Characterization of polarized THP-1 macrophages and polarizing ability of LPS and food compounds

GIV/Girdin Modulation of Microglial Activation in Ischemic Stroke: Impact of FTO-Mediated m6A Modification

Ischemic stroke (IS) is one of the most common causes of death in the world. The lack of effective pharmacological treatments for IS was primarily due to a lack of understanding of its pathogenesis. Gα-Interacting vesicle-associated protein (GIV/Girdin) is a multi-modular signal transducer and guanine nucleotide exchange factor that controls important signaling downstream of multiple receptors. The purpose of this study was to investigate the role of GIV in IS. In the present study, we found that GIV is highly expressed in the central nervous system (CNS). GIV protein level was decreased, while GIV transcript level was increased in the middle cerebral artery occlusion reperfusion (MCAO/R) mice model. Additionally, GIV was insensitive lipopolysaccharide (LPS) exposure. Interestingly, we found that GIV overexpression dramatically restrained microglial activation, inflammatory response, and M1 polarization in BV-2 microglia induced by oxygen-glucose deprivation and reoxygenation (OGD/R). On the contrary, GIV knockdown had the opposite impact. Mechanistically, we found that GIV activated the Wnt/β-catenin signaling pathway by interacting with DVL2 (disheveled segment polarity protein 2). Notably, m6A demethylase fat mass and obesity-associated protein (FTO) decreased the N6-methyladenosine (m6A) modification-mediated increase of GIV expression and attenuated the inflammatory response in BV-2 stimulated by OGD/R. Taken together, our results demonstrate that GIV inhibited the inflammatory response via activating the Wnt/β-catenin signaling pathway which expression regulated in an FTO-mediated m6A modification in IS. These results broaden our understanding of the role of the FTO-GIV axis in IS development.

EHF promotes liver cancer progression by meditating IL-6 secretion through transcription regulation of KDM2B in TAMs

BACKGROUND

Macrophages are key immune cell types in liver, which are thought to be involved in tumor development. Recent studies indicated that TAMs exhibit M2 phenotypes. However, the mechanism of macrophages related to tumor progression in liver cancer is largely unknown. We aim to investigate the mechanism of EHF in TAMs associated with liver cancer progression.

METHODS

The differently expressed genes of M0, M1, and M2 macrophages were analyzed by RNA sequencing. Cytokine array was used to detect the differently expressed cytokines in M2 macrophages. We performed CUT-Tag analysis for the identification of promoter regions that interacting with EHF protein. ChIP and luciferase analysis were used to verify the interaction between EHF and KDM2B.

RESULTS

EHF was overexpressed in M2 macrophages. Knockdown of EHF in M2 macrophages could inhibit migration and invasion of MHCC97-L cells co-cultured with M2 macrophages in vitro and in vivo. The level of IL-6 was decreased in M2 macrophages with lower expression of EHF. EHF could bind the promoter region of KDM2B. The transcription level of KDM2B was down-regulated by knockdown of EHF in M2 macrophages. The results of this study indicated that EHF could promote liver cancer cell metastasis by IL-6 through regulating the transcription level of KDM2B in M2 macrophages.

CONCLUSION

Our study revealed a novel aspect of macrophages in liver cancer and showed EHF could be a promising therapeutic target of liver cancer.

EGR2 promotes liver cancer metastasis by enhancing IL-8 expression through transcription regulation of PDK4 in M2 macrophages

Liver tumor is a common digestive system tumor, and its development is closely related to complex cytokines, tumor microenvironment and immunoregulatory mechanisms. Tumor-associated macrophages play a great role in a series of liver cancer development by secreting various cytokines and transmitting multiple signals, but how macrophages regulate the various biological behaviors of liver cancer cells at the microscopic level is a challenge we still need to overcome. In this research, we first identified the Early Growth Response 2 (EGR2) gene, which exhibited significant expression in M2 macrophages in comparison to M0 and M1 cell types, utilizing RNA sequencing. Subsequently, we validated this finding through a battery of methodologies, including WB, qRT-PCR, and immunofluorescence assays. We further employed a co-culture model involving MHCC97L and macrophages to investigate the impact of EGR2 downregulation within M2 cells on the in vivo and in vitro metastatic and invasive capabilities of MHCC97L cells. Subsequently, we directed our attention to investigating the impact of EGR2 on the levels of interleukin-8 (IL-8). Through comprehensive analyses including RNA sequencing, CUT-and-Tag, and ChIP techniques, we demonstrated that EGR2 can bind to the promoter region of the Pyruvate Dehydrogenase Kinase 4 (PDK4) gene. Finally, we introduced a virus overexpressing PDK4 and demonstrated that EGR2 could regulate the transcriptional level of PDK4 to affect the expression of IL-8, and ultimately alter the metastatic ability of hepatocellular carcinoma cells. Our study demonstrates that EGR2 may be a valuable target for future intervention in the disease process of hepatocellular carcinoma and refines the mechanism at the microscopic level of Tumor-associated macrophages.

Radiation-induced rescue effect on human breast carcinoma cells is regulated by macrophages

The susceptibility of cancer cells to DNA damages is influenced by their microenvironment. For example, unirradiated neighbors of irradiated cells can produce signals that reduce DNA damages. This phenomenon, known as Radiation-Induced Rescue Effect (RIRE), has profound implications on the efficacy of radiotherapy. Using bystander cells co-cultured with mock-irradiated cells as a control, we demonstrated, for the first time, two types of RIRE. Conditioned medium from naïve by stander cells, i.e., cells not exposed to irradiated cells, could mitigate UV-induced DNA damages in human breast carcinoma MCF7 cells, as judged by phospho-H2AX and 53BP1 immunostaining. This protective effect could be further enhanced by the prior treatment of bystander cells with factors from UV-irradiated cells. We named the former effect "basal RIRE" and the latter "active RIRE" which were cell type-dependent. As bystanders, MCF7 showed a significant active RIRE, whereas THP1-derived macrophages showed a strong basal RIRE but no active RIRE. Interestingly, RIRE of macrophages could further be modulated by polarisation. The basal RIRE of macrophages was abolished by M1 polarisation, while M2 and Tumour Associated Macrophages (TAM) demonstrated pronounced basal and active RIRE. When mixtures of MCF7 cells and polarised macrophages were used as bystanders, the overall RIRE was dictated by macrophage phenotypes: RIRE was suppressed by M1 macrophages but significantly enhanced by M2 and TAM. This study shows a previously unappreciated role of the innate immune system in RIRE. Depending on polarised phenotypes, macrophages in the tumour microenvironment can interfere with the effectiveness of radiotherapy by adjusting the RIRE magnitudes.

TissueGene-C induces anti-inflammatory activity and M2 macrophage polarization via activation of prostaglandin E2 signaling

BACKGROUND AND AIM

Osteoarthritis (OA) is the most common form of degenerative joint disease that commonly affects the knees, hips and hands. OA is a mechano-inflammatory disease characterized by low-grade inflammation, which results in breakdown of the cartilage extracellular matrix within joints, leading to pain, stiffness and inflammation. TissueGene-C (TG-C) is a cell and gene therapy investigational drug for treating knee OA that comprises human allogeneic chondrocytes and an irradiated modified cell line stably expressing transforming growth factor beta 1 (TGF-β1). Previous pre-clinical animal studies have shown that TG-C provides pain relief via its anti-inflammatory effects and cartilage structural improvement in a rat OA model. The goal of this study was to investigate the mechanism of action of TG-C, explore its anti-inflammatory activity and identify the TG-C-derived active factor(s) responsible for its efficacy.

METHODS

In this study, we utilized THP-1 cell line to develop an macrophage polarization model to test the anti-inflammatory activity of TG-C.

RESULTS

Our data showed that TG-C induces the polarization of M2 macrophages and the upregulation of interleukin 10 (IL-10) and interleukin 1 receptor antagonist (IL-1ra) while inhibiting tumor necrosis factor alpha (TNF-α) expression. Additionally, this study identified prostaglandin E2 (PGE2) as the main bioactive factor responsible for the anti-inflammatory activity of TG-C.

CONCLUSIONS

Our results demonstrated that PGE2 is expressed by the TG-C chondrocyte component and modulated by TGF-β1 derived from the second component of TG-C. Finally, the present study provides insight into the mechanism of action of TG-C in the treatment of OA.

Potential mechanisms for chorioamniotic membrane rupture after subchorionic hematoma

BACKGROUND

Subchorionic hematoma is a risk factor for preterm prelabor rupture of membranes and preterm birth. A small proportion of persistent subchorionic hematoma leads to a chronic abruption-oligohydramnios sequence.

OBJECTIVE

To determine the mechanism by which subchorionic hematomas may damage chorioamniotic membranes.

STUDY DESIGN

1) The number and subtype of macrophages were determined by immunohistochemistry in chorioamniotic membranes from 8 subchorionic hematoma patients who delivered preterm (25.5 (24-32) weeks of gestation (median and range)) and 6 gestational age-matched control patients (25.5 (25-28) weeks of gestation (median and range)). Further, the thickness and fibrosis of the membranes were quantified. 2) We also developed an intrauterine hematoma model in pregnant mice, and the effects of hematoma on the amnion were analyzed by histology and immunofluorescence. 3) In vitro, primary human amnion mesenchymal cells were cocultured with M2-differentiated macrophages, and changes in mesenchymal cells were analyzed.

RESULTS

1) Subchorionic hematoma increased the number of iron-laden macrophages in the human amnion. These macrophages were CD206+, a marker of macrophages required for the maintenance of homeostasis, tissue remodeling, and metabolic adaptations. The collagen layer of the amnion tended to be thickened in patients with subchorionic hematoma. Interestingly, α-smooth muscle actin+ myofibroblasts were increased in the amnion mesenchymal layer in patients with subchorionic hematoma. Vimentin, a mesenchymal marker, was expressed in the epithelial layer of the hematoma amnion. Together, these findings indicate epithelial-mesenchymal transition in the amnion of membranes from pregnancies with subchorionic hematomas. 2) These findings in human amnion were confirmed in a mouse model of intrauterine hematoma. 3) Further, in vitro, coculture of human amnion mesenchymal cells with M2-differentiated human macrophages resulted in transformation of these cells into α-smooth muscle actin-expressing myofibroblasts via the TGF-β‒Smad3 pathway.

CONCLUSION

Subchorionic hematoma induces migration of macrophages to chorioamniotic membranes which activate the transition of amnion mesenchymal cells to myofibroblasts. These myofibroblasts may contribute to fibrosis of the amnion and damage chorioamniotic membranes.

Cell Membrane-Integrated Neuroligin-1 Regulates the Anti-Inflammatory Effects of CRC Cell-Derived Exosomes

Tumor-associated macrophages (TAMs) are one of the most abundant cell types in the colorectal cancer (CRC) tumor microenvironment (TME). CRC cell-derived exosomes support macrophage polarization toward an M2-like phenotype, which leads to tumor growth and metastasis. Neuroligin 1 (NLG1) is a transmembrane protein critical in synaptic function. We reported that NLG1 via an autocrine manner promotes CRC progression by modulating the APC/β-catenin pathway. This study aimed to answer whether NLG1 is involved in the exosome-mediated intercellular cross-talk between CRC and TAMs. Our results showed that exosomes of NLG1-expressing CRC cells induce M2-like (CD206high CD80low) polarization in macrophages. On the other hand, we found that the exosomes of the NLG1 knocked-down CRC cells reinforce the expression of CD80 and pro-inflammatory genes, including IL8, IL1β, and TNFα, in the macrophages, indicating an M1-like phenotype polarization. In conclusion, NLG1, as a cell-membrane-integrated protein, could be a therapeutic target on the surface of the CRC cells for developing clinical treatments to inhibit exosome-induced anti-inflammatory immune responses in TME.

Crosstalk between GBP2 and M2 macrophage promotes the ccRCC progression

Clear cell renal cell carcinoma (ccRCC) represents a highly heterogeneous kidney malignancy associated with the poorest prognosis. The metastatic potential of advanced ccRCC tumors is notably high, posing significant clinical challenges. There is an urgent imperative to develop novel therapeutic approaches to address ccRCC metastasis. Recent investigations indicated a potential association between GBP2 and tumor immunity. However, the precise functional role of GBP2 in the progression of ccRCC remains poorly understood. The present study revealed a strong correlation between GBP2 and M2 macrophages. Specifically, our findings demonstrated that the inhibition of GBP2 significantly impedes the migratory and invasive capabilities of ccRCC cells. We observed that the presence of M2 macrophages can reverse the effects of GBP2 knockdown on tumor cell migration and invasion. Mechanistically, we demonstrated that M2 macrophages promote the expression of the GBP2/p-STAT3 and p-ERK axis in tumor cells through the secretion of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), thereby substantially enhancing the migratory and invasive capacities of the tumor cells. Simultaneously, we have identified that GBP2 promotes the polarization of macrophages to the M2 phenotype by stimulating the secretion of interleukin-18 (IL-18). In summary, our investigation anticipates that the GBP2/IL-18/M2 macrophages/IL-10 and the TGF-β/GBP2, p-STAT3, p-ERK loop plays a crucial role in ccRCC metastasis. The collective findings from our research underscore the significant role of GBP2 in tumor immunity and emphasize the potential for modulating GBP2 as a promising therapeutic strategy for targeting ccRCC metastasis.

Reprogramming of breast tumor-associated macrophages with modulation of arginine metabolism

HER2+ breast tumors have abundant immune-suppressive cells, including M2-type tumor-associated macrophages (TAMs). Although TAMs consist of the immune-stimulatory M1 type and immune-suppressive M2 type, the M1/M2-TAM ratio is reduced in immune-suppressive tumors, contributing to their immunotherapy refractoriness. M1- versus M2-TAM formation depends on differential arginine metabolism, where M1-TAMs convert arginine to nitric oxide (NO) and M2-TAMs convert arginine to polyamines (PAs). We hypothesize that such distinct arginine metabolism in M1- versus M2-TAMs is attributed to different availability of BH4 (NO synthase cofactor) and that its replenishment would reprogram M2-TAMs to M1-TAMs. Recently, we reported that sepiapterin (SEP), the endogenous BH4 precursor, elevates the expression of M1-TAM markers within HER2+ tumors. Here, we show that SEP restores BH4 levels in M2-like macrophages, which then redirects arginine metabolism to NO synthesis and converts M2 type to M1 type. The reprogrammed macrophages exhibit full-fledged capabilities of antigen presentation and induction of effector T cells to trigger immunogenic cell death of HER2+ cancer cells. This study substantiates the utility of SEP in the metabolic shift of the HER2+ breast tumor microenvironment as a novel immunotherapeutic strategy.

The role of Pim-1 kinases in inflammatory signaling pathways

OBJECTIVE AND DESIGN

This observational study investigated the regulatory mechanism of Pim-1 in inflammatory signaling pathways.

MATERIALS

THP-1, RAW 264.7, BV2, and Jurkat human T cell lines were used.

TREATMENT

None.

METHODS

Lipopolysaccharide (LPS) was used to induce inflammation, followed by PIM1 knockdown. Western blot, immunoprecipitation, immunofluorescence, and RT-PCR assays were used to assess the effect of PIM1 knockdown on LPS-induced inflammation.

RESULTS

PIM1 knockdown in macrophage-like THP-1 cells suppressed LPS-induced upregulation of pro-inflammatory cytokines, inducible nitric oxide synthase, cyclooxygenase-2, phosphorylated Janus kinase, signal transducer and activator of transcription 3, extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and nuclear factor kappa B p65 (NF-κB p65). It also suppressed upregulation of inhibitor of NF-κB kinase α/β and enhanced the nuclear translocation of NF-κB p65. Moreover, it inhibited the upregulation of Nod-like receptor family pyrin domain-containing 3 (NLRP3) and cleavage of caspase-1 induced by co-treatment of LPS with adenosine triphosphate. Additionally, p-transforming growth factor-β-activated kinase 1 (TAK1) interacted with Pim-1. All three members of Pim kinases (Pim-1, Pim-2, and Pim-3) were required for LPS-mediated inflammation in macrophages; however, unlike Pim-1 and Pim-3, Pim-2 functioned as a negative regulator of T cell activity.

CONCLUSIONS

Pim-1 interacts with TAK1 in LPS-induced inflammatory responses and is involved in MAPK/NF-κB/NLRP3 signaling pathways. Additionally, considering the negative regulatory role of Pim-2 in T cells, further in-depth studies on their respective functions are needed.

JDF promotes the apoptosis of M2 macrophages and reduces epithelial-mesenchymal transition and migration of liver cancer cells by inhibiting CSF-1/PI3K/AKT signaling pathway

Background

The interaction between cancer cells and the tumor microenvironment is of critical importance in liver cancer. Jiedu Granule formula (JDF) has been shown to minimize the risk of recurrence and metastasis following liver cancer resection. Investigating the mechanism underlying the therapeutic effects of JDF can extend its field of application and develop novel treatment approaches.

Methods

We established a rat liver orthotopic transplantation tumor model, and recorded the prognostic effects of JDF adjuvant therapy on the recurrence and metastasis of liver cancer. Liver and lung tissues were collected for immunofluorescence staining and H&E staining, respectively. In addition, THP-1 cells were incubated with PMA and IL-4 to induce them to differentiate into M2 macrophages. CSF-1 expression was knocked down using lentivirus to determine the function of CSF-1. Liver cancer cells were cultured with a conditioned medium (CM) or co-cultured with macrophages. Cell viability was determined using the MTT assay. The levels of CSF-1, CSF-1R, E-cadherin, N-cadherin, PI3K, AKT, and cleaved caspase-3 were detected using ELISA, Western blotting and qPCR. The ability of cells to migrate was assessed using cell scratch and transwell assays. Apoptosis was evaluated using flow cytometry.

Results

The JDF treatment decreased the risk of liver cancer metastasis after surgery and the infiltration of CD206/CD68 cells in liver cancer tissue. In cell experiments, JDF showed effects in suppressing M2 macrophages activity and downregulating the expression of CSF-1 and CSF-1R. The concentration of CSF-1 in the supernatant was also lower in the JDF-treated group. Futhermore, M2-CM was found to promote cancer cell migration and epithelial-mesenchymal transition (EMT); however, these effects were weakened after administering JDF. Knocking down endogenous CSF-1 in M2 macrophages resulted in a comparable suppression of cancer cell migration and EMT. Additionally, JDF treatment inhibited activation of the PI3K/AKT pathway, thus promoting the apoptosis of M2 macrophages.

Conclusions

Treatment with JDF reduced the EMT and migratory capacity of liver cancer cells, which might be attributed to the inhibition of M2 macrophage infiltration and interruption of the CSF-1/PI3K/AKT signaling pathway. This mechanism may hold significant implications for mitigating the risk of metastatic spread in the aftermath of hepatic surgery.

The PD-1 /PD-L1 signaling pathway regulates decidual macrophage polarization and may participate in preeclampsia

The pathogenesis of preeclampsia (PE) has not been elucidated, but immune imbalance is known to be one of the main pathogeneses. Dysfunction of decidual macrophages can lead to PE, and the PD-1/PD-L1 signaling pathway is associated with macrophage polarization. However, the relationship between the influence of the PD-1/PD-L1 signaling pathway on macrophage polarization and the onset of PE has not been fully elucidated. In this study, we analyzed the expression of CD68, iNOS, CD206, PD-1 and PD-L1 and the coexpression of CD68+PD-1+ and CD68+PD-L1+ in the decidual tissue of PE patients (n= 18) and healthy pregnant women (n=20). We found that CD68 and iNOS expression was increased in the decidua of PE patients (P < 0.001) and that CD206, PD-1 and PD-L1 expression and CD68+PD-1+ and CD68+PD-L1+ coexpression were decreased (P < 0.001). To assess the influence of the PD-1/PD-L1 signaling pathway on macrophage polarization, we added an anti-PD-1 mAb (pembrolizumab) or an anti-PD-L1 mAb (durvalumab) during THP-1 differentiation into M1 macrophages. Then, we detected the polarization of CD68+CD80+ macrophages and the expression of iNOS. To examine the effect of macrophage polarization on the invasion ability of trophoblast cells, macrophages were cocultured with HTR8/SVneo cells, and the invasion ability of HTR8/SVneo cells was detected via transwell assays. We found that CD68+CD80+ macrophage polarization was enhanced (P<0.05) and that iNOS expression was greater (P<0.01) in the pembrolizumab group. In the durvalumab group, CD68+CD80+ macrophage polarization and iNOS expression were also increased (P<0.05 and P<0.001). Compared with that in the untreated group, the aggressiveness of HTR8/SVneo cells was decreased in both the pembrolizumab group (P < 0.01) and the durvalumab group (P < 0.001). These findings indicate that the PD-1/PD-L1 signaling pathway may play an important role in the pathogenesis of PE by influencing macrophage polarization and reducing the invasion ability of trophoblasts.

Transcriptional profiling links unique human macrophage phenotypes to the growth of intracellular Salmonella enterica serovar Typhi

Macrophages provide a crucial environment for Salmonella enterica serovar Typhi (S. Typhi) to multiply during typhoid fever, yet our understanding of how human macrophages and S. Typhi interact remains limited. In this study, we delve into the dynamics of S. Typhi replication within human macrophages and the resulting heterogeneous transcriptomic responses of macrophages during infection. Our study reveals key factors that influence macrophage diversity, uncovering distinct immune and metabolic pathways associated with different stages of S. Typhi intracellular replication in macrophages. Of note, we found that macrophages harboring replicating S. Typhi are skewed towards an M1 pro-inflammatory state, whereas macrophages containing non-replicating S. Typhi exhibit neither a distinct M1 pro-inflammatory nor M2 anti-inflammatory state. Additionally, macrophages with replicating S. Typhi were characterized by the increased expression of genes associated with STAT3 phosphorylation and the activation of the STAT3 transcription factor. Our results shed light on transcriptomic pathways involved in the susceptibility of human macrophages to intracellular S. Typhi replication, thereby providing crucial insight into host phenotypes that restrict and support S. Typhi infection.

Image-Guided Photothermal and Immune Therapy of Tumors via Melanin-Producing Genetically Engineered Bacteria

Photothermal therapy (PTT) is a new treatment modality for tumors. However, the efficient delivery of photothermal agents into tumors remains difficult, especially in hypoxic tumor regions. In this study, an approach to deliver melanin, a natural photothermal agent, into tumors using genetically engineered bacteria for image-guided photothermal and immune therapy is developed. An Escherichia coli MG1655 is transformed with a recombinant plasmid harboring a tyrosinase gene to produce melanin nanoparticles. Melanin-producing genetically engineered bacteria (MG1655-M) are systemically administered to 4T1 tumor-bearing mice. The tumor-targeting properties of MG1655-M in the hypoxic environment integrate the properties of hypoxia targeting, photoacoustic imaging, and photothermal therapeutic agents in an "all-in-one" manner. This eliminates the need for post-modification to achieve image-guided hypoxia-targeted cancer photothermal therapy. Tumor growth is significantly suppressed by irradiating the tumor with an 808 nm laser. Furthermore, strong antitumor immunity is triggered by PTT, thereby producing long-term immune memory effects that effectively inhibit tumor metastasis and recurrence. This work proposes a new photothermal and immune therapy guided by an "all-in-one" melanin-producing genetically engineered bacteria, which can offer broad potential applications in cancer treatment.

Investigation of the immunological effects of escitalopram oxalate in the breast cancer co-culture model

Background

During breast cancer treatment, approximately half of the patients are prescribed psychotropic medication, such as selective serotonin reuptake inhibitors (SSRIs). Escitalopram oxalate is an SSRI used as an antidepressant.

Objectives

In this study, by creating a breast cancer microenvironment with THP-1, MCF-7 and MDA-MB-231 breast cancer co-culture models were created.

Methods

MCF-7, MDA-MB-231, and THP-1 cell lines to determine the concentration range of the cytotoxic effect of escitalopram oxalate MTS and MTT test were used. IC50 values were determined by the xCELLigence real-time cell analysis (RTCA) system. Apoptotic activities and cytokine levels were determined by flow cytometry.

Results

In the xCELLigence real-time analysis made according to the results, the IC50 value of escitalopram oxalate was measured as 13.7 μM for MCF-7 and 10.9 μM for MDA-MB-231. The IC50 value was measured as 54.6 μM for MCF-7 and 58.4 μM for MDA-MB-231 in xCELLigence analysis with tamoxifen. According to the MTS test results, the IC50 value of tamoxifen for THP-1 was 92.03 μM and the IC50 value for escitalopram oxalate was 95.32 μM. In the co-culture model, the immunological effects of escitalopram oxalate on MCF-7 cells were 2.8%, 11.1%, 15.6%, 10.6%, and 12.1% for interleukin (IL)-1β, IL-6, IL-8, IL-10, and TNF-α, respectively, while MDA effects on MB-231 cells, respectively, were 2.1%, 15.9%, 16.2%, 8.8%, and 11.8%.

Conclusions

According to the results obtained, it was concluded that the immunological effects of escitalopram oxalate are more effective than tamoxifen and that it can be used as an adjunctive agent in breast cancer treatment.

Targeting NF-κB Signaling: Selected Small Molecules Downregulate Pro-Inflammatory Cytokines in Both Food Allergen and LPS-Induced Inflammation

Although inflammation is primarily a protective response guarding the human body, it can result in a variety of chronic diseases such as allergies, auto-immune, cardiovascular diseases, and cancer. In NF-κB-mediated inflammation, many small molecules and food compounds characterized as nutraceuticals have shown positive effects associated with immunomodulatory properties. We investigated the effects of selected bioactive small molecules, commonly found in food components, vanillyl alcohol (VA) and lauric acid (LA), on different cell lines exposed to pro-inflammatory stimuli, lipopolysaccharide (LPS), and the food allergen actinidin (Act d 1). Pro-inflammatory cytokines were downregulated in response to both VA and LA, and this downregulation was caused by a decrease in the activation of the NF-κB pathway and the translocation of p65, the pathway's major component. Small nutraceutical molecules, VA and LA, showed not only inhibition of the pro-inflammatory cytokines, but also inhibition of the NF-κB activation, and reduced translocation of the p65 component. The present study may contribute to the therapeutic use of these molecules for various inflammatory diseases, which have in common an increased expression of pro-inflammatory cytokines and NF-κB-mediated inflammation.

A Lacticaseibacillus rhamnosus secretome induces immunoregulatory transcriptional, functional and immunometabolic signatures in human THP-1 monocytes

Macrophage responses to activation are fluid and dynamic in their ability to respond appropriately to challenges, a role integral to host defence. While bacteria can influence macrophage differentiation and polarization into pro-inflammatory and alternatively activated phenotypes through direct interactions, many questions surround indirect communication mechanisms mediated through secretomes derived from gut bacteria, such as lactobacilli. We examined effects of secretome-mediated conditioning on THP-1 human monocytes, focusing on the ability of the Lacticaseibacillus rhamnosus R0011 secretome (LrS) to drive macrophage differentiation and polarization and prime immune responses to subsequent challenge with lipopolysaccharide (LPS). Genome-wide transcriptional profiling revealed increased M2-associated gene transcription in response to LrS conditioning in THP-1 cells. Cytokine and chemokine profiling confirmed these results, indicating increased M2-associated chemokine and cytokine production (IL-1Ra, IL-10). These cells had increased cell-surface marker expression of CD11b, CD86, and CX3CR1, coupled with reduced expression of the M1 macrophage-associated marker CD64. Mitochondrial substrate utilization assays indicated diminished reliance on glycolytic substrates, coupled with increased utilization of citric acid cycle intermediates, characteristics of functional M2 activity. LPS challenge of LrS-conditioned THP-1s revealed heightened responsiveness, indicative of innate immune priming. Resting stage THP-1 macrophages co-conditioned with LrS and retinoic acid also displayed an immunoregulatory phenotype with expression of CD83, CD11c and CD103 and production of regulatory cytokines. Secretome-mediated conditioning of macrophages into an immunoregulatory phenotype is an uncharacterized and potentially important route through which lactic acid bacteria and the gut microbiota may train and shape innate immunity at the gut-mucosal interface.

Lentinan-loaded GelMA hydrogel accelerates diabetic wound healing through enhanced angiogenesis and immune microenvironment modulation

Diabetic wound healing is a substantial clinical challenge, characterized by delayed angiogenesis and unresolved inflammation. Lentinan, a polysaccharide extracted from shiitake mushrooms, has the potential to regulate both macrophage polarization and angiogenesis, though this aspect remains inadequately explored. To facilitate lentinan's clinical utility, we have developed a GelMA hydrogel encapsulated with lentinan (10 μM), offering a controlled release mechanism for sustained lentinan delivery at the wound site. Application of the lentinan-encapsulated delivery system topically significantly expedites wound closure compared to control groups. Furthermore, histological examination demonstrates enhanced neovascularization and reduced inflammation in lentinan-treated wounds, as evidenced by increased M2 macrophage infiltration. Moreover, our results indicated that lentinan-induced AMPK activation promotes DAF16 expression, enhancing the resistance of macrophages and HUVECs to oxidative stress in high-glucose environments, thereby promoting M2 macrophage polarization and angiogenesis. All these findings underscore lentinan's capacity to modulate macrophage polarization and angiogenesis via the AMPK/DAF16 pathway, ultimately facilitating the healing of diabetic wounds.

Preparation, characterization, and toxicity evaluation of microemulsion formulation containing prunetin for potential oral applications

Phytochemicals as therapeutic alternatives can have a fundamental impact on the various stages of inflammation and its resolution. Prunetin is a naturally occurring isoflavone and has been claimed to have numerous therapeutic potentials. The objective of this study is preparation, characterization, and toxicity evaluation of microemulsion formulation containing prunetin (PMF) for potential oral applications. With this research, it was targeted to emphasize the way of improving the therapeutic efficacy of natural biomolecules with a nontoxic and effective formulation. In the study, the pseudo-ternary phase diagram was developed and PMF was characterized by conductivity, droplet size, viscosity and pH. Effects against to cytokines (IL-1β and IL-6) and TNF-α levels of the PMF were determined by ELISA technique. Genotoxicity and acute oral toxicity tests were carried out according to OECD guidelines. The results showed that PMF is a colloid system that reduced proinflammatory cytokine levels in LPS-induced macrophage cells compared to the control group. PMF demonstrated no mutagenic activity against TA98, TA100, TA1535, and TA1537 Salmonella strains. The in vivo oral acute toxicity test results indicated that PMF did not show mortality or significant side effects even at 2000 mg/kg bw. This study represents PMF showed a good safety profile in animal study. It is thought that this formulation may have anti-inflammatory potential with further in vivo testing.

Mercury-containing preparations attenuate neutrophil extracellular trap formation in mice and humans through inhibiting the ERK1/2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Neutrophil extracellular trap (NET) formation plays a crucial role in wound healing disorders, including chronic skin ulcers and diabetic foot ulcers (DFUs). Over the years, traditional Chinese topical medications, such as Cinnabar (composed of HgS and soluble mercury salt) and hydrargyria oxydum rubrum (containing HgO and soluble mercury salt), have been utilized for treating these ailments. Nevertheless, the fundamental processes remain mostly ambiguous.

AIM OF THE STUDY

This study sought to investigate the potential effects of topical mercury-containing preparations on the process of NET formation.

MATERIALS AND METHODS

Neutrophils isolated from healthy individuals and mouse models of type 1 and type 2 diabetes were cultured with phorbol 12-myristate 13-acetate (PMA), both with and without the mercury-containing preparations (MCP). The formation of NETs was monitored using confocal and scanning electron microscopes. Immunofluorescence and fluorescent probes were employed to assess the levels of citrulline histone H3 (Cit-H3) and intracellular reactive oxygen species (ROS), respectively. The impact of MCP extracts on cytokine expression, peptidylarginine deiminase 4 (PAD4), and myeloperoxidase (MPO) was measured through Luminex and ELISA assays. Phagocytosis of human neutrophils was analyzed using Flow Cytometry. Finally, the phosphorylation levels of ERK were detected by western blotting.

RESULTS

Treatment with MCP led to a reduction in PAD4, Cit-H3, and MPO expressions in neutrophils, consequently inhibiting PMA-induced NET formation. MCP treatment also dampened ERK1/2 activation in neutrophils. Furthermore, MCP exhibited inhibitory effects on the secretion of the cytokine IL-8 and ROS production while enhancing neutrophil phagocytosis.

CONCLUSION

Our findings suggest that MCP can mitigate the release of NETs, likely by suppressing the ERK1/2 signaling pathway.

Investigating the immunological function of alpha-2-glycoprotein 1, zinc-binding in regulating tumor response in the breast cancer microenvironment

BACKGROUND

Alpha-2-glycoprotein 1, zinc-binding (ZAG), a secreted protein encoded by the AZGP1 gene, is structurally similar to HLA class I. Despite its presumed immunological function, little is known about its role in tumor immunity. In this study, we thus aimed to determine the relationship between the expression of AZGP1/ZAG and the immunological profiles of breast cancer tissues at both the gene and protein level.

METHODS

Using a publicly available gene expression dataset from a large-scale breast cancer cohort, we conducted gene set enrichment analysis (GSEA) to screen the biological processes associated with AZGP1. We analyzed the correlation between AZGP1 expression and immune cell composition in breast cancer tissues, estimated using CIBERSORTx. Previously, we evaluated the infiltration of 11 types of immune cells for 45 breast cancer tissues using flow cytometry (FCM). ZAG expression was evaluated by immunohistochemistry on these specimens and analyzed for its relationship with immune cell infiltration. The action of ZAG in M1/M2 polarization models using primary cultures of human peripheral blood mononuclear cells (PBMC)-derived macrophage (Mφ) was analyzed based on the expression of M1/M2 markers (CD86, CD80/CD163, MRC1) and HLA class I/II by FCM.

RESULTS

AZGP1 expression was negatively correlated with multiple immunological processes and specific immune cell infiltration including Mφ M1 using GSEA and CIBERSORTx. ZAG expression was associated with decreased infiltration of monocytes/macrophages, non-classical monocytes, and myeloid-derived suppressor cells in tumor tissues assessed using FCM. In in vitro analyses, ZAG decreased the expression of CD80, CD163, MRC1, and HLA classes I/II in the M1 polarization model and the expression of CD163 and MRC1 in the M2 polarization model.

CONCLUSION

ZAG is suggested to be a novel immunoregulatory factor affecting the Mφ phenotype in breast cancer tissues.

Extracellular succinate derived from ectopic milieu drives adhesion and implantation growth of ectopic endometrial stromal cells via the SUCNR1 signal in endometriosis

BACKGROUND

As a dual-function metabolite, succinate has emerged in cell function and plays a key signaling role in linking mitochondrial function to other cellular functions. Succinate accumulation in the cytoplasm is commonly associated with hypoxia in the microenvironment and immune cell activation. Extracellular succinate released into the microenvironment is considered an inflammatory alarm that can be sensed by its membrane receptor SUCNR1, which boosts proinflammatory responses and acts akin to classical hormones and cytokines. Succinate plays an important role in the development of inflammatory diseases. Whether succinate facilitates the progression of endometriosis (EMs), characterized by chronic inflammation and peritoneal adhesion, is worth exploring.

OBJECTIVE

We mimicked the ectopic milieu in vitro and in vivo to evaluate the main source and potential role of succinate in endometriosis. We assessed the molecular and functional effects of succinate on macrophages and peritoneal mesothelial cells in peritoneal cavity. The effect of succinate/SUCNR1 signaling on ectopic endometrial stromal cells (ESCs) was further explored in this study.

METHODS

In this study, we used targeted organic acid metabolomics analysis and in vitro assays to assess the potential accumulation of succinate in the peritoneal fluid of EMs patients. We examined its correlation with disease severity, Visual Analogue Scale, and the Endometriosis Fertility Index. Flow cytometry, enzyme linked immunosorbent assay, western blot assay, quantitative real-time PCR, and other molecular biology techniques were used to explore the potential mechanisms.

RESULTS

By mimicking the ectopic milieu, we constructed an in vitro co-culture system and found that M1 polarized macrophages and that the peritoneal mesothelial cell line (HMrSV5) mainly released succinate into their microenvironment and activated the succinate receptor (SUCNR1) signal, which further polarized the macrophages and significantly enhanced the invasive survival of ESCs, and the adhesion to the peritoneum. We further investigated the pathological effects of extracellular succinate in vivo using a xenograft mouse models of endometriosis.

CONCLUSIONS

Succinate-SUCNR1 signaling facilitates the creation of inflammatory cells and plays a vital role in EMs progression and peritoneal adhesion. Our work on the molecular mechanisms underlying succinate accumulation and function will help elucidate the phenotypic mysteries of pain and infertility in EMs. Video Abstract.

Decades Long Involvement of THP-1 Cells as a Model for Macrophage Research: A Comprehensive Review

Over the years, researchers have endeavored to identify dependable and reproducible in vitro models for examining macrophage behavior under controlled conditions. The THP-1 cell line has become a significant and widely employed tool in macrophage research within these models. Originating from the peripheral blood of individuals with acute monocytic leukemia, this human monocytic cell line can undergo transformation into macrophage-like cells, closely mirroring primary human macrophages when exposed to stimulants. Macrophages play a vital role in the innate immune system, actively regulating inflammation, responding to infections, and maintaining tissue homeostasis. A comprehensive understanding of macrophage biology and function is crucial for gaining insights into immunological responses, tissue healing, and the pathogenesis of diseases such as viral infections, autoimmune disorders, and neoplastic conditions. This review aims to thoroughly evaluate and emphasize the extensive history of THP-1 cells as a model for macrophage research. Additionally, it will delve into the significance of THP-1 cells in advancing our comprehension of macrophage biology and their invaluable contributions to diverse scientific domains.

Effect of Milk Origin and Seasonality of Yogurt Acid Whey on Antioxidant Activity before and after In Vitro Gastrointestinal Digestion

Yogurt acid whey (YAW) is a by-product of Greek strained yogurt production. The disposal of YAW constitutes an environmental problem, and given the increasing demand of Greek yogurt worldwide, its handling is a challenge. However, whey-derived peptides, resulting from microbial fermentation as well as those resulting from further hydrolysis during the digestion process, have been linked to enhanced biological activities. In this study, the antioxidant capacity of 33 samples of YAW obtained from Greek dairy companies of bovine, ovine or caprine origin was investigated using both cell-free and cell-based assays. The YAW samples, their in vitro digestion products (YAW-Ds) and a fraction of the digests (less than 3 kDa; YAW-D-P3) were assessed using four biochemical assays, namely ORAC, ABTS, FRAP and P-FRAP. Our data revealed a higher antioxidant capacity for digested samples compared with undigested samples, with all four methods. ORAC values after in vitro digestion were higher for the ovine samples compared to their bovine (YAW-D and YAW-D-P3) and caprine (YAW-D-P3) counterparts. Furthermore, the YAW-D-P3 fraction derived from samples collected in the summer months exhibited higher ORAC values when compared to the respective fraction from the winter months' samples. The cellular antioxidant activity of ovine YAW-D-P3 was improved in H2O2-treated HT29 cells compared to the control H2O2-treated cells. However, YAW-D-P3 could not trigger either the pathways involving the transcription factors NF-κB or NFE2L2 or the gene expression of SOD1, CAT and HMOX1 in LPS-challenged THP-1-derived macrophages. These results suggest that YAW, and particularly YAW from ovine origin, could be used as a natural source for its antioxidant potential in human and animal nutrition.

Effects of myeloid immune cells on the metabolic process of biomimetic bone regeneration

AIMS

As the process of bone regeneration is preceded by an inflammatory response, the immune system has long been considered important for fracture healing. Despite many studies on the contribution of immune cells to bone-related diseases, the role of immune cells in the regeneration therapy of lost bone is not well understood. In addition, various types of cells are involved in the clinical bone regeneration environment, but most of the osteo-biology studies are conducted in an osteoblast-only environment.

MATERIALS AND METHODS

Here, we investigated the effects of macrophages and dendritic cells on osteogenic differentiation in a co-culture environment involving human periosteal cell-derived osteoblasts, human monocyte-derived osteoclasts, and myeloid-derived cells. In addition, the cluster of myeloid immune cells involved in the clinical bone regeneration process was analyzed through bone defect rat modeling.

KEY FINDINGS

We found that specific types of myeloid cells and related cytokines increased osteogenic differentiation. These results were confirmed in experiments using myeloid cells originating from human primitive peripheral blood mononuclear cells and by measuring the colonization of macrophages and dendritic cells in an in vivo bone defect environment. In addition, Next generation sequencing (NGS) analysis was performed through RNA sequencing for osteogenesis caused by macrophages and dendritic cells in vitro, which implemented a clinical bone regeneration environment. The results of these experiments suggest that the role of M2 macrophages or dendritic cells is markedly increased during osteogenic differentiation. Therefore, we propose that the exchange of bioactive factors between macrophages and dendritic cells during the bone formation metabolic process is a crucial step of tissue regeneration rather than limited to the initial inflammatory response.

SIGNIFICANCE

This study indicates that M2 macrophages, among myeloid cells, can be mediators that play a vital role in the effective bone regeneration process and shows the potential as a useful next-generation advanced cell therapy for bone regeneration treatment.

GSK2656157, a PERK Inhibitor, Alleviates Pyroptosis of Macrophages Induced by Mycobacterium Bacillus Calmette-Guerin Infection

Tuberculosis (TB) is the leading cause of human death worldwide due to Mycobacterium tuberculosis (Mtb) infection. Mtb infection can cause macrophage pyroptosis. PERK, as a signaling pathway protein on the endoplasmic reticulum, plays an important role in infectious diseases. It is not clear whether PERK is involved in the regulation of pyroptosis of macrophages during Mtb infection. In this study, Bacillus Calmette-Guerin (BCG) infection resulted in high expression of pro-caspase-1, caspase-1 p20, GSDMD-N, and p-PERK in the THP-1 macrophage, being downregulated with the pre-treatment of GSK2656157, a PERK inhibitor. In addition, GSK2656157 inhibited the secretion of IL-1β and IL-18, cell content release, and cell membrane rupture, as well as the decline in cell viability induced by BCG infection. Similarly, GSK2656157 treatment downregulated the expressions of pro-caspase-1, caspase-1 p20, caspase-11, IL-1β p17, IL-18 p22, GSDMD, GSDMD-N, and p-PERK, as well as reducing fibrous tissue hyperplasia, inflammatory infiltration, and the bacterial load in the lung tissue of C57BL/6J mice infected with BCG. In conclusion, the inhibition of PERK alleviated pyroptosis induced by BCG infection, which has an effect of resisting infection.

L-arabinose Attenuates LPS-Induced Intestinal Inflammation and Injury through Reduced M1 Macrophage Polarization

BACKGROUND

L-arabinose has anti-inflammatory and metabolism-promoting properties, and macrophages participate in the alleviation of inflammation; however, the mechanism by which they contribute to the anti-inflammatory effects of L-arabinose is unknown.

OBJECTIVES

To investigate the involvement of macrophages in the mitigation of L-arabinose in an intestinal inflammation model induced by lipopolysaccharide (LPS).

METHODS

Five-week-old male C57BL/6 mice were divided into 3 groups: a control and an LPS group that both received normal water supplementation, and an L-arabinose (ARA+LPS) group that received 5% L-arabinose supplementation. Mice in the LPS and ARA+LPS groups were intraperitoneally injected with LPS (10 mg/kg body weight), whereas the control group was intraperitoneally injected with the same volume of saline. Intestinal morphology, cytokines, tight junction proteins, macrophage phenotypes, and microbial communities were profiled at 6 h postinjection.

RESULTS

L-arabinose alleviated LPS-induced damage to intestinal morphology. L-arabinose down-regulated serum tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6, and messenger RNA (mRNA) levels of TNF-α, IL-1β, interferon-γ (IFN-γ), and toll-like receptor-4 in jejunum and colon compared with those of the LPS group (P < 0.05). The mRNA and protein levels of occludin and claudin-1 were significantly increased by L-arabinose (P < 0.05). Interferon regulatory factor-5 (IRF-5) and signal transducer and activator of transcription-1 (STAT-1), key genes characterized by M1 macrophages, were elevated in the jejunum and colon of LPS mice (P < 0.05) but decreased in the ARA+LPS mice (P < 0.05). In vitro, L-arabinose decreased the proportion of M1 macrophages and inhibited mRNA levels of TNF-α, IL-1β, IL-6, IFN-γ, as well as IRF-5 and STAT-1 (P < 0.01). Moreover, L-arabinose restored the abundance of norank_f__Muribaculaceae, Faecalibaculum, Dubosiella, Prevotellaceae_UCG-001, and Paraasutterella compared with those of LPS (P < 0.05) and increased the concentration of short-chain fatty acids (P < 0.05).

CONCLUSION

The anti-inflammatory effects of L-arabinose are achieved by reducing M1 macrophage polarization, suggesting that L-arabinose could be a candidate functional food or nutritional strategy for intestinal inflammation and injury.

Reprogramming of breast tumor-associated macrophages with modulation of arginine metabolism

HER2+ breast tumors have abundant immune-suppressive cells, including M2-type tumor associated macrophages (TAMs). While TAMs consist of the immune-stimulatory M1-type and immune-suppressive M2-type, M1/M2-TAM ratio is reduced in immune-suppressive tumors, contributing to their immunotherapy refractoriness. M1 vs. M2-TAM formation depends on differential arginine metabolism, where M1-TAMs convert arginine to nitric oxide (NO) and M2-TAMs convert arginine to polyamines (PAs). We hypothesize that such distinct arginine metabolism in M1- vs M2-TAMs is attributed to different availability of BH4 (NO synthase cofactor) and that its replenishment would reprogram M2-TAMs to M1-TAMs. Recently, we reported that sepiapterin (SEP), the endogenous BH4 precursor, elevates the expression of M1-TAM markers within HER2+ tumors. Here, we show that SEP restores BH4 levels in M2-TAMs, which then redirects arginine metabolism to NO synthesis and converts M2-TAMs to M1-TAMs. The reprogrammed TAMs exhibit full-fledged capabilities of antigen presentation and induction of effector T cells to trigger immunogenic cell death of HER2+ cancer cells. This study substantiates the utility of SEP in metabolic shift of HER2+ breast tumor microenvironment as a novel immunotherapeutic strategy.

Optimization of differentiation and transcriptomic profile of THP-1 cells into macrophage by PMA

THP-1 monocyte, which can be differentiated into macrophages by PMA, is widely used in researches on pathogen infection and host innate immunity, but reports on the induction methods of PMA are different and lack a unified standard, and the transcriptome characteristics of macrophage compared with THP-1 cells remains unclear. In this research, we examined the differentiation effect of three factors including induction time, cell seeding density and PMA concentration by detecting the positive rate of CD14 expression. The concentration of 80ng/ml of PMA, the induction time of 24h, and the cell seeding density of 5×105 cells/ml, could respectively facilitates a relatively higher CD14 positive rate in THP-1 cells. Under this optimized conditions, the CD14 positive rate of THP-1 cells can reach 66.52%. Transcriptome sequencing showed that after the above induction, the mRNA expression of 3113 genes which were closely related to cell communication, signal transduction, cell response to stimulus, signaling receptor binding and cytokine activity were up-regulated, and the top 10 genes were RGS1, SPP1, GDF15, IL-1B, HAVCR2, SGK1, EGR2, TRAC, IL-8 and EBI3. While the mRNA expression of 2772 genes which were associated with cell cycle process, DNA binding and replication and cell division, were down-regulated, and the top genes were SERPINB10, TRGC2, SERPINB2, TRGC1, MS4A3, MS4A4E, TRGJP1, MS4A6A, TRGJP2, MS4A4A. This research optimized the induction method on THP-1 cell differentiation from three aspects and delineated the transcriptomic profile of PMA-induced THP-1 cells, laying a foundation for the construction method of cell model and for the functional study of macrophage.

Identification and Characterization of an HtrA Sheddase Produced by Coxiella burnetii

Having previously shown that soluble E-cadherin (sE-cad) is found in sera of Q fever patients and that infection of BeWo cells by C. burnetii leads to modulation of the E-cad/β-cat pathway, our purpose was to identify which sheddase(s) might catalyze the cleavage of E-cad. Here, we searched for a direct mechanism of cleavage initiated by the bacterium itself, assuming the possible synthesis of a sheddase encoded in the genome of C. burnetii or an indirect mechanism based on the activation of a human sheddase. Using a straightforward bioinformatics approach to scan the complete genomes of four laboratory strains of C. burnetii, we demonstrate that C. burnetii encodes a 451 amino acid sheddase (CbHtrA) belonging to the HtrA family that is differently expressed according to the bacterial virulence. An artificial CbHtrA gene (CoxbHtrA) was expressed, and the CoxbHtrA recombinant protein was found to have sheddase activity. We also found evidence that the C. burnetii infection triggers an over-induction of the human HuHtrA gene expression. Finally, we demonstrate that cleavage of E-cad by CoxbHtrA on macrophages-THP-1 cells leads to an M2 polarization of the target cells and the induction of their secretion of IL-10, which "disarms" the target cells and improves C. burnetii replication. Taken together, these results demonstrate that the genome of C. burnetii encodes a functional HtrA sheddase and establishes a link between the HtrA sheddase-induced cleavage of E-cad, the M2 polarization of the target cells and their secretion of IL-10, and the intracellular replication of C. burnetii.

Heme-Induced Macrophage Phenotype Switching and Impaired Endogenous Opioid Homeostasis Correlate with Chronic Widespread Pain in HIV

Chronic widespread pain (CWP) is associated with a high rate of disability and decreased quality of life in people with HIV-1 (PWH). We previously showed that PWH with CWP have increased hemolysis and elevated plasma levels of cell-free heme, which correlate with low endogenous opioid levels in leukocytes. Further, we demonstrated that cell-free heme impairs β-endorphin synthesis/release from leukocytes. However, the cellular mechanisms by which heme dampens β-endorphin production are inconclusive. The current hypothesis is that heme-dependent TLR4 activation and macrophage polarization to the M1 phenotype mediate this phenomenon. Our novel findings showed that PWH with CWP have elevated M1-specific macrophage chemokines (ENA-78, GRO-α, and IP-10) in plasma. In vitro, hemin-induced polarization of M0 and M2 macrophages to the M1 phenotype with low β-endorphins was mitigated by treating cells with the TLR4 inhibitor, TAK-242. Similarly, in vivo phenylhydrazine hydrochloride (PHZ), an inducer of hemolysis, injected into C57Bl/6 mice increased the M1/M2 cell ratio and reduced β-endorphin levels. However, treating these animals with the heme-scavenging protein hemopexin (Hx) or TAK-242 reduced the M1/M2 ratio and increased β-endorphins. Furthermore, Hx attenuated heme-induced mechanical, heat, and cold hypersensitivity, while TAK-242 abrogated hypersensitivity to mechanical and heat stimuli. Overall, these results suggest that heme-mediated TLR4 activation and M1 polarization of macrophages correlate with impaired endogenous opioid homeostasis and hypersensitivity in people with HIV.

Subaqueous free-standing 3D cell culture system for ultrafast cell compaction, mechano-inductive immune control, and improving therapeutic angiogenesis

Conventional 3D cell culture methods require a comprehensive complement in labor-intensive and time-consuming processes along with in vivo circumstantial mimicking. Here, we describe a subaqueous free-standing 3D cell culture (FS) device that can induce the omnidirectional environment and generate ultrafast human adipose-derived stem cells (hADSCs) that efficiently aggregate with compaction using acoustic pressure. The cell culture conditions were optimized using the FS device and identified the underlying molecular mechanisms. Unique phenomena in cell aggregation have led to extraordinary cellular behavior that can upregulate cell compaction, mechanosensitive immune control, and therapeutic angiogenesis. Therefore, we designated the resulting cell aggregates as "pressuroid." Notably, external acoustic stimulation produced by the FS device affected the pressuroids. Furthermore, the pressuroids exhibited upregulation in mechanosensitive genes and proteins, PIEZO1/2. CyclinD1 and PCNA, which are strongly associated with cell adhesion and proliferation, were elevated by PIEZO1/2. In addition, we found that pressuroids significantly increase angiogenic paracrine factor secretion, promote cell adhesion molecule expression, and enhance M2 immune modulation of Thp1 cells. Altogether, we have concluded that our pressuroid would suggest a more effective therapy method for future cell therapy than the conventional one.

The potential immunotoxicity of emamectin benzoate on the human THP-1 macrophages

Emamectin benzoate (EMB) as one of the typical biological pesticides has a wide range of applications in agriculture. However, the immune toxic effects of EMB in human received limited attention. In our study, THP-1 macrophage as an in vitro model was used to evaluate immune functions exposed to EMB. We observed that EMB inhibited phagocytic activity and respiratory burst capacity of macrophages without inducing cellular toxicity, implying the potential immunosuppression. Besides, EMB disturbed the cytokines balance embodied in the increase of TNF-α, IL-1β, IL-6, CCL27, CXCL8 mRNA expression and the decrease of IL-4, IL-13, IL-10 mRNA expression. EMB could exhibit pro-inflammatory responses in macrophages and promote the conversion of macrophages to M1 phenotype. Moreover, NF-κB pathway involved in regulating immune function from KEGG pathway analysis. EMB exposure could activate the NF-κB pathway in THP-1 macrophages by exploring the critical proteins. This research provided insights on immunotoxicity evaluation and clarified EMB-induced immunotoxicity was related to NF-κB pathway activation.

Development of an Untargeted Metabolomics Strategy to Study the Metabolic Rewiring of Dendritic Cells upon Lipopolysaccharide Activation

Dendritic cells (DCs) are essential immune cells for defense against external pathogens. Upon activation, DCs undergo profound metabolic alterations whose precise nature remains poorly studied at a large scale and is thus far from being fully understood. The goal of the present work was to develop a reliable and accurate untargeted metabolomics workflow to get a deeper insight into the metabolism of DCs when exposed to an infectious agent (lipopolysaccharide, LPS, was used to mimic bacterial infection). As DCs transition rapidly from a non-adherent to an adherent state upon LPS exposure, one of the leading analytical challenges was to implement a single protocol suitable for getting comparable metabolomic snapshots of those two cellular states. Thus, a thoroughly optimized and robust sample preparation method consisting of a one-pot solvent-assisted method for the simultaneous cell lysis/metabolism quenching and metabolite extraction was first implemented to measure intracellular DC metabolites in an unbiased manner. We also placed special emphasis on metabolome coverage and annotation by using a combination of hydrophilic interaction liquid chromatography and reverse phase columns coupled to high-resolution mass spectrometry in conjunction with an in-house developed spectral database to identify metabolites at a high confidence level. Overall, we were able to characterize up to 171 unique meaningful metabolites in DCs. We then preliminarily compared the metabolic profiles of DCs derived from monocytes of 12 healthy donors upon in vitro LPS activation in a time-course experiment. Interestingly, the resulting data revealed differential and time-dependent activation of some particular metabolic pathways, the most impacted being nucleotides, nucleotide sugars, polyamines pathways, the TCA cycle, and to a lesser extent, the arginine pathway.

Transcriptomic Analysis of Macrophage Polarization Protocols: Vitamin D3 or IL-4 and IL-13 Do Not Polarize THP-1 Monocytes into Reliable M2 Macrophages

Two main types of macrophages (Mφ) include inflammatory (M1) and anti-inflammatory (M2) macrophages. These cells can be obtained in vitro by polarization of monocytic cell lines using various stimuli. Since there is currently no consensus on the best method for the acquisition of reliable M1 and M2 macrophages from the THP-1 cell line, we decided to compare three different polarization protocols at the transcriptomic level. Whole transcriptomes of Mφ polarized according to the chosen protocols were analyzed using RNA-seq. Differential expression of genes and functional enrichment for gene ontology terms were assessed. Compared with other protocols, M1 macrophages polarized using PMA (61.3 ng/mL) and IFN-γ along with LPS had the highest expression of M1-associated regulatory genes and genes for M1 cytokines and chemokines. According to the GO enrichment analysis, genes involved in defensive and inflammatory processes were differentially expressed in these Mφ. However, all three chosen protocols which use Vit D₃, IL-13/IL-4, and IL-4, respectively, failed to promote the polarization of macrophages with a reliable M2 phenotype. Therefore, optimization or development of a new M2 polarization protocol is needed to achieve macrophages with a reliable anti-inflammatory phenotype.

Immunomodulatory effect of IL-1RA in LPS-activated macrophage/dental pulp stem cells co-culture

AIMS

Lipopolysaccharides (LPS)-activated human dental pulp stem cells (hDPSCs) and macrophage co-cultures showed downregulated TNF-α secretion that is modulated by hDPSCs through IDO axis, whereas the secretory levels of IL-1β remained unchanged. Therefore, sustained production of IL-1β could contribute to progressive dental pulp inflammation. However, the role of interleukin-1 receptor antagonist (IL-1RA) in downregulating the secretion of IL-1β and TNF-α in LPS-activated M0/M1/M2 macrophage and hDPSCs co-culture has not been studied yet. Therefore, the aim of the present study was to determine the immunomodulatory role of blocking IL-1 receptors in DPSCs macrophage co-culture activated with LPS.

METHODOLOGY

Human monocytic cell line THP-1 was polarized to M0, M1 and M2 macrophages and co-cultured with hDPSCs. The viability of the co-cultured cells was assessed by apoptosis assay. Co-cultures were activated with LPS followed by the assessment of gene expression and protein levels of IL-1β and TNF-α with and without IL-1RA blocking via qRT-PCR and cytokine flex assay by flow cytometry. Data from three separate experiments were analysed using one-way anova followed by Tukey's post hoc test and a p-value of <.05 was considered statistically significant.

RESULTS

THP-1-derived M0, M1 and M2 macrophages co-cultured with hDPSCs showed spindle and round-shaped cells, with >90% viability when assessed by apoptosis assay. Inflammatory TNF-α and IL-1β profiles in stimulated co-cultures showed upregulated IL-1β, whereas TNF-α was downregulated (p < .05). Anti-inflammatory gene expression levels of IL-10 and TGF-β were downregulated (p < .05). Blocking with IL-1RA resulted in a remarkable decrease in IL-1β at the gene expression and protein production levels whilst TNF-α levels remained low (p < .05). Levels of anti-inflammatory cytokine IL-10 showed no significant difference.

CONCLUSION

Blocking the IL-1 receptor in hDPSCs and macrophage (M0, M1, M2) co-cultures activated with LPS resulted in downregulation of inflammatory cytokines IL-1β and TNF-α. These findings highlight the immunomodulatory effect of IL-1RA in inflammatory conditions of dental pulp infections.

Monophosphoryl lipid A ameliorates radiation-induced lung injury by promoting the polarization of macrophages to the M1 phenotype

Background

Radiation-induced lung injury (RILI) often occurs during clinical chest radiotherapy and acute irradiation from accidental nuclear leakage. This study explored the role of monophosphoryl lipid A (MPLA) in RILI.

Materials and Methods

The entire thoracic cavity of C57BL/6N mice was irradiated at 20 Gy with or without pre-intragastric administration of MPLA. HE staining, Masson trichrome staining, and TUNEL assay were used to assess lung tissue injury after treatment. The effect of irradiation on the proliferation of MLE-12 cells was analyzed using the Clonogenic assay. The effect of MPLA on the apoptosis of MLE-12 cells was analyzed using flow cytometry. Expression of γ-H2AX and epithelial-mesenchymal transition (EMT) markers in MLE-12 cells was detected by immunofluorescence and Western blot, respectively.

Results

MPLA attenuated early pneumonitis and late pulmonary fibrosis after thoracic irradiation and reversed radiation-induced EMT in C57 mice. MPLA further promoted proliferation and inhibited apoptosis of irradiated MLE-12 cells in vitro. Mechanistically, the radioprotective effect of MPLA was mediated by exosomes secreted by stimulated macrophages. Macrophage-derived exosomes modulated DNA damage in MLE-12 cells after irradiation. MPLA promoted the polarization of RAW 264.7 cells to the M1 phenotype. The exosomes secreted by M1 macrophages suppressed EMT in MLE-12 cells after irradiation.

Conclusion

MPLA is a novel treatment strategy for RILI. Exosomes derived from macrophages are key to the radioprotective role of MPLA in RILI.

Structural and Immunologic Properties of the Major Soybean Allergen Gly m 4 Causing Anaphylaxis

Gly m 4 is the major soybean allergen, causing birch pollen cross allergic reactions. In some cases, Gly m 4-mediated anaphylaxis takes place, but the causative factors are still unknown. Here, we studied the structural and immunologic properties of Gly m 4 to shed light on this phenomenon. We showed that Gly m 4 retained its structure and IgE-binding capacity after heating. Gly m 4 was cleaved slowly under nonoptimal gastric conditions mimicking duodenal digestion, and IgE from the sera of allergic patients interacted with the intact allergen rather than with its proteolytic fragments. Similar peptide clusters of Bet v 1 and Gly m 4 were formed during allergen endolysosomal degradation in vitro, but their sequence identity was insignificant. Animal polyclonal anti-Gly m 4 and anti-Bet v 1 IgG weakly cross-reacted with Bet v 1 and Gly m 4, respectively. Thus, we supposed that not only conserved epitopes elicited cross-reactivity with Bet v 1, but also variable epitopes were present in the Gly m 4 structure. Our data suggests that consumption of moderately processed soybean-based drinks may lead to the neutralizing of gastric pH as a result of which intact Gly m 4 can reach the human intestine and cause IgE-mediated system allergic reactions.

Arsenic Induces M2 Macrophage Polarization and Shifts M1/M2 Cytokine Production via Mitophagy

Arsenic is an environmental factor associated with epithelial-mesenchymal transition (EMT). Since macrophages play a crucial role in regulating EMT, we studied the effects of arsenic on macrophage polarization. We first determined the arsenic concentrations to be used by cell viability assays in conjunction with previous studies. In our results, arsenic treatment increased the alternatively activated (M2) macrophage markers, including arginase 1 (ARG-1) gene expression, chemokine (C-C motif) ligand 16 (CCL16), transforming growth factor-β1 (TGF-β1), and the cluster of differentiation 206 (CD206) surface marker. Arsenic-treated macrophages promoted A549 lung epithelial cell invasion and migration in a cell co-culture model and a 3D gel cell co-culture model, confirming that arsenic treatment promoted EMT in lung epithelial cells. We confirmed that arsenic induced autophagy/mitophagy by microtubule-associated protein 1 light-chain 3-II (LC3 II) and phosphor-Parkin (p-Parkin) protein markers. The autophagy inhibitor chloroquine (CQ) recovered the expression of the inducible nitric oxide synthase (iNOS) gene in arsenic-treated M1 macrophages, which represents a confirmation that arsenic indeed induced the repolarization of classically activated (M1) macrophage to M2 macrophages through the autophagy/mitophagy pathway. Next, we verified that arsenic increased M2 cell markers in mouse blood and lungs. This study suggests that mitophagy is involved in the arsenic-induced M1 macrophage switch to an M2-like phenotype.

Involvement of M1/M2 Macrophage Polarization in Reparative Dentin Formation

In cases in which dental pulp tissue is accidentally exposed, direct pulp capping is often performed to induce reparative dentin formation. Although macrophages are essential for the inflammatory response and tissue repair, the emergence pattern and the role of macrophages in dental pulp tissue have not been clarified. Here, we investigated the emergence of M1/M2 macrophages in dental pulp tissue after a direct pulp capping and the effects of M2 macrophages on odontoblastic differentiation of the dental pulp stem cell (DPSC) clones. The emergence of macrophages in dental pulp tissue was investigated using a rat direct pulp capping model. Alizarin Red S staining and quantitative RT-PCR was performed to examine the effect of M2 macrophages on the mineralization and odontoblastic differentiation of DPSC clones. Immunohistochemical staining revealed that M1 macrophages were detected in dental pulp tissue after treatment and increased in number at three days after treatment. However, M2 macrophages gradually increased in number in dental pulp tissue after treatment, with the highest level recorded at seven days post-operation. Additionally, conditioned medium from M2 macrophages induced odontoblast-like differentiation of DPSC clones. These results suggest that macrophages play a role in the inflammatory response and reparative dentin formation after dental pulp exposure.

Lacticaseibacillus casei Strain Shirota Modulates Macrophage-Intestinal Epithelial Cell Co-Culture Barrier Integrity, Bacterial Sensing and Inflammatory Cytokines

Probiotic bacteria modulate macrophage immune inflammatory responses, with functional cytokine responses determined by macrophage subset polarisation, stimulation and probiotic strain. Mucosal macrophages exhibit subset functional heterogeneity but are organised in a 3-dimensional tissue, over-laid by barrier epithelial cells. This study aimed to investigate the effects of the probiotic Lacticaseibacillus casei strain Shirota (LcS) on macrophage-epithelial cell cytokine responses, pattern recognition receptor (PRR) expression and LPS responses and the impacts on barrier integrity. THP-1-derived M1 and M2 subset macrophages were co-cultured in a transwell system with differentiated Caco-2 epithelial cells in the presence or absence of enteropathogenic LPS. Both Caco-2 cells in monoculture and macrophage co-culture were assayed for cytokines, PRR expression and barrier integrity (TEER and ZO-1) by RT-PCR, ELISA, IHC and electrical resistance. Caco-2 monocultures expressed distinct cytokine profiles (IL-6, IL-8, TNFα, endogenous IL-10), PRRs and barrier integrity, determined by inflammatory context (TNFα or IL-1β). In co-culture, LcS rescued ZO-1 and TEER in M2/Caco-2, but not M1/Caco-2. LcS suppressed TLR2, TLR4, MD2 expression in both co-cultures and differentially regulated NOD2, TLR9, Tollip and cytokine secretion. In conclusion, LcS selectively modulates epithelial barrier integrity, pathogen sensing and inflammatory cytokine profile; determined by macrophage subset and activation status.

Untargeted metabolomics analysis reveals Mycobacterium tuberculosis strain H37Rv specifically induces tryptophan metabolism in human macrophages

Background

Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) remains a global health issue. The characterized virulent M. tb H37Rv, avirulent M. tb H37Ra and BCG strains are widely used as reference strains to investigate the mechanism of TB pathogenicity. Here, we attempted to determine metabolomic signatures associated with the Mycobacterial virulence in human macrophages through comparison of metabolite profile in THP-1-derived macrophages following exposure to the M. tb H37Rv, M. tb H37Ra and BCG strains.

Results

Our findings revealed remarkably changed metabolites in infected macrophages compared to uninfected macrophages. H37Rv infection specifically induced 247 differentially changed metabolites compared to H37Ra or BCG infection. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed H37Rv specifically induces tryptophan metabolism. Moreover, quantitative PCR (qPCR) results showed that indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2) which converts the tryptophan to a series of biologically second metabolites were up-regulated in H37Rv-infected macrophages compared to H37Ra- or BCG-infected macrophages, confirming the result of enhanced tryptophan metabolism induced by H37Rv infection. These findings indicated that targeting tryptophan (Trp) metabolism may be a potential therapeutic strategy for pulmonary TB.

Conclusions

We identified a number of differentially changed metabolites that specifically induced in H37Rv infected macrophages. These signatures may be associated with the Mycobacterial virulence in human macrophages. The present findings provide a better understanding of the host response associated with the virulence of the Mtb strain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02659-y.

Lacticaseibacillus rhamnosus R0011 secretome attenuates Salmonella enterica serovar Typhimurium secretome-induced intestinal epithelial cell monolayer damage and pro-inflammatory mediator production in intestinal epithelial cell and antigen-presenting cell co-cultures

Certain lactic acid bacteria (LAB) are associated with immune modulatory activities including down-regulation of pro-inflammatory gene transcription and expression. While host antigen-presenting cells (APCs) and intestinal epithelial cells (IEC) can interact directly with both pathogenic and commensal bacteria through innate immune pattern recognition receptors, recent evidence indicates indirect communication through secreted molecules is an important inter-domain communication mechanism. This communication route may be especially important in the context of IEC and APC interactions which shape host immune responses within the gut environment. We have previously shown that the Lacticaseibacillus rhamnosus R0011 secretome (LrS) dampens pro-inflammatory gene transcription and mediator production from Tumor Necrosis Factor-α and Salmonella enterica serovar Typhimurium secretome (STS)-challenged HT-29 IECs through the induction of negative regulators of innate immunity. However, many questions remain about interactions mediated through these bacterial-derived soluble components and the resulting host immune outcomes in the context of IEC and APC interactions. In the present study, we examined the ability of the LrS to down-regulate pro-inflammatory gene transcription and cytokine production from STS-challenged T84 human IEC and THP-1 human monocyte co-cultures. Cytokine and chemokine profiling revealed that apically delivered LrS induces apical secretion of macrophage inhibitory factor (MIF) and down-regulates STS-induced pro-inflammatory mediator secretion into the apical and basolateral chambers of the T84/THP-1 co-culture. Transcriptional profiling confirmed these results, as the LrS attenuated STS challenge-induced CXCL8 and NFκB1 expression in T84 IECs and THP-1 APCs. Interestingly, the LrS also reversed STS-induced damage to monolayer transepithelial resistance (TER) and permeability, results which were confirmed by ZO-1 gene expression and immunofluorescence visualization of ZO-1 expression in T84 IEC monolayers. The addition of a MIF-neutralizing antibody abrogated the ability of the LrS to reverse STS-induced damage to T84 IEC monolayer integrity, suggesting a novel role for MIF in maintaining IEC barrier function and integrity in response to soluble components derived from LAB. The results presented here provide mechanistic evidence for indirect communication mechanisms used by LAB to modulate immune responses to pathogen challenge, using in vitro approaches which allow for IEC and APC cell communication in a context which more closely mimics that which occurs in vivo.

1,25(OH)2D3 promotes the elimination of Klebsiella pneumoniae infection by inducing autophagy through the VDR-ATG16L1 pathway

OBJECTIVE

Previous studies have shown that vitamin D has regulatory functions in both innate and adaptive immune responses, indicating that it can perform essential roles in host resistance to pathogen infections. This study aimed to verify its effects on Klebsiella pneumoniae (Kp) infection and explore the underlying mechanisms.

METHODS

THP-1-derived macrophages were infected with Kp and then incubated with 1,25(OH)₂D₃. Autophagy induced by 1,25(OH)₂D₃ was investigated by western blotting and immunofluorescence. Real-time PCR (qPCR) was performed to determine the expression of inflammatory mediators. Baf A1 and 3-MA were used to inhibit autophagy. The intracellular killing of Kp was measured using qPCR and colony-forming unit assays. RNA interference assays were used to silence VDR or ATG16L1. The lungs of C57BL/6 mice were infected with Kp via intratracheal instillation, and the established pneumonia models were used for in vivo validation experiments.

RESULTS

Treatment with 1,25(OH)₂D₃ enhanced the bactericidal activity of macrophages and concomitantly reduced the expression of the pro-inflammatory mediators TNF-α and IL-6. Kp infection led to a lower expression level of VDR in macrophages than in the control, whereas co-treatment with 1,25(OH)₂D₃ up-regulated VDR expression and robustly induced autophagy via the VDR signaling pathway. Silencing ATG16L1 significantly counteracted autophagy induced by 1,25(OH)₂D₃ in Kp-infected macrophages. Furthermore, we found that when autophagy activity was diminished by ATG16L1 siRNA or blocked by Baf A1, the ability of 1,25(OH)₂D₃ to promote macrophages to eliminate Kp infection was obviously impaired, as were its anti-inflammatory effects. These protective efficacies of 1,25(OH)₂D₃ against Kp infection were also validated in vivo using a mouse model of pneumonia.

CONCLUSIONS

The present study demonstrated the protective features of 1,25(OH)₂D₃ in macrophages against Kp infection and may provide evidence for further exploration of its potential as an adjunctive therapy agent for the treatment of bacterial infections.

Echovirus 11 infection induces pyroptotic cell death by facilitating NLRP3 inflammasome activation

Echovirus 11 (ECHO 11) is a positive-strand RNA virus belonging to the genus Enterovirus of the family Picornaviridae. ECHO 11 infections can cause severe inflammatory illnesses in neonates, including severe acute hepatitis with coagulopathy. The activation of NLRP3 inflammasome is important for host defense against invading viruses, which also contributes to viral pathogenicity. However, whether and how ECHO 11 induces NLRP3 inflammasome activation remains unclear. In this study, we isolated a clinical strain of ECHO 11 from stools of an ECHO 11-infected newborn patient with necrotizing hepatitis. This virus shared 99.95% sequence identity with the previously published ECHO 11 sequence. The clinically isolated ECHO 11 can efficiently infect liver cells and strongly induces inflammation. Moreover, we showed that ECHO 11 induced IL-1β secretion and pyroptosis in cells and mouse bone marrow-derived macrophages (BMDMs). Furthermore, ECHO 11 infection triggered NLRP3 inflammasome activation, as evidenced by cleavages of GSDMD, pro-IL-1β and pro-caspase-1, and the release of LDH. ECHO 11 2B protein was required for NLRP3 inflammasome activation via interacting with NLRP3 to facilitate the inflammasome complex assembly. In vivo, expression of ECHO 11 2B also activated NLRP3 inflammasome in the murine liver. Besides, 2Bs of multiple EVs can also interact with NLRP3 and induce NLRP3 inflammasome activation. Together, our findings demonstrate a mechanism by which ECHO 11 induces inflammatory responses by activating NLRP3 inflammasome, providing novel insights into the pathogenesis of ECHO 11 infection.

NLRP3 inflammasome is important for host defense against invading viruses, and contributes to viral pathogenicity. Human echovirus 11 (ECHO 11) belongs to the Enterovirus genus from the family Picornavirida, and it can cause severe acute hepatitis in newborns with high morbidity and mortality. However, the knowledge about the pathogenesis of ECHO 11 infection is limited. Whether and how ECHO 11 induces NLRP3 inflammasome activation remains unclear. This work provides the first demonstration that ECHO 11 can induce inflammatory responses via activating NLRP3 inflammasome and pyroptosis. More importantly, ECHO 11-encoded 2B protein was found to activate NLRP3 inflammasome in cells and in vivo, and the interaction between 2B and NLRP3 was required for inflammasome complex assembly. Furthermore, we uncovered that 2Bs of other enteroviruses, including enterovirus 71, coxsackievirus A16 (CVA16) and CVB3 could induce NLRP3 inflammasome and interact with NLRP3. Our findings uncover a mechanism by which ECHO 11 induces inflammatory responses and demonstrate a novel function of ECHO 11 2B.

In vitro assessment of the probiotic properties of an industrial preparation containing Lacticaseibacillus paracasei in the context of athlete health

Intense physical activity is often associated with undesirable physiological changes, including increased inflammation, transient immunodepression, increased susceptibility to infections, altered intestinal barrier integrity, and increased oxidative stress. Several trials suggested that probiotics supplementation may have beneficial effects on sport-associated gastro-intestinal and immune disorders. Recently, in a placebo-controlled human trial, the AminoAlta™ probiotic formulation (AApf) was demonstrated to increase the absorption of amino acids from pea protein, suggesting that the administration of AApf could overcome the compositional limitations of plant proteins. In this study, human cell line models were used to assess in vitro the potential capacity of AApf to protect from the physiological damages that an intense physical activity may cause. The obtained results revealed that the bacteria in the AApf have the ability to adhere to differentiated Caco-2 epithelial cell layer. In addition, the AApf was shown to reduce the activation of NF-κB in Caco-2 cells under inflammatory stimulation. Notably, this anti-inflammatory activity was enhanced in the presence of partially hydrolyzed plant proteins. The AApf also triggered the expression of cytokines by the THP-1 macrophage model in a dose-dependent manner. In particular, the expression of cytokines IL-1β, IL-6, and TNF-α was higher than that of the regulatory cytokine IL-10, resembling a cytokine profile characteristic of M1 phenotype, which typically intervene in counteracting bacterial and viral infections. Finally, AApf was shown to reduce transepithelial permeability and increase superoxide dismutase activity in the Caco-2 cell model. In conclusion, this study suggests that the AApf may potentially provide a spectrum of benefits useful to dampen the gastro-intestinal and immune detrimental consequences of an intense physical activity.