TGF-β1 signalling in Alzheimer's pathology and cytoskeletal reorganization: a specialized Tau perspective

Altered glia-neuron communication in Alzheimer's Disease affects WNT, p53, and NFkB Signaling determined by snRNA-seq

BACKGROUND

Alzheimer's disease is the most common cause of dementia and is characterized by amyloid-β plaques, tau neurofibrillary tangles, and neuronal loss. Although neuronal loss is a primary hallmark of Alzheimer's disease, it is known that non-neuronal cell populations are ultimately responsible for maintaining brain homeostasis and neuronal health through neuron-glia and glial cell crosstalk. Many signaling pathways have been proposed to be dysregulated in Alzheimer's disease, including WNT, TGFβ, p53, mTOR, NFkB, and Pi3k/Akt signaling. Here, we predict altered cell-cell communication between glia and neurons.

METHODS

Using public snRNA-sequencing data generated from postmortem human prefrontal cortex, we predicted altered cell-cell communication between glia (astrocytes, microglia, oligodendrocytes, and oligodendrocyte progenitor cells) and neurons (excitatory and inhibitory). We confirmed interactions in a second and third independent orthogonal dataset. We determined cell-type-specificity using Jaccard Similarity Index and investigated the downstream effects of altered interactions in inhibitory neurons through gene expression and transcription factor activity analyses of signaling mediators. Finally, we determined changes in pathway activity in inhibitory neurons.

RESULTS

Cell-cell communication between glia and neurons is altered in Alzheimer's disease in a cell-type-specific manner. As expected, ligands are more cell-type-specific than receptors and targets. We identified ligand-receptor pairs in three independent datasets and found involvement of the Alzheimer's disease risk genes APP and APOE across datasets. Most of the signaling mediators of these interactions were not significantly differentially expressed, however, the mediators that are also transcription factors had differential activity between AD and control. Namely, MYC and TP53, which are associated with WNT and p53 signaling, respectively, had decreased TF activity in Alzheimer's disease, along with decreased WNT and p53 pathway activity in inhibitory neurons. Additionally, inhibitory neurons had both increased NFkB signaling pathway activity and increased TF activity of NFIL3, an NFkB signaling-associated transcription factor.

CONCLUSIONS

Cell-cell communication between glia and neurons in Alzheimer's disease is altered in a cell-type-specific manner involving Alzheimer's disease risk genes. Signaling mediators had altered transcription factor activity suggesting altered glia-neuron interactions may dysregulate signaling pathways including WNT, p53, and NFkB in inhibitory neurons.

The potential protective role of peripheral immunophenotypes in Alzheimer's disease: a Mendelian randomization study

Introduction

Alzheimer's disease (AD) is the most widespread neurodegenerative disease in the world. Previous studies have shown that peripheral immune dysregulation plays a paramount role in AD, but whether there is a protective causal relationship between peripheral immunophenotypes and AD risk remains ambiguous.

Methods

Two-sample Mendelian randomization (MR) was performed using large genome-wide association study (GWAS) genetic data to assess causal effects between peripheral immunophenotypes and AD risk. Utilizing the genetic associations of 731 immune cell traits as exposures. We adopted the inverse variance weighted method as the primary approach. The Weighted median and MR-Egger regression methods were employed as supplements. Various sensitivity analyses were performed to assess the robustness of the outcomes.

Results

Based on the IVW method, we identified 14 immune cell traits that significantly reduced the risk of AD, of which six demonstrated statistical significance in both IVW and Weighted median methods. Among the seven immune traits, four were related to regulatory T (Treg) cells : (1) CD25++ CD45RA- CD4 not regulatory T cell % T cell (odds ratio (OR) [95% confidence interval (CI)] = 0.96 [0.95, 0.98], adjusted P = 1.17E-02), (2) CD25++ CD45RA- CD4 not regulatory T cell % CD4+ T cell (OR [95% CI] = 0.97 [0.96, 0.99], adjusted P = 3.77E-02), (3) Secreting CD4 regulatory T cell % CD4 regulatory T cell (OR [95% CI] = 0.98 [0.97, 0.99], adjusted P = 7.10E-03), (4) Activated & secreting CD4 regulatory T cell % CD4 regulatory T cell(OR [95% CI] = 0.98 [0.97, 0.99], adjusted P = 7.10E-03). In addition, HLA DR++ monocyte % monocyte (OR [95% CI] = 0.93 [0.89, 0.98], adjusted P = 4.87E-02) was associated with monocytes, and HLA DR on myeloid Dendritic Cell (OR [95% CI] = 0.93 [0.89, 0.97], adjusted P = 1.17E-02) was related to dendritic cells (DCs).

Conclusion

These findings enhance the comprehension of the protective role of peripheral immunity in AD and provide further support for Treg and monocyte as potential targets for immunotherapy in AD.

Pseudostellaria heterophylla polysaccharide mitigates Alzheimer's-like pathology via regulating the microbiota-gut-brain axis in 5 × FAD mice

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterised by neuroinflammation, for which gut dysbiosis may be implicated. Our previous study showed that treatment with Pseudostellaria heterophylla aqueous extract and one of its cyclopeptides, heterophyllin B, attenuate memory deficits via immunomodulation and neurite regeneration. However, whether Pseudostellaria heterophylla polysaccharide (PH-PS) exerts neuroprotective effects against AD and its underlying mechanisms remain unclear. The infrared spectrum, molecular weight, and carbohydrate composition of the PH-PS were determined. The results showed that PH-PS (Mw 8.771 kDa) was composed of glucose (57.78 %), galactose (41.52 %), and arabinose (0.70 %). PH-PS treatment ameliorated learning and spatial memory deficits, reduced amyloid β build-up, and suppressed reactive glia and astrocytes in 5 × FAD mice. 16S rRNA sequencing further showed that PH-PS remodelled the intestinal flora composition by promoting probiotic microbiota, such as Lactobacillus, Muribaculum, Monoglobus, and [Eubacterium]_siraeum_group, and suppressing inflammation-related UCG-009 and Blautia. Additionally, PH-PS restored intestinal barrier function; ameliorated peripheral inflammation by reducing the secretion of inflammatory cytokines, thereby converting M1 microglia and A1 astrocyte toward beneficial M2 and A2 phenotypes; and contributed to Aβ plaques clearance by upregulation of insulin degradation enzyme and neprilysin. Collectively, our findings demonstrate that PH-PS may prevent the progression of AD via modulation of the gut microbiota and regulation of glial polarisation, which could provide evidence to design a potential diet therapy for preventing or curing AD.

Altered Glia-Neuron Communication in Alzheimer's Disease Affects WNT, p53, and NFkB Signaling Determined by snRNA-seq

Background

Alzheimer's disease is the most common cause of dementia and is characterized by amyloid-β plaques, tau neurofibrillary tangles, and neuronal loss. Although neuronal loss is a primary hallmark of Alzheimer's disease, it is known that non-neuronal cell populations are ultimately responsible for maintaining brain homeostasis and neuronal health through neuron-glia and glial cell crosstalk. Many signaling pathways have been proposed to be dysregulated in Alzheimer's disease, including WNT, TGFβ, p53, mTOR, NFkB, and Pi3k/Akt signaling. Here, we predict altered cell-cell communication between glia and neurons.

Methods

Using public snRNA-sequencing data generated from postmortem human prefrontal cortex, we predicted altered cell-cell communication between glia (astrocytes, microglia, oligodendrocytes, and oligodendrocyte progenitor cells) and neurons (excitatory and inhibitory). We confirmed interactions in a second and third independent orthogonal dataset. We determined cell-type-specificity using Jaccard Similarity Index and investigated the downstream effects of altered interactions in inhibitory neurons through gene expression and transcription factor activity analyses of signaling mediators. Finally, we determined changes in pathway activity in inhibitory neurons.

Results

Cell-cell communication between glia and neurons is altered in Alzheimer's disease in a cell-type-specific manner. As expected, ligands are more cell-type-specific than receptors and targets. We identified ligand-receptor pairs in three independent datasets and found involvement of the Alzheimer's disease risk genes APP and APOE across datasets. Most of the signaling mediators of these interactions were not differentially expressed, however, the mediators that are also transcription factors had differential activity between AD and control. Namely, MYC and TP53, which are associated with WNT and p53 signaling, respectively, had decreased TF activity in Alzheimer's disease, along with decreased WNT and p53 pathway activity in inhibitory neurons. Additionally, inhibitory neurons had both increased NFkB signaling pathway activity and increased TF activity of NFIL3, an NFkB signaling-associated transcription factor.

Conclusions

Cell-cell communication between glia and neurons in Alzheimer's disease is altered in a cell-type-specific manner involving Alzheimer's disease risk genes. Signaling mediators had altered transcription factor activity suggesting altered glia-neuron interactions may dysregulate signaling pathways including WNT, p53, and NFkB in inhibitory neurons.

Potential Alzheimer's disease drug targets identified through microglial biology research

INTRODUCTION

Microglia, the primary immune cells in the brain, play multifaceted roles in Alzheimer's disease (AD). Microglia can potentially mitigate the pathological progression of AD by clearing amyloid beta (Aβ) deposits in the brain and through neurotrophic support. In contrast, disproportionate activation of microglial pro-inflammatory pathways, as well as excessive elimination of healthy synapses, can exacerbate neurodegeneration in AD. The challenge, therefore, lies in discerning the precise regulation of the contrasting microglial properties to harness their therapeutic potential in AD.

AREAS COVERED

This review examines the evidence relevant to the disease-modifying effects of microglial manipulators in AD preclinical models. The deleterious pro-inflammatory effects of microglia in AD can be ameliorated via direct suppression or indirectly through metabolic manipulation, epigenetic targeting, and modulation of the gut-brain axis. Furthermore, microglial clearance of Aβ deposits in AD can be enhanced via strategically targeting microglial membrane receptors, lysosomal functions, and metabolism.

EXPERT OPINION

Given the intricate and diverse nature of microglial responses throughout the course of AD, therapeutic interventions directed at microglia warrant a tactical approach. This could entail employing therapeutic regimens, which concomitantly suppress pro-inflammatory microglial responses while selectively enhancing Aβ phagocytosis.

Transcriptomic analysis reveals sex-specific patterns in the hippocampus in Alzheimer's disease

Background

The hippocampus, vital for memory and learning, is among the first brain regions affected in Alzheimer's Disease (AD) and exhibits adult neurogenesis. Women face twice the risk of developing AD compare to men, making it crucial to understand sex differences in hippocampal function for comprehending AD susceptibility.

Methods

We conducted a comprehensive analysis of bulk mRNA postmortem samples from the whole hippocampus (GSE48350, GSE5281) and its CA1 and CA3 subfields (GSE29378). Our aim was to perform a comparative molecular signatures analysis, investigating sex-specific differences and similarities in the hippocampus and its subfields in AD. This involved comparing the gene expression profiles among: (a) male controls (M-controls) vs. female controls (F-controls), (b) females with AD (F-AD) vs. F-controls, (c) males with AD (M-AD) vs. M-controls, and (d) M-AD vs. F-AD. Furthermore, we identified AD susceptibility genes interacting with key targets of menopause hormone replacement drugs, specifically the ESR1 and ESR2 genes, along with GPER1.

Results

The hippocampal analysis revealed contrasting patterns between M-AD vs. M-controls and F-AD vs. F-controls, as well as M-controls vs. F-controls. Notably, BACE1, a key enzyme linked to amyloid-beta production in AD pathology, was found to be upregulated in M-controls compared to F-controls in both CA1 and CA3 hippocampal subfields. In M-AD vs. M-controls, the GABAergic synapse was downregulated, and the Estrogen signaling pathway was upregulated in both subfields, unlike in F-AD vs. F-controls. Analysis of the whole hippocampus also revealed upregulation of the GABAergic synapse in F-AD vs. F-controls. While direct comparison of M-AD vs. F-AD, revealed a small upregulation of the ESR1 gene in the CA1 subfield of males. Conversely, F-AD vs. F-controls exhibited downregulation of the Dopaminergic synapse in both subfields, while the Calcium signaling pathway showed mixed regulation, being upregulated in CA1 but downregulated in CA3, unlike in M-AD vs. M-controls. The upregulated Estrogen signaling pathway in M-AD, suggests a compensatory response to neurodegenerative specifically in males with AD. Our results also identified potential susceptibility genes interacting with ESR1 and ESR2, including MAPK1, IGF1, AKT1, TP53 and CD44.

Conclusion

These findings underscore the importance of sex-specific disease mechanisms in AD pathogenesis. Region-specific analysis offers a more detailed examination of localized changes in the hippocampus, enabling to capture sex-specific molecular patterns in AD susceptibility and progression.

Nucleic acid-based small molecules as targeted transcription therapeutics for immunoregulation

Transcription therapy is an emerging approach that centers on identifying the factors associated with the malfunctioning gene transcription machinery that causes diseases and controlling them with designer agents. Until now, the primary research focus in therapeutic gene modulation has been on small-molecule drugs that target epigenetic enzymes and critical signaling pathways. However, nucleic acid-based small molecules have gained popularity in recent years for their amenability to be pre-designed and realize operative control over the dynamic transcription machinery that governs how the immune system responds to diseases. Pyrrole-imidazole polyamides (PIPs) are well-established DNA-based small-molecule gene regulators that overcome the limitations of their conventional counterparts owing to their sequence-targeted specificity, versatile regulatory efficiency, and biocompatibility. Here, we emphasize the rational design of PIPs, their functional mechanisms, and their potential as targeted transcription therapeutics for disease treatment by regulating the immune response. Furthermore, we also discuss the challenges and foresight of this approach in personalized immunotherapy in precision medicine.

Low TGF-β1 plasma levels are associated with cognitive decline in Down syndrome

Almost all individuals with Down's syndrome (DS) show the characteristic neuropathological features of Alzheimer's disease (AD) by the age of 40, yet not every individual with DS experiences symptoms of AD later in life. Similar to neurotypical developing subjects, AD in people with DS lasts for a long preclinical phase in which biomarkers follow a predictable order of changes. Hence, a prolonged asymptomatic period precedes the onset of dementia, underscoring the importance of identifying new biomarkers for the early detection and monitoring of cognitive decline in individuals with DS. Blood-based biomarkers may offer an alternative non-invasive strategy for the detection of peripheral biological alterations paralleling nervous system pathology in an early phase of the AD continuum. In the last few years, a strong neurobiological link has been demonstrated between the deficit of transforming growth factor-β1 (TGF-β1) levels, an anti-inflammatory cytokine endowed with neuroprotective activity, and early pro-inflammatory processes in the AD brain. In this clinical prospective observational study, we found significant lower plasma TGF-β1 concentrations at the first neuropsychological evaluation (baseline = T0) both in young adult DS individuals (19-35 years) and older DS subjects without AD (35-60 years) compared to age- and sex-matched healthy controls. Interestingly, we found that the lower TGF-β1 plasma concentrations at T0 were strongly correlated with the following cognitive decline at 12 months. In addition, in young individuals with DS, we found, for the first time, a negative correlation between low TGF-β1 concentrations and high TNF-α plasma concentrations, a pro-inflammatory cytokine that is known to be associated with cognitive impairment in DS individuals with AD. Finally, adopting an ex vivo approach, we found that TGF-β1 concentrations were reduced in parallel both in the plasma and in the peripheral blood mononuclear cells (PBMCs) of DS subjects, and interestingly, therapeutic concentrations of fluoxetine (FLX) applied to cultured PBMCs (1 µM for 24 h) were able to rescue TGF-β1 concentrations in the culture media from DS PBMCs, suggesting that FLX, a selective serotonin reuptake inhibitor (SSRI) endowed with neuroprotective activity, might rescue TGF-β1 concentrations in DS subjects at higher risk to develop cognitive decline.

Clinical evidence of hyperbaric oxygen therapy for Alzheimer's disease: a systematic review and meta-analysis of randomized controlled trials

Objective

To evaluate the potential benefits of hyperbaric oxygen intervention on people with Alzheimer's disease (AD) based on the existing randomized controlled trials (RCTs).

Methods

A systematic search was conducted in nine databases until November 17, 2023, for RCTs assessing the effect of hyperbaric oxygen intervention for AD. The primary outcomes included Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog), activities of daily living (ADL), and adverse events. All results were shown in forest plots, and sensitivity analysis was adopted to further verify the robustness of the pooled results.

Results

A total of 11 RCTs recruiting 847 participants were included in this meta-analysis. Based on the pooled evidence, hyperbaric oxygen could remarkably ameliorate MMSE [MD = 3.08, 95%CI (2.56, 3.61), p < 0.00001], ADAS-Cog [MD = -4.53, 95%CI (-5.05, -4.00), p < 0.00001], ADL [MD = 10.12, 95%CI (4.46, 15.79), p = 0.0005], MDA levels [SMD = -2.83, 95%CI (-5.27, -0.38), p = 0.02], SOD levels [SMD = 2.12, 95%CI (1.10, 3.15), p < 0.0001], IL-1-β levels [SMD = -1.00, 95%CI (-1.48, -0.53), p < 0.0001], and TGF-β1 levels [MD = 4.87, 95%CI (3.98, 5.76), p < 0.00001] without adverse events [OR = 1.17, 95%CI (0.68, 2.03), p = 0.58] for people with AD. The pooled results were robust after checking by sensitivity analysis.

Conclusion

These evidences suggest that hyperbaric oxygen is an effective and safe intervention for the treatment of AD. Further studies with more rigorous design will help to fully evaluate the clinical value of hyperbaric oxygen on cognition function in people with AD.

Systematic review registration

https://www.crd.york.ac.uk, identifier CRD42023483726.

Epigenetic regulation of autophagy in neuroinflammation and synaptic plasticity

Autophagy is a conserved cellular mechanism that enables the degradation and recycling of cellular organelles and proteins via the lysosomal pathway. In neurodevelopment and maintenance of neuronal homeostasis, autophagy is required to regulate presynaptic functions, synapse remodeling, and synaptic plasticity. Deficiency of autophagy has been shown to underlie the synaptic and behavioral deficits of many neurological diseases such as autism, psychiatric diseases, and neurodegenerative disorders. Recent evidence reveals that dysregulated autophagy plays an important role in the initiation and progression of neuroinflammation, a common pathological feature in many neurological disorders leading to defective synaptic morphology and plasticity. In this review, we will discuss the regulation of autophagy and its effects on synapses and neuroinflammation, with emphasis on how autophagy is regulated by epigenetic mechanisms under healthy and diseased conditions.

Role of transforming growth factor-β in peripheral nerve regeneration

Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits. Unlike in the central nervous system, damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells. However, axon regeneration and repair do not automatically result in the restoration of function, which is the ultimate therapeutic goal but also a major clinical challenge. Transforming growth factor (TGF) is a multifunctional cytokine that regulates various biological processes including tissue repair, embryo development, and cell growth and differentiation. There is accumulating evidence that TGF-β family proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells; recruiting specific immune cells; controlling the permeability of the blood-nerve barrier, thereby stimulating axon growth; and inhibiting remyelination of regenerated axons. TGF-β has been applied to the treatment of peripheral nerve injury in animal models. In this context, we review the functions of TGF-β in peripheral nerve regeneration and potential clinical applications.

Structure characterisation of polysaccharides purified from Boletus aereus Bull. and its improvement on AD-like behaviours via reliving neuroinflammation in APP/PS1 mice

The water-soluble neutral polysaccharide BEP2, with a molecular weight of 26.65 kDa, was isolated from the aqueous extract obtained from the fruiting bodies of Boletus aereus Bull. BEP2 primarily comprises Gal, with specific site substitutions speculated at partial positions, such as the substitution of -OCH3 at position H-3 or the branch at position C-2 including α-L-Fucp-(1→, α-D-Manp-(1 → and α-D-Manp-(1 → 3)-α-L-Fucp-(1 → 6)-β-D-Glcp-(1→. Treatment with BEP2 significantly enhanced learning, memory, and cognitive function, while concurrently reducing the accumulation of β-amyloid and suppressing neuroinflammation within the brains of APP/PS1 mice. Based on the results of biochemical detection, gut microbiota analysis, and metabolomic profiling, we found that BEP2 significantly upregulated the abundance of two bacterial families while downregulation that of seven bacterial families within the intestinal ecosystem. Notably, the abundance of the S24-7 family was significantly increased. Treatment with BEP2 upregulated five metabolites, while downregulating three metabolites, including norepinephrine. Additionally, BEP2 decreased the levels of interleukin (IL)-1β and IL-6, regulated the activities of microglial cells and astrocytes and increased the levels of the chemokine fractalkine (CX3CL1) and its receptor on microglia (CX3CR1), as well as that of transforming growth factor (TGF)-β1. These findings confirmed the suppressive effects of BEP2 on neuroinflammation.

Biomarkers in Alzheimer's Disease: Are Olfactory Neuronal Precursors Useful for Antemortem Biomarker Research?

Alzheimer's disease (AD), as the main cause of dementia, affects millions of people around the world, whose diagnosis is based mainly on clinical criteria. Unfortunately, the diagnosis is obtained very late, when the neurodegenerative damage is significant for most patients. Therefore, the exhaustive study of biomarkers is indispensable for diagnostic, prognostic, and even follow-up support. AD is a multifactorial disease, and knowing its underlying pathological mechanisms is crucial to propose new and valuable biomarkers. In this review, we summarize some of the main biomarkers described in AD, which have been evaluated mainly by imaging studies in cerebrospinal fluid and blood samples. Furthermore, we describe and propose neuronal precursors derived from the olfactory neuroepithelium as a potential resource to evaluate some of the widely known biomarkers of AD and to gear toward searching for new biomarkers. These neuronal lineage cells, which can be obtained directly from patients through a non-invasive and outpatient procedure, display several characteristics that validate them as a surrogate model to study the central nervous system, allowing the analysis of AD pathophysiological processes. Moreover, the ease of obtaining and harvesting endows them as an accessible and powerful resource to evaluate biomarkers in clinical practice.

Exploring cerebral amyloid angiopathy: Insights into pathogenesis, diagnosis, and treatment

Cerebral Amyloid Angiopathy (CAA) is a neurological disorder characterized by the deposition of amyloid plaques in the walls of cerebral blood vessels. This condition poses significant challenges in terms of understanding its underlying mechanisms, accurate diagnosis, and effective treatment strategies. This article aims to shed light on the complexities of CAA by providing insights into its pathogenesis, diagnosis, and treatment options. The pathogenesis of CAA involves the accumulation of amyloid beta (Aβ) peptides in cerebral vessels, leading to vessel damage, impaired blood flow, and subsequent cognitive decline. Various genetic and environmental factors contribute to the development and progression of CAA, and understanding these factors is crucial for targeted interventions. Accurate diagnosis of CAA often requires advanced imaging techniques, such as magnetic resonance imaging (MRI) or positron emission tomography (PET) scans, to detect characteristic amyloid deposits in the brain. Early and accurate diagnosis enables appropriate management and intervention strategies. Treatment of CAA focuses on preventing further deposition of amyloid plaques, managing associated symptoms, and reducing the risk of complications such as cerebral hemorrhage. Currently, there are no disease-modifying therapies specifically approved for CAA. However, several experimental treatments targeting Aβ clearance and anti-inflammatory approaches are being investigated in clinical trials, offering hope for future therapeutic advancements.

A glance through the effects of CD4+ T cells, CD8+ T cells, and cytokines on Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia. Unfortunately, despite numerous studies, an effective treatment for AD has not yet been established. There is remarkable evidence indicating that the innate immune mechanism and adaptive immune response play significant roles in the pathogenesis of AD. Several studies have reported changes in CD8+ and CD4+ T cells in AD patients. This mini-review article discusses the potential contribution of CD4+ and CD8+ T cells reactivity to amyloid β (Aβ) protein in individuals with AD. Moreover, this mini-review examines the potential associations between T cells, heme oxygenase (HO), and impaired mitochondria in the context of AD. While current mathematical models of AD have not extensively addressed the inclusion of CD4+ and CD8+ T cells, there exist models that can be extended to consider AD as an autoimmune disease involving these T cell types. Additionally, the mini-review covers recent research that has investigated the utilization of machine learning models, considering the impact of CD4+ and CD8+ T cells.

Circadian therapy interventions for glymphatic dysfunction in concussions injuries: A narrative review

There are two primary threats to the brain after concussion. The first is a buildup of neurotoxic proteins in the brain. The second, a partial consequence of the first, is a sustained neuroinflammatory response that may lead to central sensitization and the development of persistent post-concussive symptoms. These threats make neurotoxin clearance a high clinical priority in the acute period after injury. The glymphatic system is the brain's primary mechanism for clearing neurotoxic waste. The glymphatic system is intimately tied to the sleep cycle and circadian dynamics. However, glymphatic dysfunction and sleep disturbances are nearly ubiquitous in the acute period after concussion injury. Because of this, sleep optimization via circadian therapy is a time-sensitive and critical tool in acute concussion management.

The S2 Subunit of Infectious Bronchitis Virus Affects Abl2-Mediated Syncytium Formation

The S2 subunit serves a crucial role in infectious bronchitis virus (IBV) infection, particularly in facilitating membrane fusion. Using reverse genetic techniques, mutant strains of the S2 locus exhibited substantially different syncytium-forming abilities in chick embryonic kidney cells. To determine the precise formation mechanism of syncytium, we demonstrated the co-ordinated role of Abl2 and its mediated cytoskeletal regulatory pathway within the S2 subunit. Using a combination of fluorescence quantification, RNA silencing, and protein profiling techniques, the functional role of S2 subunits in IBV-infected cells was exhaustively determined. Our findings imply that Abl2 is not the primary cytoskeletal regulator, the viral S2 component is involved in indirect regulation, and the three different viral strains activate various cytoskeletal regulatory pathways through Abl2. CRK, CRKL, ABI1, NCKAP1, and ENAH also play a role in cytoskeleton regulation. Our research provides a point of reference for the development of an intracellular regulatory network for the S2 subunit and a foundation for the rational design of antiviral drug targets against Abl2.

Identification of prognostic cancer-associated fibroblast markers in luminal breast cancer using weighted gene co-expression network analysis

Background

Cancer-associated fibroblasts (CAFs) play a pivotal role in cancer progression and are known to mediate endocrine and chemotherapy resistance through paracrine signaling. Additionally, they directly influence the expression and growth dependence of ER in Luminal breast cancer (LBC). This study aims to investigate stromal CAF-related factors and develop a CAF-related classifier to predict the prognosis and therapeutic outcomes in LBC.

Methods

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were utilized to obtain mRNA expression and clinical information from 694 and 101 LBC samples, respectively. CAF infiltrations were determined by estimating the proportion of immune and cancer cells (EPIC) method, while stromal scores were calculated using the Estimation of STromal and Immune cells in MAlignant Tumors using Expression data (ESTIMATE) algorithm. Weighted gene co-expression network analysis (WGCNA) was used to identify stromal CAF-related genes. A CAF risk signature was developed through univariate and least absolute shrinkage and selection operator method (LASSO) Cox regression model. The Spearman test was used to evaluate the correlation between CAF risk score, CAF markers, and CAF infiltrations estimated through EPIC, xCell, microenvironment cell populations-counter (MCP-counter), and Tumor Immune Dysfunction and Exclusion (TIDE) algorithms. The TIDE algorithm was further utilized to assess the response to immunotherapy. Additionally, Gene set enrichment analysis (GSEA) was applied to elucidate the molecular mechanisms underlying the findings.

Results

We constructed a 5-gene prognostic model consisting of RIN2, THBS1, IL1R1, RAB31, and COL11A1 for CAF. Using the median CAF risk score as the cutoff, we classified LBC patients into high- and low-CAF-risk groups and found that those in the high-risk group had a significantly worse prognosis. Spearman correlation analyses demonstrated a strong positive correlation between the CAF risk score and stromal and CAF infiltrations, with the five model genes showing positive correlations with CAF markers. In addition, the TIDE analysis revealed that high-CAF-risk patients were less likely to respond to immunotherapy. Gene set enrichment analysis (GSEA) identified significant enrichment of ECM receptor interaction, regulation of actin cytoskeleton, epithelial-mesenchymal transition (EMT), and TGF-β signaling pathway gene sets in the high-CAF-risk group patients.

Conclusion

The five-gene prognostic CAF signature presented in this study was not only reliable for predicting prognosis in LBC patients, but it was also effective in estimating clinical immunotherapy response. These findings have significant clinical implications, as the signature may guide tailored anti-CAF therapy in combination with immunotherapy for LBC patients.