Disease Models Research Articles

Collagen I Increases Palmitate-Induced Lipotoxicity in HepG2 Cells via Integrin-Mediated Death.

Various strategies have been employed to improve the reliability of 2D, 3D, and co-culture in vitro models of nonalcoholic fatty liver disease, including using extracellular matrix proteins such as collagen I to promote cell adhesion. While studies have demonstrated the significant benefits of culturing cells on collagen I, its effects on the HepG2 cell line after exposure to palmitate (PA) have not been investigated. Therefore, this study aimed to assess the effects of PA-induced lipotoxicity in HepG2 cultured in the absence or presence of collagen I. HepG2 cultured in the absence or presence of collagen I was exposed to PA, followed by analyses that assessed cell proliferation, viability, adhesion, cell death, mitochondrial respiration, reactive oxygen species production, gene and protein expression, and triacylglycerol accumulation. Culturing HepG2 on collagen I was associated with increased cell proliferation, adhesion, and expression of integrin receptors, and improved cellular spreading compared to culturing them in the absence of collagen I. However, PA-induced lipotoxicity was greater in collagen I-cultured HepG2 than in those cultured in the absence of collagen I and was associated with increased α2β1 receptors. In summary, the present study demonstrated for the first time that collagen I-cultured HepG2 exhibited exacerbated cell death following exposure to PA through integrin-mediated death. The findings from this study may serve as a caution to those using 2D models or 3D scaffold-based models of HepG2 in the presence of collagen I.

Unraveling the role of gut microbiota by fecal microbiota transplantation in rat model of kidney stone disease

Emerging research on the microbiome highlights the significant role of gut health in the development of kidney stones, indicating that an imbalance in gut bacteria or dysbiosis can influence the formation of stones by altering oxalate metabolism and urinary metabolite profiles. In particular, the overabundance of specific bacteria such as Enterococcus and Oxalobacter spp., which are known to affect oxalate absorption, is observed in patients with urolithiasis. This study investigates the effects of gut dysbiosis on urolithiasis through fecal microbiota transplantation (FMT) from patients to rats and its impact on urinary mineral excretion and stone formation. Fecal samples from eight patients with calcium oxalate stones and ten healthy volunteers were collected to assess the gut microbiome. These samples were then transplanted to antibiotic-pretreated Wistar rats for a duration of four weeks. After transplantation, we evaluated changes in the fecal gut microbiome profile, urinary mineral excretion rates, and expression levels of intestinal zonula occluden-1 (ZO-1), SLC26A6 and renal NF-κB. In humans, patients with urolithiasis exhibited increased urinary calcium and oxalate levels, along with decreased citrate excretion and increased urinary supersaturation index. The fecal microbiota showed a notable abundance of Bacteroidota. In rodents, urolithiasis-FMT rats showed urinary disturbances similar to patients, including elevated pH, oxalate level, and supersaturation index, despite negative renal pathology. In addition, a slight elevation in the expression of renal NF-κB, a significant intestinal SLC26A6, and a reduction in ZO-1 expression were observed. The gut microbiome of urolithiasis-FMT rats showed an increased abundance of Bacteroidota, particularly Muribaculaceae, compared to their healthy FMT counterparts. In conclusion, the consistent overabundance of Bacteroidota in both urolithiasis patients and urolithiasis-FMT rats is related to altered intestinal barrier function, hyperoxaluria, and renal inflammation. These findings suggest that gut dysbiosis, characterized by an overgrowth of Bacteroidota, plays a crucial role in the pathogenesis of calcium oxalate urolithiasis, underscoring the potential of targeting the gut microbiota as a therapeutic strategy.

Deep-Learning-Driven Discovery of SN3-1, a Potent NLRP3 Inhibitor with Therapeutic Potential for Inflammatory Diseases.

The NLRP3 inflammasome plays a central role in the pathogenesis of various intractable human diseases, making it an urgent target for therapeutic intervention. Here, we report the development of SN3-1, a novel orally potent NLRP3 inhibitor, designed through a lead compound strategy centered on deep-learning-based molecular generative models. Our strategy enables rapid fragment enumeration and takes into account the synthetic accessibility of the compounds, thereby significantly enhancing the optimization of lead compounds and facilitating the discovery of potent inhibitors. X-ray crystallography provided insights into the SN3-1 inhibitory mechanism. SN3-1 has shown a favorable safety profile in both acute and chronic toxicity assessments and exhibits robust pharmacokinetic properties. Furthermore, SN3-1 demonstrated significant therapeutic efficacy in various disease models characterized by NLRP3 activation. This study introduces a potent candidate for developing NLRP3 inhibitors and significantly expands the repertoire of tools available for the discovery of novel inhibitors.

Cdc25A phosphatase is activated and mediates neuronal cell death by PUMA via pRb/E2F1 pathway in a model of Parkinson's disease

Parkinson's disease (PD) is a predominant movement disorder caused mainly due to selective loss of the dopaminergic neurons in the substantia nigra pars compacta of the mid brain. There is currently no cure for PD barring treatments to manage symptoms. The reasons might be due to lack of precise understanding of molecular mechanisms leading to neurodegeneration. Aberrant cell cycle activation has been implicated in neuronal death pathways of various neurodegenerative diseases including PD. This study investigates the role of cell cycle regulator Cell division cycle 25A (Cdc25A) in a PD-relevant neuron death model induced by 6-OHDA treatment. We find Cdc25A is rapidly elevated, activated and is playing a key role in neuron death by regulating Rb phosphorylation and E2F1 activity. Knockdown of Cdc25A via shRNA downregulates the levels of pro-apoptotic PUMA, an E2F1 target and cleaved Caspase-3 levels, suggesting Cdc25A may regulate neuronal apoptosis through these effectors. Our work sheds light on the intricate signaling networks involved in neurodegeneration and highlights Cdc25A as a potential therapeutic target for mitigating aberrant cell cycle re-entry underlying PD pathogenesis. These novel insights into molecular mechanisms provide a foundation for future development of neuroprotective strategies to slow or prevent progression of this debilitating disease.

Follistatin lowers blood pressure and improves vascular structure and function in essential and secondary hypertension.

Hypertension is characterized by resistance artery remodeling driven by oxidative stress and fibrosis. We previously showed that an activin A antagonist, follistatin, inhibited renal oxidative stress and fibrosis in a model of hypertensive chronic kidney disease. Here, we investigate the effects of follistatin on blood pressure and vascular structure and function in models of essential and secondary hypertension. 5/6 nephrectomised mice, a model of secondary hypertension, were treated with either exogenous follistatin or with a follistatin miRNA inhibitor to increase endogenous follistatin for 9 weeks. Blood pressure in mice was measured by tail cuff. Spontaneously hypertensive rats, a model of essential hypertension, were treated with follistatin for 8 weeks. Wistar Kyoto (WKY) rats were used as the normotensive control. Blood pressure in rats was measured by radiotelemetry. Mouse superior mesenteric arteries and rat first branch mesenteric arteries were isolated for structural and functional analyses. In both models, follistatin significantly lowered blood pressure and improved vascular structure, decreasing medial thickness and collagen content. Follistatin also reduced agonist-induced maximum contraction and improved endothelium-dependent relaxation. Increased vessel oxidative stress was attenuated by follistatin in both models. In ex vivo WKY vessels, activin A increased oxidative stress, augmented constriction, and decreased endothelium-dependent relaxation. Inhibition of oxidative stress restored vessel relaxation. This study demonstrates that follistatin lowers blood pressure and improves vascular structure and function in models of essential and secondary hypertension. Effects were likely mediated through its inhibition of activin A and oxidative stress. These data suggest a potential therapeutic role for follistatin as a novel antihypertensive agent. Follistatin, through antagonization of activin A, inhibits oxidative stress and improves vascular structure and function in resistance arteries from models of essential and secondary HTN. FST decreases collagen content and vascular ROS. Functionally, FST improves endothelium-dependent relaxation and decreases maximal vasoconstriction. Improved resistance artery structure and function are correlated with a decrease in BP in both models.

Impact of non-selective beta blockers on further decompensation and death in decompensated cirrhosis: Benefit and risk stratification by MELD score.

Non-selective beta blockers (NSBBs) can reduce the risk of decompensation, but their impact on further decompensation has been rarely investigated. The aim is to evaluate the impact of NSBBs on further decompensation and death in decompensated cirrhosis stratified by the severity of liver disease. Overall, 332 decompensated cirrhotic patients were retrospectively included, of whom 149 used NSBBs. Kaplan-Meier and Nelson-Aalen cumulative risk curves as well as Cox regression and competing risk analyses were used to estimate the associations of NSBBs with further decompensation and death, if appropriate. Hazard ratio (HR) and sub-distribution HR (sHR) were calculated. Subgroup analyses were performed based on the model for end-stage liver disease (MELD) score at admission. In the overall analysis, the use of NSBBs was not significantly associated with further decompensation in multivariate competing risk analysis (sHR = 1.09, p = 0.580). In the subgroup analysis of patients with a MELD score of ≤9, the use of NSBBs was significantly associated with decreased risk of further decompensation in multivariate competing risk analysis (sHR = 0.57, p = 0.021). In the subgroup analysis of patients with a MELD score of >9, the use of NSBBs was associated with increased risk of further decompensation in multivariate competing risk analysis (sHR = 1.45, p = 0.044). Regardless of overall and subgroup analyses, the use of NSBBs was not significantly associated with death in multivariate Cox regression analyses. NSBBs may be beneficial for the prevention of further decompensation in cirrhotic patients with a MELD score of ≤9, but deleterious in those with a MELD score of >9.

Isoflurane Titration Improves Detection of Hippocampal Lactate by 1H-MRS

Abstract Lactate has increasingly been recognized as both an important fuel source and signaling molecule within the brain. Alterations in brain lactate levels are associated with various neurological diseases. Thus, there is great interest in the in vivo detection and measurement of cerebral lactate levels in animals used for investigation of normal brain function and models of disease. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive technique used to measure lactate and other metabolites within the brain. However, lactate can be difficult to detect with conventional 1H-MRS due to its low abundance and spectral overlap with lipids. In addition, volatile anesthetics used during image acquisition increase lactate production, potentially masking any subtle physiological changes in lactate levels. Here we made use of a transgenic mouse model in which expression of lactate dehydrogenase A (Ldha), the rate-limiting enzyme of lactate production, was induced within cortical and hippocampal neurons. Unexpectedly, 1H-MRS analysis under typical isoflurane-induced anesthesia of 4% induction followed by 1.6-2% maintenance, revealed no significant elevation of hippocampal lactate levels in neuronal Ldha induction mice compared to control mice. In contrast, 1H-MRS analysis using an isoflurane titration protocol in which mice were sequentially exposed to 1.6%, 2%, then finally 3% isoflurane, revealed significantly higher hippocampal lactate levels in Ldha transgenic mice compared to controls. In addition, significantly fewer mice were required to detect differences in lactate levels using the isoflurane titration protocol compared to conventional isoflurane-induced anesthesia. Our findings highlight the importance of controlling for the effects of anesthesia when detecting changes in hippocampal lactate levels in vivo and offer a novel protocol for enhanced cerebral lactate detection.

Proteomic analysis of the SMN complex reveals conserved and etiologic connections to the proteostasis network.

Molecular chaperones and co-chaperones are highly conserved cellular components that perform a variety of duties related to the proper three-dimensional folding of the proteome. The web of factors that carries out this essential task is called the proteostasis network (PN). Ribonucleoproteins (RNPs) represent an underexplored area in terms of the connections they make with the PN. The Survival Motor Neuron (SMN) complex is an assembly chaperone and serves as a paradigm for studying how specific RNAs are identified and paired with their client substrate proteins to form RNPs. SMN is the eponymous component of a large complex, required for the biogenesis of uridine-rich small nuclear ribonucleoproteins (U-snRNPs), that localizes to distinct membraneless organelles in both the nucleus and cytoplasm of animal cells. SMN protein forms the oligomeric core of this complex, and missense mutations in the human SMN1 gene are known to cause Spinal Muscular Atrophy (SMA). The basic framework for understanding how snRNAs are assembled into U-snRNPs is known. However, the pathways and mechanisms used by cells to regulate their biogenesis are poorly understood. Given the importance of these processes to normal development as well as neurodegenerative disease, we set out to identify and characterize novel SMN binding partners. We carried out affinity purification mass spectrometry (AP-MS) of Drosophila SMN complexes using fly lines exclusively expressing either wildtype or SMA-causing missense alleles. Bioinformatic analyses of the pulldown data, along with comparisons to proximity labeling studies carried out in human cells, revealed conserved connections to at least two other major chaperone systems including heat shock folding chaperones (HSPs) and histone/nucleosome assembly chaperones. Notably, we found that heat shock cognate protein Hsc70-4 and other HspA family members preferentially associated with SMA-causing alleles of SMN. Hsc70-4 is particularly interesting because its mRNA is aberrantly sequestered by a mutant form of TDP-43 in mouse and Drosophila ALS (Amyotrophic Lateral Sclerosis) disease models. Most important, a missense allele of Hsc70-4 (HspA8 in mammals) was recently identified as a bypass suppressor of the SMA phenotype in mice. Collectively, these findings suggest that chaperone-related dysfunction lies at the etiological root of both ALS and SMA.

Personalized Nutrition for Obesity Management: A Mini-Review

Abstract Obesity is a pro-inflammatory state and a chronic health condition, which falls within the spectrum of immune-mediated inflammatory diseases (IMIDs). It is caused mainly by the consumption of excess calories and egregious food substances. A Personalized Food Avoidance Dietary Approach for Management of IMIDs (PFA-DAMI) addresses primary and secondary immune intolerances of different individuals to dietary constituents. Exposure to toxic food substances is responsible for inflammatory immune dysfunction that mediates obesity. Hence, a PFA-DAMI is promising for the management of obesity. T cell dysfunction disease mediating models describing inflammatory disease processes underlying IMIDs exist. However, they do not highlight inflammatory processes underlying the diseases concerning toxin-mediated epigenetic T cell dysfunction. Online searches were conducted on databases, such as Google Scholar, PubMed, Biomed Central, and SciELO. Articles were reviewed using keywords, such as obesity, personalized nutrition, immune optimization/dysfunction, T lymphocyte activation/dysfunction, cytokines, and adipokines. There is a putative T cell toxin-mediated dysfunction disease model for IMIDs, which may apply to other diseases. The putative disease model may highlight the actual inflammatory immune dysfunctional processes underlying T cell disease mediation in inflammatory diseases, which may be validated by multiomic studies. Validation of the putative disease model using obesity as an example should pave the way for a better understanding of the role of personalized nutrition in obesity management.

CNPY2 protects against ER stress and is expressed by corticostriatal neurons together with CTIP2 in a mouse model of Huntington's disease.

Canopy Homolog 2 (CNPY2) is an endoplasmic reticulum (ER) localized protein belonging to the CNPY gene family. We show here that CNPY2 is protective against ER stress induced by tunicamycin in neuronal cells. Overexpression of CNPY2 enhanced, while downregulation of CNPY2 using shRNA expression, reduced the viability of neuroblastoma cells after tunicamycin. Likewise, recombinant CNPY2 increased survival of cortical neurons in culture after ER stress. CNPY2 reduced the activating transcription factor 6 (ATF6) branch of ER stress and decreased the expression of CCAT/Enhancer-Binding Protein Homologous Protein (CHOP) involved in cell death. Immunostaining using mouse brain sections revealed that CNPY2 is expressed by cortical and striatal neurons and is co-expressed with the transcription factor, COUPTF-interacting protein 2 (CTIP2). In transgenic N171-82Q mice, as a model for Huntington's disease (HD), the number of CNPY2-immunopositive neurons was increased in the cortex together with CTIP2. In the striatum, however, the number of CNPY2 decreased at 19 weeks of age, representing a late-stage of pathology. Striatal cells in culture were shown to be more susceptible to ER stress after downregulation of CNPY2. These results demonstrate that CNPY2 is expressed by corticostriatal neurons involved in the regulation of movement. CNPY2 enhances neuronal survival by reducing ER stress and is a promising factor to consider in HD and possibly in other brain diseases.

Extract from Nasco pomace loaded in nutriosomes exerts anti-inflammatory effects in the MPTP mouse model of Parkinson's disease

Neuroinflammation has recently emerged as a key event in Parkinson's disease (PD) pathophysiology and as a potential target for disease-modifying therapies. Plant-derived extracts, rich in bioactive phytochemicals with antioxidant properties, have shown potential in this regard. Yet their clinical utility is hampered by poor systemic availability and rapid metabolism. Recently, our group demonstrated that intragastric delivery of Nasco pomace extract via nutriosomes (NN), a novel nanoliposome formulation, contrasts the degeneration of nigrostriatal dopaminergic neurons in a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. In the present study, we investigated the impact of intragastric NN treatment on the reactivity of glial cells in the substantia nigra pars compacta (SNc) and caudate-putamen (CPu) of MPTP-treated mice. To this scope, in mice exposed to MPTP (20 mg/kg/day, × 4 days), we conducted immunohistochemistry analyses of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adapter molecule 1 (IBA1) to assess the responsiveness of astrocytes and microglial cells, respectively. Additionally, we studied the co-localization of the pro-inflammatory interleukin (IL)-1β and tumor necrosis factor (TNF)-α with IBA1 to obtain insights into microglial phenotype. Immunohistochemical results showed that NN administration significantly mitigated astrogliosis and microgliosis in the CPu and SNc of mice receiving subacute MPTP treatment, with region-specific variations in anti-inflammatory efficacy. Remarkably, the CPu showed a heightened response to NN treatment, including a pronounced decrease in microglial IL-1β and TNF-α production. Altogether, these findings underscore the anti-inflammatory effects of NN treatment and provide a potential mechanism underlying the neuroprotective effects previously observed in a subacute MPTP mouse model of PD.

Analysis of Brain Protein Stability Changes in a Mouse Model of Alzheimer's Disease.

The stability of proteins from rates of oxidation (SPROX), thermal proteome profiling (TPP), and limited proteolysis (LiP) techniques were used to profile the stability of ∼2500 proteins in hippocampus tissue cell lysates from 2- and 8-months-old wild-type (C57BL/6J; n = 7) and transgenic (5XFAD; n = 7) mice with five Alzheimer's disease (AD)-linked mutations. Approximately 200-500 protein hits with AD-related stability changes were detected by each technique at each age point. The hit overlap from technique to technique was low, and all of the techniques generated protein hits that were more numerous and largely different from those identified in protein expression level analyses, which were also performed here. The hit proteins identified by each technique were enriched in a number of the same pathways and biological processes, many with known connections to AD. The protein stability hits included 25 high-value conformation biomarkers with AD-related stability changes detected using at least 2 techniques at both age points. Also discovered were subunit- and age-specific AD-related stability changes in the proteasome, which had reduced function at both age points. The different folding stability profiles of the proteasome at the two age points are consistent with a different mechanism for proteasome dysfunction at the early and late stages of AD.

Visual information guided multi-modal model for plant disease anomaly detection

Plant diseases significantly impact the quality and yield of agricultural products, leading to considerable economic losses. Most existing plant disease recognition systems are limited to identifying categories within the training set, which poses potential systemic risks. Rejecting unknown samples is crucial for the safety and reliability of practical applications. This study aims to harness the strong generalization capabilities of vision-language models to address plant disease anomaly detection. To this end, we comprehensively explore prompt tuning paradigms based on vision-language models. We observe that anomaly detection methods guided by textual concepts perform poorly in the fine-grained task of plant disease due to their focus on concept matching. We argue that visual information is crucial for anomaly detection in plant diseases. Therefore, we propose guiding the vision-language model with visual information to address this issue. Additionally, we find that utilizing the general knowledge extracted by the original vision-language model can further enhance anomaly detection performance. Extensive experimental results demonstrate that our method significantly improves the current baseline methods by incorporating visual information. Notably, deploying our method under vision-language prompt tuning achieved an AUROC score of 99.85% in the all-shot setting. Even in a challenge 2-shot setting, our approach achieves an AUROC score of 93.81%, significantly outperforming CoCoOp fine-tuned on the entire dataset (88.61%). We believe that our study will contribute to the community and, to fuel the field, our code will be released.

Survival benefit of liver transplantation utilizing marginal donor organ according to ABO blood type.

The current liver transplantation (LT) allocation policy focuses on the Model for End-Stage Liver Disease (MELD) scores, often overlooking factors like blood type and survival benefits. Understanding blood types' impact on survival benefits is crucial for optimizing the MELD 3.0 classification. This study used the United Network for Organ Sharing national registry database (2003-2020) to identify LT characteristics per ABO blood type and to determine the optimal MELD 3.0 scores for each blood type, based on survival benefits. The study included LT candidates aged 18 years or older listed for LT (total N=150,815; A:56,546, AB:5,841, B:18,500, O:69,928). Among these, 87,409 individuals (58.0%) underwent LT (A:32,156, AB:4,362, B:11,786, O:39,105). Higher transplantation rates were observed in AB and B groups, with lower median MELD 3.0 scores at transplantation (AB:21, B:24 vs. A/O:26, p<0.01) and shorter waiting times (AB:101 days, B:172 days vs. A:211 days, O:201 days, p<0.01). A preference for Donation after Cardiac Death (DCD) was seen in A and O recipients. Survival benefit analysis indicated that B blood type required higher MELD 3.0 scores for transplantation than A and O (Donation after Brain Death transplantation: ≥15 in B vs. ≥11 in A/O; DCD transplantation: ≥21 in B vs. ≥11 in A, ≥15 in O). The study suggests revising the allocation policy to consider blood type for improved post-LT survival. This calls for personalized LT policies, recommending higher MELD 3.0 thresholds, particularly for individuals with type B blood.

An integrated strategy for in-depth profiling of N-acylethanolamines in biological samples by UHPLC-HRMS

BackgroundN-acylethanolamines (NAEs) are a class of naturally occurring bioactive lipids that play crucial roles in various physiological processes, particularly exhibiting neuroprotective and anti-inflammatory properties. However, the comprehensive profiling of endogenous NAEs in complex biological matrices is challenging due to their low abundance, structural similarity and the limited availability of commercial standards. Here, we propose an integrated strategy for comprehensive profiling of NAEs that combines chemical derivatization and a three-dimensional (3D) prediction model based on quantitative structure-retention time relationship (QSRR) using liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS). ResultsAfter acetyl chloride (ACC) derivatization, the detection sensitivity of NAEs was significantly improved. We developed a QSRR prediction model to construct an in-house database for 141 NAEs, encompassing information on RT, MS1 (m/z), and MS/MS spectra. Propargylamine-labeled fatty acids were synthesized as RT calibrants across various analytical conditions to enhance the robustness of the RT prediction model. NAEs in biological samples were then in-depth profiled using parallel reaction monitoring (PRM) acquisition. This integrated strategy identified and annotated a total of 50 NAEs across serum, hippocampus and cortex tissues from a 5xFAD mouse model of Alzheimer's disease (AD). Notably, the levels of polyunsaturated NAEs, particularly NAE 20:5 and NAE 22:6, were significantly decreased in 5xFAD mice compared to WT mice, as confirmed by accurate quantitation using ACC-d0/d3 derivatization. SignificanceOur integrated strategy exhibits great potential for the in-depth profiling of NAEs in complex biological samples, facilitating the elucidation of NAE functions in diverse physiological and pathological processes.

Synergistic association of Aβ and tau pathology with cortical neurophysiology and cognitive decline in asymptomatic older adults.

Animal and computational models of Alzheimer's disease (AD) indicate that early amyloid-β (Aβ) deposits drive neurons into a hyperactive regime, and that subsequent tau depositions manifest an opposite, suppressive effect as behavioral deficits emerge. Here we report analogous changes in macroscopic oscillatory neurophysiology in the human brain. We used positron emission tomography and task-free magnetoencephalography to test the effects of Aβ and tau deposition on cortical neurophysiology in 104 cognitively unimpaired older adults with a family history of sporadic AD. In these asymptomatic individuals, we found that Aβ depositions colocalize with accelerated neurophysiological activity. In those also presenting medial-temporal tau pathology, linear mixed effects of Aβ and tau depositions indicate a shift toward slower neurophysiological activity, which was also linked to cognitive decline. We conclude that early Aβ and tau depositions relate synergistically to human cortical neurophysiology and subsequent cognitive decline. Our findings provide insight into the multifaceted neurophysiological mechanisms engaged in the preclinical phases of AD.

The p53 target DRAM1 modulates calcium homeostasis and ER stress by promoting contact between lysosomes and the ER through STIM1

It is well established that DNA Damage Regulated Autophagy Modulator 1 (DRAM1), a lysosomal protein and a target of p53, participates in autophagy. The cellular functions of DRAM1 beyond autophagy remain elusive. Here, we show p53-dependent upregulation of DRAM1 in mitochondrial damage-induced Parkinson's disease (PD) models and exacerbation of disease phenotypes by DRAM1. We find that the lysosomal location of DRAM1 relies on its intact structure including the cytosol-facing C-terminal domain. Excess DRAM1 disrupts endoplasmic reticulum (ER) structure, triggers ER stress, and induces protective ER-phagy. Mechanistically, DRAM1 interacts with stromal interacting molecule 1 (STIM1) to tether lysosomes to the ER and perturb STIM1 function in maintaining intracellular calcium homeostasis. STIM1 overexpression promotes cellular health by restoring calcium homeostasis, ER stress response, ER-phagy, and AMP-activated protein kinase (AMPK)-Unc-51 like autophagy activating kinase 1 (ULK1) signaling in cells with excess DRAM1. Thus, by promoting organelle contact between lysosomes and the ER, DRAM1 modulates ER structure and function and cell survival under stress. Our results suggest that DRAM1 as a lysosomal protein performs diverse roles in cellular homeostasis and stress response. These findings may have significant implications for our understanding of the role of the p53/DRAM1 axis in human diseases, from cancer to neurodegenerative diseases.

PROBLEMS OF MANAGING THE IMMUNE RESPONSE UNDER CONDITIONS OF COMPETITIVE ADSORPTION, DIFFUSION PERTURBATIONS AND TEMPERATURE RESPONSE OF THE ORGANISM

Analysis of the problems associated with the rapid spread of infectious diseases indicates the need for new approaches to the diagnosis and develop- ment of effective personalized treatment programs. One of the important aspects of solving this problem is the creation of a mathematical modeling toolkit for predicting the dynamics of infectious diseases, taking into account spatial effects, concentrated effects, various mechanisms of body protec- tion in the conditions of the application of various types of therapeutic methods of treatment. An important component of complex methods of treat- ment of a wide range of infectious diseases is the use of adsorption drugs, which, along with detoxification of the body, are able to provide an addi- tional mechanism of neutralization of viral elements. In the process of using such means, not only pathogenic elements and toxins will be adsorbed, but also various types of immune agents, which will affect the dynamics of the immune response. In the paper the infectious disease model is generalized to take into account the features of competitive adsorption of antigens and immune agents in the conditions of diffusion perturbations, concentrated influences and temperature reaction of the body. By synthesizing the ideas of step-by-step procedures, asymptotic and numerical methods, an effective computational technology of step-by-step approximation of the solution of the original model singularly perturbed problem was built. The results of the computer experiments presented in the paper illustrate the features of reducing the predicted concentration of viral elements during their competi- tive adsorption together with immune agents, in particular, the effect of reducing the efficiency of the use of non-specific adsorbents. It is emphasized that taking into account the features of the action of competitive adsorption is important for making decisions regarding the formation of rational treatment programs with the complex use of adsorbing substances and immunological drugs.

Inhibiting Ca2+ channels in Alzheimer's disease model mice relaxes pericytes, improves cerebral blood flow and reduces immune cell stalling and hypoxia.

Early in Alzheimer's disease (AD), pericytes constrict capillaries, increasing their hydraulic resistance and trapping of immune cells and, thus, decreasing cerebral blood flow (CBF). Therapeutic approaches to attenuate pericyte-mediated constriction in AD are lacking. Here, using in vivo two-photon imaging with laser Doppler and speckle flowmetry and magnetic resonance imaging, we show that Ca2+ entry via L-type voltage-gated calcium channels (CaVs) controls the contractile tone of pericytes. In AD model mice, we identifed pericytes throughout the capillary bed as key drivers of an immune reactive oxygen species (ROS)-evoked and pericyte intracellular calcium concentration ([Ca2+]i)-mediated decrease in microvascular flow. Blocking CaVs with nimodipine early in disease progression improved CBF, reduced leukocyte stalling at pericyte somata and attenuated brain hypoxia. Amyloid β (Aβ)-evoked pericyte contraction in human cortical tissue was also greatly reduced by CaV block. Lowering pericyte [Ca2+]i early in AD may, thus, offer a therapeutic strategy to enhance brain energy supply and possibly cognitive function in AD.

Fast Computer Model Calibration using Annealed and Transformed Variational Inference

Computer models play a crucial role in numerous scientific and engineering domains. To ensure the accuracy of simulations, it is essential to properly calibrate the input parameters of these models through statistical inference. While Bayesian inference is the standard approach for this task, employing Markov chain Monte Carlo methods often encounters computational hurdles due to the costly evaluation of likelihood functions and slow mixing rates. Although variational inference (VI) can be a fast alternative to traditional Bayesian approaches, VI has limited applicability due to boundary issues and local optima problems. To address these challenges, we propose flexible VI methods based on deep generative models that do not require parametric assumptions on the variational distribution. We embed a surjective transformation in our framework to avoid posterior truncation at the boundary. Additionally, we provide theoretical conditions that guarantee the success of the algorithm. Furthermore, our temperature annealing scheme and fine-tuning can prevent being trapped in local optima through a series of intermediate posteriors and weight adjustment. We apply our method to infectious disease models and a geophysical model, illustrating that the proposed method can provide fast and accurate inference compared to its competitors.