Total Glucosides of Paeony Ameliorate Pristane-Induced Lupus Nephritis by Inducing PD-1 ligands+ Macrophages via Activating IL-4/STAT6/PD-L2 Signaling

Regulation of macrophage polarization by targeted metabolic reprogramming for the treatment of lupus nephritis

Lupus nephritis (LN) is a severe and common manifestation of systemic lupus erythematosus (SLE) that is frequently identified with a poor prognosis. Macrophages play an important role in its pathogenesis. Different macrophage subtypes have different effects on lupus-affected kidneys. Based on their origin, macrophages can be divided into monocyte-derived macrophages (MoMacs) and tissue-resident macrophages (TrMacs). During nephritis, TrMacs develop a hybrid pro-inflammatory and anti-inflammatory functional phenotype, as they do not secrete arginase or nitric oxide (NO) when stimulated by cytokines. The infiltration of these mixed-phenotype macrophages is related to the continuous damage caused by immune complexes and exposure to circulating inflammatory mediators, which is an indication of the failure to resolve inflammation. On the other hand, MoMacs differentiate into M1 or M2 cells under cytokine stimulation. M1 macrophages are pro-inflammatory and secrete pro-inflammatory cytokines, while the M2 main phenotype is essentially anti-inflammatory and promotes tissue repair. Conversely, MoMacs undergo differentiation into M1 or M2 cells in response to cytokine stimulation. M1 macrophages are considered pro-inflammatory cells and secrete pro-inflammatory mediators, whereas the M2 main phenotype is primarily anti-inflammatory and promotes tissue repair. Moreover, based on cytokine expression, M2 macrophages can be further divided into M2a, M2b, and M2c phenotypes. M2a and M2c have anti-inflammatory effects and participate in tissue repair, while M2b cells have immunoregulatory and pro-inflammatory properties. Further, memory macrophages also have a role in the advancement of LN. Studies have demonstrated that the polarization of macrophages is controlled by multiple metabolic pathways, such as glycolysis, the pentose phosphate pathway, fatty acid oxidation, sphingolipid metabolism, the tricarboxylic acid cycle, and arginine metabolism. The changes in these metabolic pathways can be regulated by substances such as fish oil, polyenylphosphatidylcholine, taurine, fumaric acid, metformin, and salbutamol, which inhibit M1 polarization of macrophages and promote M2 polarization, thereby alleviating LN.

Combination of total glucosides of paeony, narrow-band ultraviolet B, and oral corticosteroid mini-pulse therapy for nonsegmental vitiligo: A retrospective study

BACKGROUND

The total glucoside of paeony (TGP) is recognized for its immunomodulatory properties and anti-inflammatory effects. This study evaluates the efficacy of TGP combined with oral mini-pulse therapy (OMP) and narrow-band ultraviolet B (NB-UVB) in treating active nonsegmental vitiligo (NSV).

MATERIALS AND METHODS

The combination therapy was contrasted against those from a group treated solely with OMP and NB-UVB. Data from 62 patients undergoing TGP combination treatment and 55 without were analyzed over a 3-month period. After 6 months, the differences in recurrence rate were investigated by follow-up.

RESULTS

The findings indicate that integrating TGP may yield superior outcomes compared to OMP + NB-UVB alone. Moreover, the patient's oxidative stress makers were significantly reduced after the treatment. The majority of patients in the TGP cohort exhibited enhanced skin pigmentation over the duration. Notably, no increase in side effects or recurrence was observed in this group. Especially, patients with vitiligo on their head and neck experienced pronounced improvements.

CONCLUSION

The efficacy of the combination treatment group was better than that of the control group at 2 and 3 months, and there was no difference in recurrence rate and side effects, suggesting that TGP may continue to show efficacy in NSV for a longer period of time by reducing the level of oxidative stress, and is especially suitable for patients with head and neck lesions.

PD-1 and LAG-3 positive T cells are related with the prognosis of patients with chronic kidney disease

OBJECTIVE

Our objective was to study the frequency of circulating LAG-3+ and PD-1+ T cells in chronic kidney disease (CKD) patients and their correlation with cytokines and patient prognosis.

METHODS

A total of 83 patients with CKD between June 2020 and June 2022 were enrolled. We measured serum levels of IL-6, CRP, IL-1β, and TNF-α by ELISA. The frequency of PD-1+ and LAG-3+ T cells was measured using flow cytometry. All patients were followed up for 1 year, and the occurrence of any of the following conditions during the follow-up period was considered as major adverse cardiac events (MACE) indicating poor prognosis.

RESULTS

The frequencies of LAG-3+PD-1+, LAG-3+ and PD-1+ cells were significantly increased in CKD group compared to healthy volunteers. Additionally, CKD patients had remarkably enhanced levels of cytokines. Compared to the non-MACE group, MACE group had significantly higher frequencies of LAG-3PD-1, LAG-3 and PD-1 expression on CD8 and CD4. Positive correlations were observed between IL-1β, IL-6 and frequencies of PD-1+LAG-3+. CD4+LAG-3+PD-1+ frequency displayed the highest diagnostic value for CKD patients with MACE. Moreover, CD8+LAG-3+, CD4+LAG-3+PD-1+, CD4+PD-1+, IL-1β and IL-6 were identified as risk factors for the occurrence of MACE in patients with CKD.

CONCLUSION

In summary, the present research showed that the frequencies of LAG-3+ and PD-1+ T cells were remarkably enhanced in CKD patients. These findings offer novel insights and potential therapeutic targets for the management of CKD.

The role of mitophagy in the development of chronic kidney disease

Chronic kidney disease (CKD) represents a significant global health concern, with renal fibrosis emerging as a prevalent and ultimate manifestation of this condition. The absence of targeted therapies presents an ongoing and substantial challenge. Accumulating evidence suggests that the integrity and functionality of mitochondria within renal tubular epithelial cells (RTECs) often become compromised during CKD development, playing a pivotal role in the progression of renal fibrosis. Mitophagy, a specific form of autophagy, assumes responsibility for eliminating damaged mitochondria to uphold mitochondrial equilibrium. Dysregulated mitophagy not only correlates with disrupted mitochondrial dynamics but also contributes to the advancement of renal fibrosis in CKD. While numerous studies have examined mitochondrial metabolism, ROS (reactive oxygen species) production, inflammation, and apoptosis in kidney diseases, the precise pathogenic mechanisms underlying mitophagy in CKD remain elusive. The exact mechanisms through which modulating mitophagy mitigates renal fibrosis, as well as its influence on CKD progression and prognosis, have not undergone systematic investigation. The role of mitophagy in AKI has been relatively clear, but the role of mitophagy in CKD is still rare. This article presents a comprehensive review of the current state of research on regulating mitophagy as a potential treatment for CKD. The objective is to provide fresh perspectives, viable strategies, and practical insights into CKD therapy, thereby contributing to the enhancement of human living conditions and patient well-being.

Extra villous trophoblast-derived PDL1 can ameliorate macrophage inflammation and promote immune adaptation associated with preeclampsia

INTRODUCTION

Severe preeclampsia (sPE) is a systemic syndrome that may originate from chronic inflammation. Maintaining maternal-fetal hemostasis by the co-inhibitory molecule programmed death ligand 1 (PDL1) can be favorable for ameliorating inflammation from immune cells. Apart from programmed death 1 (PD1) expression, decidual macrophages (dMs) produce inflammatory cytokines, in response to cells which express PDL1. However, strong evidence is lacking regarding whether the PDL1/PD1 interaction between trophoblasts and decidual macrophages affects inflammation during sPE development.

METHODS

To determine whether the trophoblast-macrophage crosstalk via the PDL1/PD1 axis modulates the inflammatory response in sPE-like conditions, at first, maternal-fetal tissues from sPE and normal patients were collected, and the PDL1/PD1 distribution was analyzed by Western blot, immunohistochemistry/ immunofluorescence and flow cytometry. Next, a coculture system was established and flow cytometry was used to identify how PDL1 was involved in macrophage-related inflammation under hypoxic stress. Transcriptional analysis was performed to clarify the inflammation-associated pathway induced by the PDL1/PD1 interaction. Finally, the Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) mouse model was used to examine the effect of PDL1 on macrophage-related inflammation by measuring PE-like symptoms.

RESULTS

In maternal-fetal tissue from sPE patients, placental extravillous trophoblasts (EVTs) and dMs had a surprisingly increase of PDL1 and PD1 expression, respectively, accompanied by a higher percentage of CD68 +CD86 + dMs. In vitro experiments showed that trophoblast-derived PDL1 under hypoxia interacted with PD1 on CD14 +CD80 +macrophages, leading to suppression of inflammation through the TNFα-p38/NFκB pathway. Accordingly, the PE-like mouse model showed a reversal of PE-like symptoms and a reduced F4/80 + CD86 + macrophage percentage in the uterus in response to recombinant PDL1 protein administration, indicating the protective effect of PDL1.

DISCUSSION

Our results initially explained an immunological adaptation of trophoblasts under placental hypoxia, although this protection was insufficient. Our findings suggest the possible capacity of modulating PDL1 expression as a potential therapeutic strategy to target the inflammatory response in sPE.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

ANKRD22 promotes M2 polarization in lung adenocarcinoma macrophages via the glycolytic pathway

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer with a low 5-year survival rate. ANKRD22 is an ankyrin repeat protein capable of promoting tumor progression, and its mechanism in LUAD remains elusive. Our study aims to investigate the mechanisms underlying the involvement of ANKRD22 in the progression of LUAD. The expression of ANKRD22 in LUAD and its enriched pathway were analyzed by bioinformatics analysis. Meanwhile, the correlation between ANKRD22 and the expression of glycolysis-related genes and M2 macrophage marker genes was analyzed. qRT-PCR was used for determination of the expression of ANKRD22, IL-10 and CCL17, CCK-8 for cell viability, and western blot for expression of ANKRD22, LDHA, HK2, PGK1, and PKM2. Immunofluorescence and flow cytometry were utilized to examine the level of CD163, and kits were used to measure the contents of pyruvic acid, lactate, citrate, and malate. Seahorse XF96 analyzer was employed to determine extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Mitochondrial membrane potential was assessed using the JC-1 probe. Bioinformatics analysis, qRT-PCR, and western blot showed that ANKRD22 was highly expressed in LUAD, which had a positive connection with M2 marker genes. Knockdown of ANKRD22 considerably attenuated the expression of ANKRD22, IL-10, and CCL17 in M2. ANKRD22 overexpression demonstrated the opposite results. Bioinformatics analysis uncovered that ANKRD22 was enriched in the glycolytic pathway and positively correlated with glycolysis-related genes. The knockdown of ANKRD22 substantially attenuated pyruvic acid, lactate, citrate, malate, and ECAR levels and elevated OCR levels in cells. The knockdown of ANKRD22 also reduced mitochondrial membrane potential. Further, it was discovered that glycolysis-related genes had a positive correlation with M2 marker genes. It was revealed by rescue experiments that the usage of 2-DG, a glycolytic inhibitor, remarkably reversed the facilitating effect of overexpression of ANKRD22 on M2 polarization. This study demonstrates that ANKRD22 can facilitate LUAD M2 polarization through glycolysis, and targeting ANKRD22 to inhibit M2 polarization has the potential to be a new strategy for LUAD treatment.

Imatinib and M351-0056 enhance the function of VISTA and ameliorate the development of SLE via IFN-I and noncanonical NF-κB pathway

V-domain immunoglobulin suppressor of T-cell activation (VISTA), an important negative checkpoint protein, participates in immunoregulation. Systemic lupus erythematosus (SLE) is an autoimmune disease in which patients exhibit high levels of autoantibodies and multi-organ tissue injury, primarily involving the kidney and skin. In wild-type (WT) mice and Vsir-/- mice with pristane-induced lupus-like disease, we found that VISTA deficiency exacerbated the lupus-like disease in mice, possibly through aberrant activation of type I interferon (IFN-I) signaling, CD4+ T cell, and noncanonical nuclear factor-κB (NF-κB) pathway. Surface plasmon resonance results showed that imatinib, an FDA-approved tyrosine kinase inhibitor, may have a high affinity for human VISTA-ECD with a KD value of 0.2009 μM. The biological activities of imatinib and VISTA agonist M351-0056 were studied in monocytes and T cells and in lupus-like disease murine model of chronic graft-versus-host disease (cGVHD) and lupus-prone MRL/lpr mice. VISTA small-molecule agonist reduced the cytokine production of peripheral blood mononuclear cells (PBMCs) and Jurkat cells and inhibited PBMCs proliferation. Moreover, they attenuated the levels of autoantibodies, renal injury, inflammatory cytokines, chemokines, and immune cell expansion in the cGVHD mouse model and MRL/lpr mice. Our findings also demonstrated that VISTA small-molecule agonist ameliorated the development of SLE through improving aberrantly activated IFN-I signaling and noncanonical NF-κB pathway. In conclusion, VISTA has a protective effect on the development and progression of SLE. VISTA agonist M351-0056 and imatinib have been firstly demonstrated to attenuate SLE, suggesting interventions to enhance VISTA function may be effective in treating SLE. VISTA deficiency exacerbates pristane-induced lupus-like disease in mice by promoting activation of the IFN-I and noncanonical NF-κB pathway. Imatinib was screened as a small-molecule VISTA agonist by molecular docking, SPR, and cellular level experiments. VISTA agonists (M351-0056 and imatinib) alleviated lupus-like disease progression in the cGVHD mouse model and MRL/lpr mice by inhibiting activation of IFN-I and noncanonical NF-κB pathway.

STAT6 promoting oxalate crystal deposition-induced renal fibrosis by mediating macrophage-to-myofibroblast transition via inhibiting fatty acid oxidation

OBJECTIVE AND DESIGN

Kidney stones commonly occur with a 50% recurrence rate within 5 years, and can elevate the risk of chronic kidney disease. Macrophage-to-myofibroblast transition (MMT) is a newly discovered mechanism that leads to progressive fibrosis in different forms of kidney disease. In this study, we aimed to investigate the role of MMT in renal fibrosis in glyoxylate-induced kidney stone mice and the mechanism by which signal transducer and activator of transcription 6 (STAT6) regulates MMT.

METHODS

We collected non-functioning kidneys from patients with stones, established glyoxylate-induced calcium oxalate stone mice model and treated AS1517499 every other day in the treatment group, and constructed a STAT6-knockout RAW264.7 cell line. We first screened the enrichment pathway of the model by transcriptome sequencing; detected renal injury and fibrosis by hematoxylin eosin staining, Von Kossa staining and Sirius red staining; detected MMT levels by multiplexed immunofluorescence and flow cytometry; and verified the binding site of STAT6 at the PPARα promoter by chromatin immunoprecipitation. Fatty acid oxidation (FAO) and fibrosis-related genes were detected by western blot and real-time quantitative polymerase chain reaction.

RESULTS

In this study, we found that FAO was downregulated, macrophages converted to myofibroblasts, and STAT6 expression was elevated in stone patients and glyoxylate-induced kidney stone mice. The promotion of FAO in macrophages attenuated MMT and upregulated fibrosis-related genes induced by calcium oxalate treatment. Further, inhibition of peroxisome proliferator-activated receptor-α (PPARα) eliminated the effect of STAT6 deletion on FAO and fibrosis-associated protein expression. Pharmacological inhibition of STAT6 also prevented the development of renal injury, lipid accumulation, MMT, and renal fibrosis. Mechanistically, STAT6 transcriptionally represses PPARα and FAO through cis-inducible elements located in the promoter region of the gene, thereby promoting MMT and renal fibrosis.

CONCLUSIONS

These findings establish a role for STAT6 in kidney stone injury-induced renal fibrosis, and suggest that STAT6 may be a therapeutic target for progressive renal fibrosis in patients with nephrolithiasis.

Activation of BZW1 by CEBPB in macrophages promotes eIF2α phosphorylation-mediated metabolic reprogramming and endoplasmic reticulum stress in MRL/lpr lupus-prone mice

BACKGROUND

Lupus nephritis (LN) is associated with significant mortality and morbidity, while effective therapeutics and biomarkers are limited since the pathogenesis is complex. This study investigated the roles of the CEBPB/BZW1/eIF2α axis in metabolic reprogramming and endoplasmic reticulum stress in LN.

METHOD

The differentially expressed genes in LN were screened using bioinformatics tools. The expression of CEBPB in the renal tissue of patients with LN and its correlation with the levels of creatinine and urinary protein were analyzed. We used adenoviral vectors to construct LN mice with knockdown CEBPB using MRL/lpr lupus-prone mice and analyzed the physiological and autoimmune indices in mice. Chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR) and dual-luciferase reporter assays were conducted to explore the regulation of BZW1 by CEBPB, followed by glycolytic flux analysis, glucose uptake, and enzyme-linked immunosorbent assay (ELISA). Finally, the role of eIF2α phosphorylation by BZW1 in bone marrow-derived macrophages (BMDM) was explored using eIF2α phosphorylation and endoplasmic reticulum stress inhibitors.

RESULTS

CEBPB was significantly increased in renal tissues of patients with LN and positively correlated with creatinine and urine protein levels in patients. Downregulation of CEBPB alleviated the autoimmune response and the development of nephritis in LN mice. Transcriptional activation of BZW1 by CEBPB-mediated glucose metabolic reprogramming in macrophages, and upregulation of BZW1 reversed the mitigating effect of CEBPB knockdown on LN. Regulation of eIF2α phosphorylation levels by BZW1 promoted endoplasmic reticulum stress-amplified inflammatory responses in BMDM.

CONCLUSION

Transcriptional activation of BZW1 by CEBPB promoted phosphorylation of eIF2α to promote macrophage glycolysis and endoplasmic reticulum stress in the development of LN.

FKN secreted by kidney epithelial cells regulates macrophage activation in lupus nephritis via the Hippo signaling pathway

BACKGROUND

Lupus nephritis (LN) is a serious complication of systemic lupus erythematosus (SLE), and its pathogenesis is not fully understood. Previously, we showed that fractalkine (FKN) expression was positively correlated with the severity of LN. Here, we aimed to study the role of the Hippo signaling pathway (HSP) and its interaction with FKN in LN in an attempt to provide novel strategies for LN treatment.

METHODS

In this study, lipopolysaccharide (LPS)/interferon-γ (IFN-γ)-stimulated THP-1 cells were co-cultured with FKN up-regulated or down-regulated kidney epithelial cells Hkb20. FKN-knockout (KO-FKN) mice were used to construct LN model. Flow cytometric analysis, quantitative real-time polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), pathological staining, Western blot, and immunofluorescence (IF) staining were employed to investigate the role of FKN and its interaction with the Hippo signaling pathway (HSP) in LN.

RESULTS

Up-regulation of FKN in kidney epithelial cells was associated with increased macrophage activation. FKN overexpression in kidney epithelial cells suppressed apoptosis, inflammation levels, and M1 polarization of THP-1 cells and inhibited the HSP. Oppositely, FKN knockdown in kidney epithelial cells increased apoptosis, inflammation, and M1 polarization and activated the HSP. HSP inhibitor reversed the effect of FKN knockdown on THP-1 cells. In LN mice, FKN knockout and YAP inhibitor decreased the levels of renal function markers, alleviated kidney injury induced by LN, and inhibited macrophage activation in LN mice.

CONCLUSIONS

FKN down-regulation reduced the activation of macrophages in renal tissue and alleviated kidney damage by activating HSP. The regulatory effect of FKN on HSP should be confirmed in patients with LN, and the mechanism of FKN in LN should be further explored.

Efficacy and safety of total glucosides of paeony in the treatment of 5 types of inflammatory arthritis: A systematic review and meta-analysis

OBJECTIVE

To evaluate efficacy and safety of total glucosides of paeony in the treatment of 5 types of inflammatory arthritis METHODS: Databases such as Pubmed, Cochran Library, Embase were searched to collect RCTs about TGP in the treatment of inflammatory arthritis. Then, the RCTs were assessed for risk of bias and RCT data were extracted. Finally, RevMan 5.4 was used for the meta-analysis.

RESULTS

A total of 63 RCTs were finally included, involving 5293 participants and 5 types of types of inflammatory arthritis: rheumatoid arthritis (RA), ankylosing spondylitis (AS), osteoarthritis (OA), juvenile idiopathic arthritis (JIA), psoriatic arthritis. For AS, TGP may improve AS disease activity score (ASDAS), decrease erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tumor necrosis factor (TNF)- α and interleukin (IL)- 6; for RA, TGP may improve disease activity of 28 joints (DAS28), decrease ESR, CRP, rheumatoid factor (RF), TNF-α and IL-6; for psoriatic arthritis, TGP may improve psoriasis area and severity index (PASI) and decrease ESR; for OA, TGP may improve visual analogue scale (VAS) and decrease nitric oxide (NO); for JIA, TGP may increase total efficiency rate, decrease ESR, CRP and TNF-α. For safety, RCTs showed that the addition of TGP did not increase adverse events, and may even reduce adverse events.

CONCLUSION

TGP may improve symptoms and inflammation levels in patients with inflammatory arthritis. However, due to the low quality and small number of RCTs, large-sample, multi-center clinical trials are still needed for revision or validation.

TRAF3/STAT6 axis regulates macrophage polarization and tumor progression

Converting tumor-associated macrophages (TAMs) from the M2 to the M1 phenotype is considered an effective strategy for cancer therapy. TRAF3 is known to regulate NF-κB signaling. However, the role of TRAF3 in TAM polarization has not yet been completely elucidated. Here, we found that ablation of TRAF3 increased M1 markers, iNOS, FGR and SLC4A7, while down-regulated M2 markers, CD206, CD36 and ABCC3, expression levels in macrophages. Moreover, TRAF3 deficiency enhanced LPS-induced M1 and abolished IL-4-induced macrophage polarization. Next, quantitative ubiquitomics assays demonstrated that among the quantitative 7618 ubiquitination modification sites on 2598 proteins, ubiquitination modification of IL-4 responding proteins was the most prominently reduced according to enrichment analysis. STAT6, a key factor of IL-4 responding protein, K450 and K129 residue ubiquitination levels were dramatically decreased in TRAF3-deficient macrophages. Ubiquitination assay and luciferase assay demonstrated that TRAF3 promotes STAT6 ubiquitination and transcriptional activity. Site mutation analysis revealed STAT6 K450 site ubiquitination played a vital role in TRAF3-mediated STAT6 activation. Finally, B16 melanoma mouse model demonstrated that myeloid TRAF3 deficiency suppressed tumor growth and lung metastasis in vivo. Taken together, TRAF3 plays a vital role in M2 polarization via regulating STAT6 K450 ubiquitination in macrophages.

Immunotherapies in chronic pain through modulation of neuroimmune interactions

It is generally believed that immune activation can elicit pain through production of inflammatory mediators that can activate nociceptive sensory neurons. Emerging evidence suggests that immune activation may also contribute to the resolution of pain by producing distinct pro-resolution/anti-inflammatory mediators. Recent research into the connection between the immune and nervous systems has opened new avenues for immunotherapy in pain management. This review provides an overview of the most utilized forms of immunotherapies (e.g., biologics) and highlight their potential for immune and neuronal modulation in chronic pain. Specifically, we discuss pain-related immunotherapy mechanisms that target inflammatory cytokine pathways, the PD-L1/PD-1 pathway, and the cGAS/STING pathway. This review also highlights cell-based immunotherapies targeting macrophages, T cells, neutrophils and mesenchymal stromal cells for chronic pain management.

Exploring the potential common denominator pathogenesis of system lupus erythematosus with COVID-19 based on comprehensive bioinformatics analysis

Objective

Evidences show that there may be a link between SLE and COVID-19. The purpose of this study is to screen out the diagnostic biomarkers of systemic lupus erythematosus (SLE) with COVID-19 and explore the possible related mechanisms by the bioinformatics approach.

Methods

SLE and COVID-19 datasets were extracted separately from the NCBI Gene Expression Omnibus (GEO) database. The limma package in R was used to obtain the differential genes (DEGs). The protein interaction network information (PPI) and core functional modules were constructed in the STRING database using Cytoscape software. The hub genes were identified by the Cytohubba plugin, and TF-gene together with TF-miRNA regulatory networks were constructed via utilizing the Networkanalyst platform. Subsequently, we generated subject operating characteristic curves (ROC) to verify the diagnostic capabilities of these hub genes to predict the risk of SLE with COVID-19 infection. Finally, a single-sample gene set enrichment (ssGSEA) algorithm was used to analyze immune cell infiltration.

Results

A total of 6 common hub genes (CDC6, PLCG1, KIF15, LCK, CDC25C, and RASGRP1) were identified with high diagnostic validity. These gene functional enrichments were mainly involved in cell cycle, and inflammation-related pathways. Compared to the healthy controls, abnormal infiltration of immune cells was found in SLE and COVID-19, and the proportion of immune cells linked to the 6 hub genes.

Conclusion

Our research logically identified 6 candidate hub genes that could predict SLE complicated with COVID-19. This work provides a foothold for further study of potential pathogenesis in SLE and COVID-19.

Regulatory Mechanism of M1/M2 Macrophage Polarization in the Development of Autoimmune Diseases

Macrophages are innate immune cells in the organism and can be found in almost tissues and organs. They are highly plastic and heterogeneous cells and can participate in the immune response, thereby playing a crucial role in maintaining the immune homeostasis of the body. It is well known that undifferentiated macrophages can polarize into classically activated macrophages (M1 macrophages) and alternatively activated macrophages (M2 macrophages) under different microenvironmental conditions. The directions of macrophage polarization can be regulated by a series of factors, including interferon, lipopolysaccharide, interleukin, and noncoding RNAs. To elucidate the role of macrophages in various autoimmune diseases, we searched the literature on macrophages with the PubMed database. Search terms are as follows: macrophages, polarization, signaling pathways, noncoding RNA, inflammation, autoimmune diseases, systemic lupus erythematosus, rheumatoid arthritis, lupus nephritis, Sjogren's syndrome, Guillain-Barré syndrome, and multiple sclerosis. In the present study, we summarize the role of macrophage polarization in common autoimmune diseases. In addition, we also summarize the features and recent advances with a particular focus on the immunotherapeutic potential of macrophage polarization in autoimmune diseases and the potentially effective therapeutic targets.

Paeoniflorin suppresses kidney inflammation by regulating macrophage polarization via KLF4-mediated mitophagy

BACKGROUND

Macrophages M1 polarization involved in the process of renal inflammatory injury, is a well-established hallmark of chronic kidney disease (CKD). Paeoniflorin (PF), a water-soluble monoterpene glycoside extracted from Paeonia lactiflora, revealed renal anti-inflammatory activities in our previous study. However, the potential molecular mechanism of PF on CKD remains unknown.

PURPOSE

The present study aims to investigate the regulation of PF on macrophage polarization in CKD.

METHODS

A CKD model was established by cationic bovine serum albumin and a murine macrophage cell line RAW264.7 induced with lipopolysaccharide (LPS) were used to clarify the underlying mechanisms of PF in CKD.

RESULTS

Results showed that PF exhibited favorable protective effects on CKD model mice by promoting renal function, ameliorating renal pathological injury and podocyte damage. Furthermore, PF inhibited the infiltration of M1 macrophage marker CD68 and iNOS in kidney tissue, but increased the proportion of M2 macrophage marker CD206. In RAW264.7 cells stimulated with LPS, the levels of cytokines including IL-6, IL-1β, TNF-α, MCP-1 were lessened under PF treatment, while the levels of Arg1, Fizz1, IL-10 and Ym-1 were augmented. These results indicated that PF promoted macrophage polarization from M1 to M2 in vivo and in vitro. More importantly, PF repaired the damaged mitochondria through increasing mitochondrial membrane potential and reducing ROS accumulation. The mitophagy-related proteins PINK1, Parkin, Bnip3, P62 and LC3 were up-regulated by PF, accompanied by the incremental expressions of Krüppel-like transcription factor 4 (KLF4). Moreover, the promotion of mitophagy and inhibition of M1 macrophage polarization owing to PF were reversed by mitophagy inhibitor Mdivi-1 or silencing KLF4.

CONCLUSION

Overall, PF suppressed renal inflammation by promoting macrophage polarization from M1 to M2 and inducing mitophagy via regulating KLF4. It is expected to provide a new strategy for exploring the effects of PF in treating CKD.

Pulsatilla Saponins Inhibit Experimental Lung Metastasis of Melanoma via Targeting STAT6-Mediated M2 Macrophages Polarization

Pulsatilla saponins (PS) extracts from Pulsatilla chinensis (Bge.) Regel, are a commonly used traditional Chinese medicine. In the previous study, we found Pulsatilla saponins displayed anti-tumor activity without side effects such as bone marrow suppression. However, the mechanism of the anti-tumor effect was not illustrated well. Since M2-like tumor-associated macrophages (TAMs) that required activation of the signal transducer and activator of transcription 6 (STAT6) for polarization are the important immune cells in the tumor microenvironment and play a key role in tumor progress and metastasis, this study aimed to confirm whether Pulsatilla saponins could inhibit the development and metastasis of tumors by inhibiting the polarization of M2 macrophages. We investigated the relevance of M2 macrophage polarization and the anti-tumor effects of Pulsatilla saponins in vitro and in vivo. In vitro, Pulsatilla saponins could decrease the mRNA level of M2 marker genes Arg1, Fizz1, Ym1, and CD206, and the down-regulation effect of phosphorylated STAT6 induced by IL-4; moreover, the conditioned medium (CM) from bone marrow-derived macrophages (BMDM) treated with Pulsatilla saponins could inhibit the proliferation and migration of B16-F0 cells. In vivo, Pulsatilla saponins could reduce the number of lung metastasis loci, down-regulate the expression of M2 marker genes, and suppress the expression of phosphorylated STAT6 in tumor tissues. Furthermore, we used AS1517499 (AS), a STAT6 inhibitor, to verify the role of PS on M2 macrophage polarization both in vitro and in vivo. We found that Pulsatilla saponins failed to further inhibit STAT6 activation; the mRNA level of Arg1, Fizz1, Ym1, and CD206; and the proliferation and migration of B16-F0 cells after AS1517499 intervention in vitro. Similar results were obtained in vivo. These results illustrated that Pulsatilla saponins could effectively suppress tumor progress by inhibiting the polarization of M2 macrophages via the STAT6 signaling pathway; this revealed a novel mechanism for its anti-tumor activity.

Role of regulation of PD-1 and PD-L1 expression in sepsis

Long term immunosuppression is problematic during sepsis. The PD-1 and PD-L1 immune checkpoint proteins have potent immunosuppressive functions. Recent studies have revealed several features of PD-1 and PD-L1 and their roles in sepsis. Here, we summarize the overall findings of PD-1 and PD-L1 by first reviewing the biological features of PD-1 and PD-L1 and then discussing the mechanisms that control the expression of PD-1 and PD-L1. We then review the functions of PD-1 and PD-L1 in physiological settings and further discuss PD-1 and PD-L1 in sepsis, including their involvement in several sepsis-related processes and their potential therapeutic relevance in sepsis. In general, PD-1 and PD-L1 have critical roles in sepsis, indicating that their regulation may be a potential therapeutic target for sepsis.

Exploration of the mechanism by which Huangqi Guizhi Wuwu decoction inhibits Lps-induced inflammation by regulating macrophage polarization based on network pharmacology

BACKGROUND

Huangqi Guizhi Wuwu decoction (HQGZWWD) is a traditional Chinese herbal medicine formulation with significant anti-inflammatory activity. However, its underlying mechanism remains unknown. Through network pharmacology and experimental validation, this study aimed to examine the potential mechanism of HQGZWWD in regulating macrophage polarization and inflammation.

METHODS

The active components were obtained from the Traditional Chinese Medicine Systems Pharmacology database and Analysis Platform (TCMSP), whereas the corresponding targets were obtained from the TCMSP and Swiss Target Prediction database. The GeneCards database identified targets associated with macrophage polarization and inflammation. Multiple networks were developed to identify the key compounds, principal biological processes, and pathways of HQGZWWD that regulate macrophage polarization and inflammation. Autodock Vina is utilized to assess the binding ability between targets and active compounds. Finally, confirm the experiment's central hypothesis. Human histiocytic lymphoma (U-937) cells were transformed into M1 macrophages following stimulation with Lipopolysaccharide (LPS) to evaluate the effect of HQGZWWD drug-containing mouse serum (HQGZWWD serum) on regulating macrophage polarization and inflammation.

RESULTS

A total of 54 active components and 859 HQGZWWD targets were obtained. There were 9972 targets associated with macrophage polarization and 11,109 targets associated with inflammation. After screening, 34 overlapping targets were identified, of which 5 were identified as central targets confirmed by experiments, including the α7 nicotinic acetylcholine receptor (α7 nAchR), interleukin 6 (IL-6), Interleukin-1 beta (IL-1β), interleukin 10 (IL-10) and growth factor beta (TGF-β1). Pathway enrichment analysis revealed that 34 overlapping targets were enriched in multiple pathways associated with macrophage polarization and inflammation, including the TGF beta signaling pathway, NF-kappa B signaling pathway, JAK-STAT signaling pathway, and TNF signaling pathway. Molecular docking confirmed that the majority of HQGZWWD's compounds can bind to the target. In vitro experiments, HQGZWWD serum was shown to up-regulate the expression of α7 nAchR, reduce the number of M1 macrophages, stimulate the production of M2 macrophages, inhibit the expression of pro-inflammatory cytokines IL-6 and IL1-β, and increase the expression of anti-inflammatory cytokines IL-10 and TGF-β1.

CONCLUSION

HQGZWWD can regulate the number of M1/M2 macrophages and the level of inflammatory cytokines, and the underlying mechanism may be related to the up-regulation of α7 nAchR expression.

Macrophage polarization states in atherosclerosis

Atherosclerosis, a chronic inflammatory condition primarily affecting large and medium arteries, is the main cause of cardiovascular diseases. Macrophages are key mediators of inflammatory responses. They are involved in all stages of atherosclerosis development and progression, from plaque formation to transition into vulnerable plaques, and are considered important therapeutic targets. Increasing evidence suggests that the modulation of macrophage polarization can effectively control the progression of atherosclerosis. Herein, we explore the role of macrophage polarization in the progression of atherosclerosis and summarize emerging therapies for the regulation of macrophage polarization. Thus, the aim is to inspire new avenues of research in disease mechanisms and clinical prevention and treatment of atherosclerosis.

Vitamin D protects silica particles induced lung injury by promoting macrophage polarization in a KLF4-STAT6 manner

Silicosis is one of the severest occupational diseases worldwide, manifesting as infiltration of inflammatory cells, excessive secretion of pro-inflammatory mediators and pulmonary diffuse fibrosis. Macrophages polarization to M2 is one of the major strategies that attenuates inflammatory response. Our previous study found that vitamin D could protect against silica-induced lung injury by damping the secretion of pro-inflammatory cytokines. Here we further identified that vitamin D attenuated silica particles-induced lung inflammation by regulating macrophage polarization in a KLF4-STAT6 manner. Myeloid-specific Stat6 knockout (cKO) mice were generated for in vivo studies. Primary macrophages purified from bronchoalveolar lavage fluid (BALF) of wildtype or Stat6 cKO mice and differentiated THP-1 cells were used for in vitro studies. Vitamin D was found to promote alveolar macrophage polarizing to M2 phenotype through the STAT6 signaling pathway, as demonstrated by worse lung inflammation and ablated protection of vitamin D in silica particles-instilled Stat6 cKO mice. Mechanismly, vitamin D upregulated KLF4 expression in the alveolar macrophage, which synergistically activated STAT6. Additionally, KLF4 was found to upregulate macrophages autophagy, which protected them from silica particles-induced oxidative stress and cell apoptosis. The protective effects of vitamin D were dismissed by silencing KLF4. Our study demonstrates the potential mechanism of vitamin D-mediated macrophage polarization and reveals the therapeutic application of vitamin D in inflammatory disease.

Application of herbal traditional Chinese medicine in the treatment of lupus nephritis

Lupus nephritis (LN) is a secondary renal disease caused by systemic lupus erythematosus affecting the kidneys. It is one of the main causes of end-stage renal disease and a serious risk factor for early mortality and disability of systemic lupus erythematosus patients. Existing LN treatment is mainly based on hormones, cytotoxic drugs, and biological agents. Nevertheless, the prognosis of LN patients remains poor because of frequent recurrence and exacerbation of adverse drug reactions. Hence, LN is still the most important cause of end-stage renal disease. In recent years, traditional Chinese medicine (TCM) has attracted increasing attention because of encouraging evidence that it alleviates LN and the well-described mechanisms underlying renal injury. TCM has therapeutic benefits for treating LN patients. This review article elucidates TCM preparations, TCM monomers, and herbal or natural extraction for LN treatment to provide effective supplementary evidence for promoting the development of TCM treatment for LN and reference for future research and clinical practice.

Loss of LXN promotes macrophage M2 polarization and PD-L2 expression contributing cancer immune-escape in mice

Latexin (LXN) plays an important role in tumorigenesis and inflammatory response and as a tumor suppressor in many tumors. However, whether LXN regulates tumorigenesis through immune regulation remains uncertain. Here, we demonstrate that LXN deficiency increases hematopoietic stem cells, as well as affects the proportion of immune cells in the peripheral system. Animal studies show that mice loss of LXN promotes tumor growth in subcutaneous tumor model and AOM/DSS-induced colorectal cancer model. We found that loss of LXN promotes macrophage M2 polarization and PD-L2 expression in macrophage, thus, inhibits the function of T cells. Adoptive transfer of wild-type macrophage rescues the function of T cells in LXN-deficient mice. LXN deficiency in hematopoietic lineage exacerbates colorectal carcinogenesis, and targeted inhibition of PD-L2 ameliorates cancer growth in LXN-deficient mice. Mechanistically, we demonstrate that LXN inhibits STAT3 transcriptional activity by targeting inhibition of JAK1 in macrophages. LXN deficiency enhances PD-L2 expression rather than PD-L1 in macrophages, which lead to inhibition of T cells in tumor microenvironment. Collectively, we define a critical role of LXN/JAK1/STAT3 signal in macrophage and highlights the potential role of LXN in tumor immune-escape by regulating macrophage polarization, as well as the expression of immune checkpoint PD-L2.

Perspectives of herbs and their natural compounds, and herb formulas on treating diverse diseases through regulating complicated JAK/STAT signaling

JAK/STAT signaling pathways are closely associated with multiple biological processes involved in cell proliferation, apoptosis, inflammation, differentiation, immune response, and epigenetics. Abnormal activation of the STAT pathway can contribute to disease progressions under various conditions. Moreover, tofacitinib and baricitinib as the JAK/STAT inhibitors have been recently approved by the FDA for rheumatology disease treatment. Therefore, influences on the STAT signaling pathway have potential and perspective approaches for diverse diseases. Chinese herbs in traditional Chinese medicine (TCM), which are widespread throughout China, are the gold resources of China and have been extensively used for treating multiple diseases for thousands of years. However, Chinese herbs and herb formulas are characterized by complicated components, resulting in various targets and pathways in treating diseases, which limits their approval and applications. With the development of chemistry and pharmacology, active ingredients of TCM and herbs and underlying mechanisms have been further identified and confirmed by pharmacists and chemists, which improved, to some extent, awkward limitations, approval, and applications regarding TCM and herbs. In this review, we summarized various herbs, herb formulas, natural compounds, and phytochemicals isolated from herbs that have the potential for regulating multiple biological processes via modulation of the JAK/STAT signaling pathway based on the published work. Our study will provide support for revealing TCM, their active compounds that treat diseases, and the underlying mechanism, further improving the rapid spread of TCM to the world.

Losartan attenuates sepsis-induced cardiomyopathy by regulating macrophage polarization via TLR4-mediated NF-κB and MAPK signaling

Sepsis-induced cardiomyopathy (SIC) is a serious complication of sepsis with high mortality but no effective treatment. The renin angiotensin (Ang) aldosterone system (RAAS) is activated in patients with sepsis but it is unclear how the Ang II/Ang II type 1 receptor (AT1R) axis contributes to SIC. This study examined the link between the Ang II/AT1R axis and SIC as well as the protective effect of AT1R blockers (ARBs). The Ang II level in peripheral plasma and AT1R expression on monocytes were significantly higher in patients with SIC compared with those in non-SIC patients and healthy controls and were correlated with the degree of myocardial injury. The ARB losartan reduced the infiltration of neutrophils, monocytes, and macrophages into the heart and spleen of SIC mice. Additionally, losartan regulated macrophage polarization from the M1 to the M2 subtype via nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thereby maintaining the mitochondrial dynamics balance in cardiomyocytes and reducing oxidative stress and cardiomyocyte apoptosis. In conclusion, the plasma Ang II level and AT1R expression on plasma monocytes are an important biomarker in SIC. Therapeutic targeting of AT1R, for example with losartan, can potentially protect against myocardial injury in SIC.

Total glucosides of paeony inhibit breast cancer growth by inhibiting TAMs infiltration through NF-κB/CCL2 signaling

PURPOSE

The high density of tumor-associated macrophages (TAMs) and inflammatory factors are crucial elements leading to tumor immune tolerance. Previously, we found that total glucosides of paeony (TGP) have strong inhibitory effects on the release of various inflammatory factors; however, it is unclear whether the inhibitory effects can improve the inflammatory microenvironment of tumors. Therefore, in the present study, we investigated the mechanism via which TGP depresses tumor growth and metastasis via modulation of TAM infiltration in breast cancer.

METHODS

We assessed the effects of TGP on various mouse models of tumor. Lung metastasis was detected using hematoxylin and eosin staining. T cell (CD3⁺CD4⁺ and CD3⁺CD8⁺) effector and memory subsets, and TAM (CD45⁺CD11b⁺F4/80⁺) populations in the tumor microenvironment (TME) were examined using flow cytometry. Lipopolysaccharide (LPS)-stimulated macrophage experiments were used to investigate the TGP anti-inflammatory effects in vitro. Furthermore, conditional medium (CM) was added to detect 4T1 breast cancer cell growth using a Real-Time Cell Analyzer (RTCA) xCELLigence system. Inflammatory cytokine and chemokine levels were measured using cytometric bead array (CBA) kits and quantitative polymerase chain reaction (qPCR). NF-κB expression in the nucleus was examined by immunofluorescence and Western blot analysis.

RESULTS

TGP suppressed tumor growth and lung metastasis, decreased CD45⁺CD11b⁺F4/80⁺ (TAMs) population obviously, and increased CD44^LowCD62L^Hi (T memory stem cells) and CD44^HiCD62L^Hi (central memory cells) populations in the tumor-infiltrating CD4⁺ and CD8⁺ T cells. In addition, TGP reduced inflammatory factor levels in tumors, thus inhibiting the infiltration of TAMs to improve the inflammation immunosuppressive microenvironment. In the in vitro experiment, TGP inhibited IL-10 and C-C Motif Chemokine Ligand 2 (CCL2) secretion and mRNA expression in LPS-stimulated macrophages to inhibit 4T1 cell growth and restrain macrophages M2 polarization. In addition, TGP can directly inhibit 4T1 cell proliferation by restraining autocrine CCL2 and IL-10. Further mechanistic studies reavealed that TGP inhibited CCL2 secretion by inhibiting NF-κB accumulation in the nucleus in macrophages.

CONCLUSION

TGP reduced TAM recruitment mainly through the NF-κB/CCL2 signaling pathway, thereby promoting T cell infiltration in the TME. TGP has a unique advantage in balancing the inflammatory response. Furthermore, our results present novel insights on the mechanisms underlying TAM infiltration that were inhibited by TGP, with potential application in development of novel therapies targeting CCL2 pathways.

Total glucosides of paeony inhibits liver fibrosis and inflammatory response associated with cirrhosis via the FLI1/NLRP3 axis

BACKGROUND

Total glucosides of paeony (TGP) has a myriad of hepatoprotective activities. However, its role in cirrhosis, a major risk factor for hepatocellular carcinoma, remains largely unexplored. Here, we determined the impact of TGP on liver fibrosis and inflammation in mice modeled by carbon tetrachloride with an aim to explore a possible molecular mechanism.

METHODS

Liver fibrosis and inflammation in mice were evaluated using ELISA, hematoxylin-eosin, Masson's trichrome, immunohistochemical staining and TUNEL methods. The impact of TGP on gene expression in the liver tissues of the mice was investigated using microarray analysis, showing the most significant increase in expression of friend leukemia integration 1 transcription factor (FLI1). After loss-of-functions assays of FLI1, the downstream gene of FLI1 was searched by bioinformatics analysis and verified.

RESULTS

TGP reduced liver tissue damage, inhibited apoptosis, and alleviated liver fibrosis and inflammation in cirrhotic mice. FLI1 was downregulated in the liver of cirrhotic mice and lipopolysaccharide-treated hepatocytes, and TGP promoted the expression of FLI1. FLI1 depletion inhibited the effects of TGP on alleviating liver fibrosis and inflammatory responses in mice. FLI1 repressed Nod-like receptor protein 3 (NLRP3) transcription by binding to its promoter. Further silencing of NLRP3 in the presence of shFLI1 alleviated histopathological changes, inhibited apoptosis, and attenuated liver fibrosis and inflammatory responses in the liver of cirrhotic mice.

CONCLUSIONS

TGP promotes the expression of FLI1, which in turn inhibits NLRP3 expression, thereby reducing cirrhosis-induced liver fibrosis and inflammatory response in mice.

Exploring the relationship between systemic lupus erythematosus and osteoporosis based on bioinformatics

OBJECTIVE

This study aimed to explore the relationship between systemic lupus erythematosus (SLE) and osteoporosis (OP) based on bioinformatics.

METHODS

The expression profiles of SLE and OP gene chips were searched through the GEO database, and the differentially expressed genes (DEGs) were screened out to obtain the intersection. Then, the Funrich software was used to predict the upstream miRNAs of the intersection genes, and the miRNA-mRNA relationship network was constructed. Afterward, the String database and Cytoscape software were used to construct the protein interaction network of the intersection genes to screen out the key genes. Finally, the functions and related pathways of key genes were analyzed by using the DAVID database.

RESULTS

①A total of 140 intersection genes of SLE and OP were obtained; ②There were 217 miRNAs regulating the intersection genes; ③IL-4, FOS, TLR1, TLR6, CD40LG, CCR1 were the key genes in the protein interaction network; ④The DAVID enrichment analysis mainly covered the positive regulation of cytokine production, the regulation of osteoclast differentiation, macrophage activation and other biological processes, involving Toll-like receptor signaling pathway, T cell receptor signaling pathway, Th1, Th2, and Th17 cells Differentiation, IL-17 signaling pathway.

CONCLUSIONS

SLE and OP still have some highly overlapping differential gene expressions under the background of complex gene networks. The gene functions and signaling pathways involved can simultaneously regulate the two diseases, suggesting that there is a close relationship between the molecular mechanisms of the two diseases, and that it may be a target of drugs that interfere with two diseases at the same time.

MicroRNA-214-3p facilitates M2 macrophage polarization by targeting GSK3B

Allergic rhinitis (AR) is a chronic inflammatory disease of the nasal mucosa. M2 macrophage polarization can reduce inflammation and repair tissue injury during AR development. Studies have substantiated the involvement of miRNAs in AR pathogenesis. Herein, the molecular mechanism of miR-214-3p in AR development was explored. To mimic the AR environment, ovalbumin (OVA) was used to treat macrophages. MiR-214-3p and glycogen synthase kinase 3 beta (GSK3B) expression in nasal mucus tissues and macrophages was assessed by RT-qPCR. The M2 phenotypic signature of CD206 in macrophages was assessed by flow cytometry. The protein expression of GSK3B and M2 macrophage markers (ARG-1 and IL-10) was evaluated by western blotting. The correlation between miR-214-3p and GSK3B was validated by a luciferase reporter assay. We found that miR-214-3p was overexpressed in macrophages and nasal mucus tissues from AR patients. MiR-214-3p facilitated M2 polarization of macrophages upon OVA stimulation. Mechanistically, miR-214-3p targeted the GSK3B 3' untranslated region in macrophages. In addition, GSK3B was downregulated in macrophages and nasal mucus tissues from AR patients. In rescue assays, GSK3B downregulation reversed the inhibitory effects of miR-214-3p silencing on M2 polarization of macrophages treated with OVA. Overall, miR-214-3p facilitates M2 macrophage polarization by targeting GSK3B.