LPS Stimulation Research Articles

A sex-dependent role of Kv1.3 channels from macrophages in metabolic syndrome

IntroductionCoronary artery disease (CAD) is the foremost single cause of mortality and disability globally. Patients with type 2 diabetes (T2DM) have a higher incidence of CAD, and poorer prognosis. The low-grade inflammation associated to T2DM contributes to increased morbidity and worst outcomes after revascularization. Inflammatory signaling in the vasculature supports endothelial dysfunction, leukocyte infiltration, and macrophage activation to a metabolic disease (MMe) specific phenotype, which could contribute to the metabolic disorders and ascular damage in T2DM. We have previously found that Kv1.3 blockers inhibit the development of intimal hyperplasia, thereby preventing restenosis. This inhibition was enhanced in a mouse model of T2DM, where systemic Kv1.3 blockers administration also improve metabolic dysfunction by acting on unidentified cellular targets other than vascular smooth muscle. Here we characterize the MMe phenotype in our T2DM model with a focus on macrophage Kv1.3 channels, to explore their contribution to vascular disease and their potential role as targets to ameliorate T2DM vascular risk.Methods and ResultsMale and female BPH mice fed on high-fat diet (HFD) develop metabolic syndrome (MetS) and T2DM. mRNA levels of several K+ channels (KV1.3, KCa3.1, Kir2.1) and macrophage markers (TNFα, NOS2, CD36) were analyzed. The MMe phenotype associated with increased CD36 expression. Channel-specific fingerprinting highlights a gender-specific increase of KV1.3 mRNA fold change in LPS stimulated macrophages from HFD compared to standard diet (SD). KV1.3 functional expression was also significantly increased after LPS stimulation in female HFD macrophages compared to SD. Functional studies showed that macrophage's KV1.3 channels of BPH female mice did not contribute to phagocytosis or metabolic profile but were relevant in cell migration rate.ConclusionAltogether, our data suggest that by inhibiting macrophage infiltration, Kv1.3 blockers could contribute to disrupt the vicious cycle of inflammation and insulin resistance, offering a novel approach to prevent MetS, T2DM and its associated cardiovascular complications in females.

Abstract 4136901: Mechanosensitive channel protein Piezo1 synergizes with TLR4 to enhance osteogenic responses in human aortic valve interstitial cells

Background: Calcific aortic valve disease (CAVD), a common heart valve disease in the elderly, has a complex pathogenesis. Abnormal blood flow shear can be regarded as an important factor in the development of CAVD, and a key molecule that responds to mechanical stress is the mechanosensitive ion channel protein Piezo1; however, the role of Piezo1 in CAVD has not been clarified. Methods and results: We collected CAVD patients and their age- and sex-matched controls, and compared the differences in the protein expression levels of Piezo1 and TLR4 between the two using Western blot and other techniques, and found that the expression of Piezo1 and TLR4 proteins was elevated in the CAVD group. We gave LPS or Piezo1 agonist Yoda1 to stimulate aortic valve mesenchymal stromal cells, respectively, and the Western blot results showed that ALP and Runx2 expression were elevated after LPS and Yoda1 stimulation, and immunofluorescence and alizarin red staining showed similar results. Inhibition of TLR4 or Piezo1 attenuated the osteogenic differentiation of AVICs. Cellular immunofluorescence results showed that TLR4 could be transported from the Golgi to the cell membrane under Yoda stimulation, and Golgi-cell membrane transport of TLR4 was attenuated after Rab3b knockdown by siRNA. After first pre-stimulation with Yoda1 and then stimulation with LPS, Western blot and immunofluorescence results showed that the protein levels of ALP and Runx2 as well as NF-κB phosphorylation were to be significantly increased. Conclusion: Stimulation of Piezo1 and TLR4 can enhance the osteogenic response of AVICs. Stimulation of Piezo1 enhances the transport of TLR4 from the Golgi to the cell membrane via Rab3b, and Piezo1 synergistically enhances the osteogenic response of AVICs with TLR4, thus promoting the development of CAVD.

MiR-92a-3p Promotes Renal Injury and Fibrosis Through Facilitating M1 Macrophage Polarization via Targeting LIN28A

Infiltrated and activated M1 macrophages play a role in kidney injury and fibrosis during chronic kidney disease (CKD) progression. However, the specific ways that M1 macrophage polarization contributes to renal fibrosis are not fully understood. The study seeks to investigate how miR-92a-3p regulates M1 macrophage polarization and its connection to renal fibrosis in the development of CKD. Our results revealed that miR-92a-3p overexpression increased M1-macrophage activation, iNOS, IL-6, and TNF-α expression in RAW264.7 upon LPS stimulation. LIN28A overexpression reversed these effects. Moreover, miR-92a-3p overexpression in RAW264.7 exacerbated NRK-52E cell apoptosis induced by LPS, but LIN28A overexpression counteracted this effect. MiR-92a-3p knockout in unilateral ureteral obstruction (UUO) C57BL/6 mice led to reduced renal infiltration and fibrosis, accompanied by decreased iNOS, α-SMA, IL-6, TNF-α, and increased LIN28A. In summary, our findings suggest that miR-92a-3p may play a role in promoting renal injury and fibrosis both in vitro and in vivo. This effect is potentially achieved by facilitating M1 macrophage polarization through the targeting of LIN28A.

Alveolar and Bone Marrow-derived Macrophages Differ in Metabolism and Glutamine Utilization.

Changes in metabolic activity are key regulators of macrophage activity. Pro-inflammatory macrophages upregulate glycolysis, which promotes an inflammatory phenotype, whereas pro-repair macrophages rely upon oxidative metabolism and glutaminolysis to support their activity. Work to understand how metabolism regulates macrophage phenotype has been done primarily in macrophage cell lines and bone marrow-derived macrophages (BMDM). Our study sought to understand changes in metabolic activity of murine tissue-resident alveolar macrophages (AM) in response to LPS stimulation and to contrast them to BMDM. These studies also determined the contribution of glutamine metabolism using the glutamine inhibitor, DON. We found that compared to BMDM, AM have higher rates of oxygen consumption and contain a higher concentration of intracellular metabolites involved in fatty acid oxidation. In response to LPS, BMDM but not AM increased rates of glycolysis. Inhibition of glutamine metabolism using DON altered the metabolic activity of AM but not BMDM. Within AM, glutamine inhibition led to increases in intracellular metabolites involved in glycolysis, the TCA cycle, fatty acid oxidation, and amino acid metabolism. Glutamine inhibition also altered the metabolic response to LPS within AM but not BMDM. Our data reveal striking differences in the metabolic activity of AM and BMDM.

Flavonoids attenuate inflammation of HGF and HBMSC while modulating the osteogenic differentiation based on microfluidic chip

BackgroundWhen inflammation occurs in periodontal tissues, a dynamic cellular crosstalk interacts between gingival fibroblasts and bone marrow mesenchymal stem cells (BMSCs), which plays a crucial role in the biological behaviour and differentiation of the cells. Recently, flavonoids are increasingly recognized for their therapeutic potential in modulating inflammation and osteogenic differentiation. Owing to their varied molecular structures and mechanisms, there are more needs that flavonoid compounds should be identified by extensive screening. However, current drug research mostly relies on static, single-type cell cultures. In this study, an innovative bionic microfluidic chip system tailored for both soft and hard tissues was developed to screen for flavonoids suitable for treating periodontitis.MethodsThis study developed a microfluidic system that bionically simulates the soft and hard structures of periodontal tissues. Live/dead staining, reactive oxygen species (ROS) staining, and RT-qPCR analysis were employed. These techniques evaluated the effects of flavonoid compounds on the levels of inflammatory factors and ROS contents in HGF and HBMSC under LPS stimulation. Additionally, the impact of these compounds on osteogenic induction in HBMSC and the exploration of the underlying mechanisms were assessed.ResultsThe microfluidic chip used in this study features dual chambers separated by a porous membrane, allowing cellular signal communication via bioactive factors secreted by cells in both layers under perfusion. The inflammatory response within the chip under LPS stimulation was lower compared to individual static cultures of HGF and HBMSC. The selected flavonoids-myricetin, catechin, and quercetin-significantly reduced cellular inflammation, decreased ROS levels, and enhanced osteogenic differentiation of BMSCs. Additionally, fisetin, silybin, and icariside II also demonstrated favorable outcomes in reducing inflammation, lowering ROS levels, and promoting osteogenic differentiation through the Wnt/β-catenin pathway.ConclusionsThe bionic microfluidic chip system provides enhanced capabilities for drug screening and evaluation, delivering a more precise assessment of drug efficacy and safety compared to traditional in vitro methods. This study demonstrates the efficacy of flavonoids in influencing osteogenic processes in BMSCs primarily through the Wnt/β-catenin pathway. These results uncover the potential of flavonoids as therapeutic medicine for treating periodontitis, meriting further research and development.Graphical

Effects of miR-204-5p modulation on PAX6 regulation and corneal inflammation

Congenital aniridia is a rare eye disease characterized by loss of PAX6 protein leading to aniridia-associated keratopathy that significantly reduces vision. The miR-204-5p is a possible regulator of PAX6 function and here we evaluate its effect in multiple in vitro and in vivo models. In vitro, miR-204-5p overexpression suppressed vascular factor ANGPT1 in human limbal stem cells (T-LSC) and Pax6-knockdown LSC (mut-LSC), and in primary human limbal epithelial cells (LEC) at the gene and protein levels and following LPS stimulation. However, miR-204-5p inhibited VEGFA expression only in mut-LSCs and LPS-stimulated LEC. Also, miR-204-5p increased PAX6 expression in mut-LSC and differentiated corneal epithelial cells, but not in LEC. Topical miR-204-5p after LPS-induced keratitis in mice failed to suppress Vegfa, Angpt1, Il-1β, and Tnf-α or rescue Pax6 levels in contrast to in vitro results, although it significantly reduced the inflammatory infiltrate in the cornea. In Pax6Sey/+ aniridia mice, miR-204-5p did not rescue PAX6 levels or suppress Vegfa, Angpt1, or inhibit the ERK1/2 pathway. While short-term miR-204-5p treatment effectively suppresses VEGFA and ANGPT1 and enhances PAX6 expression in multiple corneal epithelia, effects are variable across primary and immortalized cells. Effects of longer-term in vivo treatment, however, require further study.

In Vitro Anti-inflammatory Effect of Secretome from Umbilical Cord-derived Mesenchymal Stem Cells in COVID-19 Patient Blood: A Study on sIL-6R, sgp130, IL-1RA and Anti/pro Inflammatory Cytokines

COVID-19 exhibits a wide range of clinical manifestations which severity of the disease is linked to uncontrolled escalation of inflammatory mediators. Ongoing research has identified the immunomodulatory effects of the MSC-derived secretome as a potential therapy for COVID-19. However, the precise mechanism by which the secretome exerts its therapeutic effect on COVID-19 remains unclear. This study aims to investigate whether the components of the UC-MSC-derived secretome can alter the inflammatory characteristics of immune cells. To achieve this, an in vitro study will be conducted involving co-incubation of whole blood with secretomes, followed by LPS stimulation. A total of 12 blood samples from severe COVID-19 and healthy subjects were cultured into three groups (RPMI control, 3μl and 9μl secretome group) incubated for 24 hours. Then, the cultures were exposed to LPS for 48 hours. The levels of sIL-6R, sgp130, IL-1RA, IL-6, TNF-α, IFN-γ, and IL-10 were measured. Results showed that LPS increased IL-6, TNF-α, and IL-10 production, while reducing sIL-6R, and sgp130, but no changes seen in IFN-γ in secretome-incubated blood cultures. The post-LPS/pre-LPS ratio analysis was conducted to investigate the anti-inflammatory potential of secretome. It was found that the secretome provides its anti-inflammatory effects through the role of IL-1RA.

Modification of MWCNTs with Bi2WO6 nanoparticles targeting IL-1β and NLRP3 inflammasome via augmented autophagy.

This study reports the facile hydrothermal synthesis of pure Bi2WO6 and Bi2WO6\MWCNTs nanocomposite at specific molar ratio 1:2.5 of Bi2WO6:MWCNTs and elucidates their role in modulating the NLRP3 inflammasome pathway via autophagy induction. Comprehensive characterization techniques, including XRD, Raman, UV.Vis PL,FESEM,EDS and TEM, revealed the successful incorporation of MWCNTs into the Bi2WO6 structures, leading to enhanced crystattlinity, reduced band gap energy (2.4 eV) suppressed charge carrier recombination and mitigated nanoparticles aggregation. Notably, the reduced band gap facikitaed improved visible light harvesting, a crucial attribute for photocatalytic applications. Significantly, the nanocompsoite exhibited a remarkable capacity to augment autophagy in bone marrow-derived macrophages (BMDMs), consequently down-regulating the NLRP3 inflammasom activation and IL-1β secretion upon LPS and ATP stimulation. Immunofluorescence assays unveiled increased co-localization of LC3 and NLRP3, suggestion enhanced targeting of NLRP3 by autophagy. Inhibition of autophagy by 3-MA reversed these effects, confirming the pivotal role of autophagy induction. Furthermore, the nanocomposite attenuated caspase-1 activation and ASC oligomerzation, thereby impeding inflammasome assembly. Collectively, these findings underscore the potential of Bi2WO6\MWCNTs nanocompsite as a multifaceted therapeutic platform, levering its tailored optoelectronic properties and sbility to modulate the NLRP3 infalmmasome via autophagy augmentation. This work covers the way for the development of advanced nanomaterials with tunable functionalities for combating inflammatory disorders and antimicrobial applications.

Patients with coronary atherosclerosis had an altered ratio of monocyte subpopulations in the blood, which was associated with an inflammatory cell response

Coronary artery disease (CAD) is one of the leading causes of death in developed countries. Experimental data confirm the role of monocytes in the development of CAD. Three main subpopulations of circulating blood monocytes are known: classical CD14++CD16- (~80%), intermediate CD14+CD16+ (~5%) and non-classical CD14+CD16++(~15%). It is believed that each of the subpopulations of monocytes performs different functions. There are studies that demonstrate that classical monocytes respond more to the bacterial presence, whereas non-classical ones respond to the viral one. However, the functions of monocyte subpopulations have not been fully studied. Previously, we demonstrated that circulating monocytes of the blood of patients with atherosclerosis had increased proinflammatory activity. We decided to find out how the ratio of monocyte subpopulations in the blood is related to the inflammatory response of cells in atherosclerosis. The aim of our work was to investigate the relationship of the inflammatory response of primary monocytes with the distribution of monocyte subpopulations relative to the total pool of monocytes in healthy and sick CAD. The study included 20 men aged 46 to 70 years, 10 of them without CAD and 10 patients with CAD. A coronary angiography was performed, according to the results of which the patients were divided into patients with coronary atherosclerosis with detected stenosis in 2 or more arteries (CAD) and healthy ones without stenosis in the arteries. Next, blood was taken to study circulating monocytes. Monocyte subpopulations were detected by flow cytometry from the leukocyte fraction using antibodies against CD14- FITC and CD16-PB450-A. Immediately after isolation, monocytes were stimulated with LPS with a final concentration of 1 ug/mL, and a supernatant was selected 24 hours later for further enzyme immunoassay. The inflammatory response was assessed by the secretion of cytokines TNFα, IL-1β, IL-6, IL-8, IL-10, and CCL2 using ELISA. The monocytes of CAD patients had an altered inflammatory response in response to LPS stimulation compared to patients without CAD. This was manifested in increased secretion of IL-1β and TNF, and decreased secretion of CCL2 and IL-6. An increase in the number of intermediate and non-classical monocytes in patients with CAD was associated with changes in the inflammatory response of cells to the secretion of cytokines IL-1β and CCL2. It can be assumed that pathological changes in the representation of monocyte subpopulations in the bloodstream may be one of the causes of chronic inflammation in the walls of the arteries, contributing to the progression of atherosclerotic lesions.

Deleting fibroblast growth factor 2 in macrophages aggravates septic acute lung injury by increasing M1 polarization and inflammatory cytokine secretion.

Septic lung injury is strongly associated with polarization of M1 macrophages and excessive cytokine release. Fibroblast growth factor (FGF) signaling plays a role in both processes. However, the impact of FGF2 deficiency on macrophage polarization and septic acute lung injury remains unclear. To investigate this, we obtained macrophages from FGF2 knockout mice and examined their polarization and inflammatory cytokine expression. We also eliminated endogenous macrophages using clodronate liposomes and administered FGF2 knockout or WT macrophages intravenously in conjunction with cecal ligation and puncture (CLP) surgery to induce sepsis. In vitro analysis by flow cytometry and real-time PCR analysis demonstrated that FGF2 deficiency resulted in increased expression of M1 markers (iNOS and CD86) and inflammatory cytokines (CXCL1, IL1β, and IL6), especially after LPS stimulation. Additionally, immunofluorescence demonstrated increased nuclear translocation of p65 NF-κB in FGF2 knockout macrophages and RNA-seq analysis showed enrichment of differentially expressed genes in the IL17 and TNFα inflammatory signaling pathways. Furthermore, in vivo experiments revealed that depletion of FGF2 in macrophages worsened sepsis-induced lung inflammation, lung vascular leak, and lung histological injury, accompanied by an increase in CD86-positive cells and apoptosis. Our study suggests that FGF2 deficiency in macrophages plays a critical role in the pathogenesis of septic ALI, possibly because of the enhanced M1 macrophage polarization and production of proinflammatory cytokines. These findings provide empirical evidence for potential therapeutic interventions targeting FGF2 signaling to modulate the polarization of M1 and M2 macrophages in the management of sepsis-induced acute lung injury.

Indigo alleviates psoriasis through the AhR/NF-κB signaling pathway: an in vitro and in vivo study.

Psoriasis is a chronic inflammatory skin disease. A strong association between the AhR/ NFκB axis and the inflammatory response in psoriasis. Indigo (IDG) has demonstrated significant anti-inflammatory properties. This study aimed to assess the anti-psoriatic efficacy of IDG while investigating the underlying mechanisms involved. In the in vitro experiments, cell viability was assessed using the CCK-8. qRT-PCR was employed to measure the mRNA levels of NF-κB, TNF-α, IL-1β, AhR, and CYP1A1. Western blotting was conducted to examine alterations in cytoplasmic and nuclear AhR protein levels. Additionally, an IDG nanoemulsion (NE) cream was prepared for the in vivo experiments. A psoriasis-like skin lesion mice model was induced using IMQ (62.5 mg/day for 7 days). The severity of psoriasis was evaluated using PASI, and skin lesions were scored while epidermal thickness was assessed via HE staining. The expression of inflammatory markers, including IL-6, IL-13, IL-17A, MCP-1, and TNF-α, was detected in skin lesions using Luminex. The levels of CYP1A1, p65, and p-p65 proteins were determined by Western blotting. LPS stimulation significantly elevated TNF-α, IL-6, and NF-κB mRNA levels, which were notably reduced by IDG treatment. Additionally, IDG significantly enhanced the expression of AhR and CYP1A1 mRNA. Further investigation revealed that IDG facilitated AhR translocation from the cytoplasm to the nucleus. In the IMQ-induced psoriasis-like mouse model, IDG NE substantially ameliorated the severity of skin lesions. Moreover, IDG NE treatment reduced the upregulation of inflammatory cytokines such as IL-6, IL-17A, MCP-1, and TNF-α in IMQ-induced skin lesions. It was also observed that IDG NE treatment increased CYP1A1 protein expression while inhibiting p65 and p-p65 protein expression. IDG emerges as a promising treatment for psoriasis, demonstrating effective therapeutic outcomes. Its mechanism of action is likely linked to the modulation of the AhR/NFκB signaling pathway.

Tongsai Granules inhibit autophagy and macrophage-mediated inflammatory response to improve acute exacerbations of chronic obstructive pulmonary disease in rats

To investigate the inhibitory effect of Tongsai Granules (TSG) on macrophage-mediated inflammatory response to alleviate acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in rats and explore the underlying mechanism. Twenty-four rats were divided into control group, AECOPD model group, TSG treatment group, and moxifloxacin+salbutamol (MXF+STL) treatment group. In the rat models of COPD, AECOPD was induced by nasal instillation of Klebsiella pneumoniae on day 3 of week 9 after modeling, and saline, TSG or MXF+STL were administered via gavage on days 1 and 2 and days 4 to 7 of week 9. After the treatments, lung tissues were collected for examining for pathologies and expressions of inflammatory markers, MMP2, and MMP9. In cultured macrophage MH-S cells with LPS stimulation, the effect of TSG-medicated serum on IL-1β, IL-6, TNF-α, COX-2, and iNOS expressions and phosphorylation levels of p38, p-p62, LC3, FoxO3a, and mTOR were evaluated. TSG significantly improved lung pathologies and lung function in AECOPD rats by reducing bronchial wall thickness and mean alveolar linear intercept, increasing alveolar numbers, and reducing pulmonary expression of IL-1β, IL-6, TNF- α, MMP2 and MMP9. In MH-S cells, TSG significantly suppressed LPS-induced expressions of inflammatory cytokines, COX-2 and iNOS. Serum pharmacology coupled with network pharmacology identified 10 chemical components in TSG-medicated serum, and functional analysis of their 466 targets suggested that the therapeutic effect of TSG on AECOPD was mediated primarily by luteolin and quercetin, which regulate the MAPK, mTOR, FoxO, and autophagy pathways. In MH-S cells, luteolin significantly inhibited LPS-induced inflammatory responses and expressions of p-p38, FoxO3a, mTOR, p-p62 and LC3. TSG reduces macrophage-mediated inflammatory responses to alleviate AECOPD in rats possibly by modulating p38, mTOR, and FoxO3a pathways and inhibiting autophagy.

Enhancement of Autophagy in Macrophages via the p120-Catenin-Mediated mTOR Signaling Pathway.

Autophagy serves as a critical regulator of immune responses in sepsis. Macrophages are vital constituents of both innate and adaptive immunity. In this study, we delved into the intricate role of p120-catenin (p120) in orchestrating autophagy in macrophages in response to endotoxin stimulation. Depletion of p120 effectively suppressed LPS-induced autophagy in both J774A.1 macrophages and murine bone marrow-derived macrophages. LPS not only elevated the interaction between p120 and L chain 3 (LC3) I/II but also facilitated the association of p120 with mammalian target of rapamycin (mTOR). p120 depletion in macrophages by small interfering RNA reduced LPS-induced dissociation of mTOR and Unc-51-like kinase 1 (ULK1), leading to an increase in the phosphorylation of ULK1. p120 depletion also enhanced LPS-triggered macrophage apoptosis, as evidenced by increased levels of cleaved caspase 3, 7-aminoactinomycin D staining, and TUNEL assay. Notably, inhibiting autophagy reversed the decrease in apoptosis caused by LPS stimulation in macrophages overexpressing p120. Additionally, the ablation of p120 inhibited autophagy and accentuated apoptosis in alveolar macrophages in LPS-challenged mice. Collectively, our findings strongly suggest that p120 plays a pivotal role in fostering autophagy while concurrently hindering apoptosis in macrophages, achieved through modulation of the mTOR/ULK1 signaling pathway in sepsis. This underscores the potential of targeting macrophage p120 as an innovative therapeutic avenue for treating inflammatory disorders.

Sex-specific phenotypical, functional and metabolic profiles of human term placenta macrophages

BackgroundPlacental macrophages, Hofbauer cells (HBC) are the only fetal immune cell population within the stroma of healthy placenta along pregnancy. They are central players in maintaining immune tolerance during pregnancy. Immunometabolism emerged a few years ago as a new field that integrates cellular metabolism with immune responses, however, the immunometabolism of HBC has not been explored yet. Here we studied the sex-specific differences in the phenotypic, functional and immunometabolic profile of HBC.MethodsHBC were isolated from human term placentas (N = 31, 16 from male and 15 female neonates). Ex vivo assays were carried out to assess active metabolic and endoplasmic reticulum stress pathways by flow cytometry, confocal microscopy, gene expression and in silico approaches.ResultsHBC from female placentas displayed a stronger M2 phenotype accompanied by high rates of efferocytosis majorly sustained on lipid metabolism. On the other hand, male HBC expressed a weaker M2 phenotype with higher glycolytic metabolism. LPS stimulation reinforced the glycolytic metabolism in male but not in female HBC. Physiological endoplasmic reticulum stress activates IRE-1 differently, since its pharmacological inhibition increased lipid mobilization, accumulation and efferocytosis only in female HBC. Moreover, differential sex-associated pathways accompanying the phenotypic and functional profiles of HBC appeared related to the placental villi environment.ConclusionsThese results support sex-associated effects on the immunometabolism of the HBC and adds another layer of complexity to the intricate maternal-fetal immune interaction.Graphical abstract

Retinal Organoid Microenvironment Enhanced Bioactivities of Microglia-Like Cells Derived From HiPSCs.

Microglia-like cells derived from stem cells (iMG) provide a plentiful cell source for studying the functions of microglia in both normal and pathological conditions. Our goal is to establish a simplified and effective method for generating iMG in a precisely defined system. Additionally, we aim to achieve functional maturation of iMG through coculture with retinal organoids. In this study, iMG were produced under precisely defined conditions. They were subjected to LPS and poly IC stimulation. Additionally, we examined distinct phenotypic and functional variances between iMG and HMC3, a commonly used human microglia cell line. To investigate how the retinal cell interaction enhances microglial properties, iMG were cocultured with retinal organoids, producing CC-iMG. We performed RNA sequencing, electrophysiological analysis, and transmission electron microscope (TEM) to examine the maturation of CC-iMG compared to iMG. Our results demonstrated that iMG performed immune-responsive profiles closely resembling those of primary human microglia. Compared to HMC3, iMG expressed a higher level of typical microglial markers and exhibited enhanced phagocytic activity. The transcriptomic analysis uncovered notable alterations in the ion channel profile of CC-iMG compared to iMG. Electrophysiological examination demonstrated a heightened intensity of inward- and outward-rectifying K+ currents in CC-iMG. Furthermore, CC-iMG displayed elevated numbers of lysosomes and mitochondria, coupled with increased phagocytic activity. These findings contribute to advancing our understanding of human microglial biology, specifically in characterizing and elucidating the functions of CC-iMG, thereby offering an in vitro microglial model for future scientific research and potential clinical applications in cell therapy.

The Anti-Inflammatory Activities of Benzylideneacetophenone Derivatives in LPS Stimulated BV2 Microglia Cells and Mice.

A previously reported study highlighted the neuroprotective potential of the novel benzylideneacetophenone derivative, JC3, in mice. In pursuit of compounds with even more robust neuroprotective and anti-inflammatory properties compared to JC3, we synthesized substituted 1,3-diphenyl-2-propen-1-ones based on chalcones. Molecular modeling studies aimed at discerning the chemical structural features conducive to heightened biological activity revealed that JCII-8,10,11 exhibited the widest HOMOLUMO gap within this category, indicating facile electron and radical transfer between HOMO and LUMO in model assessments. From the pool of synthesized compounds, JCII-8,10,11 were selected for the present investigation. The biological assays involving JCII-8,10,11 demonstrated their concentration-dependent suppression of iNOS and COX-2 protein levels, alongside various cytokine mRNA expressions in LPS-induced murine microglial BV2 cells. Furthermore, western blot analyses were conducted to investigate the MAPK pathways and NF-κB/p65 nuclear translocation. These evaluations conclusively confirmed the inflammatory inhibition effects in both in vitro and in vivo inflammation models. These findings establish JCII-8,10,11 as potent anti-inflammatory agents, hindering inflammatory mediators and impeding NF-κB/p65 nuclear translocation via JNK and ERK MAPK phosphorylation in BV2 cells. The study positions them as potential therapeutics for inflammation-related conditions. Additionally, JCII-11 exhibited greater activity compared to other tested JCII compounds.

The protective effect of Amitriptyline on experimental colitis through inhibiting TLR4/MD2 signaling pathway.

Amitriptyline, a pleiotropic tricyclic antidepressant, possesses anti-oxidant and anti-inflammatory properties. Despite its diverse benefits, the specific effects of amitriptyline on IBD are not yet well defined. To explore this, we utilized a DSS-induced colitis model to examine the anti-inflammatory effects of amitriptyline and the underlying mechanisms by which it operates. Our research revealed that amitriptyline is effective in alleviating several pathological manifestations associated with colitis. This includes improvements in body weight retention, reductions in DAI, lessening of colon length shortening, and repair of colonic mucosal damage. Treatment with amitriptyline significantly protected mucosal injury by preserving the population of goblet cells and increasing the expression of tight junction proteins. Furthermore, we observed that amitriptyline effectively countered immune cell infiltration, specifically neutrophils and macrophages, while simultaneously lowering the levels of inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Additionally, RNA sequencing analysis pointed to the potential involvement of the TLR pathway in the anti-colitic effects induced by amitriptyline. Subsequent Western blot analysis indicated that amitriptyline significantly inhibited the TLR4-mediated NF-κB signaling pathway. To bolster our findings, in vitro studies demonstrated that amitriptyline down-regulated the TLR4/NF-κB/MAPK signaling cascades in mouse macrophages stimulated with LPS. Further molecular investigations revealed that amitriptyline was able to suppress the elevated expression of MD-2 that LPS stimulation typically induces. In summary, our findings suggest that amitriptyline effectively mitigates DSS-induced colitis in mice through the inhibition of TLR4/MD-2 pathway signaling, indicating its potential repurposing for IBD treatment. Significance Statement The potential of utilizing amitriptyline in treating IBD appears promising, leveraging its established safety and dosing profile as an antidepressant. Our observations show that amitriptyline can alleviate pathological symptoms, inflammation, and intestinal mucosal damage in mice with colitis induced by DSS. The protective effect observed appear to be linked to the inhibition of the TLR4/MD2 signaling pathway. By exploring novel applications for existing medications, we can optimize amitriptyline's efficacy and broaden its impact in both medical and commercial contexts.

In-vitro scientific validation of anti-inflammatory activity of Punica granatum L. on Leukemia monocytic cell line

Background: The induction of the inflammatory cascade results in the production of a number of inflammatory mediators, including prostaglandin E2 (PGE2), nitric oxide (NO), and proinflammatory cytokines like TNF-, IL-, and IL-6. This study examined the cytotoxicity and anti-inflammatory properties of a methanolic crude extract of Punica granatum L. peel (PPM) on monocytic leukaemia cell line (THP-1). Materials and methods: The PPM along with Quercetin as reference was used to assess the cytotoxic effect on THP-1 cells and describe its effect on pro-inflammatory cytokines such as COX-2, TNF-α, IL-6 against cancer cell line by flow cytometry. Results: The percentage of viable cells significantly decreased which correlates to non-toxicity whereas quercetin was found to be highly toxic, the IC50 could not be calculated because of drug precipitation. There was a significant decrease in the expressions of inflammatory cytokines upon pre-treatment of the cells with PPM prior to LPS stimulation. Conclusion: Our findings indicate that no cytotoxicity was observed after the treatment of THP-1 cells with PPM (25-400 µg/ml), but at higher concentration (400µg/ml), the cell viability decreased to 84% and attenuated the expression level of inflammatory cytokines. The inhibitory effect of the extract on pro-inflammatory factors production may provide a theoretical source on upcoming treatment of inflammation. Keywords: Punica granatum L; Monocytic leukaemia cell line; cytotoxicity; anti-inflammation.

Development of a New Isoxsuprine Hydrochloride-Based Hydroxylated Compound with Potent Antioxidant and Anti-Inflammatory Activities.

The scientific community actively pursuits novel compounds with biological activities. In this context, our study utilized the predicted data mining approach (PDMA), which can efficiently screen out biotransformable precursor candidates to produce new bioactive compounds. The PDMA was applied to Bacillus megaterium tyrosinase (BmTYR) to form new bioactive hydroxyl compounds from isoxsuprine hydrochloride (isoxsuprine). The results show that isoxsuprine could be biotransformed by BmTYR to form a new compound, 3''-hydroxyisoxsuprine. 3''-Hydroxyisoxsuprine exhibited 40- fold and 10-fold higher potent antioxidant and anti-inflammation activities than the precursor, isoxsuprine. The 3''-hydroxyisoxsuprine effectively mitigates the hyperimmune response in RAW 264.7 macrophages by inhibiting the upregulation of pro-inflammatory cytokine (IL-1β and IL-6) and inflammatory enzyme COX-2 gene expression triggered by LPS stimulation. This study illustrates that PDMA is an effective strategy for screening known natural and chemical compounds and for generating new bioactive compounds through biotransformation. Our newly produced compound has potential future applications in pharmacology and biotechnology.

Whole transcription analysis identified the regulation of hypoxia-inducible factors in monocytes with immune suppression: implications for clinical outcomes.

Sepsis progression is marked by a complex immune response, where the involvement of hypoxia-inducible factors (HIF) plays an uncertain role. The study aims to elucidate the involvement of HIF-1α in monocyte function during sepsis and its potential as a prognostic indicator. Transcriptomic data from healthy individuals and septic patients in datasets GSE54514, GSE167363, and GSE46955 were analyzed. Additionally, human monocytes were employed to elucidate how HIF regulates immune responses in the context of sepsis. Septic non-survivors exhibited sustained upregulation of HIF-1α expression alongside compromised inflammatory response and antigen presentation, with downregulation of NF-κB and HLADRB1 genes associated with poor sepsis prognosis. Conversely, septic survivors displayed an increased proportion of classical monocytes and enhanced inflammation and expression of antigen presentation-related genes. During the recovery phase of sepsis, monocytes continued to demonstrate elevated HIF-1α expression. In cultured THP1 cells and septic CD14+ monocytes, HIF hindered inflammatory responses and antigen presentation, while also suppressing the proportion of classical monocytes after LPS stimulation. Mechanistically, HIF significantly attenuated LPS-induced immune responses in monocytes by inhibiting the phosphorylation of IKK. HIF in monocytes acts as a suppressor of immune-inflammatory responses and antigen presentation, and may serve as a negative molecular marker for sepsis development.