Hypertension is highly prevalent in chronic kidney disease (CKD). Hydrogen sulfide (H2S) is an endogenously produced gasotransmitter with vasodilator properties. We, hence, investigated whether oral administration of sodium thiosulfate (STS), a clinically applicable H2S-based therapy, can exert a protective effect against hypertension in an adenine-induced CKD rat model. Eight-week-old male Sprague-Dawley rats were fed with 0.5% adenine chow for 3 weeks to induce CKD. After 1 week, the rats were divided into two groups: one without and one with STS (2 g/kg body weight/day) in drinking water for 2 weeks. Treatment with STS lowered systolic and diastolic blood pressure by 7 and 9 mm Hg, respectively. Renal H2S-generating enzyme expression was inhibited by CKD, while STS therapy increased plasma levels of H2S and thiosulfate. Additionally, restoration of nitric oxide bioavailability and rebalance of the renin-angiotensin system may contribute to the protective effects of STS. Our data suggest that the oral administration of STS improves hypertension in an adenine-induced CKD model, which brings us closer to the clinical translation of H2S-targeting therapy in CKD-induced hypertension.

Emerging evidence supports that early-life disturbance of gut microbiota has an impact on adult disease in later life. Offspring hypertension can be programmed by maternal chronic kidney disease (CKD). Conversely, perinatal use of gut microbiota-targeted therapy has been implemented to reverse programming processes and prevent hypertension. Short-chain fatty acids (SCFAs), the major gut microbiota-derived metabolites, can be applied as postbiotics. Propionate, one of predominant SCFAs, has been shown to have antihypertensive property. We examined whether perinatal propionate supplementation can prevent offspring hypertension induced by maternal CKD. CKD was induced by chow supplemented with 0.5% adenine for 3 weeks before pregnancy. Propionate (P) was supplemented at 200 mmol/L in drinking water during pregnancy and lactation. Male offspring were divided into four groups (n = 7-8/group): control, CKD, control+propionate (CP), and CKD+propionate (CKDP). Maternal CKD-induced offspring hypertension was reversed by perinatal propionate supplementation. The protective effects of perinatal propionate treatment were related to increased propionate-generating bacteria Clostridium spp. and plasma propionate level, increased expression of renal G protein-coupled receptor 41 (GPR41, a SCFA receptor), augmentation of α-diversity, and shifts in gut microbiota composition. In summary, our results highlight that maternal CKD-induced offspring hypertension can be prevented by the use of gut microbial metabolite SCFAs in early life, which could shed light on the prevention of the current hypertension pandemic.

Hypertension can originate in early life caused by perinatal high-fat (HF) consumption. Gut microbiota and their metabolites short chain fatty acids (SCFAs), trimethylamine (TMA), and trimethylamine N-oxide (TMAO) are involved in the development of hypertension. Despite the beneficial effects of prebiotic/probiotic on human health, little is known whether maternal use of prebiotics/probiotics could protect offspring against the development of hypertension in adulthood. We investigated whether perinatal HF diet-induced programmed hypertension in adult offspring can be prevented by therapeutic uses of prebiotic inulin or probiotic Lactobacillus casei during gestation and lactation. Pregnant Sprague-Dawley rats received regular chow or HF diet (D12331, Research Diets), with 5% w/w long chain inulin (PRE), or 2 × 108 CFU/day Lactobacillus casei via oral gavage (PRO) during pregnancy and lactation. Male offspring (n = 8/group) were assigned to four groups: control, HF, PRE, and PRO. Rats were sacrificed at 16 weeks of age. Maternal prebiotic or probiotic therapy prevents elevated blood pressure (BP) programmed by perinatal HF consumption. Both prebiotic and probiotic therapies decreased the Firmicutes to Bacteroidetes ratio and renal mRNA expression of Ace, but increased abundance of genus Lactobacillus and Akkermansia. Additionally, prebiotic treatment prevents HF-induced elevation of BP is associated with reduced fecal propionate and acetate levels, while probiotic therapy restored several Lactobacillus species. Maternal probiotic or prebiotic therapy caused a reduction in plasma TMAO level and TMAO-to-TMA ratio. The beneficial effects of prebiotic or probiotic therapy on elevated BP programmed by perinatal HF diet are relevant to alterations of microbial populations, modulation of microbial-derived metabolites, and mediation of the renin-angiotensin system. Our results cast a new light on the use of maternal prebiotic/probiotic therapy to prevent hypertension programmed by perinatal HF consumption. The possibility of applying gut microbiota-targeted therapies as a reprogramming strategy for hypertension warrants further clinical translation.

Chronic kidney disease (CKD) affects 10% of the global population, including pregnant women. Adverse maternal conditions determine the developmental programming of many diseases later in life. We previously demonstrated that adult rat offspring born to dams with CKD developed hypertension and renal hypertrophy. Trimethylamine-N-oxide (TMAO), a uremic toxin derived from the gut microbiota, has been linked to hypertension. This study assesses the effects of TMAO inhibition by iodomethylcholine (IMC) treatment on offspring hypertension programmed by maternal CKD. Female rats were fed either a control or a 0.5% adenine diet before conception, with or without IMC treatment during pregnancy and lactation. Maternal IMC treatment averted maternal CKD-primed offspring hypertension and renal hypertrophy in 12-week-old offspring. Offspring hypertension is associated with increases in the plasma TMAO concentration and oxidative stress and shifts in gut microbiota. The beneficial effects of IMC are related to a reduction in TMAO; increases in genera Acetatifactor, Bifidobacterium, and Eubacterium; and decreases in genera Phocacecola and Bacteroides. Our findings afford insights into the targeting of the gut microbiota to deplete TMAO production, with therapeutic potential for the prevention of offspring hypertension programmed by maternal CKD, although these results still need further clinical translation.

Exposure to environmental chemicals during pregnancy and lactation is a contributing factor in gut microbiota dysbiosis and linked to programming of hypertension. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic dioxin, induces toxic effects by mediating aryl hydrocarbon receptor (AHR). Resveratrol, a potent antioxidant with prebiotic properties, can possess high affinity for AHR and protect against TCDD-activated AHR attack. We examined whether perinatal resveratrol therapy prevents offspring hypertension programmed by maternal TCDD exposure and whether its beneficial effects are related to reshaping gut microbiota and antagonizing AHR-mediated T helper 17 (TH17) cells responses using a maternal TCDD exposure rat model. Pregnant Sprague-Dawley rats were given a weekly oral dose of TCDD 200 ng/kg for four doses (T), 50 mg/L of resveratrol in drinking water (CR), TCDD + resveratrol (TR), or vehicle (C) in pregnancy and lactation periods. Male offspring (n = 7-8/group) were sacrificed at the age of 12 weeks. Perinatal TCDD exposure caused elevated blood pressure in adult male offspring, which resveratrol supplementation prevented. Additionally, the TCDD-induced programming of hypertension is coincided with the activation of AHR signaling, TH17-induced renal inflammation, and alterations of gut microbiota compositions. Conversely, TCDD-mediated induction of AHR signaling and TH17 responses were restored by maternal resveratrol supplementation. Furthermore, maternal resveratrol supplementation prevented the programming of hypertension and was related to increased genera Bacteroides, ASF356, and Lachnoclostridium. Taken together, these results suggest that the interplay between gut microbiota, AHR-mediated TH17 responses, and renal inflammation in the gut and kidneys may play an important role in the action of resveratrol against TCDD-induced programming of hypertension.

Maternal nutrition, gut microbiome composition, and metabolites derived from gut microbiota are closely related to the development of hypertension in offspring. A plethora of metabolites generated from diverse tryptophan metabolic pathways show both beneficial and harmful effects. Butyrate, one of the short-chain fatty acids (SCFAs), has shown vasodilation effects. We examined whether sodium butyrate administration in pregnancy and lactation can prevent hypertension induced by a maternal tryptophan-free diet in adult progeny and explored the protective mechanisms. Pregnant Sprague-Dawley rats received normal chow (CN), tryptophan-free diet (TF), sodium butyrate 400 mg/kg/d in drinking water (CNSB), or TF diet plus sodium butyrate (TFSB) in pregnancy and lactation. Male offspring were sacrificed at the age of 16 weeks (n=8 per group). Compared with normal chow, offspring exposed to the maternal tryptophan-free diet had markedly increased blood pressure, associated with activation of the renin-angiotensin system (RAS). Treatment with sodium butyrate rescued maternal TF-exposed offspring from hypertension. The protective effect of sodium butyrate is related to alterations to microbiome composition, increased renal expression of SCFA receptor G protein-coupled receptor 41 (GPR41) and GPR109A, and restoration of RAS balance. In summary, these results suggest that sodium butyrate protects against maternal TF-induced offspring hypertension, likely by modulating gut microbiota, its derived metabolites, and the RAS.

Despite recent advances in pharma-nutritional management, chronic kidney disease (CKD) remains an increasingly prevalent disorder. Resveratrol, a pleiotropic phytochemical, has been found to reduce the risk for several chronic diseases. Considering the low bioavailability of resveratrol, we recently synthesized resveratrol butyrate ester (RBE) via the esterification of resveratrol with butyrate. The aim of this study was to examine the effectiveness of RBE as regards protection from hypertension and kidney damage and explore the underlying mechanisms using a young rat adenine-induced CKD model. Three-week-old male Sprague Dawley rats received regular or 0.5% adenine chow for three weeks. Three groups of adenine-fed CKD rats (N = 8/group) received resveratrol (50 mg/L), or a low dose (25 mg/L) or high dose (50 mg/L) of RBE in drinking water from week 6 to week 12. As compared with the controls, adenine-treated rats had markedly increased creatinine levels and blood pressure, which was associated with renal hypertrophy and decreased creatinine clearance. Treatment with resveratrol or a low or high dose of RBE, similarly protected adenine-fed rats against hypertension and kidney damage. CKD-induced hypertension is associated with an altered gut microbiota profile, dysregulated renal short chain fatty acid (SCFA) receptor expression, activation of the aryl hydrocarbon receptor (AhR) signaling pathway, and reduced nitric oxide bioavailability. We found gut microbiota compositions were shaped differentially by resveratrol and RBE treatment in adenine-treated CKD rats. The beneficial effect of high-dose RBE was associated with reduced renal expression of SCFA G protein-coupled receptor 41 (GPR41) and olfactory receptor 78 (Olfr78), antagonizing the AhR signaling pathway, and increased abundance of beneficial bacteria such as genera Akkermansia, Blautia, and Enterococcus. Our study provided the first evidence documenting RBE as a novel phytochemical supplement targeting the gut-kidney axis to protect against adenine-induced kidney damage and hypertension.

Chronic kidney disease (CKD) remains a public health problem. Certain dietary supplements can assist in the prevention of CKD progression. In this regard, resveratrol is a polyphenol and has a potential therapeutic role in alleviating CKD. We previously utilized butyrate in order to improve the bioavailability of resveratrol via esterification and generated a resveratrol butyrate monoester (RBM). In this study, the hypothesis that RBM supplementation is able to protect against kidney dysfunction and hypertension was tested by using an adenine-induced CKD model. For this purpose, three-week-old male Sprague Dawley rats (n = 40) were equally categorized into: group 1-CN (sham control); group 2-CKD (adenine-fed rats); group 3-REV (CKD rats treated with 50 mg/L resveratrol); group 4-MEL (CKD rats treated with 25 mg/L RBM); and group 5-MEH (CKD rats treated with 50 mg/L RBM). At the end of a 12-week period, the rats were then euthanized. The adenine-fed rats displayed hypertension and kidney dysfunction, which were attenuated by dietary supplementation with RBM. The CKD-induced hypertension coincided with: decreased nitric oxide (NO) bioavailability; augmented renal protein expression of a (pro)renin receptor and angiotensin II type 1 receptor; and increased oxidative stress damage. Additionally, RBM and resveratrol supplementation shaped distinct gut microbiota profiles in the adenine-treated CKD rats. The positive effect of high-dose RBM was shown together with an increased abundance of the genera Duncaniella, Ligilactobacillus, and Monoglobus, as well as a decrease in Eubacterium and Schaedierella. Importantly, the mechanism of action of the RBM supplementation may be related to the restoration of NO, rebalancing of the RAS, a reduction in oxidative stress, and alterations to the gut microbiota. Moreover, RBM supplementation shows promise for the purposes of improving CKD outcomes and hypertension. As such, further translation to human studies is warranted.

Melatonin, a signaling hormone with pleiotropic biofunctions, has shown health benefits. Trimethylamine-N-oxide (TMAO) and asymmetric dimethylarginine (ADMA) are uremic toxins involved in the development of hypertension. TMAO originates from trimethylamine (TMA), a gut microbial product. ADMA is an endogenous nitric oxide (NO) synthase inhibitor. We examined whether melatonin therapy could prevent hypertension and kidney disease by mediating gut microbiota-derived metabolites and the NO pathway using an adenine-induced chronic kidney disease (CKD) young rat model. Six-week-old young Sprague Dawley rats of both sexes were fed a regular diet (C group), a diet supplemented with 0.5% adenine (CKD group), or adenine plus 0.01% melatonin in their drinking water (CKD + M group) for three weeks (N = 8/group). Adenine-fed rats developed renal dysfunction, hypertension, renal hypertrophy and increased uremic toxin levels of TMAO and ADMA. Melatonin therapy prevented hypertension in both sexes and attenuated kidney injury in males. Melatonin reversed the changes to the plasma TMAO-to-TMA ratio induced by CKD in both sexes. Besides, the protective effects of melatonin were associated with restoration of gut microbiota alterations, including increased α-diversity, and enhancement of the abundance of the phylum Proteobacteria and the genus Roseburia in male rats. Melatonin therapy also partially prevented the increases in ADMA in male CKD rats. Melatonin sex-specifically protected young rats against hypertension and kidney injury induced by CKD. The results of this study contribute toward a greater understanding of the interaction between melatonin, gut microbiota-derived metabolites, and the NO pathway that is behind CKD, which will help to prevent CKD-related disorders in children.

Hypertension can come from early life. N-acetylcysteine (NAC), a hydrogen sulfide (H2S) precursor as well as an antioxidant, has antihypertensive effect. We investigated whether maternal NAC therapy can protect spontaneously hypertensive rats (SHR) male offspring against hypertension. The pregnant rats were assigned to four groups: SHRs without treatment; Wistar Kyoto (WKY) without treatment; SHR+NAC, SHRs received 1% NAC in drinking water throughout pregnancy and lactation; and, WKY+NAC, WKY rats received 1% NAC in drinking water during pregnancy and lactation. Male offspring (n = 8/group) were killed at 12 weeks of age. Maternal NAC therapy prevented the rise in systolic blood pressure (BP) in male SHR offspring at 12 weeks of age. Renal cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulphurtransferase (3MST) protein levels and H2S-releasing activity were increased in the SHR+NAC offspring. Maternal NAC therapy increased fecal H2S and thiosulfate levels in the SHR+NAC group. Additionally, maternal NAC therapy differentially shaped gut microbiota and caused a distinct enterotype in each group. The protective effect of maternal NAC therapy against hypertension in SHR offspring is related to increased phylum Actinobacteria and genera Bifidobacterium and Allobaculum, but decreased phylum Verrucomicrobia, genera Turicibacter, and Akkermansia. Several microbes were identified as microbial markers, including genera Bifidobacterium, Allobaculum, Holdemania, and Turicibacter. Our results indicated that antioxidant therapy by NAC in pregnant SHRs can prevent the developmental programming of hypertension in male adult offspring. Our findings highlight the interrelationships among H2S-generating pathway in the kidneys and gut, gut microbiota, and hypertension. The implications of maternal NAC therapy elicited long-term protective effects on hypertension in later life that still await further clinical translation.

Resveratrol (REV) is a plant polyphenol with a plethora of beneficial properties. We previously enhanced the efficacy of REV via esterification of REV with butyrate to form resveratrol butyrate ester (RBE). Compared with REV, RBE exhibits higher bioavailability and better antioxidant effects. Hypertension can originate in early life because of maternal toxic chemical exposure. This study aims to examine the effectiveness of RBE in the protection of offspring hypertension induced by maternal di-2-ethylhexylphthalate (DEHP) exposure and to explore the underlying mechanisms. DEHP (10 mg/kg/day) was used as oral gavage to pregnant rats during gestation and lactation. The control group received the vehicle. Three groups of DEHP-exposed dams received REV (6.67 mg/kg/day), or low-dose (3.33 mg/kg/day) or high-dose (6.67 mg/kg/day) RBE in drinking water during gestation and lactation. Perinatal DEHP exposure resulted in hypertension and bodyweight gain in adult male offspring, which was prevented by high-dose RBE. REV supplementation attenuated DEHP exposure-induced increases in blood pressure but not bodyweight. High-dose RBE decreased renal oxidative damage, increased plasma butyrate concentrations, and altered short chain fatty acid receptor (SCFA) expression. Low-dose RBE treatment reduced downstream mediators of the acryl hydrocarbon receptor (AHR) signaling pathway. Moreover, DEHP exposure, REV and RBE treatment differentially shaped the offspring's gut microbiota. In particular, high-dose RBE increased the abundance of the genus Duncaniella. The beneficial effects of RBE treatment were related to reducing oxidative damage, increasing plasma butyrate concentrations, downregulating SCFA receptor expression, antagonizing AHR signaling, and altering the gut microbiota. This study provides the first evidence of RBE as a novel plant polyphenol bioproduct targeting the oxidative stress and gut microbiota to protect against maternal DEHP exposure-primed offspring hypertension.

Maternal chronic kidney disease (CKD) during pregnancy causes adverse fetal programming. Nitric oxide (NO) deficiency, gut microbiota dysbiosis, and dysregulated renin-angiotensin system (RAS) during pregnancy are linked to the development of hypertension in adult offspring. We examined whether maternal adenine-induced CKD can program hypertension and kidney disease in adult male offspring. We also aimed to identify potential mechanisms, including alterations of gut microbiota composition, increased trimethylamine-N-oxide (TMAO), reduced NO bioavailability, and dysregulation of the RAS. To construct a maternal CKD model, female Sprague-Dawley rats received regular chow (control group) or chow supplemented with 0.5% adenine (CKD group) for 3 weeks before pregnancy. Mother rats were sacrificed on gestational day 21 to analyze placentas and fetuses. Male offspring (n = 8/group) were sacrificed at 12 weeks of age. Adenine-fed rats developed renal dysfunction, glomerular and tubulointerstitial damage, hypertension, placental abnormalities, and reduced fetal weights. Additionally, maternal adenine-induced CKD caused hypertension and renal hypertrophy in adult male offspring. These adverse pregnancy and offspring outcomes are associated with alterations of gut microbiota composition, increased uremic toxin asymmetric and symmetric dimethylarginine (ADMA and SDMA), increased microbiota-derived uremic toxin TMAO, reduced microbiota-derived metabolite acetate and butyrate levels, and dysregulation of the intrarenal RAS. Our results indicated that adenine-induced maternal CKD could be an appropriate model for studying uremia-related adverse pregnancy and offspring outcomes. Targeting NO pathway, microbiota metabolite TMAO, and the RAS might be potential therapeutic strategies to improve maternal CKD-induced adverse pregnancy and offspring outcomes.

Excessive intake of fructose is associated with hypertension. Gut microbiota and their metabolites are thought to be associated with the development of hypertension. We examined whether maternal high-fructose (HF) diet-induced programmed hypertension via altering gut microbiota, regulating short-chain fatty acids (SCFAs) and their receptors, and mediating nutrient-sensing signals in adult male offspring. Next, we aimed to determine whether early gut microbiota-targeted therapies with probiotic Lactobacillus casei and prebiotic inulin can prevent maternal HF-induced programmed hypertension. Pregnant rats received 60% high-fructose (HF) diet, with 2 × 10⁸ CFU/day Lactobacillus casei via oral gavage (HF+Probiotic), or with 5% w/w long chain inulin (HF+prebiotic) during pregnancy and lactation. Male offspring (n = 7⁻8/group) were assigned to four groups: control, HF, HF+Probiotic, and HF+Prebiotic. Rats were sacrificed at 12 weeks of age. Maternal probiotic Lactobacillus casei and prebiotic inulin therapies protect against hypertension in male adult offspring born to fructose-fed mothers. Probiotic treatment prevents HF-induced hypertension is associated with reduced plasma acetate level and decreased renal mRNA expression of Olfr78. While prebiotic treatment increased plasma propionate level and restored HF-induced reduction of Frar2 expression. Maternal HF diet has long-term programming effects on the adult offspring's gut microbiota. Probiotic and prebiotic therapies exerted similar protective effects on blood pressure but they showed different mechanisms on modulation of gut microbiota. Maternal HF diet induced developmental programming of hypertension, which probiotic Lactobacillus casei or prebiotic inulin therapy prevented. Maternal gut microbiota-targeted therapies could be reprogramming strategies to prevent the development of hypertension caused by maternal consumption of fructose-rich diet.

Hypertension is the most common complication of chronic kidney disease (CKD) in children but is still poorly controlled. Nitric oxide (NO) deficiency plays a pivotal role in CKD and hypertension. NO is known to have health benefits, while NO typically has a short half-life and is not specifically targeted. In this study, we used a pediatric CKD model, which was induced in young rats by feeding them 0.25% adenine. We investigated two different NO donors, namely S-nitrosoglutathione (GSNO) and diethylenetriamine/NO adduct (DETA NONOate) via intraperitoneal injection at 10 mg/kg/day daily for 3 weeks. GSNO was delivered by Cu2+-doped zeolitic imidazolate framework (Cu/ZIF-8) nanoparticles to generate NO. As a result, we observed Cu/ZIF-8 nanoparticles were successfully loaded with GSNO and were able to release NO. Young rats fed with adenine displayed kidney dysfunction and hypertension at 9 weeks of age, which were prevented by GSNO-loaded nanoparticle or DETA NONOate treatment. GSNO-loaded nanoparticles reduced CKD-induced hypertension, which was related to an enhanced endogenous NO-generating system, reduced renal oxidative stress, and downregulated several components belonging to the classic renin-angiotensin (RAS) system. Our results cast new light on targeting NO delivery through the use of nanoparticles aiming to improve child-focused outcomes related to CKD worthy of clinical translation.

Both kidney disease and hypertension can originate from early life. Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of chronic kidney disease (CKD) in children. Since gut microbiota and their metabolite short chain fatty acids (SCFAs) have been linked to CKD and hypertension, we examined whether gut microbial composition and SCFAs are correlated with blood pressure (BP) load and renal outcome in CKD children with CAKUT. We enrolled 78 children with CKD stage G1-G4. Up to 65% of children with CAKUT had BP abnormalities on 24 h ambulatory blood pressure monitoring (ABPM). CKD children with CAKUT had lower risk of developing BP abnormalities and CKD progression than those with non-CAKUT. Reduced plasma level of propionate was found in children with CAKUT, which was related to increased abundance of phylum Verrucomicrobia, genus Akkermansia, and species Bifidobacterium bifidum. CKD children with abnormal ABPM profile had higher plasma levels of propionate and butyrate. Our findings highlight that gut microbiota-derived SCFAs like propionate and butyrate are related to BP abnormalities in children with an early stage of CKD. Early assessments of these microbial markers may aid in developing potential targets for early life intervention for lifelong hypertension prevention in childhood CKD.

Antrodia cinnamomea (AC), a medicinal mushroom, has multiple beneficial actions, such as acting as a prebiotic. The incidence of chronic kidney disease (CKD) in children has steadily increased year by year, and CKD is related to gut microbiota dysbiosis. Herein, we investigated the renoprotection of solid-state cultivated AC in adenine-induced CKD juvenile rats. CKD was induced in 3-week-old male rats by feeding with adenine (0.5%) for three weeks. Treated groups received oral administration of AC extracts at either a low (10 mg/kg/day) or high dose (100 mg/kg/day) for six weeks. At nine weeks of age, the rats were sacrificed. Renal outcomes, blood pressure, and gut microbiome composition were examined. Our results revealed that AC treatment, either low- or high-dose, improved kidney function, proteinuria, and hypertension in CKD rats. Low-dose AC treatment increased plasma concentrations of short-chain fatty acids (SCFAs). Additionally, we observed that AC acts like a prebiotic by enriching beneficial bacteria in the gut, such as Akkermansia and Turicibacter. Moreover, the beneficial action of AC against CKD-related hypertension might also be linked to the inhibition of the renin-angiotensin system. This study brings new insights into the potential application of AC as a prebiotic dietary supplement in the prevention and treatment of pediatric CKD.