidence supports that gut microbiota can protect or promote the development of hypertension by interacting with gut secondary lymph organs and altering T helper 17/regulatory T cells polarization, with subsequent changes in T cells infiltration in vascular tissues. Here, we also describe the bidirectional communication between the microbiome and the host via the sympathetic nervous system and its role in BP regulation. Dysbiosis in hypertension is mainly associated with reduced proportions of short-chain fatty acid-producing bacteria, mainly acetate- and butyrate-producing bacteria, and an increased enrichment of the genes for lipopolysaccharide biosynthesis and export, lending to moderate endotoxemia. The role of these metabolic and structural products in both immune and sympathetic system regulation and vascular inflammation was also analyzed. Overall, gut microbiota is now recognized as a well-established target to dietary interventions with prebiotics or probiotics to reduce BP.

Protective Effects of Short-Chain Fatty Acids on Endothelial Dysfunction Induced by Angiotensin II.

Short-chain fatty acids (SCFAs) are among the main classes of bacterial metabolic products and are mainly synthesized in the colon through bacterial fermentation. Short-chain fatty acids, such as acetate, butyrate, and propionate, reduce endothelial activation induced by proinflammatory mediators, at least in part, by activation of G protein-coupled receptors (GPRs): GPR41 and GPR43. The objective of the study was to analyze the possible protective effects of SCFAs on endothelial dysfunction induced by angiotensin II (AngII). Rat aortic endothelial cells (RAECs) and rat aortas were incubated with AngII (1 µM) for 6 h in the presence or absence of SCFAs (5-10 mM). In RAECs, we found that AngII reduces the production of nitric oxide (NO) stimulated by calcium ionophore A23187; increases the production of reactive oxygen species (ROS), both from the nicotinamide adenine dinucleotide phosphate oxidase system and the mitochondria; diminishes vasodilator-stimulated phosphoprotein (VASP) phosphorylation at Ser239; reduces GPR41 and GPR43 mRNA level; and reduces the endothelium-dependent relaxant response to acetylcholine in aorta. Coincubation with butyrate and acetate, but not with propionate, increases both NO production and pSer239-VASP, reduces the concentration of intracellular ROS, and improves relaxation to acetylcholine. The beneficial effects of butyrate were inhibited by the GPR41 receptor antagonist, ß-hydroxybutyrate, and by the GPR43 receptor antagonist, GLPG0794. Butyrate inhibited the down-regulation of GPR41 and GPR43 induced by AngII, being without effect acetate and propionate. Neither ß-hydroxybutyrate nor GLPG0794 affects the protective effect of acetate in endothelial dysfunction. In conclusion, acetate and butyrate improve endothelial dysfunction induced by AngII by increasing the bioavailability of NO. The effect of butyrate seems to be related to GPR41/43 activation, whereas acetate effects were independent of GPR41/43.

Lactobacillus fermentum CECT5716 prevents renal damage in the NZBWF1 mouse model of systemic lupus erythematosus.

The aim of this work was to evaluate whether the immune-modulatory bacterium Lactobacillus fermentum CECT5716 (LC40) protects the kidneys in a female mouse model of lupus with hypertension. Twenty-week-old female NZBWF1 (lupus) and NZW/LacJ (control) mice were treated with vehicle or LC40 (5 × 108 colony-forming units day-1) for 13 weeks. LC40 treatment reduced the increased plasma anti-dsDNA, endotoxemia, and high blood pressure in NZBWF1 mice. In parallel, LC40 also prevented alterations in kidney function parameters, measured by reduced creatinine and urea in urine excretion, and kidney injury, evaluated by albumin excretion in lupus mice. The main histological features found in the kidneys of lupus mice, such as glomerular, tubulointerstitial or vascular lesions present in the renal parenchyma, accompanied by immune-complex deposition and inflammatory infiltrates were also reduced by LC40. In addition, LC40 inhibited the increased levels of pro-inflammatory cytokines, NADPH oxidase activity and infiltration of Th17 and Th1 cells in the kidneys of NZBWF1 mice. Interestingly, no significant changes were observed in control mice treated with LC40. In conclusion, these results indicate that the consumption of LC40 can prevent the impairment of kidney function and damage, in part due to its capacity to reduce anti-dsDNA production and circulating levels of lipopolysaccharides, with the subsequent reduction of immune complex deposition, inflammation and oxidative stress. These results open new possibilities for the prevention of renal complications associated with hypertensive systemic lupus erythematosus by the chronic administration of the probiotic LC40.

Toll-like receptor 7-driven lupus autoimmunity induces hypertension and vascular alterations in mice.

OBJECTIVE: To investigate whether toll-like receptor 7 (TLR7) activation induces an increase in blood pressure and vascular damage in wild-type mice treated with the TLR7 agonist imiquimod (IMQ). METHODS: Female BALB/c mice (7-9 week old) were randomly assigned to two experimental groups: an untreated control group and a group treated topically with IMQ (IMQ-treated) for 4 or 8 weeks. A group of IMQ-treated mice that take a combination of the antioxidants tempol and apocynin, and another treated IL-17-neutralizing antibody were also performed. RESULTS: TLR7 activation gradually increased blood pressure, associated with elevated plasma levels of anti-dsDNA autoantibodies, splenomegaly, hepatomegaly, and severe expansion of splenic immune cells with an imbalance between proinflammatory T cells and regulatory T cells. TLR7 activation induced a marked vascular remodeling in mesenteric arteries characterized by an increased media--lumen ratio (≈40%), and an impaired endothelium-dependent vasorelaxation in aortas from wild-type mice after 8 weeks of treatment. In addition, an increased ROS production, as a result of the upregulation of NADPH oxidase subunits, and an enhanced vascular inflammation were found in aortas from IMQ-treated mice. These functional and structural vascular alterations induced by IMQ were improved by antioxidant treatment. Anti-IL-17 treatment reduced blood pressure and improved endothelial dysfunction in IMQ-treated mice. CONCLUSION: Our results demonstrate that TLR7 activation induces the development of hypertension and vascular damage in BALB/c mice, and further underscore the increased vascular inflammation and oxidative stress, mediated in part by IL-17, as key factors contributing to cardiovascular complications in this TLR7-driven lupus autoimmunity model.

Probiotics Prevent Dysbiosis and the Rise in Blood Pressure in Genetic Hypertension: Role of Short-Chain Fatty Acids.

SCOPE: The objective of this study is to determine the cardiovascular effects of the probiotics Bifidobacterium breve CECT7263 (BFM) and Lactobacillus fermentum CECT5716 (LC40), and the short chain fatty acids butyrate, and acetate in spontaneously hypertensive rats (SHR). METHODS AND RESULTS: Ten five-week old Wistar Kyoto rats (WKY) and fifty aged-matched SHR are randomly distributed into six groups: control WKY, control SHR, treated SHR-LC40, treated SHR-BMF, treated SHR-butyrate, and treated SHR-acetate. Chronic treatments with LC40 or BFM increase butyrate-producing bacteria and prevent the blood pressure increase in SHR. Oral treatment with butyrate or acetate also prevents the increase in both blood pressure and Firmicutes/Bacteroidetes (F/B) ratio. All treatments restore the Th17/Treg balance in mesenteric lymph nodes, normalized endotoxemia, and prevent the impairment of endothelium-dependent relaxation to acetylcholine, as a result of reduced NADPH oxidase-driven reactive oxygen species production. These protective effects might be mediated by both the reduction in vascular lipopolysaccharide (LPS)/toll-like receptor 4 (TLR4) pathway and the increase in Treg infiltration in the vasculature. CONCLUSION: The probiotics LC40 and BFM prevent dysbiosis and the development of endothelial dysfunction and high blood pressure in genetic hypertension. These effects seem to be related to endotoxemia reduction and to increase Treg accumulation in the vasculature.