Inflammation: A Mediator Between Hypertension and Neurodegenerative Diseases

Neuro- and vasoprotective potential of neuropeptide Y Y2 receptor agonist, NPY13-36, against transient focal cerebral ischemia in spontaneously hypertensive rats

Numerous in vitro and in vivo experimental studies indicate that neuropeptide Y Y2 receptors (Y2R) are potential targets for neuroprotective therapy, including neuroprotection against ischemic stroke in healthy rats. Since stroke in humans is typically associated with comorbidities and long-term hypertension is the most common comorbidity leading to stroke, this study aimed to assess the neuroprotective potential of the Y2R agonist NPY13-36 in the rats with essential hypertension (SHR) subjected to 90 min middle cerebral artery suture occlusion with subsequent reperfusion (MCAOR). The cerebrocortical microflow in the ischemic focus and penumbra was continuously monitored with a Laser-Doppler flowmeter. NPY13-36 (10 μg/6 μl physiological saline solution) was administered intracerebroventricularly (i.c.v.) during ischemia or early reperfusion. The infarct area (triphenyltetrazolium chloride staining), behavioral tests (gait, mobility, and sensorimotor functions), and the response of the cerebrocortical microcirculation in the penumbra to hypercapnia and to the inhibition of the synthesis of nitric oxide were studied. Our results demonstrate that administration of NPY13-36 reduces the size of the infarct, improves motor functions, and restores microcirculatory response to the blockade of nitric oxide synthase when administered during reperfusion. The novelty of this study is a finding of the vasoprotective effect of NPY13-36 in brain ischemia/reperfusion. Moreover, this study provides evidence of the beneficial effects of NPY13-36 in animals with essential hypertension and indicates that Y2R ligands may be promising candidates for treating the ischemic brain in the case of this disease.

Association and interaction analysis of NLRP3 gene polymorphisms with hypertension risk: a case-control study in China

BACKGROUND

The NLRP3 inflammasome, a pivotal mechanism regulating inflammatory responses and featuring the pyrin domain containing 3 (NLRP3) within the NOD-like receptor family, is widely recognized as a central pathogenic factor in cardiovascular diseases. The present study endeavors to delve into the correlation and potential interplay between the rs10754558 polymorphism of NLRP3 and the predisposition to hypertension among the Chinese adult population.

METHODS

All the participants who came from a community in Bengbu, China were investigated by being interviewed with a questionnaire. Overall, 354 paired case-control participants were analyzed. Genomic DNA was extracted from 5ml venous blood using the Tiangen DNA extraction kit. The rs10754558 polymorphism of the NLRP3 gene was genotyped by TaqMan allelic discrimination real-time PCR.The association between the rs10754558 polymorphism and hypertension risk was investigated by a logistic regression analysis. Furthermore, an additive interaction analysis was conducted using related indicators, including the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (SI).

RESULTS

Participants carrying the GG genotype were more likely to develop hypertension than participants carrying the CC genotype (adjusted odds ratio [OR]: 2.16, 95% confidence interval [CI]: 1.33-3.52). A significant additive interaction between the NLRP3 polymorphism and obesity status concerning the risk of hypertension was observed, as estimated by all indicators: RERI (1.12, 95% CI: 0.70-1.5), AP (0.34, 95% CI: 0.14-0.53), and SI (1.92, 95% CI: 1.03-3.59). The values of RERI (1.74, 95% CI: 0.37-3.11), AP (0.46, 95% CI: 0.21-0.70), and SI (2.62, 95% CI: 1.18-5.83) showed that a significant interaction between the rs10754558 polymorphism and a family history of hypertension.

CONCLUSIONS

Our findings indicate a significant association between the NLRP3 rs10754558 polymorphism and the risk of hypertension in Chinese adults. Moreover, a notable additive interaction emerges between NLRP3 polymorphisms and obesity status, further amplifying the risk of hypertension.

High Blood Pressure and Impaired Brain Health: Investigating the Neuroprotective Potential of Magnesium

High blood pressure (BP) is a significant contributor to the disease burden globally and is emerging as an important cause of morbidity and mortality in the young as well as the old. The well-established impact of high BP on neurodegeneration, cognitive impairment, and dementia is widely acknowledged. However, the influence of BP across its full range remains unclear. This review aims to explore in more detail the effects of BP levels on neurodegeneration, cognitive function, and dementia. Moreover, given the pressing need to identify strategies to reduce BP levels, particular attention is placed on reviewing the role of magnesium (Mg) in ageing and its capacity to lower BP levels, and therefore potentially promote brain health. Overall, the review aims to provide a comprehensive synthesis of the evidence linking BP, Mg and brain health. It is hoped that these insights will inform the development of cost-effective and scalable interventions to protect brain health in the ageing population.

The Association Between Inflammatory Dietary Pattern and Risk of Cognitive Impairment Among Older Adults with Chronic Diseases and Its Multimorbidity: A Cross-Sectional Study

Background

The present study aimed to explore the association between the inflammatory potential of diet, assessed by energy-adjusted dietary inflammatory index (E-DII) and reduced rank regression (RRR)-derived inflammatory dietary pattern, and the risk for cognitive impairment (CI) in community-dwelling older adults, especially in older adults with chronic diseases and multimorbidity.

Methods

A total of 549 older adults from Taiyuan city were included in the present cross-sectional study. The Chinese Version of the Mini-Mental State Examination (CMMSE) was used for the evaluation of cognitive function. E-DII score was calculated based on semi-quantitative food frequency questionnaire (FFQ). Blood samples, including interleukin (IL)-1β, interleukin (IL)-18, tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP), were tested for calculating RRR-derived inflammatory dietary pattern. Logistic regression was used to assess the association between inflammatory dietary pattern and risk of CI. In addition, patients with diabetes, hypertension, hyperlipidemia and multimorbidity were screened for further analysis among 549 older adults.

Results

In those 549 older adults, adjusting for demographic characteristics and chronic disease status, there was no association between E-DII score tertile (OR T3VST1 : 1.357, 95%CI:0.813~2.265, P trend = 0.267), RRR-derived inflammatory dietary pattern score tertile (OR T3VST1 : 1.092, 95%CI:0.679~ 1.758, P trend = 0.737) and risk of CI. However, in older adults with diabetes and multimorbidity, the score tertile of E-DII and RRR-derived inflammatory dietary pattern were positively correlated with risk of CI in a dose-responsive manner (All P trend < 0.05). There is insufficient evidence to reach similar conclusion in patients with hypertension and hyperlipidemia (All P trend > 0.05).

Conclusion

In the present study, pro-inflammatory diet contributed to the increased risk of CI in older adults with diabetes and multimorbidity. These results supplemented vital evidence for the prevention and treatment of CI in older adults with chronic diseases.

The circadian syndrome is a better predictor for psoriasis than the metabolic syndrome via an explainable machine learning method - the NHANES survey during 2005-2006 and 2009-2014

Objective

To explore the association between circadian syndrome (CircS) and Metabolic Syndrome (MetS) with psoriasis. Compare the performance of MetS and CircS in predicting psoriasis.

Methods

An observational study used data from the NHANES surveys conducted in 2005-2006 and 2009-2014. We constructed three multiple logistic regression models to investigate the relationship between MetS, CircS, and their components with psoriasis. The performance of MetS and CircS in predicting psoriasis was compared using five machine-learning algorithms, and the best-performing model was explained via SHAP. Then, bidirectional Mendelian randomization analyses with the inverse variance weighted (IVW) as the primary method were employed to determine the causal effects of each component.

Result

A total of 9,531 participants were eligible for the study. Both the MetS (OR = 1.53, 95%CI: 1.07-2.17, P = 0.02) and CircS (OR = 1.40, 95%CI: 1.02-1.91, P = 0.039) positively correlated with psoriasis. Each CircS algorithmic model performs better than MetS, with Categorical Features+Gradient Boosting for CircS (the area under the precision-recall curve = 0.969) having the best prediction effect on psoriasis. Among the components of CircS, elevated blood pressure, depression symptoms, elevated waist circumference (WC), and short sleep contributed more to predicting psoriasis. Under the IVW methods, there were significant causal relationships between WC (OR = 1.52, 95%CI: 1.34-1.73, P = 1.35e-10), hypertension (OR = 1.68, 95%CI: 1.19-2.37, P = 0.003), depression symptoms (OR = 1.39, 95%CI: 1.17-1.65, P = 1.51e-4), and short sleep (OR = 2.03, 95%CI: 1.21-3.39, p = 0.007) with psoriasis risk.

Conclusion

CircS demonstrated superior predictive ability for prevalent psoriasis compared to MetS, with elevated blood pressure, depression symptoms, and elevated WC contributing more to the prediction.

Blood-brain barrier pathology in cerebral small vessel disease

ABSTRACT

Cerebral small vessel disease is a neurological disease that affects the brain microvasculature and which is commonly observed among the elderly. Although at first it was considered innocuous, small vessel disease is nowadays regarded as one of the major vascular causes of dementia. Radiological signs of small vessel disease include small subcortical infarcts, white matter magnetic resonance imaging hyperintensities, lacunes, enlarged perivascular spaces, cerebral microbleeds, and brain atrophy; however, great heterogeneity in clinical symptoms is observed in small vessel disease patients. The pathophysiology of these lesions has been linked to multiple processes, such as hypoperfusion, defective cerebrovascular reactivity, and blood-brain barrier dysfunction. Notably, studies on small vessel disease suggest that blood-brain barrier dysfunction is among the earliest mechanisms in small vessel disease and might contribute to the development of the hallmarks of small vessel disease. Therefore, the purpose of this review is to provide a new foundation in the study of small vessel disease pathology. First, we discuss the main structural domains and functions of the blood-brain barrier. Secondly, we review the most recent evidence on blood-brain barrier dysfunction linked to small vessel disease. Finally, we conclude with a discussion on future perspectives and propose potential treatment targets and interventions.

The neutrophil-to-lymphocyte ratio is associated with all-cause and cardiovascular mortality among individuals with hypertension

BACKGROUND

Identifying reliable prognostic markers is crucial for the effective management of hypertension. The neutrophil-to-lymphocyte ratio (NLR) has emerged as a potential inflammatory marker linked to cardiovascular outcomes. This study aims to investigate the association of NLR with all-cause and cardiovascular mortality among patients with hypertension.

METHODS

This study analyzed data from 3067 hypertensive adults in the National Health and Nutritional Examination Surveys (NHANES) from 2009 to 2014. Mortality details were obtained from the National Death Index (NDI). Restricted cubic spline (RCS) was deployed to visualize the association of the NLR with mortality risk. Weighted Cox proportional hazards models were employed to assess the independent association of NLR with mortality risk. Time-dependent receiver operating characteristic curve (ROC) analysis was conducted to access the predictive ability of NLR for survival. Mediation analysis was used to explore the indirect impact of NLR on mortality mediated through eGFR.

RESULTS

Over a median 92.0-months follow-up, 538 deaths occurred, including 114 cardiovascular deaths. RCS analysis revealed a positive association between NLR and both all-cause and cardiovascular mortality. Participants were stratified into higher (> 3.5) and lower (≤ 3.5) NLR groups. Weighted Cox proportional hazards models demonstrated that individuals with higher NLR had a significantly increased risk of all-cause (HR 1.96, 95% confidence interval (CI) 1.52-2.52, p < 0.0001) and cardiovascular mortality (HR 2.33, 95% CI 1.54-3.51, p < 0.0001). Stratified and interaction analysis confirmed the stability of the core results. Notably, eGFR partially mediated the association between NLR and both all-cause and cardiovascular mortality by a 5.4% and 4.7% proportion, respectively. Additionally, the areas under the curve (AUC) of the 3-, 5- and 10- year survival was 0.68, 0.65 and 0.64 for all-cause mortality and 0.68, 0.70 and 0.69 for cardiovascular mortality, respectively.

CONCLUSION

Elevated NLR independently confers an increased risk for both all-cause and cardiovascular mortality in individuals with hypertension.

Methylglyoxal accumulation contributes to accelerated brain aging in spontaneously hypertensive rats

While it is well-acknowledged that neurovascular dysfunction in hypertension is tightly associated with accelerated brain aging, we contend that the deleterious effects of hypertension may extend beyond affecting only the arteries. Methylglyoxal (MG) derived from glycolysis, is involved in the accumulation of advanced glycated end products (AGEs), which are the hallmarks of neurodegenerative disorders. Therefore, the present study aims to firstly investigate the role of MG metabolism in the hypertension-accelerated brain aging process. The results of our study indicate that the levels of MG increase with age in both the plasma and hippocampus of SHRs at 12, 16, and 30 weeks old. AGE methylglyoxal-hydro imidazoline-1 (MG-H1) is primarily localized in astrocytes, while its presence was not observed in neurons and microglia within the hypertensive hippocampus. Our observations also suggest that angiotensin II (Ang II) enhances glucose uptake and glycolysis while reducing the expression of Glo1 in cultured astrocytes. N-acetylcysteine (NAC) was found to counteract the increase in escape latency and inhibit the activation of the AGEs-RAGE axis in 30-week-old SHRs. NAC decreased Iba-1 immunofluorescence intensity, inhibited the levels of pro-inflammatory markers, and enhanced the abundance of anti-inflammatory markers in the hippocampus of SHRs. Moreover, NAC reduced the immunofluorescence signal of 4HNE and increased the content of GSH and SOD in SHRs. Finally, NAC was observed to inhibit apoptosis in the hippocampus of SHRs. Collectively, we firstly showed the enhanced accumulation of MG in the hypertensive brain, whereas the clearance of MG by NAC treatment mitigated the aging process and attenuated AGEs generation, neuroinflammation, and oxidative damage.

Tale of Two Cities: narrative review of oxygen

The human brain contributes 2% of the body weight yet receives 15% of cardiac output and demands a constant supply of oxygen (O ₂) and nutrients to meet its metabolic needs. Cerebral autoregulation is responsible for maintaining a constant cerebral blood flow that provides the supply of oxygen and maintains the energy storage capacity. We selected oxygen administration-related studies published between 1975-2021 that included meta-analysis, original research, commentaries, editorial, and review articles. In the present narrative review, several important aspects of the oxygen effects on brain tissues and cerebral autoregulation are discussed, as well the role of exogenous O ₂ administration in patients with chronic ischemic cerebrovascular disease: We aimed to revisit the utility of O ₂ administration in pathophysiological situations whether or not being advantageous. Indeed, a compelling clinical and experimental body of evidence questions the utility of routine oxygen administration in acute and post-recovery brain ischemia, as evident by studies in neurophysiology imaging. While O ₂ is still part of common clinical practice, it remains unclear whether its routine use is safe.

Assessing fatigue and sleep in chronic diseases using physiological signals from wearables: A pilot study

Problems with fatigue and sleep are highly prevalent in patients with chronic diseases and often rated among the most disabling symptoms, impairing their activities of daily living and the health-related quality of life (HRQoL). Currently, they are evaluated primarily via Patient Reported Outcomes (PROs), which can suffer from recall biases and have limited sensitivity to temporal variations. Objective measurements from wearable sensors allow to reliably quantify disease state, changes in the HRQoL, and evaluate therapeutic outcomes. This work investigates the feasibility of capturing continuous physiological signals from an electrocardiography-based wearable device for remote monitoring of fatigue and sleep and quantifies the relationship of objective digital measures to self-reported fatigue and sleep disturbances. 136 individuals were followed for a total of 1,297 recording days in a longitudinal multi-site study conducted in free-living settings and registered with the German Clinical Trial Registry (DRKS00021693). Participants comprised healthy individuals (N = 39) and patients with neurodegenerative disorders (NDD, N = 31) and immune mediated inflammatory diseases (IMID, N = 66). Objective physiological measures correlated with fatigue and sleep PROs, while demonstrating reasonable signal quality. Furthermore, analysis of heart rate recovery estimated during activities of daily living showed significant differences between healthy and patient groups. This work underscores the promise and sensitivity of novel digital measures from multimodal sensor time-series to differentiate chronic patients from healthy individuals and monitor their HRQoL. The presented work provides clinicians with realistic insights of continuous at home patient monitoring and its practical value in quantitative assessment of fatigue and sleep, an area of unmet need.

Neurodegenerative diseases and blood pressure variability: A comprehensive review from HOPE Asia

Asia has an enormous number of older people and is the primary contributor to the rise in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The therapy of many neurodegenerative diseases has not yet progressed to the point where it is possible to alter the course of the disease. Mid-life hypertension is an important predictor of later-life cognitive impairment and brain neurodegenerative conditions. These findings highlight the pivotal role of preventing and managing hypertension as a risk factor for neurodegenerative disease. Autonomic dysfunction, neuropsychiatric and sleep disturbances can arise in neurodegenerative diseases, resulting in blood pressure variability (BPV). The BPV itself can worsen the progression of the disease. In older people with neurodegenerative disease and hypertension, it is critical to consider 24-h blood pressure monitoring and personalized blood pressure therapy.

Targeting the blood-brain barrier disruption in hypertension by ALK5/TGF-Β type I receptor inhibitor SB-431542 and dynamin inhibitor dynasore

INTRODUCTION

In this study, we aimed to target two molecules, transforming growth factor-beta (TGF-β) and dynamin to explore their roles in blood-brain barrier (BBB) disruption in hypertension.

METHODS

For this purpose, angiotensin (ANG) II-induced hypertensive mice were treated with SB-431542, an inhibitor of the ALK5/TGF-β type I receptor, and dynasore, an inhibitor of dynamin. Albumin-Alexa fluor 594 was used to assess BBB permeability. The alterations in the expression of claudin-5, caveolin (Cav)-1, glucose transporter (Glut)-1, and SMAD4 in the cerebral cortex and the hippocampus were evaluated by quantification of immunofluorescence staining intensity.

RESULTS

ANG II infusion increased BBB permeability to albumin-Alexa fluor 594 which was reduced by SB-431542 (P < 0.01), but not by dynasore. In hypertensive animals treated with dynasore, claudin-5 immunofluorescence intensity increased in the cerebral cortex and hippocampus while it decreased in the cerebral cortex of SB-431542 treated hypertensive mice (P < 0.01). Both dynasore and SB-431542 prevented the increased Cav-1 immunofluorescence intensity in the cerebral cortex and hippocampus of hypertensive animals (P < 0.01). SB-431542 and dynasore decreased Glut-1 immunofluorescence intensity in the cerebral cortex and hippocampus of mice receiving ANG II (P < 0.01). SB-431542 increased SMAD4 immunofluorescence intensity in the cerebral cortex of hypertensive animals, while in the hippocampus a significant decrease was noted by both SB-431542 and dynasore (P < 0.01).

CONCLUSION

Our data suggest that inhibition of the TGFβ type I receptor prevents BBB disruption under hypertensive conditions. These results emphasize the therapeutic potential of targeting TGFβ signaling as a novel treatment modality to protect the brain of hypertensive patients.

Kinin B1R Activation Induces Endoplasmic Reticulum Stress in Primary Hypothalamic Neurons

The endoplasmic reticulum (ER) is a key organelle involved in homeostatic functions including protein synthesis and transport, and the storage of free calcium. ER stress potentiates neuroinflammation and neurodegeneration and is a key contributor to the pathogenesis of neurogenic hypertension. Recently, we showed that kinin B1 receptor (B1R) activation plays a vital role in modulating neuroinflammation and hypertension. However, whether B1R activation results in the progression and enhancement of ER stress has not yet been studied. In this brief research report, we tested the hypothesis that B1R activation in neurons contributes to unfolded protein response (UPR) and the development of ER stress. To test this hypothesis, we treated primary hypothalamic neuronal cultures with B1R specific agonist Lys-Des-Arg⁹-Bradykinin (LDABK) and measured the components of UPR and ER stress. Our data show that B1R stimulation via LDABK, induced the upregulation of GRP78, a molecular chaperone of ER stress. B1R stimulation was associated with an increased expression and activation of transmembrane ER stress sensors, ATF6, IRE1α, and PERK, the critical components of UPR. In the presence of overwhelming ER stress, activated ER stress sensors can lead to oxidative stress, autophagy, or apoptosis. To determine whether B1R activation induces apoptosis we measured intracellular Ca²⁺ and extracellular ATP levels, caspases 3/7 activity, and cell viability. Our data show that LDABK treatment does increase Ca²⁺ and ATP levels but does not alter caspase activity or cell viability. These findings suggest that B1R activation initiates the UPR and is a key factor in the ER stress pathway.

Gut Microbiome, Inflammation, and Cerebrovascular Function: Link Between Obesity and Cognition

Obesity affects 13% of the adult population worldwide and this number is only expected to increase. Obesity is known to have a negative impact on cardiovascular and metabolic health, but it also impacts brain structure and function; it is associated with both gray and white matter integrity loss, as well as decreased cognitive function, including the domains of executive function, memory, inhibition, and language. Especially midlife obesity is associated with both cognitive impairment and an increased risk of developing dementia at later age. However, underlying mechanisms are not yet fully revealed. Here, we review recent literature (published between 2010 and March 2021) and discuss the effects of obesity on brain structure and cognition, with a main focus on the contributions of the gut microbiome, white adipose tissue (WAT), inflammation, and cerebrovascular function. Obesity-associated changes in gut microbiota composition may cause increased gut permeability and inflammation, therewith affecting cognitive function. Moreover, excess of WAT in obesity produces pro-inflammatory adipokines, leading to a low grade systemic peripheral inflammation, which is associated with decreased cognition. The blood-brain barrier also shows increased permeability, allowing among others, peripheral pro-inflammatory markers to access the brain, leading to neuroinflammation, especially in the hypothalamus, hippocampus and amygdala. Altogether, the interaction between the gut microbiota, WAT inflammation, and cerebrovascular integrity plays a significant role in the link between obesity and cognition. Future research should focus more on the interplay between gut microbiota, WAT, inflammation and cerebrovascular function to obtain a better understanding about the complex link between obesity and cognitive function in order to develop preventatives and personalized treatments.