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Introduction: This study was designed to explore the association between the TMEM173 polymorphism (rs7447927) and the severity of enterovirus 71 (EV71) infection among Chinese children. Methods: The TMEM173 polymorphism was identified in EV71‐infected patients (n = 497) and healthy controls (n = 535) using the improved multiplex ligation detection reaction (iMLDR). The interferon‐α (IFN‐α) serum levels were detected using enzyme linked immunosorbent assay (ELISA). Results: The frequencies of the GG genotype and G allele of TMEM173 rs7447927 in the mild EV71 infection and severe EV71 infection groups were markedly higher than those in the control group. The GG genotype and G allele frequencies in severely infected EV71 patients were significantly higher than those in mildly infected EV71 patients. Severely infected EV71 patients with the GG genotype had higher white blood cell counts (WBC), and C‐reactive proteins (CRP), and blood glucose (BG) levels, longer fever duration, higher vomiting frequency, spirit changes, and electroencephalography (EEG) abnormalities. IFN‐α serum concentration in severely infected patients was significantly higher than in the mildly infected group. The IFN‐α concentration in the GG genotype was significantly higher compared with those in the GC and CC genotypes in severe cases. Conclusions: The TMEM173 rs7447927 polymorphism was associated with EV71 infection susceptibility and severity. The G allele and GG genotype are susceptibility factors in the development of severe EV71 infection in Chinese children. [ABSTRACT FROM AUTHOR]

Coffin-Siris syndrome (CSS) (OMIM #135900) involves multiple congenital malformations, including hypotonia, short stature, sparse scalp hair, a coarse face, prominent eyebrows, a wide mouth, delayed bone age, and hypoplastic or absent fifth fingers/toes or nails, together with developmental delay. The cause of CSS is suggested to be related to alterations in the BRG- or HRBM-associated factor (BAF) pathway in humans. In this gene family, pathogenic variations in the AT-rich interactive domain-containing protein 1B (ARID1B) gene are revealed to be a significant element causing neurodevelopmental disability in patients with CSS. Herein, we describe the clinical features and gene variations in four Chinese patients with CSS. All the patients shared common features of short fifth fingers/toes or hypoplastic nails, coarse facial features, thick eyebrows, long cilia, a flat nasal bridge, a broad nose, a wide mouth, a high palate, and hypotonia. Besides, they had an intellectual disability, language, and motor developmental delay. Candidate genes were screened for variations using polymerase chain reaction (PCR) and sequencing. The variations were sequenced by next-generation sequencing and confirmed by first-generation sequencing. Exome sequencing suggested four de novo variations in the ARID1B gene in four unrelated patients. These included two frameshift variations (c.3581delC, c.6661_6662insG) and two nonsense variations (c.1936C>T, c.2248C>T). Of the four variations, three variations were novel. The results in our present study broaden the understanding of the disease and further interpret the molecular genetic mechanism of these rare variations in CSS. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to explore the association between the IRAK4 polymorphism rs4251545 and the severity of enterovirus 71 (EV71) infection in Chinese children. Methods: We analyzed the IRAK4 polymorphism rs4251545 in 617 EV71‐infected patients and 410 controls using the improved multiplex ligation detection reaction. IRAK4 mRNA expression was tested by qRT‐PCR. Serum concentrations of IL‐6 and NF‐κB were detected using ELISA. Results: The frequencies of the GA + AA genotype and A allele in the mild EV71 infection group and in the severe EV71 infection group were significantly higher than those in the normal control group. The frequency of the GA + AA genotype and A allele in severely infected EV71 patients was markedly higher than that in mildly infected EV71 patients. IRAK4 mRNA expression in mildly infected EV71 patients and severely infected patients was significantly higher than that in the control group. IRAK4 mRNA expression in GA + AA genotypes in both mild and severe EV71 infection groups was significantly higher than that in patients with the GG genotype. IL‐6 concentration and the ratio of IL‐6/NF‐κB in severe EV71 cases were significantly lower in patients with the GA + AA genotype than in those with the GG genotype. The ratio of IL‐6/NF‐κB was distinctly higher in severely infected EV71 patients than in mildly infected and control subjects. Conclusions: The IRAK4 polymorphism rs4251545 was associated with the susceptibility and severity of EV71 infection. The A allele is a susceptible factor in the development of severe EV71 infection in Chinese children. [ABSTRACT FROM AUTHOR]

Recently, we reported a mutation in γ-adducin (ADD3) was associated with an impaired myogenic response of the afferent arteriole and hypertension-induced chronic kidney disease (CKD) in fawn hooded hypertensive (FHH) rats. However, the mechanisms by which altered renal blood flow (RBF) autoregulation promotes hypertension-induced renal injury remain to be determined. The present study compared the time course of changes in renal hemodynamics and the progression of CKD during the development of DOCA-salt hypertension in FHH 1BN congenic rats [wild-type (WT)] with an intact myogenic response versus FHH 1BN Add3KO (Add3KO) rats, which have impaired myogenic response. RBF was well autoregulated in WT rats but not in Add3KO rats. Glomerular capillary pressure rose by 6 versus 14 mmHg in WT versus Add3KO rats when blood pressure increased from 100 to 150 mmHg. After 1 wk of hypertension, glomerular filtration rate increased by 38% and glomerular nephrin expression decreased by 20% in Add3KO rats. Neither were altered in WT rats. Proteinuria doubled in WT rats versus a sixfold increase in Add3KO rats. The degree of renal injury was greater in Add3KO than WT rats after 3 wk of hypertension. RBF, glomerular filtration rate, and glomerular capillary pressure were lower by 20%, 28%, and 19% in Add3KO rats than in WT rats, which was associated with glomerular matrix expansion and loss of capillary filtration area. The results indicated that impaired RBF autoregulation and eutrophic remodeling of preglomerular arterioles increase the transmission of pressure to glomeruli, which induces podocyte loss and accelerates the progression of CKD in hypertensive Add3KO rats. [ABSTRACT FROM AUTHOR]

20-HETE is a potent vasoconstrictor that is implicated in the regulation of blood pressure, cerebral blood flow and neuronal death following ischemia. Numerous human genetic studies have shown that inactivating variants in the cytochrome P450 enzymes that produce 20-HETE are associated with hypertension, stroke and cerebrovascular disease. However, little is known about the expression and cellular distribution of the cytochrome P450A enzymes (CYP4A) that produce 20-HETE or the newly discovered 20-HETE receptor (GPR75) in the brain. The present study examined the cell types and regions in the rat forebrain that express CYP4A and GPR75. Brain tissue slices from Sprague Dawley (SD), Dahl Salt-Sensitive (SS) and CYP4A1 transgenic rat strains, as well as cultured human cerebral pericytes and cerebral vascular smooth muscle cells, were analyzed by fluorescent immunostaining. Tissue homogenates from these strains and cultured cells were examined by Western blot. In the cerebral vasculature, CYP4A and GPR75 were expressed in endothelial cells, vascular smooth muscle cells and the glial limiting membrane of pial arteries and penetrating arterioles but not in the endothelium of capillaries. CYP4A, but not GPR75, was expressed in astrocytes. CYP4A and GPR75 were both expressed in a subpopulation of pericytes on capillaries. The diameters of capillaries were significantly decreased at the sites of first and second-order pericytes that expressed CYP4A. Capillary diameters were unaffected at the sites of other pericytes that did not express CYP4A. These findings implicate 20-HETE as a paracrine mediator in various components of the neurovascular unit and are consistent with 20-HETE's emerging role in the regulation of cerebral blood flow, blood-brain barrier integrity, the pathogenesis of stroke and the vascular contributions to cognitive impairment and dementia. Moreover, this study highlights GPR75 as a potential therapeutic target for the treatment of these devastating conditions. [ABSTRACT FROM AUTHOR]

Pitt-Hopkins syndrome (PTHS), belonging to the group of 18q-syndromes, is a rare genetic disorder caused by mutations in TCF4. PTHS is characterized by distinctive facial appearance, intermittent hyperventilation, intellectual disability and developmental delay. Although patients with PTHS generally have various systemic symptoms, most of them with a TCF4 mutation manifest the central nervous system (CNS) disorders. We described the first Chinese case with Pitt-Hopkins syndrome based on clinical presentations and genetic findings. In addition to the typical features of PTHS, the girl also had paroxysms of tachypnea followed by cyanosis and recurrent seizures. Comprehensive medical examinations were performed including metabolic screening, hepatic and renal function evaluation, abdominal and cardiac ultrasounds. The presence of epileptic discharges in electroencephalography and abnormal brain magnetic resonance imaging were found. High-throughput sequencing was used to detect genetic mutations associated with CNS disorders. Sanger sequencing was used to confirm the mutations in the patient. The c.2182C＞T (p.Arg728Ter) mutation was a de novo nonsense mutation at exon 18 in the TCF4 gene of the patient. In conclusion, we have identified a de novo nonsense mutation of TCF4 carried by a Chinese girl with PTHS. The patient underwent anti-epileptic therapy (sodium valproate, levetiracetam, clonazepam), resulting in a reduction of the seizures. [ABSTRACT FROM AUTHOR]

The tumor microenvironment (TME) is connected to immunotherapy responses, but it remains unclear how cancer cells and host tissues differentially influence the immune composition within TME. Here, we performed single-cell analyses for autologous samples from liver metastasized colorectal cancer to disentangle factors shaping TME. By aligning CD45+ cells across different tissues, we classified exhausted CD8+ T cells (Texs) and activated regulatory T cells as M-type, whose phenotypes were associated with the malignancy, while natural killer and mucosal-associated invariant T cells were defined as N-type, whose phenotypes were associated with the niche. T cell receptor sharing between Texs in primary and metastatic tumors implicated the presence of common peripheral non-exhausted precursors. For myeloid cells, a subset of dendritic cells (DC3s) and SPP1 + macrophages were M-type, and the latter were predominant in liver metastasis, indicating its pro-metastasis role. Our analyses bridge immune phenotypes of primary and metastatic tumors, thereby helping to understand the tumor-specific contexture and identify the pro-metastasis components. [Display omitted] • Immune cell phenotypic linkage with colorectal cancer and liver metastasis depicted • Malignancy-associated exhausted and regulatory T cells show diverse TCR dependency • SPP1 + TAMs are malignancy associated and are linked to liver metastasis • DCs are mainly associated with host organ except a malignancy-associated DC3 subset Liu et al. reveal the roles of malignancy and host-organ contexture in shaping immune infiltrates within a tumor microenvironment based on single-cell phenotypic alignment of colorectal cancer and the autologous liver metastasis [ABSTRACT FROM AUTHOR]

• Most rat cerebrovascular pericytes are α-SMA positive. • CYP4A and α-SMA coexpress in rat cerebral VSMCs and most pericytes. • 20-HETE is positively correlated with cerebral mural cell contractility. • 20-HETE promotes the myogenic response of rat parenchymal arterioles. • 20-HETE enhances CBF autoregulation in rat surface and deep cortex. We previously reported that deficiency in 20-HETE or CYP4A impaired the myogenic response and autoregulation of cerebral blood flow (CBF) in rats. The present study demonstrated that CYP4A was coexpressed with alpha-smooth muscle actin (α-SMA) in vascular smooth muscle cells (VSMCs) and most pericytes along parenchymal arteries (PAs) isolated from SD rats. Cell contractile capabilities of cerebral VSMCs and pericytes were reduced with a 20-HETE synthesis inhibitor, HET0016, but restored with 20-HETE analog WIT003. Similarly, intact myogenic responses of the middle cerebral artery and PA of SD rats decreased with HET0016 and were rescued by WIT003. The myogenic response of the PA was abolished in SS and was restored in SS.BN5 and SS. Cyp4a1 rats. HET0016 enhanced CBF and impaired its autoregulation in the surface and deep cortex of SD rats. These results demonstrate that 20-HETE has a direct effect on cerebral mural cell contractility that may play an essential role in controlling cerebral vascular function. [ABSTRACT FROM AUTHOR]

R1636 --> 20‐HETE is a metabolite of arachidonic acid produced by enzymes of CYP4A and CYP4F families. We previously reported that Dahl S rats have a genetic deficiency in the production of 20‐HETE and the expression of CYP4A enzymes and exhibit impaired myogenic response of the middle cerebral artery (MCA) and autoregulation of cerebral blood flow (CBF) but the mechanism is unknown. The present study explored whether 20‐HETE has direct effects on the regulation of cerebral mural cell contractility that may play an essential role in autoregulation of CBF in the surface and deep cortex. We found that CYP4A was expressed in vascular smooth muscle cells (VSMCs) and pericytes along parenchymal arteries and capillaries isolated from the MCA territory of SD rats. Gel size was reduced to a lesser extent in VSMCs treated with the 20‐HETE synthesis inhibitor, HET0016 (10 μM) versus vehicle (17.9 ± 0.5 % vs. 28.3 ± 0.5 %; n = 9), indicating loss of contractility. Similarly, constriction of cerebral pericytes treated with HET0016 was reduced relative to controls. Cell contractile capability of cerebral VSMC and pericyte collaboratively play a role in regulating CBF in the superficial and deep cortex of the brain by modulation of the myogenic response of the MCA and arterioles, respectively. CBF was well autoregulated in the surface and deep cortex in SD rats and only increased by 12.9 ± 1.7 % and 13.3 ± 1.9 %, respectively, when pressure was elevated from 100 to 140 mmHg. In contrast, CBF increased by 34.6 ± 3.2 % and 28.5 ± 2.3 %, respectively after the rats were given HET0016 (2 mg/kg). These results demonstrate that CYP4A is expressed both in VSMC and pericytes of parenchymal arteries and capillaries, that blockade of 20‐HETE reduces the contractile activity of these cells and attenuates autoregulation of CBF in the superficial and deep cortex of the brain. They provide novel insight into human genetic studies indicating that inactivate variants of 20‐HETE producing enzymes are associated with a higher incidence of hypertension, stroke, and AD. [ABSTRACT FROM AUTHOR]

Ischemic stroke is one of the most disabling diseases and a leading cause of death globally. Despite advances in medical care, the global burden of stroke continues to grow, as no effective treatments to limit or reverse ischemic injury to the brain are available. However, recent preclinical findings have revealed the potential role of transient receptor potential cation 6 (TRPC6) channels as endogenous protectors of neuronal tissue. Activating TRPC6 in various cerebral ischemia models has been found to prevent neuronal death, whereas blocking TRPC6 enhances sensitivity to ischemia. Evidence has shown that Ca2+ influx through TRPC6 activates the cAMP (adenosine 3',5'-cyclic monophosphate) response element-binding protein (CREB), an important transcription factor linked to neuronal survival. Additionally, TRPC6 activation may counter excitotoxic damage resulting from glutamate release by attenuating the activity of N-methyl-d-aspartate (NMDA) receptors of neurons by posttranslational means. Unresolved though, are the roles of TRPC6 channels in non-neuronal cells, such as astrocytes and endothelial cells. Moreover, TRPC6 channels may have detrimental effects on the blood–brain barrier, although their exact role in neurovascular coupling requires further investigation. This review discusses evidence-based cell-specific aspects of TRPC6 in the brain to assess the potential targets for ischemic stroke management. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) is a leading risk factor for aging‐related dementia. We previously demonstrated that an SGLT2 inhibitor (SGLT2i) reversed the impaired myogenic response (MR) of the middle cerebral artery (MCA) and cerebral blood flow (CBF) autoregulation on the surface cortex, and improved cognition with an eight‐arm water maze in 18‐month old diabetic rats. The present study aims to investigate whether normalizing plasma glucose by inhibition of SGLT2 also ameliorate MR of parenchymal arteriole (PA) and CBF autoregulation in the deep cortex, and the role of pericyte in the regulation of CBF autoregulation and cognitive function in DM. Method: Deep cortical CBF autoregulation was studied using laser Doppler flowmetry coupled with an implanted fiber‐optic probe. MR of PA was investigated using a pressure myography. The novel object recognition and open field tests were used to evaluate cognition. Mitochondrial‐derived superoxide production was detected by MitoSOX, and mitochondrial function was evaluated using Seahorse XFe24. Cell contraction was detected by a collagen gel‐based kit. Result: Deep cortical CBF rose by 223.34 ± 28.11, 49.03 ± 12.62, 50.12 ± 0.89%, respectively, in diabetic, SGLT2i treated diabetic and non‐diabetic rats when blood pressure was increased from 100 to 180 mmHg. PA constricted in response to elevated transmural pressure in SGLT2i treated diabetic and non‐diabetic rats, whereas dilated in diabetic rats. The percentage of time spent in the novel object was 43.32 ± 8.04%, 71.94 ± 8.48%, 75.68 ± 3.33% respectively in diabetic, SGLT2i treated diabetic, and non‐diabetic rats. No significant differences in total travel distance and resting time were found between these rats. High glucose‐treated pericytes displayed elevated mitochondrial ROS, and decreased ATP production, and lower their contractile capabilities. Conclusion: These results indicate that the SGLT2 Inhibitor reversed the impaired MR of the PA, CBF autoregulation in the deep cortex, and cognitive impairments in old DM, which may involve amelioration of hyperglycemia‐induced mitochondrial ROS production and ATP depletion in pericytes. [ABSTRACT FROM AUTHOR]

We recently reported that KO of Dual‐specificity protein phosphatase 5 (Dusp5) enhances myogenic reactivity and blood flow autoregulation in the cerebral and renal circulations in association with increased levels of pPKC and pERK1/2 in the cerebral and renal arteries and arterioles. In the kidney, hypertension‐related renal damage was significantly attenuated in Dusp5 KO rats. Elevations in pPKC and pERK1/2 promote calcium influx in VSMC and facilitate vasoconstriction. However, whether DUSP5 plays a role in altering the passive mechanical properties of cerebral and renal arterioles has never been investigated. In this study, we found that KO of Dusp5 did not alter body weights, kidney and brain weights, plasma glucose, and HbA1C levels. The expression of pERK is higher in the nucleus of primary VSMC isolated from Dusp5 KO rats. Dusp5 KO rats exhibited eutrophic vascular hypotrophy with smaller intracerebral parenchymal arterioles and renal interlobular arterioles without changing the wall‐to‐lumen ratios. These arterioles from Dusp5 KO rats displayed higher myogenic tones, better distensibility, greater compliance, and less stiffness compared with arterioles from WT control rats. VSMC of Dusp5 KO rats exhibited a stronger contractile capability. These results demonstrate, for the first time, that DUSP5 contributes to the regulation of the passive mechanical properties of cerebral and renal arterioles and provide new insights into the role of DUSP5 in vascular function, cancer, stroke, and other cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Alzheimer's Disease and Alzheimer's Disease-related dementias (AD/ADRD) pose major global healthcare challenges, with diabetes mellitus (DM) being a key risk factor. Both AD and DM-related ADRD are characterized by reduced cerebral blood flow, although the exact mechanisms remain unclear. We previously identified compromised cerebral hemodynamics as early signs in TgF344-AD and type 2 DM-ADRD (T2DN) rat models. Genome-wide studies have linked AD/ADRD to SNPs in soluble epoxide hydrolase (sEH). This study explored the effects of sEH inhibition with TPPU on cerebral vascular function and cognition in AD and DM-ADRD models. Chronic TPPU treatment improved cognition in both AD and DM-ADRD rats without affecting body weight. In DM-ADRD rats, TPPU reduced plasma glucose and HbA1C levels. Transcriptomic analysis of primary cerebral vascular smooth muscle cells from AD rats treated with TPPU revealed enhanced pathways related to cell contraction, alongside decreased oxidative stress and inflammation. Both AD and DM-ADRD rats exhibited impaired myogenic responses and autoregulation in the cerebral circulation, which were normalized with chronic sEH inhibition. Additionally, TPPU improved acetylcholine-induced vasodilation in the middle cerebral arteries (MCA) of DM-ADRD rats. Acute TPPU administration unexpectedly caused vasoconstriction in the MCA of DM-ADRD rats at lower doses. In contrast, higher doses or longer durations were required to induce effective vasodilation at physiological perfusion pressure in both control and ADRD rats. Additionally, TPPU decreased reactive oxygen species production in cerebral vessels of AD and DM-ADRD rats. These findings provide novel evidence that chronic sEH inhibition can reverse cerebrovascular dysfunction and cognitive impairments in AD/ADRD, offering a promising avenue for therapeutic development., Competing Interests: DECLARATIONS Conflict of Interest B.D. Hammock is a founder and S.H. Hwang, and J. Yang are employees of EicOsis L.L.C., a startup company with an sEH inhibitor in human clinical trials.

Alzheimer's Disease (AD) and Alzheimer's Disease-Related Dementias (ADRD) are neurodegenerative disorders. Recent studies suggest that cerebral hypoperfusion is an early symptom of AD/ADRD. Dual-specificity protein phosphatase 5 (DUSP5) has been implicated in several pathological conditions, including pulmonary hypertension and cancer, but its role in AD/ADRD remains unclear. The present study builds on our previous findings, demonstrating that inhibition of ERK and PKC leads to a dose-dependent dilation of the middle cerebral artery and penetrating arteriole, with a more pronounced effect in Dusp5 KO rats. Both ERK and PKC inhibitors resulted in a significant reduction of myogenic tone in vessels from Dusp5 KO rats. Dusp5 KO rats exhibited stronger autoregulation of the surface but not deep cortical cerebral blood flow. Inhibition of ERK and PKC significantly enhanced the contractile capacity of vascular smooth muscle cells from both strains. Finally, a significant improvement in learning and memory was observed in Dusp5 KO rats 24 hours after initial training. Our results suggest that altered vascular reactivity in Dusp5 KO rats may involve distinct mechanisms for different vascular beds, and DUSP5 deletion could be a potential therapeutic target for AD/ADRD. Further investigations are necessary to determine the effects of DUSP5 inhibition on capillary stalling, blood-brain barrier permeability, and neurodegeneration in aging and disease models., Competing Interests: Conflict of Interest The authors declare no competing interests.

Hypertension is a leading risk factor for stroke, heart disease, chronic kidney disease, vascular cognitive impairment, and Alzheimer's disease. Previous genetic studies have nominated hundreds of genes linked to hypertension, and renal and cognitive diseases. Some have been advanced as candidate genes by showing that they can alter blood pressure or renal and cerebral vascular function in knockout animals; however, final validation of the causal variants and underlying mechanisms has remained elusive. This review chronicles 40 years of work, from the initial identification of adducin (ADD) as an ACTIN-binding protein suggested to increase blood pressure in Milan hypertensive rats, to the discovery of a mutation in ADD1 as a candidate gene for hypertension in rats that were subsequently linked to hypertension in man. More recently, a recessive K572Q mutation in ADD3 was identified in Fawn-Hooded Hypertensive (FHH) and Milan Normotensive (MNS) rats that develop renal disease, which is absent in resistant strains. ADD3 dimerizes with ADD1 to form functional ADD protein. The mutation in ADD3 disrupts a critical ACTIN-binding site necessary for its interactions with actin and spectrin to regulate the cytoskeleton. Studies using Add3 KO and transgenic strains, as well as a genetic complementation study in FHH and MNS rats, confirmed that the K572Q mutation in ADD3 plays a causal role in altering the myogenic response and autoregulation of renal and cerebral blood flow, resulting in increased susceptibility to hypertension-induced renal disease and cerebral vascular and cognitive dysfunction.

Diabetes mellitus (DM) is a leading risk factor for age-related dementia, but the mechanisms involved are not well understood. We previously discovered that hyperglycemia induced impaired myogenic response (MR) and cerebral blood flow (CBF) autoregulation in 18-mo-old DM rats associated with blood-brain barrier (BBB) leakage, impaired neurovascular coupling, and cognitive impairment. In the present study, we examined whether reducing plasma glucose with a sodium-glucose cotransporter-2 inhibitor (SGLT2i) luseogliflozin can ameliorate cerebral vascular and cognitive function in diabetic rats. Plasma glucose and HbA1c levels of 18-mo-old DM rats were reduced, and blood pressure was not altered after treatment with luseogliflozin. SGLT2i treatment restored the impaired MR of middle cerebral arteries (MCAs) and parenchymal arterioles and surface and deep cortical CBF autoregulation in DM rats. Luseogliflozin treatment also rescued neurovascular uncoupling, reduced BBB leakage and cognitive deficits in DM rats. However, SGLT2i did not have direct constrictive effects on vascular smooth muscle cells and MCAs isolated from normal rats, although it decreased reactive oxygen species production in cerebral vessels of DM rats. These results provide evidence that normalization of hyperglycemia with an SGLT2i can reverse cerebrovascular dysfunction and cognitive impairments in rats with long-standing hyperglycemia, possibly by ameliorating oxidative stress-caused vascular damage. NEW & NOTEWORTHY This study demonstrates that luseogliflozin, a sodium-glucose cotransporter-2 inhibitor, improved CBF autoregulation in association with reduced vascular oxidative stress and AGEs production in the cerebrovasculature of 18-mo-old DM rats. SGLT2i also prevented BBB leakage, impaired functional hyperemia, neurodegeneration, and cognitive impairment seen in DM rats. Luseogliflozin did not have direct constrictive effects on VSMCs and MCAs isolated from normal rats. These results provide evidence that normalization of hyperglycemia with an SGLT2i can reverse cerebrovascular dysfunction and cognitive impairments in rats with long-standing hyperglycemia, possibly by ameliorating oxidative stress-caused vascular damage.

The accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated τ proteins in the brain are the hallmarks of Alzheimer's disease (AD). Much of the research into the pathogenesis of AD has focused on the amyloid or τ hypothesis. These hypotheses propose that Aβ or τ aggregation is the inciting event in AD that leads to downstream neurodegeneration, inflammation, brain atrophy and cognitive impairment. Multiple drugs have been developed and are effective in preventing the accumulation and/or clearing of Aβ or τ proteins. However, clinical trials examining these therapeutic agents have failed to show efficacy in preventing or slowing the progression of the disease. Thus, there is a need for fresh perspectives and the evaluation of alternative therapeutic targets in this field. Epidemiology studies have revealed significant overlap between cardiovascular and cerebrovascular risk factors such as hypertension, diabetes, atherosclerosis and stroke to the development of cognitive impairment. This strong correlation has given birth to a renewed focus on vascular contributions to AD and related dementias. However, few genes and mechanisms have been identified. 20-Hydroxyeicosatetraenoic acid (20-HETE) is a potent vasoconstrictor that plays a complex role in hypertension, autoregulation of cerebral blood flow and blood-brain barrier (BBB) integrity. Multiple human genome-wide association studies have linked mutations in the cytochrome P450 (CYP) 4A (CYP4A) genes that produce 20-HETE to hypertension and stroke. Most recently, genetic variants in the enzymes that produce 20-HETE have also been linked to AD in human population studies. This review examines the emerging role of 20-HETE in AD and related dementias., (© 2021 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Abstract: The monoterpene glycoside paeoniflorin (PF) is the principal active constituent of the traditional Chinese herbal medicines, Radix Paeoniae Alba and Radix Paeoniae Rubra, which have been used for millennia to treat cardiovascular diseases (eg, hypertension, bleeding, and atherosclerosis) and neurological ailments (eg, headaches, vertigo, dementia, and pain). Recent evidence has revealed that PF exerts inhibitory effects on inflammation, fibrosis, and apoptosis by targeting several intracellular signaling cascades. In this review, we address the current knowledge about the pharmacokinetic properties of PF and its molecular mechanisms of action. We also present results from recent preclinical studies supporting the utility of PF for the treatment of pain, cerebral ischemic injury, and neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Moreover, new evidence suggests a general protective role of PF in heart attack, diabetic kidney, and atherosclerosis. Mechanistically, PF exerts multiple anti-inflammatory actions by targeting toll-like receptor-mediated signaling in both parenchymal and immune cells (in particular, macrophages and dendritic cells). A better understanding of the molecular actions of PF may lead to the expansion of its therapeutic uses., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Previous studies identified a region on chromosome 1 associated with N G -nitro-L-arginine methyl ester (L-NAME) hypertension-induced renal disease in fawn-hooded hypertensive (FHH) rats. This region contains a mutant γ -adducin ( Add3 ) gene that impairs renal blood flow (RBF) autoregulation, but its contribution to renal injury is unknown. The present study evaluated the hypothesis that knockout (KO) of Add3 impairs the renal vasoconstrictor response to the blockade of nitric oxide synthase and enhances hypertension-induced renal injury after chronic administration of L-NAME plus a high-salt diet. The acute hemodynamic effect of L-NAME and its chronic effects on hypertension and renal injury were compared in FHH 1 Brown Norway (FHH 1 BN ) congenic rats (WT) expressing wild-type Add3 gene versus FHH 1 BN Add3 KO rats. RBF was well autoregulated in WT rats but impaired in Add3 KO rats. Acute administration of L-NAME (10 mg/kg) raised mean arterial pressure (MAP) similarly in both strains, but RBF and glomerular filtration rate (GFR) fell by 38% in WT versus 15% in Add3 KO rats. MAP increased similarly in both strains after chronic administration of L-NAME and a high-salt diet; however, proteinuria and renal injury were greater in Add3 KO rats than in WT rats. Surprisingly, RBF, GFR, and glomerular capillary pressure were 41%, 82%, and 13% higher in L-NAME-treated Add3 KO rats than in WT rats. Hypertensive Add3 KO rats exhibited greater loss of podocytes and glomerular nephrin expression and increased interstitial fibrosis than in WT rats. These findings indicate that loss of ADD3 promotes L-NAME-induced renal injury by altering renal hemodynamics and enhancing the transmission of pressure to glomeruli. SIGNIFICANCE STATEMENT: A mutation in the γ -adducin ( Add3 ) gene in fawn-hooded hypertensive rats that impairs autoregulation of renal blood flow is in a region of rat chromosome 1 homologous to a locus on human chromosome 10 associated with diabetic nephropathy. The present results indicate that loss of ADD3 enhanced N G -nitro-L-arginine methyl ester-induced hypertensive renal injury by altering the transmission of pressure to the glomerulus., Competing Interests: Disclosure No author has an actual or perceived conflict of interest with the contents of this article., (Copyright © 2021 by The American Society for Pharmacology and Experimental Therapeutics.)

Diabetes mellitus (DM) is one of the primary pathological factors that contributes to aging-related cognitive impairments, but the underlying mechanisms remain unclear. We recently reported that old DM rats exhibited impaired myogenic responses of the cerebral arteries and arterioles, poor cerebral blood flow autoregulation, enhanced blood-brain barrier (BBB) leakage, and cognitive impairments. These changes were associated with diminished vascular smooth muscle cell contractile capability linked to elevated reactive oxygen species (ROS) and reduced ATP production. In the present study, using a nonobese T2DN DM rat, we isolated parenchymal arterioles (PAs), cultured cerebral microvascular pericytes, and examined whether cerebrovascular pericyte in DM is damaged and whether pericyte dysfunction may play a role in the regulation of cerebral hemodynamics and BBB integrity. We found that ROS and mitochondrial superoxide production were elevated in PAs isolated from old DM rats and in high glucose (HG)-treated α-smooth muscle actin-positive pericytes. HG-treated pericytes displayed decreased contractile capability in association with diminished mitochondrial respiration and ATP production. Additionally, the expression of advanced glycation end products, transforming growth factor-β, vascular endothelial growth factor, and fibronectin were enhanced, but claudin 5 and integrin β1 was reduced in the brain of old DM rats and HG-treated pericytes. Further, endothelial tight junction and pericyte coverage on microvessels were reduced in the cortex of old DM rats. These results demonstrate our previous findings that the impaired cerebral hemodynamics and BBB leakage and cognitive impairments in the same old DM model are associated with hyperglycemia-induced cerebrovascular pericyte dysfunction. NEW & NOTEWORTHY This study demonstrates that the loss of contractile capability in pericytes in diabetes is associated with enhanced ROS and reduced ATP production. Enhanced advanced glycation end products (AGEs) in diabetes accompany with reduced pericyte and endothelial tight junction coverage in the cortical capillaries of old diabetic rats. These results suggest our previous findings that the impaired cerebral hemodynamics, BBB leakage, and cognitive impairments in old DM model are associated with hyperglycemia-induced cerebrovascular pericyte dysfunction.

We recently reported that the enhanced susceptibility to chronic kidney disease (CKD) in the fawn-hooded hypertensive (FHH) rat is caused, at least in part, by a mutation in γ-adducin (ADD3) that attenuates renal vascular function. The present study explored whether Add3 contributes to the modulation of podocyte structure and function using FHH and FHH. Add3 transgenic rats. The expression of ADD3 on the membrane of primary podocytes isolated from FHH was reduced compared with FHH. Add3 transgenic rats. We found that F-actin nets, which are typically localized in the lamellipodia, replaced unbranched stress fibers in conditionally immortalized mouse podocytes transfected with Add3 Dicer-substrate short interfering RNA (DsiRNA) and primary podocytes isolated from FHH rats. There were increased F/G-actin ratios and expression of the Arp2/3 complexes throughout FHH podocytes in association with reduced synaptopodin and RhoA but enhanced Rac1 and CDC42 expression in the renal cortex, glomeruli, and podocytes of FHH rats. The expression of nephrin at the slit diaphragm and the levels of focal adhesion proteins integrin-α 3 and integrin-β 1 were decreased in the glomeruli of FHH rats. Cell migration was enhanced and adhesion was reduced in podocytes of FHH rats as well as in immortalized mouse podocytes transfected with Add3 DsiRNA. Mean arterial pressures were similar in FHH and FHH. Add3 transgenic rats at 16 wk of age; however, FHH rats exhibited enhanced proteinuria associated with podocyte foot process effacement. These results demonstrate that reduced ADD3 function in FHH rats alters baseline podocyte pathophysiology by rearrangement of the actin cytoskeleton at the onset of proteinuria in young animals.

Epidemiological studies demonstrate that there are sex differences in the incidence, prevalence, and outcomes of cerebrovascular disease (CVD). The present study compared the structure and composition of the middle cerebral artery (MCA), neurovascular coupling, and cerebrovascular function and cognition in young Sprague-Dawley (SD) rats. Wall thickness and the inner diameter of the MCA were smaller in females than males. Female MCA exhibited less vascular smooth muscle cells (VSMCs), diminished contractile capability, and more collagen in the media, and a thicker internal elastic lamina with fewer fenestrae compared with males. Female MCA had elevated myogenic tone, lower distensibility, and higher wall stress. The stress/strain curves shifted to the left in female vessels compared with males. The MCA of females failed to constrict compared with a decrease of 15.5 ± 1.9% in males when perfusion pressure was increased from 40 to 180 mmHg. Cerebral blood flow (CBF) rose by 57.4 ± 4.4 and 30.1 ± 3.1% in females and males, respectively, when perfusion pressure increased from 100 to 180 mmHg. The removal of endothelia did not alter the myogenic response in both sexes. Functional hyperemia responses to whisker-barrel stimulation and cognition examined with an eight-arm water maze were similar in both sexes. These results demonstrate that there are intrinsic structural differences in the MCA between sexes, which are associated with diminished myogenic response and CBF autoregulation in females. The structural differences do not alter neurovascular coupling and cognition at a young age; however, they might play a role in the development of CVD after menopause. NEW & NOTEWORTHY Using perfusion fixation of the middle cerebral artery (MCA) in calcium-free solution at physiological pressure and systematically randomly sampling the sections prepared from the same M2 segments of MCA, we found that there are structural differences that are associated with altered cerebral blood flow (CBF) autoregulation but not neurovascular coupling and cognition in young, healthy Sprague-Dawley (SD) rats. Understanding the intrinsic differences in cerebrovascular structure and function in males and females is essential to develop new pharmaceutical treatments for cerebrovascular disease (CVD).

Background: The genes and mechanisms involved in the association between diabetes or hypertension and CKD risk are unclear. Previous studies have implicated a role for γ -adducin (ADD3), a cytoskeletal protein encoded by Add3 ., Methods: We investigated renal vascular function in vitro and in vivo and the susceptibility to CKD in rats with wild-type or mutated Add3 and in genetically modified rats with overexpression or knockout of ADD3. We also studied glomeruli and primary renal vascular smooth muscle cells isolated from these rats., Results: This study identified a K572Q mutation in ADD3 in fawn-hooded hypertensive (FHH) rats-a mutation previously reported in Milan normotensive (MNS) rats that also develop kidney disease. Using molecular dynamic simulations, we found that this mutation destabilizes a critical ADD3-ACTIN binding site. A reduction of ADD3 expression in membrane fractions prepared from the kidney and renal vascular smooth muscle cells of FHH rats was associated with the disruption of the F-actin cytoskeleton. Compared with renal vascular smooth muscle cells from Add3 transgenic rats, those from FHH rats had elevated membrane expression of BK α and BK channel current. FHH and Add3 knockout rats exhibited impairments in the myogenic response of afferent arterioles and in renal blood flow autoregulation, which were rescued in Add3 transgenic rats. We confirmed these findings in a genetic complementation study that involved crossing FHH and MNS rats that share the ADD3 mutation. Add3 transgenic rats showed attenuation of proteinuria, glomerular injury, and kidney fibrosis with aging and mineralocorticoid-induced hypertension., Conclusions: This is the first report that a mutation in ADD3 that alters ACTIN binding causes renal vascular dysfunction and promotes the susceptibility to kidney disease., (Copyright © 2020 by the American Society of Nephrology.)