Microglia mediated neuroinflammation in neurodegenerative diseases: A review on the cell signaling pathways involved in microglial activation

Extract of Tinospora sinensis alleviates LPS-induced neuroinflammation in mice by regulating TLR4/NF-κB/NLRP3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The dried rattan stem of Tinospora sinensis (Lour.) Merr. is valued for its efficacy of clearing heat and removing toxicity, calming and soothing the nerves. It is widely used in Tibetan medicine for the treatment of rheumatic and aging diseases. Studies have confirmed its anti-inflammatory and ameliorating effects on Alzheimer's disease; however, the anti-neuroinflammation efficacy and mechanism remain unclear.

AIM

This study aimed to explore the anti-neuroinflammation efficacy, major effective ingredients, and potential mechanism of extract of Tinosporae sinenisis (TIS).

METHODS

UPLC-Q-TOF/MS was used to identify the compounds of TIS and the plasma components of rats after gastric administration of TIS. C57BL/6 J mice were continuously intraperitoneally injected with lipopolysaccharide (LPS) (250 μg/kg) for 14 d to establish a neuroinflammation model. The effects of TIS (4.5 g/kg, 9 g/kg) on the learning and memory abilities in mice with neuroinflammation was evaluated using spontaneous activity, novel object recognition, and Morris water maze tests. Pathological changes in the hippocampus were observed using hematoxylin and eosin staining. Gene and protein levels of inflammatory factors in the brain were detected using qRT-PCR and ELISA kits. Iba-1 levels in the brain were detected using immunofluorescence to assess the degree of microglial activation. Network pharmacology, based on the components absorbed into plasma of TIS, was used to predict potential targets and pathways. Proteomics was used to study the differentially expressed proteins and related pathways in the brain tissue of mice with neuroinflammation. Finally, correlation analysis was performed on the results of network pharmacology and proteomics, and proteins related the anti-neuroinflammatory effect of TIS were detected by western blot.

RESULTS

A total of 39 compounds were identified in TIS: genipingentiobioside, isocorydin, reticuline, (-)-argemonine, tinosineside A, tinosinenside A, and costunolide were absorbed into the plasma. After continuous intraperitoneal injection of LPS into C57BL/6 J mice, microglia in the brain tissue were activated and the gene and protein levels of IL-1β, TNF-α, IL-6, and iNOS were increased in the brain tissue, suggesting that the neuroinflammation model was successfully established. TIS reduced Iba-1 levels and gene expression and protein levels of inflammatory factors in the brain of mice with neuroinflammation. Furthermore, TIS improved the pathological changes in the hippocampus and learning and memory abilities caused by neuroinflammation. Network pharmacology has predicted that TNF, IL-1β, and IκBKB are closely related to neuroinflammation. Proteomics identified key differentially expressed proteins, including TNF, NF-κB2, NF-κBIA, and TLR4. Toll-like receptor (TLR), NF-κB, and NOD-like receptor (NLR) signaling pathways are involved in neuroinflammation-related pathways. Correlation analysis revealed TLR, TNF and NLR signaling pathways were closely related to the anti-neuroinflammatory effects of TIS. We observed that TIS alleviated neuroinflammation by inhibiting the TLR4/NF-κB/NLRP3 pathway.

CONCLUSION

Thirty-nine compounds were identified from TIS, among which seven were absorbed into the plasma as prototype components. TIS alleviated LPS-induced neuroinflammation in mice, and its mechanism was related to inhibition of TLR4/NF-κB/NLRP3 signaling pathway.

Synthesis and biological evaluation of lappaconitine analogues as potential anti-neuroinflammatory agents by side chain modification and scaffold hopping strategy

Neuroinflammation mediated by microglia is widely recognized as a key pathophysiological mechanism in neurodegenerative diseases. Lappaconitine (LA) is a natural C18-diterpenoid alkaloid isolated from Aconitum sinomontanum Nakai, and previous study showed that LA and its derivatives inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells. However, the anti-neuroinflammatory effects of LA and its derivatives on microglia are still not clear. Here, LA analogues were designed and synthesized, and the anti-neuroinflammatory activity of the synthesized compounds was screened using LPS-induced overexpression of NO in BV-2 microglia. The screening results showed that compound 10 displayed the highest ability to inhibit NO production (IC50 = 9.98 ± 1.6 µM). Mechanistic investigations revealed that compound 10 attenuated LPS-activated neuroinflammation through suppression of TLR4/MyD88/NF-κB pathway in BV-2 microglia. Acute toxicity assays showed that compound 10 (LD50 = 508.1 mg/kg) was safer relative to LA (LD50 = 30.6 mg/kg). Collectively, our findings show that compound 10 could have potential as anti-neuroinflammatory agents.

USP22 inhibits microglial M1 polarization by regulating the PU.1/NLRP3 inflammasome pathway

OBJECTIVE

This study aimed to investigate the effect of Ubiquitin-Specific Peptidase 22 (USP22) on the inflammatory response mediated by BV-2 mouse microglia and explore the role of the PU box binding protein 1 (PU.1)/NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome in the USP22-induced polarization of BV-2 cells.

METHODS

The BV-2 mouse microglia line was cultured in vitro, and plasmid and siRNA transfection was performed to overexpress or knockdown USP22. Subsequently, BV-2 cells were treated with lipopolysaccharide (LPS) and interferon-gamma (IFN-γ) and interleukin (IL)-4 to induce M1 and M2 polarization, respectively. Western blot was used to detect the expression levels of USP22, PU.1, M1 polarization markers [inducible nitric oxide synthase (iNOS), and cluster of differentiation (CD) 86], M2 polarization markers [arginase 1 (Arg1), and CD206], in BV-2 cells from different treatment groups. Additionally, measurement was performed on the inflammasome NLRP3, and its activation-related proteins [NIMA-related kinase7 (NEK7), cleaved-caspase 1, apoptosis-associated speck-like protein containing a CARD (ASC)]. Enzyme-linked immunosorbent (ELISA) assay was employed to determine the levels of inflammatory cytokines tumor necrosis factor-alpha (TNF-α), IL-1 β, and IL-10 in the cells. Furthermore, immunofluorescence was utilized to analyze the levels of iNOS and Arg1-positive BV-2 cells in different treatment groups. Moreover, the ubiquitination level of PU.1 was detected using immunoprecipitation.

RESULTS

The protein expression level of USP22 was significantly down-regulated in BV-2 cells treated with M1 polarization. Overexpression of USP22 remarkably reduced the protein levels of iNOS and CD86, but markedly increased the protein levels of Arg1 and CD206 in cells. Besides, there was a notable reduction in the levels of TNF-α and IL-1 β in the cell culture medium, while a remarkable increase was observed in the level of IL-10. Additionally, the level of iNOS-positive cells was significantly decreased, while the level of Arg1-positive cells was considerably increased. However, up-regulation of PU.1 expression could reverse the above results and promoted the expression of NLRP3 and its activation-related proteins. Notably, overexpression of USP22 significantly down-regulated the protein expression and ubiquitination level of PU.1.

CONCLUSION

USP22 inhibits the M1 polarization of BV-2 mouse microglia. The PU.1/NLRP3 inflammasome pathway may be a critical regulatory pathway of USP22 in BV-2 cell polarization.

Decoding Neurodegeneration: A Review of Molecular Mechanisms and Therapeutic Advances in Alzheimer's, Parkinson's, and ALS

Neurodegenerative diseases, such as Alzheimer's, Parkinson's, ALS, and Huntington's, remain formidable challenges in medicine, with their relentless progression and limited therapeutic options. These diseases arise from a web of molecular disturbances-misfolded proteins, chronic neuroinflammation, mitochondrial dysfunction, and genetic mutations-that slowly dismantle neuronal integrity. Yet, recent scientific breakthroughs are opening new paths to intervene in these once-intractable conditions. This review synthesizes the latest insights into the underlying molecular dynamics of neurodegeneration, revealing how intertwined pathways drive the course of these diseases. With an eye on the most promising advances, we explore innovative therapies emerging from cutting-edge research: nanotechnology-based drug delivery systems capable of navigating the blood-brain barrier, gene-editing tools like CRISPR designed to correct harmful genetic variants, and stem cell strategies that not only replace lost neurons but foster neuroprotective environments. Pharmacogenomics is reshaping treatment personalization, enabling tailored therapies that align with individual genetic profiles, while molecular diagnostics and biomarkers are ushering in an era of early, precise disease detection. Furthermore, novel perspectives on the gut-brain axis are sparking interest as mounting evidence suggests that microbiome modulation may play a role in reducing neuroinflammatory responses linked to neurodegenerative progression. Taken together, these advances signal a shift toward a comprehensive, personalized approach that could transform neurodegenerative care. By integrating molecular insights and innovative therapeutic techniques, this review offers a forward-looking perspective on a future where treatments aim not just to manage symptoms but to fundamentally alter disease progression, presenting renewed hope for improved patient outcomes.

Crosstalk between peripheral inflammation and brain: Focus on the responses of microglia and astrocytes to peripheral challenge

A growing body of evidence supports the link between peripheral inflammation and impairment of neurologic functions, including mood and cognitive abilities. The pathogenic event connecting peripheral inflammation and brain dysfunction is represented by neuroinflammation, a pathogenic phenomenon that provides an important contribution to neurodegeneration and cognitive decline also in Alzheimer's, Parkinson's, Huntington's diseases, as well as in Multiple Sclerosis. It is driven by resident brain immune cells, microglia and astrocytes, that acquire an activated phenotype in response to proinflammatory molecules moving from the periphery to the brain parenchyma. Although a huge progress has been made in clarifying cellular and molecular mechanisms bridging peripheral and central inflammation, a clear picture has not been achieved so far. Therefore, experimental models are of crucial relevance to clarify knowledge gaps in this regard. Many findings demonstrate that systemic inflammation induced by pathogen-associated molecular patterns, such as lipopolysaccharide (LPS), is able to trigger neuroinflammation. Therefore, LPS-administration is widely considered a useful tool to study this phenomenon. On this basis, the present review will focus on in vivo studies based on acute and subacute effects of systemic administration of LPS, with special attention on the state of art of microglia and astrocyte response to peripheral challenge.

Design, Synthesis, and Anti-Inflammatory Activity Evaluation of Novel Indanone Derivatives for the Treatment of Vascular Dementia

Vascular dementia (VaD) is a neurodegenerative disease resulting from cerebral vascular obstruction, leading to cognitive impairment, and currently lacks effective treatment options. Due to its complex pathogenesis, multi-target drug design (MTDLs) strategies are considered among the most promising therapeutic approaches. In this study, we designed and synthesized a series of novel indanone derivatives targeting targets related to vascular health and dementia. The results indicated that compound C5 exhibited excellent acetylcholinesterase inhibitory activity (IC50 =1.16 0.41 μM) and anti-platelet aggregation activity (IC50 =4.92±0.10 μM) within ranges of 0.1-1000 μM and 0.03-300 μM, respectively, possibly mediated by molecular docking interactions. Furthermore, compound C5 demonstrated protective effects on cells at concentrations ≤50 μM, significantly reducing the release of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) in a concentration-dependent manner, showcasing its potent neuroinflammatory inhibitory effects. Anti-inflammatory therapies are regarded as effective strategies for treating VaD. Therefore, compound C5 holds promise as a novel candidate drug for further investigation into the treatment of vascular dementia.

Neuronal cathepsin S increases neuroinflammation and causes cognitive decline via CX3CL1-CX3CR1 axis and JAK2-STAT3 pathway in aging and Alzheimer's disease

Aging is an intricate process involving interactions among multiple factors, which is one of the main risks for chronic diseases, including Alzheimer's disease (AD). As a member of cysteine protease, cathepsin S (CTSS) has been implicated in inflammation across various diseases. Here, we investigated the role of neuronal CTSS in aging and AD started by examining CTSS expression in hippocampus neurons of aging mice and identified a significant increase, which was negatively correlated with recognition abilities. Concurrently, we observed an elevation of CTSS concentration in the serum of elderly people. Transcriptome and fluorescence-activated cell sorting (FACS) results revealed that CTSS overexpression in neurons aggravated brain inflammatory milieu with microglia activation to M1 pro-inflammatory phenotype, activation of chemokine C-X3-C-motif ligand 1 (CX3CL1)-chemokine C-X3-C-motif receptor 1 (CX3CR1) axis and janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway. As CX3CL1 is secreted by neurons and acts on the CX3CR1 in microglia, our results revealed for the first time the role of neuron CTSS in neuron-microglia "crosstalk." Besides, we observed elevated CTSS expression in multiple brain regions of AD patients, including the hippocampus. Utilizing CTSS selective inhibitor, LY3000328, rescued AD-related pathological features in APP/PS1 mice. We further noticed that neuronal CTSS overexpression increased cathepsin B (CTSB) activity, but decreased cathepsin L (CTSL) activity in microglia. Overall, we provide evidence that CTSS can be used as an aging biomarker and plays regulatory roles through modulating neuroinflammation and recognition in aging and AD process.

Exosomes as Vehicles for Noncoding RNA in Modulating Inflammation: A Promising Regulatory Approach for Ischemic Stroke and Myocardial Infarction

Exosomes have grown as promising carriers for noncoding RNAs (ncRNAs) in the treatment of inflammation, particularly in conditions like ischemic stroke and myocardial infarction. These ncRNAs, which include microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), play a crucial role in regulating inflammatory pathways, presenting new therapeutic opportunities. In both ischemic stroke and myocardial infarction, inflammation significantly influences disease progression and severity. Exosomes can deliver ncRNAs directly to specific cells and tissues, providing a targeted approach to modulate gene expression and reduce inflammation. Their biocompatibility and low risk of inducing immune responses make exosomes ideal therapeutic vehicles. Ongoing research is focused on optimizing the loading of ncRNAs into exosomes, ensuring efficient delivery, and understanding the mechanisms by which these ncRNAs mitigate inflammation. In ischemic stroke, exosome-derived ncRNAs originate from various cell types, including neurons, M2 microglia, patient serum, genetically engineered HEK293T cells, and mesenchymal stromal cells. In the case of myocardial infarction, these ncRNAs are sourced from mesenchymal stem cells, endothelial cells, and patient plasma. These exosome-loaded ncRNAs play a significant role in modulating inflammation in both ischemic stroke and myocardial infarction. As this research advances, therapies based on exosomes may completely change how diseases linked to inflammation are treated, offering new avenues for patient care and recovery. This review explores the latest advancements in understanding how exosomes impact specific inflammatory components, with a particular emphasis on the role of ncRNAs contained in exosomes. The review concludes by highlighting the clinical potential of exosome-derived ncRNAs as innovative therapeutic and diagnostic tools.

The Role of Ferroptosis in Amyotrophic Lateral Sclerosis Treatment

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease with a challenging treatment landscape, due to its complex pathogenesis and limited availability of clinical drugs. Ferroptosis, an iron-dependent form of programmed cell death (PCD), stands distinct from apoptosis, necrosis, autophagy, and other cell death mechanisms. Recent studies have increasingly highlighted the role of iron deposition, reactive oxygen species (ROS) accumulation, oxidative stress, as well as systemic Xc- and glutamate accumulation in the antioxidant system in the pathogenesis of amyotrophic lateral sclerosis. Therefore, targeting ferroptosis emerges as a promising strategy for amyotrophic lateral sclerosis treatment. This review introduces the regulatory mechanism of ferroptosis, the relationship between amyotrophic lateral sclerosis and ferroptosis, and the drugs used in the clinic, then discusses the current status of amyotrophic lateral sclerosis treatment, hoping to provide new directions and targets for its treatment.

PD-1 mediates microglia polarization via the MAPK signaling pathway to protect blood-brain barrier function during cerebral ischemia/reperfusion

BACKGROUND

Cerebral ischemia is characterized by its rapid onset and high rates of recurrence, morbidity, and mortality, with blood-brain barrier (BBB) permeability playing a vital role in brain injury. Therefore, it is important to understand the molecular mechanism which regulates the BBB during cerebral ischemia.

MATERIALS AND METHODS

An in vitro model of oxygen-glucose deprivation (OGD) and an in vivo model of cerebral ischemia/reperfusion (I/R) were constructed. PD-1 overexpression vectors and vectors containing si-RNA were transfected and injected into in vitro and in vivo models. Western blotting, real-time quantitative PCR (qPCR), immunofluorescence (IF) analysis, and immunohistochemical staining were employed to evaluate the expression levels of programmed cell death-1 (PD-1), microglia M1 and M2 biomarkers, and tight junction proteins. Flow cytometry and ELISA were used to measure the levels of pro-inflammatory cytokines. The BBB permeability of brain tissues was evaluated by Evans blue dye (EBD) extravasation and transendothelial electrical resistance (TEER). Brain water content was measured to assess the extent of inflammatory exudation. The infarct volume and neurological severity score (NSS) were used to assess the severity of brain injury. Brain cell apoptosis was assessed by the TUNEL assay and hematoxylin-eosin (H&E) staining.

RESULTS

PD-1 helped to convert the microglia M1 phenotype to the M2 phenotype and to reduce BBB permeability both in vitro and in vivo. Overexpression of PD-1 promoted a shift of the M1 phenotype to the M2 phenotype and reduced BBB permeability via the ERK and p38 MAPK signaling pathways. PD-1 reduced inflammatory exudation, BBB permeability, cell apoptosis, and brain injury in vivo.

CONCLUSION

Our present study verified that PD-1 exerts an anti-inflammatory effect by converting the microglia M1 phenotype to the M2 phenotype, reducing BBB permeability, and thereby relieves brain injury caused by cerebral ischemia. PD-1 is potential therapeutic target for brain injury caused by cerebral ischemia.

Inflammaging and Brain Aging

Progress made by the medical community in increasing lifespans comes with the costs of increasing the incidence and prevalence of age-related diseases, neurodegenerative ones included. Aging is associated with a series of morphological changes at the tissue and cellular levels in the brain, as well as impairments in signaling pathways and gene transcription, which lead to synaptic dysfunction and cognitive decline. Although we are not able to pinpoint the exact differences between healthy aging and neurodegeneration, research increasingly highlights the involvement of neuroinflammation and chronic systemic inflammation (inflammaging) in the development of age-associated impairments via a series of pathogenic cascades, triggered by dysfunctions of the circadian clock, gut dysbiosis, immunosenescence, or impaired cholinergic signaling. In addition, gender differences in the susceptibility and course of neurodegeneration that appear to be mediated by glial cells emphasize the need for future research in this area and an individualized therapeutic approach. Although rejuvenation research is still in its very early infancy, accumulated knowledge on the various signaling pathways involved in promoting cellular senescence opens the perspective of interfering with these pathways and preventing or delaying senescence.

Apilarnil exerts neuroprotective effects and alleviates motor dysfunction by rebalancing M1/M2 microglia polarization, regulating miR-155 and miR-124 expression in a rotenone-induced Parkinson's disease rat model

Microglial activation contributes to the neuropathology of Parkinson's disease (PD). Inhibiting M1 while simultaneously boosting M2 microglia activation may therefore be a potential treatment for PD. Apilarnil (API) is a bee product produced from drone larvae. Recent research has demonstrated the protective effects of API on multiple body systems. Nevertheless, its impact on PD or the microglial M1/M2 pathway has not yet been investigated. Thus, we intended to evaluate the dose-dependent effects of API in rotenone (ROT)-induced PD rat model and explore the role of M1/M2 in mediating its effect. Seventy-two Wistar rats were equally grouped as; control, API, ROT, and groups in which API (200, 400, and 800 mg/kg, p.o.) was given simultaneously with ROT (2 mg/kg, s.c.) for 28 days. The high dose of API (800 mg/kg) showed enhanced motor function, higher expression of tyrosine hydroxylase and dopamine levels, less dopamine turnover and α-synuclein expression, and a better histopathological picture when compared to the ROT group and the lower two doses. API's high dose exerted its neuroprotective effects through abridging the M1 microglial activity, illustrated in the reduced expression of miR-155, Iba-1, CD36, CXCL10, and other pro-inflammatory markers' levels. Inversely, API high dose enhanced M2 microglial activity, witnessed in the elevated expression of miR-124, CD206, Ym1, Fizz1, arginase-1, and other anti-inflammatory indices, in comparison to the diseased group. To conclude, our study revealed a novel neuroprotective impact for API against experimentally induced PD, where the high dose showed the highest protection via rebalancing M1/M2 polarization.

Polygonatum sibiricum Polysaccharides Alleviate Depressive-like Symptoms in Chronic Restraint Stress-Induced Mice via Microglial Regulation in Prefrontal Cortex

Microglia respond to stressors by secreting cytokines or growth factors, playing a crucial role in maintaining brain homeostasis. While the antidepressant-like effects of Polygonatum sibiricum polysaccharides (PSPs) have been observed in mice, their potential effectiveness involving microglial regulation remains unknown. This study investigates the antidepressant-like mechanism of PSP by regulating microglial phenotype and signaling pathways in the prefrontal cortex of chronic restraint stress (CRS)-induced mice. PSP was extracted, purified, characterized, and orally administered to CRS mice. High-performance gel permeation chromatography (HPGPC) revealed that PSP has a molecular weight of 5.6 kDa. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that PSP exhibited a layered structure with densely packed, irregular surfaces. PSP treatment significantly increased sucrose preference (low: 71%, p < 0.01; medium: 69%, p < 0.05; high: 75%, p < 0.001 vs. CRS: 58%) and reduced immobility time (low: 74 s, p < 0.01; medium: 68 s, p < 0.01; high: 79 s, p < 0.05 vs. CRS: 129 s), indicating the alleviation of depressive-like behaviors. PSP inhibited microglial activation (PSP, 131/mm2 vs. CRS, 173/mm2, p = 0.057), reversing CRS-induced microglial hypertrophy and hyper-ramification. Furthermore, PSP inactivated microglial activation by inhibiting NLRP3/ASC/caspase-1/IL-1β signaling pathways, increasing BDNF synthesis and activating brain-derived neurotrophic factor (BDNF)-mediated neurogenesis (PSP, 80/per DG vs. CRS, 49/per DG, p < 0.01). In conclusion, PSP exerts antidepressant-like effects through the regulation of microglial activity and neuroinflammatory pathways, indicating it as a potential natural compound for depression treatment.

β2-Integrins Regulate Microglial Responses and the Functional Outcome of Hemorrhagic Stroke In Vivo

Stroke is one of the leading causes of death and long-term disabilities worldwide. In addition to interruption of blood flow, inflammation is widely recognized as an important factor mediating tissue destruction in stroke. Depending on their phenotype, microglia, the main leukocytes in the CNS, are capable of either causing further tissue damage or promoting brain restoration after stroke. β2-integrins are cell adhesion molecules that are constitutively expressed on microglia. The function of β2-integrins has been investigated extensively in animal models of ischemic stroke, but their role in hemorrhagic stroke is currently poorly understood. We show in this study that dysfunction of β2-integrins is associated with improved functional outcome and decreased inflammatory cytokine expression in the brain in a mouse model of hemorrhagic stroke. Furthermore, β2-integrins affect microglial phenotype and cytokine responses in vivo. Therefore, our findings suggest that targeting β2-integrins in hemorrhagic stroke may be beneficial.

Brain-Gut and Microbiota-Gut-Brain Communication in Type-2 Diabetes Linked Alzheimer's Disease

The gastrointestinal (GI) tract, home to the largest microbial population in the human body, plays a crucial role in overall health through various mechanisms. Recent advancements in research have revealed the potential implications of gut-brain and vice-versa communication mediated by gut-microbiota and their microbial products in various diseases including type-2 diabetes and Alzheimer's disease (AD). AD is the most common type of dementia where most of cases are sporadic with no clearly identified cause. However, multiple factors are implicated in the progression of sporadic AD which can be classified as non-modifiable (e.g., genetic) and modifiable (e.g. Type-2 diabetes, diet etc.). Present review focusses on key players particularly the modifiable factors such as Type-2 diabetes (T2D) and diet and their implications in microbiota-gut-brain (MGB) and brain-gut (BG) communication and cognitive functions of healthy brain and their dysfunction in Alzheimer's Disease. Special emphasis has been given on elucidation of the mechanistic aspects of the impact of diet on gut-microbiota and the implications of some of the gut-microbial products in T2D and AD pathology. For example, mechanistically, HFD induces gut dysbiosis with driven metabolites that in turn cause loss of integrity of intestinal barrier with concomitant colonic and systemic chronic low-grade inflammation, associated with obesity and T2D. HFD-induced obesity and T2D parallel neuroinflammation, deposition of Amyloid β (Aβ), and ultimately cognitive impairment. The review also provides a new perspective of the impact of diet on brain-gut and microbiota-gut-brain communication in terms of transcription factors as a commonly spoken language that may facilitates the interaction between gut and brain of obese diabetic patients who are at a higher risk of developing cognitive impairment and AD. Other commonality such as tyrosine kinase expression and functions maintaining intestinal integrity on one hand and the phagocytic clarence by migratory microglial functions in brain are also discussed. Lastly, the characterization of the key players future research that might shed lights on novel potential pharmacological target to impede AD progression are also discussed.

Spinal Cord Injury: From MicroRNAs to Exosomal MicroRNAs

Spinal cord injury (SCI) is an unfortunate experience that may generate extensive sensory and motor disabilities due to the destruction and passing of nerve cells. MicroRNAs are small RNA molecules that do not code for proteins but instead serve to regulate protein synthesis by targeting messenger RNA's expression. After SCI, secondary damage like apoptosis, oxidative stress, inflammation, and autophagy occurs, and differentially expressed microRNAs show a function in these procedures. Almost all animal and plant cells release exosomes, which are sophisticated formations of lipid membranes. These exosomes have the capacity to deliver significant materials, such as proteins, RNAs and lipids, to cells in need, regulating their functions and serving as a way of communication. This new method offers a fresh approach to treating spinal cord injury. Obviously, the exosome has the benefit of conveying the transported material across performing regulatory activities and the blood-brain barrier. Among the exosome cargoes, microRNAs, which modulate their mRNA targets, show considerable promise in the pathogenic diagnosis, process, and therapy of SCI. Herein, we describe the roles of microRNAs in SCI. Furthermore, we emphasize the importance of exosomal microRNAs in this disease.

The Biological Activity of Ganoderma lucidum on Neurodegenerative Diseases: The Interplay between Different Active Compounds and the Pathological Hallmarks

Neurodegenerative diseases represent a cluster of conditions characterized by the progressive degeneration of the structure and function of the nervous system. Despite significant advancements in understanding these diseases, therapeutic options remain limited. The medicinal mushroom Ganoderma lucidum has been recognized for its comprehensive array of bioactive compounds with anti-inflammatory and antioxidative effects, which possess potential neuroprotective properties. This literature review collates and examines the existing research on the bioactivity of active compounds and extracts from Ganoderma lucidum in modulating the pathological hallmarks of neurodegenerative diseases. The structural information and preparation processes of specific components, such as individual ganoderic acids and unique fractions of polysaccharides, are presented in detail to facilitate structure-activity relationship research and scale up the investigation of in vivo pharmacology. The mechanisms of these components against neurodegenerative diseases are discussed on multiple levels and elaborately categorized in different patterns. It is clearly presented from the patterns that most polysaccharides of Ganoderma lucidum possess neurotrophic effects, while ganoderic acids preferentially target specific pathogenic proteins as well as regulating autophagy. Further clinical trials are necessary to assess the translational potential of these components in the development of novel multi-target drugs for neurodegenerative diseases.