High-fat diet exacerbates lead-induced blood-brain barrier disruption by disrupting tight junction integrity

Linking peripheral atherosclerosis to blood-brain barrier disruption: elucidating its role as a manifestation of cerebral small vessel disease in vascular cognitive impairment

Aging plays a pivotal role in the pathogenesis of cerebral small vessel disease (CSVD), contributing to the onset and progression of vascular cognitive impairment and dementia (VCID). In older adults, CSVD often leads to significant pathological outcomes, including blood-brain barrier (BBB) disruption, which in turn triggers neuroinflammation and white matter damage. This damage is frequently observed as white matter hyperintensities (WMHs) in neuroimaging studies. There is mounting evidence that older adults with atherosclerotic vascular diseases, such as peripheral artery disease, ischemic heart disease, and carotid artery stenosis, face a heightened risk of developing CSVD and VCID. This review explores the complex relationship between peripheral atherosclerosis, the pathogenesis of CSVD, and BBB disruption. It explores the continuum of vascular aging, emphasizing the shared pathomechanisms that underlie atherosclerosis in large arteries and BBB disruption in the cerebral microcirculation, exacerbating both CSVD and VCID. By reviewing current evidence, this paper discusses the impact of endothelial dysfunction, cellular senescence, inflammation, and oxidative stress on vascular and neurovascular health. This review aims to enhance understanding of these complex interactions and advocate for integrated approaches to manage vascular health, thereby mitigating the risk and progression of CSVD and VCID.

Inhibiting ferroptosis in brain microvascular endothelial cells: A potential strategy to mitigate polystyrene nanoplastics‒induced blood‒brain barrier dysfunction

Polystyrene nanoplastics (PS-NPs), a group of ubiquitous pollutants, may injure the central nervous system through the blood‒brain barrier (BBB). However, whether exposure to PS-NPs contributes to BBB disruption and the underlying mechanisms are still unclear. In vivo, we found that PS-NPs (25 mg/kg BW) could significantly increase BBB permeability in mice and downregulate the distribution of the tight junction-associated protein zona occludens 1 (ZO-1) in brain microvascular endothelial cells (BMECs). Using an in vitro BBB model, exposure to PS-NPs significantly reduced the transendothelial electrical resistance and altered ZO-1 expression and distribution in a dose-dependent manner. RNA-seq analysis and functional investigations were used to investigate the molecular pathways involved in the response to PS-NPs. The results revealed that the ferroptosis and glutathione metabolism signaling pathways were related to the disruption of the BBB model caused by the PS-NPs. PS-NPs treatment promoted ferroptosis in bEnd.3 cells by inducing disordered glutathione metabolism in addition to Fe2+ and lipid peroxide accumulation, while suppressing ferroptosis with ferrostatin-1 (Fer-1) suppressed ferroptosis-related changes in bEnd.3 cells subjected to PS-NPs. Importantly, Fer-1 alleviated the decrease in ZO-1 expression in bEnd.3 cells and the exacerbation of BBB damage induced by PS-NPs. Collectively, our findings suggest that inhibiting ferroptosis in BMECs may serve as a potential therapeutic target against BBB disruption induced by PS-NPs exposure.

Lipopolysaccharide exacerbates depressive-like behaviors in obese rats through complement C1q-mediated synaptic elimination by microglia

AIM

Prolonged high-fat diet (HFD) consumption has been shown to impair cognition and depression. The combined effects of HFD and lipopolysaccharide (LPS) administration on those outcomes have never been thoroughly investigated. This study investigated the effects of LPS, HFD consumption, and a combination of both conditions on microglial dysfunction, microglial morphological alterations, synaptic loss, cognitive dysfunction, and depressive-like behaviors.

METHODS

Sixty-four male Wistar rats were fed either a normal diet (ND) or HFD for 12 weeks, followed by single dose-subcutaneous injection of either vehicle or LPS. Then, cognitive function and depressive-like behaviors were assessed. Then, rats were euthanized, and the whole brain, hippocampus, and spleen were collected for further investigation, including western blot analysis, qRT-PCR, immunofluorescence staining, and brain metabolome determination.

RESULTS

HFD-fed rats developed obese characteristics. Both HFD-fed rats with vehicle and ND-fed rats with LPS increased cholesterol and serum LPS levels, which were exacerbated in HFD-fed rats with LPS. HFD consumption, but not LPS injection, caused oxidative stress, blood-brain barrier disruption, and decreased neurogenesis. Both HFD and LPS administration triggered an increase in inflammatory genes on microglia and astrocytes, increased c1q colocalization with microglia, and increased dendritic spine loss, which were exacerbated in the combined conditions. Both HFD and LPS altered neurotransmitters and disrupted brain metabolism. Interestingly, HFD consumption, but not LPS, induced cognitive decline, whereas both conditions individually induced depressive-like behaviors, which were exacerbated in the combined conditions.

CONCLUSIONS

Our findings suggest that LPS aggravates metabolic disturbances, neuroinflammation, microglial synaptic engulfment, and depressive-like behaviors in obese rats.

Bone-derived PDGF-BB enhances hippocampal non-specific transcytosis through microglia-endothelial crosstalk in HFD-induced metabolic syndrome

BACKGROUND

It is well known that high-fat diet (HFD)-induced metabolic syndrome plays a crucial role in cognitive decline and brain-blood barrier (BBB) breakdown. However, whether the bone-brain axis participates in this pathological process remains unknown. Here, we report that platelet-derived growth factor-BB (PDGF-BB) secretion by preosteoclasts in the bone accelerates neuroinflammation. The expression of alkaline phosphatase (ALPL), a nonspecific transcytosis marker, was upregulated during HFD challenge.

MAIN BODY

Preosteoclast-specific Pdgfb transgenic mice with high PDGF-BB concentrations in the circulation recapitulated the HFD-induced neuroinflammation and transcytosis shift. Preosteoclast-specific Pdgfb knockout mice were partially rescued from hippocampal neuroinflammation and transcytosis shifts in HFD-challenged mice. HFD-induced PDGF-BB elevation aggravated microglia-associated neuroinflammation and interleukin-1β (IL-1β) secretion, which increased ALPL expression and transcytosis shift through enhancing protein 1 (SP1) translocation in endothelial cells.

CONCLUSION

Our findings confirm the role of bone-secreted PDGF-BB in neuroinflammation and the transcytosis shift in the hippocampal region during HFD challenge and identify a novel mechanism of microglia-endothelial crosstalk in HFD-induced metabolic syndrome.

Alisol A Exerts Neuroprotective Effects Against HFD-Induced Pathological Brain Aging via the SIRT3-NF-κB/MAPK Pathway

Chronic consumption of a high-fat diet (HFD) has profound effects on brain aging, which is mainly characterized by cognitive decline, inflammatory responses, and neurovascular damage. Alisol A (AA) is a triterpenoid with therapeutic potential for metabolic diseases, but whether it has a neuroprotective effect against brain aging caused by a HFD has not been investigated. Six-month-old male C57BL6/J mice were exposed to a HFD with or without AA treatment for 12 weeks. Behavioral tasks were used to assess the cognitive abilities of the mice. Neuroinflammation and changes in neurovascular structure in the brains were examined. We further assessed the mechanism by which AA exerts neuroprotective effects against HFD-induced pathological brain aging in vitro and in vivo. Behavioral tests showed that cognitive function was improved in AA-treated animals. AA treatment reduced microglia activation and inflammatory cytokine release induced by a HFD. Furthermore, AA treatment increased the number of hippocampal neurons, the density of dendritic spines, and the expression of tight junction proteins. We also demonstrated that AA attenuated microglial activation by targeting the SIRT3-NF-κB/MAPK pathway and ameliorated microglial activation-induced tight junction degeneration in endothelial cells and apoptosis in hippocampal neurons. The results of this study show that AA may be a promising agent for the treatment of HFD-induced brain aging.

Promotion of neuroinflammation by the glymphatic system: a new insight into ethanol extracts from Alisma orientale in alleviating obesity-associated cognitive impairment

BACKGROUND

Obesity is one of the critical risk factors for cognitive dysfunction. The glymphatic system (GS) plays a key role in the pathogenesis of cognitive deficits. Alisma orientale has been shown to have anti-inflammatory and antihyperlipidemic effects, whereas its effects and underlying mechanisms on obesity-associated cognitive impairment (OACI) are unclear.

PURPOSE

This work aims to decipher the mechanism of ethanol extracts from Alisma orientale (EEAO) in restoring cognitive impairment in HFD-induced obese mice through a GS approach.

METHODS

The restoration of abnormal glucose/lipid metabolism and excess adipose deposition by EEAO were assayed by biochemical analysis and visually displayed by a micro-CT scanner and Oil Red O staining. Biochemical assays and Western blotting (WB) were used to measure cerebral blood flow (CBF), free fatty acid (FFAs) levels and the structural integrity of the blood-brain barrier (BBB). Microglial activation and neuroinflammation were assessed with immunohistochemistry staining, ELISA and WB. Moreover, GS function was determined by immunofluorescence staining, fluorescence tracer imaging and WB. Finally, the neuropathological features and cognitive functions were detested with immunohistochemistry staining, immunofluorescence and Morris Water Maze.

RESULTS

EEAO not only alleviated body weight, cerebral lipid accumulation and serum FFAs in HFD-induced obese mice, but also increased CBF and BBB integrity. EEAO suppressed microglial activation and lipid deposition in the hippocampus and reduced the level of inflammatory cytokines including IL-6, IL-1β and TNF-α in brain tissue. Interestingly, long-term HFD-induced GS dysfunction was significantly restored after EEAO intervention, and neuropathological lesions and cognitive deficits were also markedly rescued.

CONCLUSION

EEAO rescued the cognitive deficits of OACI by inhibiting neuroinflammation and restoring GS dysfunction, indicating a potential remedy for OACI.

MiR-107-3p Knockdown Alleviates Endothelial Injury in Sepsis via Kallikrein-Related Peptidase 5

INTRODUCTION

Endothelial injury is a major characteristic of sepsis and contributes to sepsis-induced multiple-organ dysfunction. In this study, we investigated the role of miR-107-3p in sepsis-induced endothelial injury.

METHODS

Human umbilical vein endothelial cells (HUVECs) were exposed to 20 μg/mL of lipopolysaccharide (LPS) for 6-48 h. The levels of miR-107-3p and kallikrein-related peptidase 5 (KLK5) were examined. HUVECs were treated with LPS for 12 h and subsequently transfected with miR-107-3p inhibitor, KLK5 siRNA, or cotransfected with KLK5 siRNA and miR-107-3p inhibitor/negative control inhibitor. Cell survival, apoptosis, invasion, cell permeability, inflammatory response, and the Toll-like receptor 4/nuclear factor κB signaling were evaluated. In addition, the relationship between miR-107-3p and KLK5 expression was predicted and verified.

RESULTS

LPS significantly elevated miR-107-3p levels, which peaked at 12 h. Conversely, the KLK5 level was lower in the LPS group than in the control group and was lowest at 12 h. MiR-107-3p knockdown significantly attenuated reductions in cell survival and invasion, apoptosis promotion, hyperpermeability and inflammation induction, and activation of the NF-κB signaling caused by LPS. KLK5 knockdown had the opposite effect. Additionally, KLK5 was demonstrated as a target of miR-107-3p. MiR-107-3p knockdown partially reversed the effects of KLK5 depletion in LPS-activated HUVECs.

CONCLUSIONS

Our findings indicate that miR-107-3p knockdown may protect against sepsis-induced endothelial cell injury by targeting KLK5. This study identified a novel therapeutic target for sepsis-induced endothelial injury.

Nicotinamide, an acetylcholinesterase uncompetitive inhibitor, protects the blood‒brain barrier and improves cognitive function in rats fed a hypercaloric diet

Oxidative stress and inflammation induced by abundant consumption of high-energy foods and caloric overload are implicated in the dysfunction of the blood‒brain barrier (BBB), cognitive impairment, and overactivation of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). These enzymes hydrolyse acetylcholine, affecting anti-inflammatory cholinergic signalling. Our aim was to evaluate whether nicotinamide (NAM) attenuates the impairment of the BBB and cognitive function, improving cholinergic signalling. Forty male rats were distributed into five groups: one group was fed a standard diet, and the remaining groups were fed a high-fat diet and a beverage with 40% sucrose (HFS; high-fat sucrose). In three of the HFS groups, the carbohydrate was replaced by drinking water containing different concentrations of NAM for 5 h every morning for 12 weeks. The biochemical profile, levels of stress and inflammation markers, cholinesterase activities, BBB permeability, and cognitive capacity were evaluated. The results showed that the HFS diet disturbed the metabolism of carbohydrates and lipids, causing insulin resistance. Simultaneously, AChE and BChE activities, levels of proinflammatory cytokines, oxidation of proteins and lipoperoxidation increased along with decreased antioxidant capacity in serum. In the hippocampus, increased activity of cholinesterases, protein carbonylation and lipoperoxidation were associated with decreased antioxidant capacity. Systemic and hippocampal changes were reflected in increased BBB permeability and cognitive impairment. In contrast, NAM attenuated the above changes by reducing oxidative stress and inflammation through decreasing cholinesterase activities, especially by uncompetitive inhibition. NAM may be a potential systemic and neuroprotective agent to mitigate cognitive damage due to hypercaloric diets.

Effects of sinapic acid on lead acetate-induced oxidative stress, apoptosis and inflammation in testicular tissue

In this study, the effect of lead acetate (PbAc) and sinapic acid (SNP) administration on oxidative stress, apoptosis, inflammation, sperm quality and histopathology in testicular tissue of rats was tried to be determined. PbAc was administered at a dose of 30 mg/kg/bw for 7 days to induce testicular toxicity in rats. Oral doses of 5 and 10 mg/kg/bw SNP were administered to rats for 7 days after PbAc administration. According to our findings, while PbAc administration increased MDA content in rats, it decreased GPx, SOD, CAT activity and GSH content. NF-kB, IL-1β, TNF-α, and COX-2, which are among the inflammation parameters that increased due to PbAc, decreased with the administration of SNP. Nrf2, HO-1, and NQO1 mRNA transcript levels decreased with PbAc, but SNP treatments increased these mRNA levels in a dose-dependent manner. RAGE and NLRP3 gene expression were upregulated in PbAc treated rats. MAPK14, MAPK15, and JNK relative mRNA levels decreased with SNP treatment in PbAc treated rats. While the levels of apoptosis markers Bax, Caspase-3, and Apaf-1 increased in rats treated with PbAc, the level of Bcl-2 decreased, but SNP inhibited this apoptosis markers. PbAc caused histopathological deterioration in testis tissue and negatively affected spermatogenesis. When the sperm quality was examined, the decrease in sperm motility and spermatozoon density caused by PbAc, and the increase in the ratio of dead and abnormal spermatozoa were inhibited by SNP. As a result, while PbAc increased apoptosis and inflammation by inducing oxidative stress in testicles, SNP treatment inhibited these changes and increased sperm quality.

Disease-associated astrocytes and microglia markers are upregulated in mice fed high fat diet

High-fat diet (HFD) is associated with Alzheimer's disease (AD) and type 2 diabetes risk, which share features such as insulin resistance and amylin deposition. We examined gene expression associated with astrocytes and microglia since dysfunction of these cell types is implicated in AD pathogenesis. We hypothesize gene expression changes in disease-associated astrocytes (DAA), disease-associated microglia and human Alzheimer's microglia exist in diabetic and obese individuals before AD development. By analyzing bulk RNA-sequencing (RNA-seq) data generated from brains of mice fed HFD and humans with AD, 11 overlapping AD-associated differentially expressed genes were identified, including Kcnj2, C4b and Ddr1, which are upregulated in response to both HFD and AD. Analysis of single cell RNA-seq (scRNA-seq) data indicated C4b is astrocyte specific. Spatial transcriptomics (ST) revealed C4b colocalizes with Gfad, a known astrocyte marker, and the colocalization of C4b expressing cells with Gad2 expressing cells, i.e., GABAergic neurons, in mouse brain. There also exists a positive correlation between C4b and Gad2 expression in ST indicating a potential interaction between DAA and GABAergic neurons. These findings provide novel links between the pathogenesis of obesity, diabetes and AD and identify C4b as a potential early marker for AD in obese or diabetic individuals.

Elevated PDGF-BB from Bone Impairs Hippocampal Vasculature by Inducing PDGFRβ Shedding from Pericytes

Evidence suggests a unique association between bone aging and neurodegenerative/cerebrovascular disorders. However, the mechanisms underlying bone-brain interplay remain elusive. Here platelet-derived growth factor-BB (PDGF-BB) produced by preosteoclasts in bone is reported to promote age-associated hippocampal vascular impairment. Aberrantly elevated circulating PDGF-BB in aged mice and high-fat diet (HFD)-challenged mice correlates with capillary reduction, pericyte loss, and increased blood-brain barrier (BBB) permeability in their hippocampus. Preosteoclast-specific Pdgfb transgenic mice with markedly high plasma PDGF-BB concentration faithfully recapitulate the age-associated hippocampal BBB impairment and cognitive decline. Conversely, preosteoclast-specific Pdgfb knockout mice have attenuated hippocampal BBB impairment in aged mice or HFD-challenged mice. Persistent exposure of brain pericytes to high concentrations of PDGF-BB upregulates matrix metalloproteinase 14 (MMP14), which promotes ectodomain shedding of PDGF receptor β (PDGFRβ) from pericyte surface. MMP inhibitor treatment alleviates hippocampal pericyte loss and capillary reduction in the conditional Pdgfb transgenic mice and antagonizes BBB leakage in aged mice. The findings establish the role of bone-derived PDGF-BB in mediating hippocampal BBB disruption and identify the ligand-induced PDGFRβ shedding as a feedback mechanism for age-associated PDGFRβ downregulation and the consequent pericyte loss.

Regional specific effect of saturated vs unsaturated fat on leptin receptor signalling in mice brain areas regulating feeding

Leptin receptors (LepR) are expressed in brain areas controlling food intake homeostasis, such as the hypothalamus, the hippocampus and the prefrontal cortex. In a previous study we reported that long-term intake of saturated and monounsaturated fat alters hypothalamic LepR signalling. The current study aims at investigating the effect of foods high in either saturated (SOLF) or monounsaturated fat (UOLF) on LepR functionality in the hippocampus and the prefrontal cortex. Male mice were placed on SOLF/UOLF (eight weeks), then treated with recombinant murine leptin (1 mg/kg). After 60 min, brain regions were dissected and processed for western blot of phosphorylated STAT3 (pSTAT3), Akt (pAkt) and AMPK (pAMPK). Levels of SOCS3 were also quantified. SOLF itself increased basal levels of pSTAT3, while UOLF impaired leptin-induced phosphorylation of both Akt and AMPK. SOCS3 levels were specifically increased by UOLF within the prefrontal cortex. Our results show that SOLF and UOLF differently affect LepR signalling within the hippocampus and the prefrontal cortex, which points to the complex effect of saturated and unsaturated fat on brain function, particularly in areas regulating food intake.

Liver Steatosis and Steatohepatitis Alter Bile Acid Receptors in Brain and Induce Neuroinflammation: A Contribution of Circulating Bile Acids and Blood-Brain Barrier

A tight relationship between gut-liver diseases and brain functions has recently emerged. Bile acid (BA) receptors, bacterial-derived molecules and the blood-brain barrier (BBB) play key roles in this association. This study was aimed to evaluate how non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) impact the BA receptors Farnesoid X receptor (FXR) and Takeda G-protein coupled receptor 5 (TGR5) expression in the brain and to correlate these effects with circulating BAs composition, BBB integrity and neuroinflammation. A mouse model of NAFLD was set up by a high-fat and sugar diet, and NASH was induced with the supplementation of dextran-sulfate-sodium (DSS) in drinking water. FXR, TGR5 and ionized calcium-binding adaptor molecule 1 (Iba-1) expression in the brain was detected by immunohistochemistry, while Zonula occludens (ZO)-1, Occludin and Plasmalemmal Vesicle Associated Protein-1 (PV-1) were analyzed by immunofluorescence. Biochemical analyses investigated serum BA composition, lipopolysaccharide-binding protein (LBP) and S100β protein (S100β) levels. Results showed a down-regulation of FXR in NASH and an up-regulation of TGR5 and Iba-1 in the cortex and hippocampus in both treated groups as compared to the control group. The BA composition was altered in the serum of both treated groups, and LBP and S100β were significantly augmented in NASH. ZO-1 and Occludin were attenuated in the brain capillary endothelial cells of both treated groups versus the control group. We demonstrated that NAFLD and NASH provoke different grades of brain dysfunction, which are characterized by the altered expression of BA receptors, FXR and TGR5, and activation of microglia. These effects are somewhat promoted by a modification of circulating BAs composition and by an increase in LBP that concur to damage BBB, thus favoring neuroinflammation.

Attenuation of Palmitic Acid-Induced Intestinal Epithelial Barrier Dysfunction by 6-Shogaol in Caco-2 Cells: The Role of MiR-216a-5p/TLR4/NF-κB Axis

Palmitic acid (PA) can lead to intestinal epithelial barrier dysfunction. In this study, the protective effects and working mechanisms of 6-shogaol against PA-induced intestinal barrier dysfunction were investigated in human intestinal epithelial Caco-2 cells. Transepithelial electrical resistance (TEER), paracellular flux, qRT-PCR, immunofluorescence, and Western blot experiments showed that the 24-h treatment with 400 μM PA damaged intestinal barrier integrity, as evidenced by a reduction of 48% in the TEER value, a 4.1-fold increase in the flux of fluorescein isothiocyanate-dextran 4000 (FD-4), and decreases in the mRNA and protein expression of tight junction (TJ)-associated proteins (claudin-1, occludin, and ZO-1), compared with the control. The PA treatment significantly (p < 0.05) increased the levels of pro-inflammatory cytokines (interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α)) in Caco-2 cells due to the upregulation of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), phosphorylated nuclear factor kappa-B (NF-κB) proteins, and downregulation of miR-216a-5p (which directly targeted TLR4). Co-treatment with PA and 6-shogaol (2.5 μM) significantly (p < 0.05) attenuated PA-induced changes through regulation of TJs via the miR-216a-5p/TLR4/NF-κB signaling pathway. This study provides insights into the functions and working mechanisms of 6-shogaol as a promising food-derived agent against PA-induced intestinal epithelial barrier dysfunction.

Long-term maintenance of synaptic plasticity by Fullerenol Ameliorates lead-induced-impaired learning and memory in vivo

Fullerenol, a functional and water-soluble fullerene derivative, plays an important role in antioxidant, antitumor and antivirus, implying its enormous potential in biomedical applications. However, the in vivo performance of fullerenol remains largely unclear. We aimed to investigate the effect of fullerenol (i.p., 5 mg/kg) on the impaired hippocampus in a rat model of lead exposure. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a kind of newly developed soft-ionization mass spectrometry technology. In the present study, an innovative strategy for biological distribution analysis using MALDI-TOF-MS confirmed that fullerenol could across the blood-brain barrier and accumulate in the brain. Results from behavioral tests showed that a low dose of fullerenol could improve the impaired learning and memory induced by lead. Furthermore, electrophysiology examinations indicated that this potential repair effect of fullerenol was mainly due to the long-term changes in hippocampal synaptic plasticity, with enhancement lasting for more than 2-3 h. In addition, morphological observations and biochemistry analyses manifested that the long-term change in synaptic efficacy was accompanied by some structural alteration in synaptic connection. Our study demonstrates the therapeutic feature of fullerenol will be beneficial to the discovery and development as a new drug and lays a solid foundation for further biomedical applications of nanomedicines.

Neurovascular Dysfunction in Diverse Communities With Health Disparities-Contributions to Dementia and Alzheimer's Disease

Alzheimer's disease and related dementias (ADRD) are an expanding worldwide crisis. In the absence of scientific breakthroughs, the global prevalence of ADRD will continue to increase as more people are living longer. Racial or ethnic minority groups have an increased risk and incidence of ADRD and have often been neglected by the scientific research community. There is mounting evidence that vascular insults in the brain can initiate a series of biological events leading to neurodegeneration, cognitive impairment, and ADRD. We are a group of researchers interested in developing and expanding ADRD research, with an emphasis on vascular contributions to dementia, to serve our local diverse community. Toward this goal, the primary objective of this review was to investigate and better understand health disparities in Alabama and the contributions of the social determinants of health to those disparities, particularly in the context of vascular dysfunction in ADRD. Here, we explain the neurovascular dysfunction associated with Alzheimer's disease (AD) as well as the intrinsic and extrinsic risk factors contributing to dysfunction of the neurovascular unit (NVU). Next, we ascertain ethnoregional health disparities of individuals living in Alabama, as well as relevant vascular risk factors linked to AD. We also discuss current pharmaceutical and non-pharmaceutical treatment options for neurovascular dysfunction, mild cognitive impairment (MCI) and AD, including relevant studies and ongoing clinical trials. Overall, individuals in Alabama are adversely affected by social and structural determinants of health leading to health disparities, driven by rurality, ethnic minority status, and lower socioeconomic status (SES). In general, these communities have limited access to healthcare and healthy food and other amenities resulting in decreased opportunities for early diagnosis of and pharmaceutical treatments for ADRD. Although this review is focused on the current state of health disparities of ADRD patients in Alabama, future studies must include diversity of race, ethnicity, and region to best be able to treat all individuals affected by ADRD.

Effects of Lipolysis-Stimulated Lipoprotein Receptor on Tight Junctions of Pancreatic Ductal Epithelial Cells in Hypertriglyceridemic Acute Pancreatitis

Objective

We investigated the effects of lipolysis-stimulated lipoprotein receptor (LSR) on the tight junctions (TJs) of pancreatic ductal epithelial cells (PDECs) in hypertriglyceridemic acute pancreatitis (HTGAP).

Methods

Sprague-Dawley rats were fed standard rat chow or a high-fat diet and injected with sodium taurocholate to obtain normal and HTGAP rats, respectively. Serum triglyceride (TG) levels, pathological changes, TJ proteins in the pancreas, and TJ ultrastructure of PDECs were assessed. LSR overexpression (OE) and knockdown (KD) HPDE6-C7 models were designed and cultured in a high-fat environment. Protein levels were quantified by Western blotting. Cell monolayer permeability was detected using FITC-Dextran.

Results

Serum TG concentration and pancreatic scores were higher in the HTGAP group than in the normal group. Among the TJ proteins, LSR protein expression was significantly lower in the HTGAP group than in the acute pancreatitis (AP) group. Tricellulin (TRIC) expression in the pancreatic ductal epithelia was higher in the HTGAP group than in the AP group. The HTGAP group had lower TJ protein levels, wider intercellular space, and widespread cellular necrosis with disappearance of cell junction structures. In the cell study, TJ proteins were downregulated and the cellular barrier was impaired by palmitic acid (PA), which was reversed by LSR-OE, whereas LSR-KD downregulated the TJ proteins and aggravated PA-induced cellular barrier impairment.

Conclusions

Hypertriglyceridemia downregulates the TJ proteins in PDECs, which may impair the pancreatic ductal mucosal barrier function. LSR regulation can change the effects of HTG on cellular barrier function by upregulating the TJ proteins.