Stressor control and regional inflammatory responses in the brain: regulation by the basolateral amygdala.

Increasing evidence has connected the development of certain neuropsychiatric disorders, as well as neurodegenerative diseases, to stress-induced dysregulation of the immune system. We have shown that escapable (ES) and inescapable (IS) footshock stress, and memories associated with ES or IS, can differentially alter inflammatory-related gene expression in brain in a region dependent manner. We have also demonstrated that the basolateral amygdala (BLA) regulates stress- and fear memory-induced alterations in sleep, and that differential sleep and immune responses in the brain to ES and IS appear to be integrated during fear conditioning and then reproduced by fear memory recall. In this study, we investigated the role of BLA in influencing regional inflammatory responses within the hippocampus (HPC) and medial prefrontal cortex (mPFC) by optogenetically stimulating or inhibiting BLA in male C57BL/6 mice during footshock stress in our yoked shuttlebox paradigm based on ES and IS. Then, mice were immediately euthanized and RNA extracted from brain regions of interest and loaded into NanoString® Mouse Neuroinflammation Panels for compilation of gene expression profiles. Results showed differential regional effects in gene expression and activated pathways involved in inflammatory-related signaling following ES and IS, and these differences were altered depending on amygdalar excitation or inhibition. These findings demonstrate that the stress-induced immune response, or "parainflammation", is affected by stressor controllability and that BLA influences regional parainflammation to ES or IS in HPC and mPFC. The study illustrates how stress-induced parainflammation can be regulated at the neurocircuit level and suggests that this approach can be useful for uncovering circuit and immune interactions in mediating differential stress outcomes.

Reversing neural circuit and behavior deficit in mice exposed to maternal inflammation by Zika virus.

Zika virus (ZIKV) infection during pregnancy is linked to various developmental brain disorders. Infants who are asymptomatic at birth might have postnatal neurocognitive complications. However, animal models recapitulating these neurocognitive phenotypes are lacking, and the circuit mechanism underlying behavioral abnormalities is unknown. Here, we show that ZIKV infection during mouse pregnancy induces maternal immune activation (MIA) and leads to autistic-like behaviors including repetitive self-grooming and impaired social memory in offspring. In the medial prefrontal cortex (mPFC), ZIKV-affected offspring mice exhibit excitation and inhibition imbalance and increased cortical activity. This could be explained by dysregulation of inhibitory neurons and synapses, and elevated neural activity input from mPFC-projecting ventral hippocampus (vHIP) neurons. We find structure alterations in the synaptic connections and pattern of vHIP innervation of mPFC neurons, leading to hyperconnectivity of the vHIP-mPFC pathway. Decreasing the activity of mPFC-projecting vHIP neurons with a chemogenetic strategy rescues social memory deficits in ZIKV offspring mice. Our studies reveal a hyperconnectivity of vHIP to mPFC projection driving social memory deficits in mice exposed to maternal inflammation by ZIKV.

Activation of cannabinoid-2 receptor protects against Pseudomonas aeruginosa induced acute lung injury and inflammation.

BACKGROUND: Bacterial pneumonia is a major risk factor for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Pseudomonas aeruginosa (PA), an opportunistic pathogen with an increasing resistance acquired against multiple drugs, is one of the main causative agents of ALI and ARDS in diverse clinical settings. Given the anti-inflammatory role of the cannabinoid-2 receptor (CB2R), the effect of CB2R activation in the regulation of PA-induced ALI and inflammation was tested in a mouse model as an alternative to conventional antibiotic therapy. METHODS: In order to activate CB2R, a selective synthetic agonist, JWH133, was administered intraperitoneally (i.p.) to C57BL/6J mice. Furthermore, SR144528 (a selective CB2R antagonist) was administered in combination with JWH133 to test the specificity of the CB2R-mediated effect. PA was administered intratracheally (i.t.) for induction of pneumonia in mice. At 24 h after PA exposure, lung mechanics were measured using the FlexiVent system. The total cell number, protein content, and neutrophil population in the bronchoalveolar lavage fluid (BALF) were determined. The bacterial load in the whole lung was also measured. Lung injury was evaluated by histological examination and PA-induced inflammation was assessed by measuring the levels of BALF cytokines and chemokines. Neutrophil activation (examined by immunofluorescence and immunoblot) and PA-induced inflammatory signaling (analyzed by immunoblot) were also studied. RESULTS: CB2R activation by JWH133 was found to significantly reduce PA-induced ALI and the bacterial burden. CB2R activation also suppressed the PA-induced increase in immune cell infiltration, neutrophil population, and inflammatory cytokines. These effects were abrogated by a CB2R antagonist, SR144528, further confirming the specificity of the CB2R-mediated effects. CB2R-knock out (CB2RKO) mice had a significantly higher level of PA-induced inflammation as compared to that in WT mice. CB2R activation diminished the excess activation of neutrophils, whereas mice lacking CB2R had elevated neutrophil activation. Pharmacological activation of CB2R significantly reduced the PA-induced NF-κB and NLRP3 inflammasome activation, whereas CB2KO mice had elevated NLRP3 inflammasome. CONCLUSION: Our findings indicate that CB2R activation ameliorates PA-induced lung injury and inflammation, thus paving the path for new therapeutic avenues against PA pneumonia.

Shifting Dynamics of Intestinal Macrophages during Simian Immunodeficiency Virus Infection in Adult Rhesus Macaques.

The intestinal tract is a primary barrier to invading pathogens and contains immune cells, including lymphocytes and macrophages. We previously reported that CD163+CD206- (single-positive [SP]) interstitial macrophages of the lung are short-lived and succumb early to SIV infection. Conversely, CD163+CD206+ (double-positive [DP]) alveolar macrophages are long-lived, survive after SIV infection, and may contribute to the virus reservoir. This report characterizes analogous populations of macrophages in the intestinal tract of rhesus macaques (Macaca mulatta) with SIV/AIDS. By flow cytometry analysis, immunofluorescence staining, and confocal microscopy, CD163+CD206+ DP macrophages predominated in the lamina propria of uninfected animals, compared with CD163+CD206- SP macrophages, which predominated in the lamina propria in animals with SIV infection that were exhibiting AIDS. In submucosal areas, CD163+CD206+ DP macrophages predominated in both SIV-infected and uninfected macaques. Furthermore, BrdU-labeled CD163+CD206+ DP and CD163+CD206- SP macrophages recently arriving in the colon, which are both presumed to be shorter-lived, were observed to localize only in the lamina propria. Conversely, longer-lived CD163+CD206+ DP macrophages that retained dextran at least 2 mo after in vivo administration localized exclusively in the submucosa. This suggests that CD163+CD206+ DP intestinal macrophages of the lamina propria were destroyed after SIV infection and replaced by immature CD163+CD206- SP macrophages, whereas longer-lived CD163+CD206+ DP macrophages remained in the submucosa, supporting their potential role as an SIV/HIV tissue reservoir. Moreover, the DP macrophages in the submucosa, which differ from lamina propria DP macrophages, may be missed from pinch biopsy sampling, which may preclude detecting virus reservoirs for monitoring HIV cure.

Rapid Turnover and High Production Rate of Myeloid Cells in Adult Rhesus Macaques with Compensations during Aging.

Neutrophils, basophils, and monocytes are continuously produced in bone marrow via myelopoiesis, circulate in blood, and are eventually removed from circulation to maintain homeostasis. To quantitate the kinetics of myeloid cell movement during homeostasis, we applied 5-bromo-2'-deoxyuridine pulse labeling in healthy rhesus macaques (Macaca mulatta) followed by hematology and flow cytometry analyses. Results were applied to a mathematical model, and the blood circulating half-life and daily production, respectively, of each cell type from macaques aged 5-10 y old were calculated for neutrophils (1.63 ± 0.16 d, 1.42 × 109 cells/l/d), basophils (1.78 ± 0.30 d, 5.89 × 106 cells/l/d), and CD14+CD16- classical monocytes (1.01 ± 0.15 d, 3.09 × 108 cells/l/d). Classical monocytes were released into the blood circulation as early as 1 d after dividing, whereas neutrophils remained in bone marrow 4-5 d before being released. Among granulocytes, neutrophils and basophils exhibited distinct kinetics in bone marrow maturation time and blood circulation. With increasing chronological age, there was a significant decrease in daily production of neutrophils and basophils, but the half-life of these granulocytes remained unchanged between 3 and 19 y of age. In contrast, daily production of classical monocytes remained stable through 19 y of age but exhibited a significant decline in half-life. These results demonstrated relatively short half-lives and continuous replenishment of neutrophils, basophils, and classical monocytes during homeostasis in adult rhesus macaques with compensations observed during increasing chronological age.

Dysregulation of sonic hedgehog pathway and pericytes in the brain after lentiviral infection.

BACKGROUND: Impairment of the blood-brain barrier (BBB) has been associated with cognitive decline in many CNS diseases, including HIV-associated neurocognitive disorders (HAND). Recent research suggests an important role for the Sonic hedgehog (Shh) signaling pathway in the maintenance of BBB integrity under both physiological and pathological conditions. METHODS: In the present study, we sought to examine the expression of Shh and its downstream effectors in relation to brain pericytes and BBB integrity in HIV-infected humans and rhesus macaques infected with simian immunodeficiency virus (SIV), an animal model of HIV infection and CNS disease. Cortical brain tissues from uninfected (n = 4) and SIV-infected macaques with (SIVE, n = 6) or without encephalitis (SIVnoE, n = 4) were examined using multi-label, semi-quantitative immunofluorescence microscopy of Shh, netrin-1, tight junction protein zona occludens 1 (ZO1), glial fibrillary acidic protein, CD163, platelet-derived growth factor receptor b (PDGFRB), glucose transporter 1, fibrinogen, and SIV Gag p28. RESULTS: While Shh presence in the brain persisted during HIV/SIV infection, both netrin-1 immunoreactivity and the size of PDGFRB+ pericytes, a cellular source of netrin-1, were increased around non-lesion-associated vessels in encephalitis compared to uninfected brain or brain without encephalitis, but were completely absent in encephalitic lesions. Hypertrophied pericytes were strongly localized in areas of fibrinogen extravasation and showed the presence of intracellular SIVp28 and HIVp24 by immunofluorescence in all SIV and HIV encephalitis cases examined, respectively. CONCLUSIONS: The lack of pericytes and netrin-1 in encephalitic lesions, in line with downregulation of ZO1 on the fenestrated endothelium, suggests that pericyte loss, despite the strong presence of Shh, contributes to HIV/SIV-induced BBB disruption and neuropathogenesis in HAND.

HIV-1 Tat and opioids act independently to limit antiretroviral brain concentrations and reduce blood-brain barrier integrity.

Poor antiretroviral penetration may contribute to human immunodeficiency virus (HIV) persistence within the brain and to neurocognitive deficits in opiate abusers. To investigate this problem, HIV-1 Tat protein and morphine effects on blood-brain barrier (BBB) permeability and drug brain penetration were explored using a conditional HIV-1 Tat transgenic mouse model. Tat and morphine effects on the leakage of fluorescently labeled dextrans (10-, 40-, and 70-kDa) into the brain were assessed. To evaluate effects on antiretroviral brain penetration, Tat+ and Tat- mice received three antiretroviral drugs (dolutegravir, abacavir, and lamivudine) with or without concurrent morphine exposure. Antiretroviral and morphine brain and plasma concentrations were determined by LC-MS/MS. Morphine exposure, and, to a lesser extent, Tat, significantly increased tracer leakage from the vasculature into the brain. Despite enhanced BBB breakdown evidenced by increased tracer leakiness, morphine exposure led to significantly lower abacavir concentrations within the striatum and significantly less dolutegravir within the hippocampus and striatum (normalized to plasma). P-glycoprotein, an efflux transporter for which these drugs are substrates, expression and function were significantly increased in the brains of morphine-exposed mice compared to mice not exposed to morphine. These findings were consistent with lower antiretroviral concentrations in brain tissues examined. Lamivudine concentrations were unaffected by Tat or morphine exposure. Collectively, our investigations indicate that Tat and morphine differentially alter BBB integrity. Morphine decreased brain concentrations of specific antiretroviral drugs, perhaps via increased expression of the drug efflux transporter, P-glycoprotein.

Lack of susceptibility in neonatally infected rhesus macaques to simian immunodeficiency virus-induced encephalitis.

Despite combination antiretroviral therapies making HIV a chronic rather than terminal condition for many people, the prevalence of HIV-associated neurocognitive disorders (HAND) is increasing. This is especially problematic for children living with HIV. Children diagnosed HAND rarely display the hallmark pathology of HIV encephalitis in adults, namely infected macrophages and multinucleated giant cells in the brain. This finding has also been documented in rhesus macaques infected perinatally with simian immunodeficiency virus (SIV). However, the extent and mechanisms of lack of susceptibility to encephalitis in perinatally HIV-infected children remain unclear. In the current study, we compared brains of macaques infected with pathogenic strains of SIV at different ages to determine neuropathology, correlates of neuroinflammation, and potential underlying mechanisms. Encephalitis was not found in the macaques infected within 24 h of birth despite similar high plasma viral load and high monocyte turnover. Macaques developed encephalitis only when they were infected after 4 months of age. Lower numbers of CCR5-positive cells in the brain, combined with a less leaky blood-brain barrier, may be responsible for the decreased virus infection in the brain and consequently the absence of encephalitis in newborn macaques infected with SIV.

Critical Role for Monocytes/Macrophages in Rapid Progression to AIDS in Pediatric Simian Immunodeficiency Virus-Infected Rhesus Macaques.

Infant humans and rhesus macaques infected with the human or simian immunodeficiency virus (HIV or SIV), respectively, express higher viral loads and progress more rapidly to AIDS than infected adults. Activated memory CD4+ T cells in intestinal tissues are major primary target cells for SIV/HIV infection, and massive depletion of these cells is considered a major cause of immunodeficiency. Monocytes and macrophages are important cells of innate immunity and also are targets of HIV/SIV infection. We reported previously that a high peripheral blood monocyte turnover rate was predictive for the onset of disease progression to AIDS in SIV-infected adult macaques. The purpose of this study was to determine if earlier or higher infection of monocytes/macrophages contributes to the more rapid progression to AIDS in infants. We observed that uninfected infant rhesus macaques exhibited higher physiologic baseline monocyte turnover than adults. Early after SIV infection, the monocyte turnover further increased, and it remained high during progression to AIDS. A high percentage of terminal deoxynucleotidyltransferase dUTP nick end label (TUNEL)-positive macrophages in the lymph nodes (LNs) and intestine corresponded with an increasing number of macrophages derived from circulating monocytes (bromodeoxyuridine positive [BrdU+] CD163+), suggesting that the increased blood monocyte turnover was required to rapidly replenish destroyed tissue macrophages. Immunofluorescence analysis further demonstrated that macrophages were a significant portion of the virus-producing cells found in LNs, intestinal tissues, and lungs. The higher baseline monocyte turnover in infant macaques and subsequent macrophage damage by SIV infection may help explain the basis of more rapid disease progression to AIDS in infants.IMPORTANCE HIV infection progresses much more rapidly in pediatric cases than in adults; however, the mechanism for this difference is unclear. Using the rhesus macaque model, this work was performed to address why infants infected with SIV progress more quickly to AIDS than do adults. Earlier we reported that in adult rhesus macaques, increasing monocyte turnover reflected tissue macrophage damage by SIV and was predictive of terminal disease progression to AIDS. Here we report that uninfected infant rhesus macaques exhibited a higher physiological baseline monocyte turnover rate than adults. Furthermore, once infected with SIV, infants displayed further increased monocyte turnover that may have facilitated the accelerated progression to AIDS. These results support a role for monocytes and macrophages in the pathogenesis of SIV/HIV and begin to explain why infants are more prone to rapid disease progression.

Effect of number of pontics and impression technique on the accuracy of four-unit monolithic zirconia fixed dental prostheses.

STATEMENT OF PROBLEM: Because of their relatively small scanning area, intraoral scanners may result in less accurate fixed dental prostheses (FDPs) than do laboratory scanners. PURPOSE: The purpose of this in vitro study was to evaluate the accuracy of monolithic zirconia FDPs with different numbers of pontics fabricated with different impression techniques. MATERIAL AND METHODS: The mandibular right premolars and molars of an acrylic resin model were prepared to receive 4-unit FDPs. Three master models were fabricated with epoxy resin: model NP, no pontic; model 1P, 1 pontic; and model 2P, 2 pontics. Each master model was scanned by using direct (DD) and indirect digitalization (ID). Four-unit monolithic zirconia FDPs were fabricated and divided into 3 groups (groups NP, 1P, and 2P) and then subdivided according to the digitalization technique (group DD and ID; n=10). The FDPs were also evaluated based on the presence (Po) or absence (NPo) of an adjacent pontic. The marginal, axial, and occlusal gap widths of each FDP were measured, and statistical analyses were performed to evaluate and compare the amount of gap present (α=.05). RESULTS: For direct digitalization, group 2P had significantly greater marginal (69.4 µm versus 60.9 µm or 62.3 µm; P<.001) and axial gap widths (127.1 µm versus 108.9 µm or 110.4 µm; P<.001) than group NP or 1P. Group DD resulted in significantly smaller gaps compared with group ID at marginal (64.8 µm versus 73.6 µm), axial (114.8 µm versus 124.3 µm), and occlusal (172.6 µm versus 184.1 µm) measurement locations (P<.001). Greater marginal and axial gaps were noted in group Po than NPo (P<.001). CONCLUSIONS: The length of the edentulous area significantly influenced the extent of the marginal and internal gap with the use of direct digitalization. Direct digitalization resulted in significantly smaller gap widths in all measurement areas than indirect digitalization; however, the mean differences were less than 12 µm, which is considered clinically insignificant. The presence of an adjacent pontic had a significant effect on the adjacent marginal and axial gap widths.

Preferential Destruction of Interstitial Macrophages over Alveolar Macrophages as a Cause of Pulmonary Disease in Simian Immunodeficiency Virus-Infected Rhesus Macaques.

To our knowledge, this study demonstrates for the first time that the AIDS virus differentially impacts two distinct subsets of lung macrophages. The predominant macrophages harvested by bronchoalveolar lavage (BAL), alveolar macrophages (AMs), are routinely used in studies on human lung macrophages, are long-lived cells, and exhibit low turnover. Interstitial macrophages (IMs) inhabit the lung tissue, are not recovered with BAL, are shorter-lived, and exhibit higher baseline turnover rates distinct from AMs. We examined the effects of SIV infection on AMs in BAL fluid and IMs in lung tissue of rhesus macaques. SIV infection produced massive cell death of IMs that contributed to lung tissue damage. Conversely, SIV infection induced minimal cell death of AMs, and these cells maintained the lower turnover rate throughout the duration of infection. This indicates that SIV produces lung tissue damage through destruction of IMs, whereas the longer-lived AMs may serve as a virus reservoir to facilitate HIV persistence.

Differentiation Kinetics of Blood Monocytes and Dendritic Cells in Macaques: Insights to Understanding Human Myeloid Cell Development.

Monocyte and dendritic cell (DC) development was evaluated using in vivo BrdU pulse-chase analyses in rhesus macaques, and phenotype analyses of these cells in blood also were assessed by immunostaining and flow cytometry for comparisons among rhesus, cynomolgus, and pigtail macaques, as well as African green monkeys and humans. The nonhuman primate species and humans have three subsets of monocytes, CD14(+)CD16(-), CD14(+)CD16(+), and CD14(-)CD16(+) cells, which correspond to classical, intermediate, and nonclassical monocytes, respectively. In addition, there exist presently two subsets of DC, BDCA-1(+) myeloid DC and CD123(+) plasmacytoid DC, that were first confirmed in rhesus macaque blood. Following BrdU inoculation, labeled cells first appeared in CD14(+)CD16(-) monocytes, then in CD14(+)CD16(+) cells, and finally in CD14(-)CD16(+) cells, thus defining different stages of monocyte maturation. A fraction of the classical CD14(+)CD16(-) monocytes gradually expressed CD16(+) to become CD16(+)CD14(+) cells and subsequently matured into the nonclassical CD14(-)CD16(+) cell subset. The differentiation kinetics of BDCA-1(+) myeloid DC and CD123(+) plasmacytoid DC were distinct from the monocyte subsets, indicating differences in their myeloid cell origins. Results from studies utilizing nonhuman primates provide valuable information about the turnover, kinetics, and maturation of the different subsets of monocytes and DC using approaches that cannot readily be performed in humans and support further analyses to continue examining the unique myeloid cell origins that may be applied to address disease pathogenesis mechanisms and intervention strategies in humans.

Development of real-time PCR for quantitation of simian immunodeficiency virus 2-LTR circles.

BACKGROUND: Non-human primates infected with simian immunodeficiency virus (SIV) represent a robust model to evaluate pre-clinical efficacy of HIV-1 preventive strategies and to determine the size of reservoir. METHODS: We developed a real-time qPCR assay to specifically quantify episomal 2-LTR circular DNA in peripheral blood mononuclear cells and brain tissues from SIV-infected macaques. RESULTS: This assay has sensitivity, accuracy and reproducibility over seven orders of magnitude. High copy numbers of SIV 2-LTR circles were correlated to high proviral DNA levels in brains of two SIV encephalitic animals. In contrast, no 2-LTR circles were detectable in two SIV-infected animals with no sign of encephalitis or two animals that had mild encephalitis with low levels of proviral DNA. CONCLUSIONS: These results suggest that simultaneous application of total proviral DNA and 2-LTR circle assays provides quantitative evaluation of pathogenesis and outcome of SIV infection in macaques.

Molecular mechanisms implicated in protein changes in the Alzheimer's disease human hippocampus.

This study aimed to elucidate the specific biochemical pathways linked to changes in proteins in the Alzheimer's disease (AD) human hippocampus. Our data demonstrate a constant rise in the expression of four proteins (VGF, GFAP, HSPB1, and APP) across all eleven studies. Notably, UBC was the most centrally involved and had increased expression in the hippocampus tissue of individuals with AD. Modified proteins in the hippocampal tissue were found to activate the innate immune system and disrupt communication across chemical synapses. Four hub proteins (CD44, APP, ITGB2, and APOE) are connected to amyloid plaques, whereas two hub proteins (RPL24 and RPS23) are related to neurofibrillary tangles (NFTs). The presence of modified proteins was discovered to trigger the activation of microglia and decrease the functioning of ribosomes and mitochondria in the hippocampus. Three significant microRNAs (hsa-miR-106b-5p, hsa-miR-17-5p, and hsa-miR-16-5p) and transcription factors (MYT1L, PIN1, and CSRNP3) have been discovered to improve our understanding of the alterations in proteins within the hippocampal tissues that lead to the progression of AD. These findings establish a path for possible treatments for AD to employ therapeutic strategies that specifically focus on the proteins or processes linked to the illness.

Cluster of differentiation molecules in the metabolic syndrome.

Metabolic syndrome (MetS) represents a significant public health concern due to its association with an increased risk of cardiovascular disease, type 2 diabetes, and other serious health conditions. Despite extensive research, the underlying molecular mechanisms contributing to MetS pathogenesis remain elusive. This review aims to provide a comprehensive overview of the molecular mechanisms linking MetS and cluster of differentiation (CD) markers, which play critical roles in immune regulation and cellular signaling. Through an extensive literature review with a systematic approach, we examine the involvement of various CD markers in MetS development and progression, including their roles in adipose tissue inflammation, insulin resistance, dyslipidemia, and hypertension. Additionally, we discuss potential therapeutic strategies targeting CD markers for the management of MetS. By synthesizing current evidence, this review contributes to a deeper understanding of the complex interplay between immune dysregulation and metabolic dysfunction in MetS, paving the way for the development of novel therapeutic interventions.

The first two case reports of confirmed Mpox in patients with syphilis in a dense urban setting, Can Tho, Vietnam: From clinical presentation, treatment, and epidemiological surveillance to prevention.

This report elucidated the first two noteworthy cases of Mpox that manifested as an emerging concern in a densely populated city in Vietnam. Two male patients (22 and 27 years old) were admitted to the hospital due to the presence of small pustules on their faces, accompanied by symptoms of fatigue, drowsiness, and muscle pain. Reverse transcription-polymerase chain reaction confirmed the presence of Mpox. The patients possessed a medical history involving four previous treatments for syphilis, a continuous antiretroviral regimen for over 3 years, no previous history of chickenpox, a lack of vaccination against chickenpox, and engagement in intimate contact with other men. Following a 14-day isolation period coupled with appropriate medical interventions, both patients exhibited stable health conditions, marked by the absence of fever and the desiccation of skin blisters. Subsequently, they were discharged with instructions for ongoing health monitoring. Comprehensive surveillance and monitoring approaches have been implemented for all individuals in close contact with the affected patients, adhering to established guidelines. Notably, no suspected cases have been identified during the current surveillance efforts. The collective findings underscore the significance of robust surveillance, continuous monitoring, and strategic vaccination initiatives, particularly in densely populated urban centers, to effectively manage and mitigate the impact of Mpox outbreaks.

Evidence for a role of the basolateral amygdala in regulating regional metabolism in the stressed brain.

The brain regulates every physiological process in the body, including metabolism. Studies investigating brain metabolism have shown that stress can alter major metabolic processes, and that these processes can vary between regions. However, no study has investigated how metabolic pathways may be altered by stressor perception, or whether stress-responsive brain regions can also regulate metabolism. The basolateral amygdala (BLA), a region important for stress and fear, has reciprocal connections to regions responsible for metabolic regulation. In this study, we investigated how BLA influences regional metabolic profiles within the hippocampus (HPC) and medial prefrontal cortex (mPFC), regions involved in regulating the stress response and stress perception, using optogenetics in male C57BL/6 mice during footshock presentation in a yoked shuttlebox paradigm based on controllable (ES) and uncontrollable (IS) stress. RNA extracted from HPC and mPFC were loaded into NanoString® Mouse Neuroinflammation Panels, which also provides a broad view of metabolic processes, for compilation of gene expression profiles. Results showed differential regulation of carbohydrate and lipid metabolism, and insulin signaling gene expression pathways in HPC and mPFC following ES and IS, and that these differences were altered in response to optogenetic excitation or inhibition of the BLA. These findings demonstrate for the first time that individual brain regions can utilize metabolites in a way that are unique to their needs and function in response to a stressor, and that vary based on stressor controllability and influence by BLA.

Galectin-3, Galectin-9, and Interleukin-18 Are Associated with Monocyte/Macrophage Activation and Turnover More so than Simian Immunodeficiency Virus-Associated Cardiac Pathology or Encephalitis.

Despite antiretroviral therapy (ART), people living with HIV (PLWH) are at increased risk of developing cardiovascular disease (CVD) and HIV-associated neurocognitive disorder (HAND), among other comorbidities. Studies from ART-treated individuals identified galectin-3 (gal-3) and interleukin (IL)-18 as CVD biomarkers, galectin-9 (gal-9) as a HAND biomarker, and sCD163, a marker of monocyte/macrophage activation, as a biomarker of both. We asked if plasma gal-3, gal-9, and IL-18 are associated with an individual comorbidity or increase in both with animals that develop AIDS with both pathologies versus (CVD-path) alone or simian immunodeficiency virus encephalitis (SIVE) alone. We found that no biomarkers were selective between individual pathologies, and all biomarkers increased with co-development of CVD-path and SIVE (gal-3, p = 0.11; gal-9, p = 0.001; IL-18, p = 0.007; sCD163, p < 0.001; %BrdU p = 0.02). Although gal-3, gal-9, and IL-18 did not distinguish between pathologies, they correlated strongly with one another, with sCD163, a marker of monocyte/macrophage activation, and the %BrdU monocytes, a marker of monocyte turnover. Compared to animals with CVD-path or SIVE alone, animals that co-developed both pathologies had consistently elevated IL-18 throughout infection (p = 0.02) and increased sCD163 in late infection (p = 0.01). These data indicate that gal-3, gal-9, and IL-18 are associated with monocyte/macrophage activation by sCD163 and monocyte turnover by the %BrdU+ monocytes more so than CVD-path or SIVE.

Functionally distinct pericyte subsets differently regulate amyloid-ß deposition in patients with Alzheimer's disease.

Although the concept that the blood-brain barrier (BBB) plays an important role in the etiology and pathogenesis of Alzheimer's disease (AD) has become increasingly accepted, little is known yet about how it actually contributes. We and others have recently identified a novel functionally distinct subset of BBB pericytes (PCs). In the present study, we sought to determine whether these PC subsets differentially contribute to AD-associated pathologies by immunohistochemistry and amyloid beta (Aß) peptidomics. We demonstrated that a disease-associated PC subset (PC2) expanded in AD patients compared to age-matched, cognitively unimpaired controls. Surprisingly, we found that this increase in the percentage of PC2 (%PC2) was correlated negatively with BBB breakdown in AD patients, unlike in natural aging or other reported disease conditions. The higher %PC2 in AD patients was also correlated with a lower Aß42 plaque load and a lower Aß42:Aß40 ratio in the brain as determined by immunohistochemistry. Colocalization analysis of multicolor confocal immunofluorescence microscopy images suggests that AD patient with low %PC2 have higher BBB breakdown due to internalization of Aß42 by the physiologically normal PC subset (PC1) and their concomitant cell death leading to more vessels without PCs and increased plaque load. On the contrary, it appears that PC2 can secrete cathepsin D to cleave and degrade Aß built up outside of PC2 into more soluble forms, ultimately contributing to less BBB breakdown and reducing Aß plaque load. Collectively our data shows functionally distinct mechanisms for PC1 and PC2 in high Aß conditions, demonstrating the importance of correctly identifying these populations when investigating the contribution of neurovascular dysfunction to AD pathogenesis.