Search Results (585)

Microglia-mediated chronic neuroinflammation is a common pathological feature of Parkinson’s disease (PD). Strong evidence suggests that activated microglia can lesion neurons by releasing exosomes. However, the mechanisms of exosome release from activated microglia remain unclear. We recently revealed a key role of complement receptor 3 (CR3) in regulating microglial activation in the process of progressive neurodegeneration. This study aimed to investigate whether CR3 can regulate exosome release from activated microglia, as well as the underlying mechanisms. We found that LPS, an inducer of microglial M1 activation, induced exosome release from activated microglia. Inhibition of exosome synthesis suppressed LPS-induced microglial activation, gene expression of proinflammatory factors, and related neurotoxicity. Silencing or knocking out CR3 attenuated LPS-induced exosome release in microglia. NADPH oxidase (NOX2) was further identified as a downstream signal of CR3, mediating microglial exosome release and related neurotoxicity. CR3 silencing blocked LPS-induced NOX2 activation and superoxide production through inhibition of p47^phox phosphorylation and membrane translocation. Moreover, NOX2 activation elicited by PMA or supplementation of H₂O₂ recovered exosome release from CR3-silenced microglia. Subsequently, we demonstrated that the CR3-NOX2 axis regulates syntenin-1 to control microglial exosome release. Finally, we observed that the expression of CR3 was increased in the brain of LPS-treated mice, and genetic ablation of CR3 significantly reduced LPS-induced NOX2 activation, microglial M1 polarization, and exosome production in mice. Overall, our findings revealed a critical role of the CR3-NOX2 axis in controlling microglial exosome release and related neurotoxicity through syntenin-1, providing a novel target for the development of a therapeutic strategy for neuroinflammation-mediated neurodegeneration. Full article

Peroxisome proliferator-activated receptor alpha (PPARα) is a key regulator of lipid metabolism, making its agonists valuable therapeutic targets for various diseases, including chronic peripheral neuropathy. Existing PPARα agonists face limitations such as poor selectivity, sub-optimal bioavailability, and safety concerns. We previously demonstrated that A190, a novel, potent, and selective PPARα agonist, effectively alleviates chemotherapy-induced peripheral neuropathy and CFA-induced inflammatory pain as a non-opioid therapeutic agent. However, A190 alone has solubility and permeability issues that limits its oral delivery. To overcome this challenge, in this study, four new-generation ester prodrugs of A190; A190-PD-9 (methyl ester), A190-PD-14 (ethyl ester), A190-PD-154 (isopropyl ester), and A190-PD-60 (cyclic carbonate) were synthesized and evaluated for their enzymatic bioconversion and chemical stability. The lead candidate, A190-PD-60, was further formulated as a microemulsion (A190-PD-60-ME) and optimized via Box–Behnken design. A190-PD-60-ME featured nano-sized droplets (~120 nm), low polydispersity (PDI < 0.3), and high drug loading (>90%) with significant improvement in artificial membrane permeability. Crucially, pharmacokinetic evaluation in rats demonstrated that A190-PD-60-ME reached a 16.6-fold higher Cmax (439 ng/mL) and a 5.9-fold increase in relative oral bioavailability compared with an A190-PD-60 dispersion. These findings support the combined prodrug-microemulsion approach as a promising strategy to overcome oral bioavailability challenges and advance PPARα-targeted therapies. Full article

Background/Objectives: Restored CD4 absolute counts (CD4AC) and CD4/CD8 ratio in the setting of continuous antiretroviral treatment (ART) do not exclude a low-level immune activation associated with HIV reservoirs, microbial translocation, or the side effects of ART itself, which accelerates the aging of people living with HIV (PLHIV). To delineate biomarkers of incomplete immune restoration in PLHIV on successful ART, we evaluated T-lymphocyte mitochondrial parameters in relation to phenotypic markers of immune exhaustion and senescence. Methods: PLHIV with sustained viral suppression, CD4AC > 500 and CD4/CD8 ratio >0.9 on ART (n = 39) were compared to age-matched ART-naïve donors (n = 27) and HIV(–) healthy controls (HC, n = 35). CD4 and CD8 differentiation and effector subsets (CCR7/CD45RA and CD27/CD28), activation, exhaustion, and senescence markers (CD38, CD39 Treg, CD57, TIGIT, and PD-1) were determined by flow cytometry. Mitochondrial mass (MM) and membrane potential (MMP) of CD8 and CD4 T cells were evaluated with MitoTracker Green and Red flow cytometry dyes. Results: ART+PLHIV differed from HC by increased CD4 TEMRA (5.3 (2.1–8.8) vs. 3.2 (1.6–4.4), p < 0.05), persistent TIGIT+CD57–CD27+CD28– CD8+ subset (53.9 (45.5–68.9) vs. 40.1 (26.7–58.5), p < 0.05), and expanding preapoptotic TIGIT–CD57+CD8+ effectors (9.2 (4.3–21.8) vs. 3.0 (1.5–7.3), p < 0.01) in correlation with increased CD8+ MMP (2527 (1675–4080) vs.1477 (1280–1691), p < 0.01). These aberrations were independent of age, time to ART, or ART duration, and were combined with increasing CD4 T cell MMP and MM. Conclusions: In spite of recovered CD4AC and CD4/CD8 ratio, the increased CD8+ MMP, combined with elevated markers of exhaustion and senescence in ART+PLHIV, signals a malfunction of the CD8 effector pool that may compromise viral reservoir latency. Full article

TREM2 (triggering receptor expressed on myeloid cells 2) is a membrane-bound receptor primarily expressed on microglia in the central nervous system (CNS). TREM2 plays a crucial role in regulating immune responses, phagocytosis, lipid metabolism, and inflammation. Mutations in the TREM2 gene have been linked to various neurodegenerative diseases, including Alzheimer’s disease (AD), frontotemporal dementia (FTD), Parkinson’s disease (PD), and Nasu–Hakola disease (NHD). These mutations are suggested to impair microglial activation and reduce the ability to clear amyloid aggregates, leading to exacerbated neuroinflammatory responses and accelerating disease progression. This review provides an overview of TREM2 structure, functions, and known pathogenic variants—including Arg47His, Arg62His, His157Tyr, Tyr38Cys, and Thr66Met. Furthermore, the molecular and cellular consequences of TREM2 mutations are introduced, such as impaired ligand binding, altered protein folding and trafficking, enhanced TREM2 shedding, and dysregulated inflammatory signaling. We also highlight recent advances in therapeutic strategies aimed at modulating TREM2 signaling. These include monoclonal antibodies (e.g., AL002, CGX101), small molecule agonists, and gene/cell-based therapies that seek to restore microglial homeostasis, enhance phagocytosis, and reduce neuroinflammation. While these approaches show promise in in vivo/in vitro studies, their clinical translation may be challenged by disease heterogeneity and mutation-specific responses. Additionally, determining the appropriate timing and precise dosing will be essential. Full article

Background/Objectives: Neuronal oscillations play a key role in the symptoms of Parkinson’s disease (PD). This study investigates the effects of random synaptic inputs, their correlations, and the interaction with synaptic dynamics and spike timing-dependent plasticity (STDP) on the membrane potential and firing patterns of subthalamic nucleus (STN) neurons, both in healthy and PD-affected states. Methods: We used a modified Hodgkin–Huxley model with a Langevin stochastic framework to study how synaptic conductance, random input fluctuations, and STDP affect STN neuron firing and membrane potential, including sensitivity to refractory period and synaptic depression variability. Results: Our results show that random inputs significantly affect the firing patterns of STN neurons, both in healthy cells and those with PD under DBS treatment. STDP, along with random refractory periods and fluctuating input currents, increases the irregularity of inter-spike intervals (ISIs) in output neuron spike trains. Sensitivity analyses highlight the key role of synaptic depression and refractory period variability in shaping firing patterns. Combining random inputs with STDP boosts the correlation between neuron activities. Furthermore, at fixed input noise levels, the model’s output closely matches experimental firing rate and ISI variability data from PD patients and animals, with statistical tests confirming significant effects of STDP on firing regularity. Conclusions: The findings suggest that the stochastic dynamics of STN neurons, combined with STDP, are crucial for shaping neuronal firing patterns in both healthy and PD-affected states. These insights improve our understanding of how noise and plasticity contribute to neural function and dysfunction, with implications for PD symptom management. Full article

Background/Objectives: This study aimed to enhance the oral delivery and therapeutic synergy of atorvastatin (AT) and docetaxel (DT) through a metronomic schedule using a transporter-targeted nanoemulsion (NE), with the goal of improving antitumor efficacy and immune modulation. Methods: AT and DT were co-encapsulated in a NE system (AT/DT-NE#E) incorporating deoxycholic acid–DOTAP (D-TAP), biotin-conjugated phospholipid (Biotin-PE), and d-α-tocopherol polyethylene glycol succinate (TPGS) to exploit bile acid and multivitamin transport pathways and inhibit P-glycoprotein efflux. The optimized NE was characterized physicochemically and evaluated for permeability in artificial membranes and Caco-2/HT29-MTX-E12 monolayers. Pharmacokinetics, tumor suppression, and immune cell infiltration were assessed in vivo using rat and CT26.CL25 mouse models. Results: AT/DT-NE#E showed enhanced permeability of AT and DT by 45.7- and 43.1-fold, respectively, across intestinal cell models and improved oral bioavailability by 118% and 376% compared to free drugs. In vivo, oral metronomic AT/DT-NE#E reduced tumor volume by 65.2%, outperforming intravenous AT/DT. Combination with anti-PD1 therapy achieved a 942% increase in tumor suppression over the control, accompanied by marked increases in tumor-infiltrating CD45⁺, CD4⁺CD3⁺, and CD8⁺CD3⁺ T cells. Conclusions: Oral metronomic administration of AT/DT via a dual-transporter-targeted NE significantly improves drug absorption, tumor inhibition, and immune response. This strategy presents a safe and effective approach for colon cancer therapy, particularly when combined with immunotherapy. Full article

Autoimmune hepatitis (AIH) is linked to an increased risk of hepatocellular carcinoma (HCC). However, the precise connection between the two remains unclear. GPR81, a G-protein-coupled receptor located on the membranes of various cell types, plays a role in numerous physiological processes. We established an AIH animal model and activated GPR81 using the agonist 3,5-dihydroxybenzoic acid (3,5-DHBA). Additionally, the effect of GPR81 inhibition on tumor and immune cell dynamics was examined using the HepG2, Hep3B, and Hepa1-6 cell lines with the antagonist 3-hydroxybutyric acid (3-OBA). Our results demonstrated that 3,5-DHBA treatment reduced T cell and pro-inflammatory cytokine secretion, while MDSC secretion increased, inhibiting Concanavalin A (Con A)-induced AIH. The inhibition of GPR81 by 3-OBA suppressed HCC cell proliferation and invasion, reduced tumor volume and weight, and downregulated PD-L1 expression. Furthermore, CTL and DC activity in the spleen and tumors increased, while MDSC activity decreased. This study confirms that GPR81 plays an important role in both inflammation and tumorigenesis, suggesting that GPR81 may serve as a bridge in the transformation of inflammation into cancer. Modulating GPR81 activity may provide a novel therapeutic strategy for hepatitis and cancer. Full article

The resistance of breast cancer cells to therapeutic antibodies such as anti-HER2 trastuzumab can be overcome by engaging natural killer (NK) cells for killing antibody-binding tumor cells via antibody-dependent cellular cytotoxicity (ADCC). Here, we investigated how autophagy modulation affects trastuzumab-mediated ADCC in HER2-positive JIMT1 breast cancer cells and NK cells. Autophagy inducers (rapamycin and resveratrol) had no significant impact, but the inhibitor bafilomycin nearly abolished ADCC. Protection occurred when either cancer or NK cells were pretreated, indicating dual effects. Bafilomycin reduced phosphatidylserine externalization, the loss of plasma membrane integrity, caspase-3/7 activity, and DNA fragmentation. It downregulated pro-apoptotic BAK1 and BAX without altering BCL-2. Additionally, bafilomycin decreased HER2 surface expression, impairing trastuzumab binding, and modulated immune regulators (STAT1, CD95, and PD-L1) in NK and/or in the cancer cells. Bafilomycin disrupted HER2 trafficking and induced HER2 internalization, leading to its accumulation in cytoplasmic vesicles. These findings show that autophagy inhibition by bafilomycin confers ADCC resistance by altering apoptosis, immune signaling, and HER2 dynamics. The study underscores autophagy’s role in antibody-based cancer therapy efficacy. Full article

Eryptosis is a programmed cellular death involving red blood cells (RBCs). It is a physiological mechanism that leads to the removal of defective erythrocytes, similarly to apoptosis. Its typical features are cell shrinkage, cell membrane blebbing, and membrane scrambling with the consequent exposure of the aminophospholipid phosphatidylserine on the outer surface of RBCs. Different mechanisms play a role in the pathogenesis of eryptosis, such as the increase in cytosolic calcium concentration, oxidative stress, inflammation, and uremic toxins. If erythrocyte synthesis does not compensate for the accelerated eryptosis, anemia may develop. Moreover, enhanced eryptosis contributes to the pathogenesis of different clinical diseases, such as diabetes, sepsis, metabolic syndrome, and uremia. In particular, in patients with chronic kidney disease (CKD), deficiencies of erythropoietin and iron may further reduce the lifespan of RBCs. In this review, we focused on eryptosis in CKD and end-stage renal disease on peritoneal dialysis (PD) and hemodialysis (HD). Full article

Parkinson’s disease (PD) is a major health concern, with no accurate or early diagnostic test available for most patients. Chronic inflammation is a recognized contributor to PD pathogenesis; thus, membrane proteins of inflammatory cells such as neutrophils present an accessible target for detecting early molecular changes. In this study, we conducted a theoretical analysis using the GSE99039 database to identify differentially expressed genes (DEGs) in leukocytes from PD patients. From this, we selected nine top candidates for digital polymerase chain reaction (dPCR) analysis in isolated neutrophils from nine PD patients and nine matched controls. Our results revealed significant upregulation of ORAI3 and CLCN2. Unexpectedly, both ACTB (β-actin) and SNCA (alpha-synuclein) were also upregulated in neutrophils. Notably, this study provides the first evidence of CLCN2 expression in neutrophils and demonstrates the significant upregulation of four genes via dPCR. These genes may serve as potential biomarkers for future research on PD detection. Full article

The focus of this work was to perform a preliminary study on the suitability of commercially available nanofiltration (NF) and reverse osmosis (RO) membranes for the separation of 1,3-propanediol (1,3-PD) post-fermentation solutions. The experiments were conducted with the use of AFC30 and AFC99 (PCI Membrane System Inc., Milford, OH, USA) as well as BW30 membranes (Dow FilmTec Co., Midland, MI, USA) and various feed solutions: selected compounds of fermentation broths, and synthetic and real fermentation broths. Firstly, it was found that for pure water, the AFC30 membrane was characterized by the highest performance. It clearly indicated that the membrane is the most open membrane and is characterized by a more porous structure. In turn, the lowest flux was noted for the AFC99 membrane. Studies performed with the use of synthetic broth found that for the BW30 membrane, the order in which the rejection coefficient (R) was obtained was glycerol~lactic acid > 1,3-propanediol > acetic acid. It clearly confirmed that the R increased with the molecular weight (MW) of the solution compounds. With regard to ions, it was found that SO₄²⁻ and PO₄³⁻ is characterized by higher R than Cl⁻ and NO₃⁻ ions. Multivalent ions are characterized by higher charge density, hydrated radius, hydration energy and MW. Finally, experiments performed with the use of the AFC30 membrane and real broths showed that the membrane ensured almost complete separation of 1,3-PD. With regard to organic acid, the separation performance was as follows: succinic acid > lactic acid > butyric acid > acetic acid > formic acid. It has been documented that the AFC30 membrane can be successfully used to concentrate the following ions: SO₄²⁻, PO₄³⁻, NO₃⁻ and Na⁺. Hence, most of the medium used for the fermentation process was retained by the membrane and may be reused, which is crucial for the scaling up of the process and reducing the total technology cost. With regard to the obtained permeate, it can be subsequently purified by other methods, such as distillation or ion exchange. For further development of the tested process, determining the retention degree for 1,3-PD and other solutes during long-term separation of real broth is necessary. Full article

Background/Objectives: Phosphate level is a critical factor in the health of dialysis patients, as it is linked to cardiovascular risk. In peritoneal dialysis (PD), phosphate removal is related to residual kidney function, dietary intervention, and the ability of the visceral peritoneum to transport phosphate. The role of dialysis prescriptions in phosphate management is not sufficiently enhanced. Standardizing a phosphate removal propensity marker could optimize the peritoneal dialytic program. Our preliminary report aims to evaluate a simple model of phosphate handling and to assess which marker during the peritoneal equilibration test (PET) could better describe the propensity of phosphate removal through the peritoneal membrane. Methods: We hypothesized a simple two-compartment model to describe phosphate removal driven by diffusion. We performed an explorer study on 10 PD patients to assess the reliability of the two-compartment model. In each patient, we evaluated the basal condition and performed a PET with 2 L of 3.86% glucose exchange to assess phosphate handling. We collected blood and peritoneal effluent samples at the beginning of the test (t0), after 1 h (t1), and after 4 h (t4). We proposed and examined the following biomarkers: the ratio between dialysis effluent phosphate and plasma at t4 (PHO-D/P4); the difference between dialysis effluent phosphate at t0 and t4 (PHOΔd0-d4); and phosphate permeability–area product at t4 (PHO-PxA4). Results: 9 men and one woman with a mean age of 58.7 ± 16.7 years and a mean dialysis vintage of 25 ± 18.3 months were enrolled. The PHO-D/P4 mean was 0.68 ± 0.18, the PHO-Δd0-d4 median was 0.89 mmol/L [0.7–1.19], and the PHO-PxA4 mean was 1.7 ± 0.85. PHO-D/P4was significantly related to creatinine D/P4 (beta 1.49, p < 0.001), PHO-Δd0-d4 was significantly influenced by plasma phosphate at t0 (beta 0.56, p < 0.001), and the PHO-PxA4 was significantly influenced by ultrafiltration (beta 0.003, p < 0.001). Conclusions: In our two-compartment model, we observed the independence of the PHO-D/P4marker, which could serve as a potential marker for standardizing phosphate handling. However, PHO-Δd0-d4 and PHO-PxA4 normalized by plasma phosphate at t0 and ultrafiltration rate were able to reserve a potential good performance as markers in phosphate handling standardization. Full article

Tobacco smoking is closely associated with pro-inflammatory immunological alterations, whereas regular physical exercise is well known to lower systemic inflammations and related immune cell activities. The combined effects of smoking, nicotine pouch use, vaping, and exercise on individual immunological responses remain incompletely understood, especially in view of alternative nicotine delivery systems. In this study, we analyzed the immediate impact of different nicotine sources on exercise monocyte subsets in 16 human subjects using a four-arm cross-over design. Distribution of circulating CD14/CD16 monocyte subsets and expression of the monocytic checkpoint molecule PD-L1 (programmed cell death ligand-1) were analysed via whole blood flow cytometry measurements. Plasma cytokines were evaluated using membrane-based cytokine arrays and enzyme-linked immunosorbent assays (ELISA). Data revealed significant distributions of circulating monocytes subsets in response to nicotine consumption and physical stress. In contrast, exercise-driven increased monocytic PD-L1 was clearly attenuated following the consumption various nicotine delivery systems. Furthermore, significantly increased plasma growth hormone levels were detected in response to physical stress in combination with cigarette consumption. Our data clearly illustrates a significant influence of nicotine consumption on the cellular characteristics of circulating monocyte subsets and on proper exercise-driven immune responses within a short period of time, which makes the widespread trivialization of alternative nicotine sources questionable. Full article

Extracellular vesicles (EVs) are membrane-bound structures released by cells that contain bioactive cargo such as cytokines or non-coding RNA. It is widely known that EVs influence the activity of other cells; they take part in the pathogenesis and compensatory mechanisms of multiple diseases. Frequently, EVs can share the properties of their source cells, thus allowing the use of EVs as non-cellular vectors or therapeutic agents. Importantly, these structures can express the ligand for the programmed cell death protein 1 (PD-L1). It binds to the PD-1 protein present on the immune cells, which suppresses the activity of T cells. The PD-1/PD-L1 axis is widely known in the field of oncology, as PD-L1 present on the surface of cancer cells inhibits cytotoxic activity of T cells, thus promoting cancer growth and treatment resistance. Immunotherapy prevents PD-1/PD-L1 binding and restores anticancer properties of the immune cells. By contrast, the above-mentioned binding is desired in the context of autoimmunity, where abnormal activity of immune cells is a hallmark element in the pathogenesis of these conditions. The aim of this review is to present and discuss the latest findings regarding the role of EVs-PD-L1 in cancer and autoimmunity. Full article

Background: Three-dimensional (3D) cell models may bridge the gap between two-dimensional (2D) cell cultures and animal models. Technical advances have led to the development of 3D-bioprinted cell models, characterized by greater reproducibility and the ability to mimic in vivo conditions. Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with poor clinical outcomes due to its heterogeneity, angiogenic activity, and invasiveness. Src family kinases (SFKs) play a crucial role in GBM progression, making them attractive targets for drug development. Here, we show results about the pharmacological profile of a new prodrug synthesized from a Src inhibitor, SI306. Methods: Three-dimensional-bioprinted GBM cell models were used in predicting the antitumor activity of the prodrug SI306-PD2 with respect to its precursor, SI306. Results: Since the prodrug releases the active inhibitor through the cleavage by specific enzymes, SI306-PD2 was analyzed for stability and release kinetics in various media, including fetal bovine serum (FBS), which is normally used in cell culture. In comparison to SI306, SI306-PD2 demonstrated higher solubility in water, higher permeability across gastrointestinal and blood–brain barrier membranes, and the ability to release the drug in the presence of FBS progressively. In the 2D GBM cell model, using U87 and U251 cell lines, both compounds similarly reduced tumor cell viability. In 3D-bioprinted cell models, in the presence of an FBS-free medium, SI306-PD2 exhibited a more effective antitumor activity compared to SI306, reducing the proliferation and diameter of U251 spheroids grown within the bioprinted scaffold in a statistically significant manner. The analysis of proteins extracted from 3D scaffolds confirmed that SI306-PD2 inhibited Src activation more efficiently than SI306. Conclusions: Our study suggests that, when tissue permeability represents a discriminating characteristic, bioprinted cell models can provide a valid alternative for studying the cytotoxicity of new antitumor compounds. This approach has permitted us to ascertain the potential of the prodrug SI306-PD2 as a therapeutic agent for GBM, demonstrating better tissue penetration and antiproliferative efficacy compared to the precursor compound SI306. Full article