Macrophages with regulatory functions, a possible new therapeutic perspective in autoimmune diseases

The anti-inflammatory activity of 2-iminothiazolidines: evidence for macrophage repolarization

Nowadays, macrophages are recognized as key cells involved in chronic inflammatory conditions, and play central roles in all inflammatory diseases and cancer. Due to their extensive involvement in the pathogenesis of inflammatory diseases, they are now considered a relevant therapeutic target in the development of new therapeutic strategies. 2-Iminothiazolidines are associated with important anti-inflammatory activity and represent a rich source for the development of new drugs and treatments. Our research focuses on evaluating the anti-inflammatory capacity of these compounds and their relationship with M1/M2 macrophage polarization. The results demonstrate that 2-iminothiazolidines have the capacity to decrease the levels of anti-inflammatory biomarkers, such as cytokines (IL-1β, TNF-α, and IL-6), nitric oxide synthase (with impact on NOx production), and COX-2, following a significant decline in NF-kB activation. We also observed an increase in levels of anti-inflammatory cytokines (IL-4 and IL-13) in the in vitro model of RAW 264.7 macrophages induced by LPS. Moreover, this is the first report, suggesting that the anti-inflammatory activity of 2-iminothiazolidines is associated with the ability to enhance phagocytosis, increase Arginase-1 and CD206 expression, and increase the secretion of IL-10. Furthermore, an in vivo study using the acute lung injury model induced by LPS proved the anti-inflammatory activity of a selected 2-iminothiazolidine, named methyl 2-(benzoylimino)-3-methyl-4-(4-nitrobenzyl)-1,3-thiazolidine-4-carboxylate. All these results, taken together, lead us to hypothesize that the mechanism of anti-inflammatory effect observed with this compound is closely related to the ability of this compound to produce macrophage repolarization, from the M1 to the M2 phenotype.

MSC-Derived Small Extracellular Vesicles Attenuate Autoimmune Dacryoadenitis by Promoting M2 Macrophage Polarization and Inducing Tregs via miR-100-5p

Background

Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have been increasingly proved as promising immunomodulators against some autoimmune disorders. However, the possible effect and the underlying mechanism of MSC-sEVs in autoimmune dry eye have been rarely studied.

Methods

Small extracellular vesicles from human umbilical cord mesenchymal stem cells (hUC-MSC-sEVs) were subconjunctivally injected to rabbit dry eye model, and their preventive or therapeutical effects were assessed by recording the clinical and histological scores. Quantitative real-time PCR (Q-PCR), western blot and flow cytometry were performed to evaluate the immunomodulatory effects of hUC-MSC-sEVs on macrophages and T regulatory cells (Tregs) both in vivo and in vitro, and the in vitro T cell proliferation was detected by Bromodeoxyuridine (BrdU) assay. In addition, high expression of miR-100-5p in hUC-MSC-sEVs was identified by Q-PCR, and the functional role of sEVs-miR-100-5p on macrophages was explored by a series of co-culture experiments using sEVs derived from hUC-MSCs transfected with miR-100-5p inhibitor.

Results

We firstly demonstrated that hUC-MSC-sEVs had the preventive and therapeutical effects on rabbit autoimmune dacryoadenitis, an animal model of Sjögren’s syndrome (SS) dry eye. Further investigation revealed that hUC-MSC-sEVs administration effectively elicited macrophages into an anti-inflammatory M2 phenotype and elevated the proportion of Tregs both in vivo and in vitro, which contributed to reduced inflammation and improved tissue damage. Importantly, hUC-MSC-sEVs-educated macrophages with M2-like phenotype exhibited strong capacity to inhibit CD4+ T cell proliferation and promote Treg generation in vitro. Mechanistically, miR-100-5p was highly enriched in hUC-MSC-sEVs, and knockdown of miR-100-5p in hUC-MSC-sEVs partially blunted the promotion of hUC-MSC-sEVs on M2 macrophage polarization and even attenuated the effect of hUC-MSC-sEVs-educated macrophages on T cell suppression and Treg expansion.

Conclusion

Our data indicated that hUC-MSC-sEVs alleviated autoimmune dacryoadenitis by promoting M2 macrophage polarization and Treg generation possibly through shuttling miR-100-5p. This study sheds new light on the application of MSC-sEVs as a promising therapeutic method for SS dry eye.

Radicals Scavenging MOFs Enabling Targeting Delivery of siRNA for Rheumatoid Arthritis Therapy

Macrophages play essential roles in the progression of rheumatoid arthritis (RA), which are polarized into the pro-inflammatory M1 phenotype with significant oxidative stress and cytokines excretion. Herein, an active targeting nanomedicine based on metal-organic frameworks (MOFs) to re-educate the diseased macrophages for RA therapy is reported. The MOFs are prepared via coordination between tannic acid (TA) and Fe³⁺ , and anti-TNF-α siRNA is loaded via a simple sonication process, achieving high loading capacity comparable to cationic vectors. The MOFs show excellent biocompatibility, and enable rapid endo/lysosome escape of siRNA via the proton-sponge effect for effective cytokines down-regulation. Importantly, such nanomedicine displays intrinsic radicals scavenging capability to eliminate a broad spectrum of reactive oxygen and nitrogen species (RONS), which in turn repolarizes the M1 macrophages into anti-inflammatory M2 phenotypes for enhanced RA therapy in combination with siRNA. The MOFs are further modified with bovine serum albumin (BSA) to allow cascade RA joint and diseased macrophages targeted delivery. As a result, an excellent anti-RA efficacy is achieved in a collagen-induced arthritis mice model. This work provides a robust gene vector with great translational potential, and offers a vivid example of rationally designing MOF structure with multifunctionalities to synergize with its payload for enhanced disease treatment.

FABP4 secreted by M1-polarized macrophages promotes synovitis and angiogenesis to exacerbate rheumatoid arthritis

Increasing evidence shows that adipokines play a vital role in the development of rheumatoid arthritis (RA). Fatty acid-binding protein 4 (FABP4), a novel adipokine that regulates inflammation and angiogenesis, has been extensively studied in a variety of organs and diseases. However, the effect of FABP4 on RA remains unclear. Here, we found that FABP4 expression was upregulated in synovial M1-polarized macrophages in RA. The increase in FABP4 promoted synovitis, angiogenesis, and cartilage degradation to exacerbate RA progression in vivo and in vitro, whereas BMS309403 (a FABP4 inhibitor) and anagliptin (dipeptidyl peptidase 4 inhibitor) inhibited FABP4 expression in serum and synovial M1-polarized macrophages in mice to alleviate RA progression. Further studies showed that constitutive activation of mammalian target of rapamycin complex 1 (mTORC1) by TSC1 deletion specifically in the myeloid lineage regulated FABP4 expression in macrophages to exacerbate RA progression in mice. In contrast, inhibition of mTORC1 by ras homolog enriched in brain (Rheb1) disruption specifically in the myeloid lineage reduced FABP4 expression in macrophages to attenuate RA development in mice. Our findings established an essential role of FABP4 that is secreted by M1-polarized macrophages in synovitis, angiogenesis, and cartilage degradation in RA. BMS309403 and anagliptin inhibited FABP4 expression in synovial M1-polarized macrophages to alleviate RA development. Hence, FABP4 may represent a potential target for RA therapy.

The Role of Reactive Oxygen Species in the Rheumatoid Arthritis-Associated Synovial Microenvironment

Rheumatoid arthritis (RA) is an inflammatory disease that begins with a loss of tolerance to modified self-antigens and immune system abnormalities, eventually leading to synovitis and bone and cartilage degradation. Reactive oxygen species (ROS) are commonly used as destructive or modifying agents of cellular components or they act as signaling molecules in the immune system. During the development of RA, a hypoxic and inflammatory situation in the synovium maintains ROS generation, which can be sustained by increased DNA damage and malfunctioning mitochondria in a feedback loop. Oxidative stress caused by abundant ROS production has also been shown to be associated with synovitis in RA. The goal of this review is to examine the functions of ROS and related molecular mechanisms in diverse cells in the synovial microenvironment of RA. The strategies relying on regulating ROS to treat RA are also reviewed.

Multifunctional nanoparticles of sinomenine hydrochloride for treat-to-target therapy of rheumatoid arthritis via modulation of proinflammatory cytokines

Sinomenine is a bioactive alkaloid isolated from the Chinese medicinal plant of Sinomenium acutum (Thunb.) Rehd.et Wils. Currently, sinomenine hydrochloride (SIN) preparations, classified as a natural disease-modifying anti-rheumatic drug (nDMARD), have been used for therapy of rheumatoid arthritis (RA); however, the efficacy of SIN was seriously limited by its short half-life, low bioavailability, and dose-dependent adverse reactions. In this study, a biomimetic nanocomplex based on Prussian blue nanoparticles (PB NPs) was developed for overcoming clinical limitations of SIN and accordingly improving its efficacy. In vitro studies showed that the nanocomplexes significantly inhibited abnormal proliferation of fibroblast-like synoviocytes (FLSs) by scavenging reactive oxygen species (ROS) and inhibiting secretion of proinflammatory cytokines. In vivo imaging demonstrated that the improved immune-escape properties of the nanocomplexes resulted in markedly increased half-life of circulation and levels of accumulated drugs at arthritic sites of adjuvant-induced arthritis (AIA) rats. Notably, the nanocomplexes significantly suppressed joint inflammation and protected against bone destruction of AIA rats by inhibiting inflammatory cytokine secretion of the synovial macrophages and FLSs. These results indicate that the nanocomplexes provide an excellent carrier for controlled release and targeted accumulation of SIN within the arthritic sites, which consequently achieve disease-remitting effects of SIN on RA.

Expanding the spectrum of the hyperferritinemic syndrome, from pathogenic mechanisms to clinical observations, and therapeutic implications

From the introduction of hyperferritinemic syndrome concept, a growing body of evidence has suggested the role of ferritin as a pathogenic mediator and a relevant clinical feature in the management of patients with inflammatory diseases. From a pathogenic point of view, ferritin may directly stimulate the aberrant immune response by triggering the production of pro-inflammatory mediators in inducing a vicious pathogenic loop and contributing to the occurrence of cytokine storm syndrome. The latter has been recently defined as a clinical picture characterised by elevated circulating cytokine levels, acute systemic inflammatory symptoms, and secondary organ dysfunction beyond that which could be attributed to a normal response to a pathogen It is noteworthy that the occurrence of hyperferritinemia may be correlated with the development of the cytokine storm syndrome in the context of an inflammatory disease. In addition to adult onset Still's disease, macrophage activation syndrome, catastrophic anti-phospholipids syndrome, and septic shock, recent evidence has suggested this association between ferritin and life-threatening evolution in patients with systemic lupus erythematosus, with anti-MDA5 antibodies in the context of poly-dermatomyositis, with severe COVID-19, and with multisystem inflammatory syndrome. The possible underlying common inflammatory mechanisms, associated with hyperferritinemia, may led to the similar clinical picture observed in these patients. Furthermore, similar therapeutic strategies could be suggested inhibiting pro-inflammatory cytokines and improving long-term outcomes in these disorders. Thus, it could be possible to expand the spectrum of the hyperferritinemic syndrome to those diseases burdened by a dreadful clinical picture correlated with hyperferritinemia and the occurrence of the cytokine storm syndrome. In addition, the assessment of ferritin may provide useful information to the physicians in clinical practice to manage these patients. Therefore, ferritin may be considered a relevant clinical feature to be used as biomarker in dissecting the unmet needs in the management of these disorders. Novel evidence may thus support an expansion of the spectrum of the hyperferritinemic syndrome to these diseases burdened by a life-threatening clinical picture correlated with hyperferritinemia and the occurrence of the cytokine storm syndrome.

Macrophage Polarization Modulated by NF-κB in Polylactide Membranes-Treated Peritendinous Adhesion

Foreign body reactions (FBR) to implants seriously impair tissue-implant integration and postoperative adhesion. The macrophage, owing to its phenotypic plasticity, is a major regulator in the formation of the inflammatory microenvironment; NF-κB signaling also plays a vital role in the process. It is hypothesized that NF-κB phosphorylation exerts a proinflammatory regulator in FBR to polylactide membranes (PLA-M) and adhesion. First, in vitro and in vivo experiments show that PLA-M induces NF-κB phosphorylation in macrophages, leading to M1 polarization and release of inflammatory factors. The inflammatory microenvironment formed due to PLA-M accelerates myofibroblast differentiation and release of collagen III and MMP2, jointly resulting in peritendinous adhesion. Therefore, JSH-23 (a selective NF-κB inhibitor)-loaded PLA membrane (JSH-23/PLA-M) is fabricated by blend electrospinning to regulate the associated M1 polarization for peritendinous anti-adhesion. JSH-23/PLA-M specifically inhibits NF-κB phosphorylation in macrophages and exhibits anti-inflammatory and anti-adhesion properties. The findings demonstrate that NF-κB phosphorylation has a critical role in PLA-induced M1 polarization and aggravating FBR to PLA-M. Additionally, JSH-23/PLA-M precisely targets modulation of NF-κB phosphorylation in FBR to break the vicious cycle in peritendinous adhesion therapy.

Cytokine Profile and Anti-Inflammatory Activity of a Standardized Conditioned Medium Obtained by Coculture of Monocytes and Mesenchymal Stromal Cells (PRS CK STORM)

Intercellular communication between monocytes/macrophages and cells involved in tissue regeneration, such as mesenchymal stromal cells (MSCs) and primary tissue cells, is essential for tissue regeneration and recovery of homeostasis. Typically, in the final phase of the inflammation-resolving process, this intercellular communication drives an anti-inflammatory immunomodulatory response. To obtain a safe and effective treatment to counteract the cytokine storm associated with a disproportionate immune response to severe infections, including that associated with COVID-19, by means of naturally balanced immunomodulation, our group has standardized the production under GMP-like conditions of a secretome by coculture of macrophages and MSCs. To characterize this proteome, we determined the expression of molecules related to cellular immune response and tissue regeneration, as well as its possible toxicity and anti-inflammatory potency. The results show a specific molecular pattern of interaction between the two cell types studied, with an anti-inflammatory and regenerative profile. In addition, the secretome is not toxic by itself on human PBMC or on THP-1 monocytes and prevents lipopolysaccharide (LPS)-induced growth effects on those cell types. Finally, PRS CK STORM prevents LPS-induced TNF-A and IL-1Β secretion from PBMC and from THP-1 cells at the same level as hydrocortisone, demonstrating its anti-inflammatory potency.

Macrophage-Targeted Hydroxychloroquine Nanotherapeutics for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is an autoimmune disease with unclear pathogenesis. Hydroxychloroquine (HCQ), despite its moderate anti-RA efficacy, is among the few clinical drugs used for RA therapy. Macrophages reportedly play a vital role in RA. Here, we designed and explored macrophage-targeted HCQ nanotherapeutics based on mannose-functionalized polymersomes (MP-HCQ) for RA therapy. Notably, MP-HCQ exhibited favorable properties of less than 50 nm size, glutathione-accelerated HCQ release, and M1 phenotype macrophage (M1M) targetability, leading to repolarization of macrophages to anti-inflammatory M2 phenotype (M2M), reduced secretion of pro-inflammatory cytokines (IL-6), and upregulation of anti-inflammatory cytokines (IL-10). The therapeutic studies in the zymosan-induced RA (ZIA) mouse model showed marked accumulation of MP-HCQ in the inflammation sites, ameliorated symptoms of RA joints, significantly reduced IL-6, TNF-α, and IL-1β, and increased IL-10 and TGF-β compared with free HCQ. The analyses of RA joints disclosed greatly amplified M2M and declined mature DCs, CD4⁺ T cells, and CD8⁺ T cells. In accordance, MP-HCQ significantly reduced the damage of RA joints, cartilages, and bones compared to free HCQ and non-targeted controls. Macrophage-targeted HCQ nanotherapeutics therefore appears as a highly potent treatment for RA.

Immune, metabolism and therapeutic targets in RA (Rheumatoid Arthritis)

Rheumatoid arthritis is a classic autoimmune disease, the pathogenesis of which is closely linked to the auto-reactivity of immune cells and joint inflammation. Three cell types, namely T cells, macrophages and fibroblast-like synoviocytes (FLS), play an important role in the pathogenesis of RA. Numerous studies have pointed to a metabolic reprogramming of T cells, macrophages and FLS in the pathogenesis of RA arthritis, with alterations in different metabolic pathways of cells, mainly producing a shift from oxidative phosphorylation (OXPHOS) to glycolysis, in addition to lipid metabolism and amino acid metabolism which are also altered in the cellular activation state. Metabolic changes are regulated by metabolism-related signalling pathways, and RA is associated with two representative signalling pathways, namely the mTOR signalling pathway and the AMPK signalling pathway. In RA, both signalling pathways are activated or inhibited, and through a series of cascade reactions, different gene expressions are ultimately induced, altering intracellular metabolic pathways and promoting pro-inflammatory functions (e.g. pro-inflammatory cytokine release and FLS phenotypes), or inhibiting the expression of genes related to immune tolerance. Targeting key components of metabolic signalling pathways and key enzymes in cellular metabolic pathways in RA has emerged as a new way of finding drugs for RA, and many modulators targeting these targets have been extensively studied for their therapeutic effects in RA. In this article, we focus on cellular metabolic alterations in RA, related signalling pathways and possible drugs targeting RA metabolic pathways.

Herbal Formula Longteng Decoction Promotes the Regression of Synovial Inflammation in Collagen-Induced Arthritis Mice by Regulating Type 2 Innate Lymphocytes

The etiology and pathogenesis of rheumatoid arthritis (RA) have not yet been fully elucidated, with greater adverse drug effects in traditional treatment of RA. It is particularly necessary to develop and study Chinese herbal formula as a supplement and alternative drug for the treatment of RA. The traditional Chinese medicine compound Longteng Decoction (LTD), as an empirical prescription in the treatment of RA in Dongzhimen Hospital of Beijing University of Chinese Medicine, has been widely used in clinic. Type 2 innate lymphocytes (ILC2s) have specific transcription factors and signature cytokines that are very similar to Th cells, which have been proved to be necessary in addressing RA inflammation, and are potential targets for RA prevention and treatment. Our previous studies have confirmed that LTD can intervene in the differentiation of peripheral blood Th17 and Treg cells, reduce joint pain index and swelling degree, shorten the time of morning stiffness, reduce ESR, and inhibit joint inflammation. However, it is unclear whether LTD can promote the regression of RA synovial inflammation by regulating the immune response mechanism of ILC2s.Therefore, our team established a collagen-induced arthritis mouse model and conducted an experimental study with LTD as the intervention object. The results showed that joint swelling, synovial inflammatory infiltration, and articular cartilage destruction were alleviated in CIA mice after intervention with LTD. The proliferation and differentiation of Th17 inflammatory cells and the secretion of proinflammatory cytokines (IL-17 and IFN-γ) were inhibited. In addition, LTD can also activate ILC2s to secrete the anti-inflammatory cytokine IL-4, activate the STAT6 signaling pathway, and act synergistic with Treg cells to inhibit the infiltration of type M1 macrophages in synovial tissue and promote its transformation to M2 phenotype. Taken together, these results confirm that LTD can be used as an adjunct or alternative to RA therapy by modulating the ILC2s immune response network and slowing down the inflammatory process of synovial tissue.

The glycolysis inhibitor 2-deoxyglucose ameliorates adjuvant-induced arthritis by regulating macrophage polarization in an AMPK-dependent manner

Macrophages are highly plastic cells critical for the development of rheumatoid arthritis (RA). Macrophages exhibit a high degree of pro-inflammatory plasticity in RA, accompanied by a metabolic reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis. 2-deoxyglucose (2-DG), a glycolysis inhibitor, has previously been shown to exhibit anti-inflammatory and anti-arthritic properties. However, the specific mechanisms of inflammatory modulation by 2-DG remain unclear. This study used 2-DG to treat rats with adjuvant arthritis (AA) and investigated its specific anti-arthritic mechanisms in the murine-derived macrophage cell line RAW264.7 in vitro. 2-DG reduced the arthritis index as well as alleviated cellular infiltration, synovial hyperplasia, and bone erosion in AA rats. Moreover, 2-DG treatment modulated peritoneal macrophage polarization, increasing levels of the arginase1 (Arg1) and decreasing expression of the inducible nitric oxide synthase (iNOS). 2-DG activated AMP-activated protein kinase (AMPK) via phosphorylation and reduced activation of the nuclear factor κB (NF-κB) in peritoneal macrophages of AA rats. In vitro, we verified that 2-DG promoted macrophage transition from M1 to M2-type by upregulating the expression of p-AMPKα and suppressing NF-κB activation in LPS-stimulated RAW264.7 cells. LPS-induced macrophages exhibited a metabolic shift from glycolysis to OXPHOS following 2-DG treatment, as observed by reduced extracellular acidification rate (ECAR), lactate export, glucose consumption, as well as an elevated oxygen consumption rate (OCR) and intracellular ATP concentration. Importantly, changes in polarization and metabolism in response to 2-DG were dampened after AMPKα knockdown. These findings indicate that the anti-arthritic 2-DG effect is mediated by a modulation of macrophage polarization in an AMPK-dependent manner.

LncRNA SNHG14 contributes to proinflammatory cytokine production in rheumatoid arthritis via the regulation of the miR-17-5p/MINK1-JNK pathway

Rheumatoid arthritis (RA) is a widespread autoimmune disorder of the joints. Long noncoding RNAs (lncRNAs) have been reported to participate in the pathogenesis of RA by serving as competitive endogenous RNAs. LncRNA small nucleolar RNA host gene 14 (SNHG14) is involved in the development of various diseases. Here, we found that high expression of SNHG14 in RA was closely related to the disease activity. Functional assays indicated that SNHG14 knockdown obviously hampered phorbol myristate acetate-activated THP-1 (pTHP-1) cell proliferation and proinflammatory cytokines production. In mechanism, SNHG14 served as a sponge of microRNA-17-5p (miR-17-5p), and misshapen like kinase 1 (MINK1) was a target of miR-17-5p. SNHG14 depletion-induced inhibitory effects on cell proliferation and inflammatory response were reversed by MINK1 overexpression in macrophages. Moreover, SNHG14 promoted the jun N-terminal kinase (JNK) signaling via the miR-17-5p/MINK1 axis. Overall, SNHG14 boosted the process of RA by MINK1 activating the JNK pathway.

The role of immune cells in pulmonary hypertension: Focusing on macrophages

Pulmonary hypertension (PH) is a life-threatening pathological state with elevated pulmonary arterial pressure, resulting in right ventricular failure and heart functional failure. Analyses of human samples and rodent models of pH support the infiltration of various immune cells, including neutrophils, mast cells, dendritic cells, B-cells, T-cells, and natural killer cells, to the lungs and pulmonary perivascular regions and their involvement in the PH development. There is evidence that macrophages are presented in the pulmonary lesions of pH patients as first-line myeloid leucocytes. Macrophage accumulation and presence, both M1 and M2 phenotypes, is a distinctive hallmark of pH which plays a pivotal role in pulmonary artery remodeling through various cellular and molecular interactions and mechanisms, including CCL2 and CX3CL1 chemokines, adventitial fibroblasts, glucocorticoid-regulated kinase 1 (SGK1), crosstalk with other immune cells, leukotriene B4 (LTB4), bone morphogenetic protein receptor 2 (BMPR2), macrophage migration inhibitory factor (MIF), and thrombospondin-1 (TSP-1). In this paper, we reviewed the molecular mechanisms and the role of immune cells and responses are involved in PH development. We also summarized the polarization of macrophages in response to different stimuli and their pathological role and their infiltration in the lung of pH patients and animal models.

Macrophage-biomimetic porous Se@SiO2 nanocomposites for dual modal immunotherapy against inflammatory osteolysis

Background

Inflammatory osteolysis, a major complication of total joint replacement surgery, can cause prosthesis failure and necessitate revision surgery. Macrophages are key effector immune cells in inflammatory responses, but excessive M1-polarization of dysfunctional macrophages leads to the secretion of proinflammatory cytokines and severe loss of bone tissue. Here, we report the development of macrophage-biomimetic porous SiO₂-coated ultrasmall Se particles (porous Se@SiO₂ nanospheres) to manage inflammatory osteolysis.

Results

Macrophage membrane-coated porous Se@SiO₂ nanospheres(M-Se@SiO₂) attenuated lipopolysaccharide (LPS)-induced inflammatory osteolysis via a dual-immunomodulatory effect. As macrophage membrane decoys, these nanoparticles reduced endotoxin levels and neutralized proinflammatory cytokines. Moreover, the release of Se could induce macrophage polarization toward the anti-inflammatory M2-phenotype. These effects were mediated via the inhibition of p65, p38, and extracellular signal-regulated kinase (ERK) signaling. Additionally, the immune environment created by M-Se@SiO₂ reduced the inhibition of osteogenic differentiation caused by proinflammation cytokines, as confirmed through in vitro and in vivo experiments.

Conclusion

Our findings suggest that M-Se@SiO₂ have an immunomodulatory role in LPS-induced inflammation and bone remodeling, which demonstrates that M-Se@SiO₂ are a promising engineered nanoplatform for the treatment of osteolysis occurring after arthroplasty.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01128-4.

Genetically Engineered Cellular Membrane Vesicles as Tailorable Shells for Therapeutics

Benefiting from the blooming interaction of nanotechnology and biotechnology, biosynthetic cellular membrane vesicles (Bio-MVs) have shown superior characteristics for therapeutic transportation because of their hydrophilic cavity and hydrophobic bilayer structure, as well as their inherent biocompatibility and negligible immunogenicity. These excellent cell-like features with specific functional protein expression on the surface can invoke their remarkable ability for Bio-MVs based recombinant protein therapy to facilitate the advanced synergy in poly-therapy. To date, various tactics have been developed for Bio-MVs surface modification with functional proteins through hydrophobic insertion or multivalent electrostatic interactions. While the Bio-MVs grow through genetically engineering strategies can maintain binding specificity, sort orders, and lead to strict information about artificial proteins in a facile and sustainable way. In this progress report, the most current technology of Bio-MVs is discussed, with an emphasis on their multi-functionalities as "tailorable shells" for delivering bio-functional moieties and therapeutic entities. The most notable success and challenges via genetically engineered tactics to achieve the new generation of Bio-MVs are highlighted. Besides, future perspectives of Bio-MVs in novel bio-nanotherapy are provided.

Functionally Heterogenous Macrophage Subsets in the Pathogenesis of Giant Cell Arteritis: Novel Targets for Disease Monitoring and Treatment

Giant cell arteritis (GCA) is a granulomatous large-vessel vasculitis that affects adults above 50 years of age. In GCA, circulating monocytes are recruited to the inflamed arteries. With cues from the vascular microenvironment, they differentiate into macrophages and play important roles in the pathogenesis of GCA via pro-inflammatory cytokine production and vascular remodeling. However, a deeper understanding of macrophage heterogeneity in GCA pathogenesis is needed to assist the development of novel diagnostic tools and targeted therapies. Here, we review the current knowledge on macrophage heterogeneity and diverse functions of macrophage subsets in the pathogenesis of GCA. We next discuss the possibility to exploit their heterogeneity as a source of novel biomarkers and as targets for nuclear imaging. Finally, we discuss novel macrophage-targeted therapies and future directions for targeting these cells in GCA.

The expansion of CD14+ CD163+ subpopulation of monocytes and myeloid cells-associated cytokine imbalance; candidate diagnostic biomarkers for celiac disease (CD)

Celiac disease (CD) is a chronic autoimmune disorder of small intestine against dietary gluten, among genetically predisposed individuals. Monocytes are versatile innate immune cells involved in the regulation of inflammation, and strongly involved in the intestinal immunity. However, the role of monocytes and their subtypes in CD is not well demonstrated.

METHODS

Here, we assessed the polarization of CD14+ monocytes by evaluating the M1 (CD16) and M2 (CD163) markers by flowcytometry, their soluble forms (sCD16 and sCD163), and the serum levels of IL-10, IL-12, TGF-β, and TNF-α cytokines using ELISA method, among 30 CD patients and 30 sex- and age-matched healthy subjects (HS). We also analyzed the diagnostic values of all variables with significant differences.

RESULTS

CD14+CD163+ monocytes were more frequent in CD patients than HS, while CD14+CD16+ monocytes were higher in HS. IL-10and TNF-α increased, and TGF-β expression was decreased among CD patients. The sCD16 serum levels were elevated in patients, while sCD163 was higher but not significant among CD patients. CD163+/CD16+ and IL-10/IL-12 ratios were higher in CD patients, and TGFβ/TNFα ratio was higher in HS group. IL-10, CD14+CD163+, TNF-α, and IL-10/IL-12 ratios with the AUC over 0.7 were introduced as fair diagnostic markers. Our findings revealed that the M2 (CD14+CD163+) monocytes were more frequent among CD patients, and the cytokine balance was disturbed.

CONCLUSION

According to the significant functional diversities of monocyte subtypes between CD patients and HS group, these immunologic markers could be introduced as specific diagnostic biomarkers for CD.

Blocking Jak/STAT signalling using tofacitinib inhibits angiogenesis in experimental arthritis

OBJECTIVE

During rheumatoid arthritis (RA), the angiogenic processes, occurring with pannus-formation, may be a therapeutic target. JAK/STAT-pathway may play a role and the aim of this work was to investigate the inhibiting role of a JAK-inhibitor, tofacitinib, on the angiogenic mechanisms occurring during RA.

METHODS

After ethical approval, JAK-1, JAK-3, STAT-1, STAT-3 and VEGF expression was evaluated on RA-synovial-tissues. In vitro, endothelial cells (ECs), stimulated with 20 ng/ml of VEGF and/or 1 μM of tofacitinib, were assessed for tube formation, migration and proliferation, by Matrigel, Boyden chamber assay and ki67 gene-expression. In vivo, 32 mice received collagen (collagen-induced arthritis (CIA)) and 32 mice PBS (control). At day 19, CIA and controls mice were divided: 16 mice receiving vehicle and 16 mice receiving tofacitinib. At day 35, the arthritis score, the thickness of paw joints and the serum levels of VEGF and Ang-2 were evaluated.

RESULTS

The expression of JAK-1, JAK-3, STAT-1, STAT-3 and VEGF in synovial tissue of RA-patients were significantly higher than healthy controls. In vitro, tofacitinib inhibited the ECs ability to form vessels, to proliferate and to migrate. In vivo, administration of tofacitinib prevented the increase of the arthritis score, the paw thickness, the synovial vessels and VEGF and Ang-2 serum-accumulation, when compared to CIA without tofacitinib.

CONCLUSIONS

We explored the anti-angiogenic role of tofacitinib, reporting its ability to inhibit in vitro the angiogenic mechanisms of ECs and in vivo the formation of new synovial vessels, occurring in CIA model. These findings suggest that the therapeutic effect of tofacitinib during RA may be also related to its anti-angiogenic activity.

Konjac Glucomannan Oligosaccharides Prevent Intestinal Inflammation Through SIGNR1-Mediated Regulation of Alternatively Activated Macrophages

SCOPE

Konjac glucomannan oligosaccharides (KMOS) are prebiotics and may improve intestinal immunity through modulation of macrophage function. However, the underlying molecular mechanisms were unclear.

METHODS AND RESULTS

Using a mouse model of dextran sulfated sodium (DSS)-induced acute colitis, the study demonstrates here that KMOS (400 mg^-1 kg^-1 d^-1 ) can ameliorate intestinal inflammation in a macrophage dependent manner. Oral exposure to KMOS prevents DSS-induced intestinal pathology, improves epithelial integrity, and decreases accumulation of colonic inflammatory leukocytes and cytokines. The therapeutic effects of KMOS are dependent on the function of macrophages, as depletion of macrophages abolished the effects. In colonic lamina propria of DSS-treated mice, as well as in vitro culture of bone marrow derived macrophages (BMDMs), KMOS skews reprogramming of classically activated macrophages (CAM/M1) into alternatively activated macrophages (AAM/M2). The study further determines that the activation of SIGNR1/phospho-c-Raf (S338)/phospho-p65 (S276)/acetyl-p65 (K310) pathway is responsible for KMOS-induced AAM/M2 polarization. Blockage of SIGNR1 abolishes KMOS-induced AAM/M2 polarization of activated macrophages, expression of phospho-p65 (S276) in colonic macrophages, and alleviation of DSS-induced colitis in mice, suggesting that SIGNR1 is critical for macrophage responses to KMOS.

CONCLUSIONS

This study reveals a SIGNR1-mediated macrophage-dependent pathway that supports regulatory function of KMOS in host immunity and intestinal homeostasis.

Identifying Immune Cell Infiltration and Effective Diagnostic Biomarkers in Rheumatoid Arthritis by Bioinformatics Analysis

Background

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disorder characterized by inflammatory cell infiltration, leading to persistent synovitis and joint destruction. The pathogenesis of RA remains unclear. This study aims to explore the immune molecular mechanism of RA through bioinformatics analysis.

Methods

Five microarray datasets and a high throughput sequencing dataset were downloaded. CIBERSORT algorithm was performed to evaluate immune cell infiltration in synovial tissues between RA and healthy control (HC). Wilcoxon test and Least Absolute Shrinkage and Selection Operator (LASSO) regression were conducted to identify the significantly different infiltrates of immune cells. Differentially expressed genes (DEGs) were screened by "Batch correction" and "RobustRankAggreg" methods. Functional correlation of DEGs were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Candidate biomarkers were identified by cytoHubba of Cytoscape, and their diagnostic effectiveness was predicted by Receiver Operator Characteristic Curve (ROC) analysis. The association of the identified biomarkers with infiltrating immune cells was explored using Spearman's rank correlation analysis in R software.

Results

Ten significantly different types of immune cells between RA and HC were identified. A total of 202 DEGs were obtained by intersection of DEGs screened by two methods. The function of DEGs were significantly associated with immune cells. Five hub genes (CXCR4, CCL5, CD8A, CD247, and GZMA) were screened by R package "UpSet". CCL5+CXCR4 and GZMA+CD8A were verified to have the capability to diagnose RA and early RA with the most excellent specificity and sensitivity, respectively. The correlation between immune cells and biomarkers showed that CCL5 was positively correlated with M1 macrophages, CXCR4 was positively correlated with memory activated CD4+ T cells and follicular helper T (Tfh) cells, and GZMA was positively correlated with Tfh cells.

Conclusions

CCL5, CXCR4, GZMA, and CD8A can be used as diagnostic biomarker for RA. GZMA-Tfh cells, CCL5-M1 macrophages, and CXCR4- memory activated CD4+ T cells/Tfh cells may participate in the occurrence and development of RA, especially GZMA-Tfh cells for the early pathogenesis of RA.

Inflammatory microenvironment-targeted nanotherapies

Inflammatory microenvironments (IMEs) are common pathological characteristics and drive the development of multiple chronic diseases. Thus, IME-targeted therapies exhibit potential for the treatment of inflammatory diseases. Nanoplatforms have significant advantages in improving the efficiency of anti-inflammatory treatments. Owing to their improved therapeutic effects and reduced side effects, IME-targeted nanotherapies have recently drawn interest from the research community. This review introduces IMEs and discusses the application of IME-targeted nanotherapies for inflammatory diseases. The development of rational targeting strategies tailored to IMEs in damaged tissues can help promote therapies for chronic diseases.

Endothelial-to-mesenchymal transition in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterized by significant vascular alterations and multi-organ fibrosis. Microvascular alterations are the first event of SSc and injured endothelial cells (ECs) may transdifferentiate towards myofibroblasts, the cells responsible for fibrosis and collagen deposition. This process is identified as endothelial-to-mesenchymal transition (EndMT), and understanding of its development is pivotal to identify early pathogenetic events and new therapeutic targets for SSc. In this review, we have highlighted the molecular mechanisms of EndMT and summarize the evidence of the role played by EndMT during the development of progressive fibrosis in SSc, also exploring the possible therapeutic role of its inhibition.

Endocan, a novel inflammatory marker, is upregulated in human chondrocytes stimulated with IL-1 beta

Endocan is a circulating proteoglycan, involved in immunity, inflammation, and endothelial function. It has been recently suggested as a biomarker of inflammation, increased angiogenesis, and cancer. In vitro studies have shown that endocan expression could be upregulated by inflammatory cytokines and proangiogenic molecules. High endocan levels were also shown in arthritic joint tissues and particularly in sites characterized by severe inflammation. This study was performed to evaluate endocan expression in chondrocytes stimulated with IL-ß. mRNA and related protein production were measured for endocan, TNF-α, and IL-6. NF-kB activity was also evaluated. IL-1ß treatment induced a significant upregulation of both endocan and the inflammatory parameters as well as NF-kB activity. The treatment of chondrocytes with the specific NF-kB inhibitor before IL-1ß stimulation was able to reduce endocan and the inflammatory markers over-expression. The results of our study indicated that endocan is also expressed in human chondrocytes; furthermore, consistent with previous results in other cell types and tissues, IL-1ß-induced inflammatory response involves the expression of endocan through NF-kB activation. In this context, endocan seems to be an important inflammatory marker associated with the activation of NF-kB pathway.

The role of CD68+ and CD163+ macrophages in immunopathogenesis of oral lichen planus and oral lichenoid lesions

Macrophages are phagocytic cells with essential participation in immunological events of the oral cavity. However, the role of these cells in oral lichen planus (OLP) and oral lichenoid lesions (OLL) remains unclear. The present study aimed to evaluate the density of macrophages in OLP and OLL, and to compare it with that of oral inflammatory fibrous hyperplasia (OIFH) (control group). 14 cases of OLP, 14 cases of OLL and 14 cases of OIFH were selected for immunohistochemical analysis of CD68⁺ (M1) and CD163⁺ (M2) macrophage expression. CD68⁺ and CD163⁺ macrophages densities were measured in the intraepithelial and subepithelial areas. The statistical tests used were multivariate analysis of variance, as well as a correlation and linear regression. OLP has more CD68+ macrophages when comparing with OLL (p = 0.001) and OIFH (p = 0.045). There is a very strong relationship between the macrophages types (p < 0.0001) in OLP and OLL. The linear regression showed that to OLL development (p < 0.0001/R^2' = 0.9584), the presence of different types of macrophages are more essential than to OLP (p < 0.0001/R^2' = 0.8983). However, in the OLP these dependencies are also largely. CD68⁺ macrophages may be associated with immunopathogenesis of OLP, indicating a pro-inflammatory activity and regulatory role in the type of T-cell response. Besides, CD68⁺ macrophages can cooperate in the diagnosis of OLP. These results are essential to future studies that seek a therapeutic target for OLP and OLL.

HLA-DRB1 allelic epitopes that associate with autoimmune disease risk or protection activate reciprocal macrophage polarization

Associations between particular human leukocyte antigen (HLA) alleles and susceptibility to-or protection from-autoimmune diseases have been long observed. Allele-specific antigen presentation (AP) has been widely proposed as a culprit, but it is unclear whether HLA molecules might also have non-AP, disease-modulating effects. Here we demonstrate differential macrophage activation by HLA-DRB1 alleles known to associate with autoimmune disease risk or protection with resultant polarization of pro-inflammatory ("M1") versus anti-inflammatory ("M2") macrophages, respectively. RNA-sequencing analyses of in vitro-polarized macrophages in the presence of AP-incompetent short synthetic peptides corresponding to the third allelic hypervariable regions coded by those two HLA-DRB1 alleles showed reciprocal activation of pro- versus anti-inflammatory transcriptomes, with implication of corresponding gene ontologies and upstream regulators. These results identify a previously unrecognized mechanism of differential immune modulation by short HLA-DRB1-coded allelic epitopes independent of AP, and could shed new light on the mechanistic basis of HLA-disease association.

Living in a Hostile World: Inflammation, New Drug Development, and Coronavirus

We present a brief history of the immune response and show that Metchnikoff's theory of inflammation and phagocytotic defense was largely ignored in the 20th century. For decades, the immune response was believed to be triggered centrally, until Lafferty and Cunningham proposed the initiating signal came from the tissues. This shift opened the way for Janeway's pattern recognition receptor theory, and Matzinger's danger model. All models failed to appreciate that without inflammation, there can be no immune response. The situation changed in the 1990s when cytokine biology was rapidly advancing, and the immune system's role expanded from host defense, to the maintenance of host health. An inflammatory environment, produced by immune cells themselves, was now recognized as mandatory for their attack, removal and repair functions after an infection or injury. We explore the cellular programs of the immune response, and the role played by cytokines and other mediators to tailor the right response, at the right time. Normally, the immune response is robust, self-limiting and restorative. However, when the antigen load or trauma exceeds the body's internal tolerances, as witnessed in some COVID-19 patients, excessive inflammation can lead to increased sympathetic outflows, cardiac dysfunction, coagulopathy, endothelial and metabolic dysfunction, multiple organ failure and death. Currently, there are few drug therapies to reduce excessive inflammation and immune dysfunction. We have been developing an intravenous (IV) fluid therapy comprising adenosine, lidocaine and Mg2+ (ALM) that confers a survival advantage by preventing excessive inflammation initiated by sepsis, endotoxemia and sterile trauma. The multi-pronged protection appears to be unique and may provide a tool to examine the intersection points in the immune response to infection or injury, and possible ways to prevent secondary tissue damage, such as that reported in patients with COVID-19.

Role of signaling pathway in biological cause of Rheumatoid arthritis

Rheumatoid Arthritis is a chronic progressive inflammatory auto-immune disease in which the immune system of the body attacks its cartilage and joints lining. It not only affects synovial joints but also many other sites including heart, blood vessels, and skins. It is more common in females than in males. The exact cause of rheumatoid arthritis is not well established but the hypothesis reported in the literature is that in the development stage of the disease, both genetics and environmental factors can play an inciting role. Along with these factors alteration in the normal physiology of enzymatic action, acts as a trigger to develop this condition. Numerous signaling pathways involved in the pathogenesis of Rheumatoid Arthritis involves activation of mitogen-activated protein kinase, kinases Janus family, P-38 Mitogen-Activated Protein Kinase, Nuclear Factor-kappa B. Interleukin-1 to play a proinflammatory cytokine that plays an important role in inflammation in RA. These are also associated with an increase in neutrophil, macrophage and lymphocytic chemotaxis, mast cell degranulation, activation, maturation and survival of T-cells and B-cells activated. These signaling pathways also show that p38α downregulation in myeloid cells exacerbates the severity of symptoms of arthritis. Thus, present review carters about the detail of different signaling pathways and their role in rheumatoid arthritis.

Crosstalk Between Mesenchymal Stromal Cells and Tumor-Associated Macrophages in Gastric Cancer

Tumor microenvironment (TME) consisting of distinct cell types including stromal cells and immune cells has recently emerged as a pivotal player in tumor development and progression. Mesenchymal stromal cells (MSCs) and tumor-associated macrophages (TAMs) are two representative cells in the TME with plastic properties. This review will focus on the evolution of phenotypes and functions of either MSCs or TAMs, which is “educated” by the TME, as well as interactions between MSCs and TAMs contributing to the distinct stages of tumor biology in gastric cancer. MSCs exert immunoregulatory effects on macrophages and polarize them toward M2-like TAMs, via cell–cell contact and paracrine or extracellular vesicle (EV) transfer mechanism. In turn, M2-TAMs modulate the transition of “naive” MSCs into tumor-derived MSCs, which possess a more potent pro-tumor role than the parent. Moreover, the cross talk between MSCs and TAMs could contribute to cancer biology by inducing the EMT process, metastasis, immune invasion, and immunotherapy resistance in cancer cells. However, molecular mechanisms underlying interactions between MSCs and TAMs in gastric cancer progression need to be thoroughly elucidated, which may provide attractive targets for making promising novel strategies for gastric cancer therapy.

Inhibitory Effects of the Lactobacillus rhamnosus GG Effector Protein HM0539 on Inflammatory Response Through the TLR4/MyD88/NF-кB Axis

Inflammatory bowel disease (IBD) is a chronic and relapsing intestinal inflammatory condition with no effective treatment. Probiotics have gained wide attention because of their outstanding advantages in intestinal health issues. In previous studies, a novel soluble protein, HM0539, which is derived from Lactobacillus rhamnosus GG (LGG), showed significant protective effects against murine colitis, but no clear precise mechanism for this effect was provided. In this study, we hypothesized that the protective function of HM0539 might be derived from its modulation of the TLR4/Myd88/NF-κB axis signaling pathway, which is a critical pathway widely involved in the modulation of inflammatory responses. To test this hypothesis, the underlying anti-inflammatory effects and associated mechanisms of HM0539 were determined both in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and in dextran sulfate sodium (DSS)-induced murine colitis. Our results showed that HM0539 inhibited the expression of cyclooxygenase-2 (COX-2) and the expression inducible nitric oxide synthase (iNOS) by down-regulating the activation of their respective promoter, and as a result this inhibited the production of prostaglandin E2 (PGE2) and nitric oxide (NO). Meanwhile, we demonstrated that HM0539 could ultimately modulate the activation of distal NF-κB by reducing the activation of TLR4 and suppressing the transduction of MyD88. However, even though the overexpression of TLR4 or MyD88 obviously reversed the effect of HM0539 on LPS-induced inflammation, HM0539 still retained some anti-inflammatory activity. Consistent with the in vitro findings, we found that HM0539 inhibited to a great extent the production of inflammatory mediators associated with the suppression of the TLR4/Myd88/NF-κB axis activation in colon tissue. In conclusion, HM0539 was shown to be a promising anti-inflammatory agent, at least in part through its down-regulation of the TLR4-MyD88 axis as well as of the downstream MyD88-dependent activated NF-κB signaling, and hence might be considered as a potential therapeutic option for IBD.

Pro-inflammatory properties of H-ferritin on human macrophages, ex vivo and in vitro observations

Ferritin is an iron-binding molecule, which comprises 24 subunits, heavy (FeH) and light (FeL) subunits, suggested to have a pathogenic role by the 'hyperferritinemic syndrome'. In this work, we tested (1) FeH and FeL in bone marrow (BM) and sera in patients with macrophage activation syndrome (MAS); (2) pro-inflammatory effects of ferritin, FeL, and FeH on macrophages; (3) ability of FeH-stimulated macrophages to stimulate the proliferation of peripheral blood mononuclear cells (PBMCs); (4) production of mature IL-1β and IL-12p70 in extracellular compartments of FeH-stimulated macrophages. Immunofluorescence analysis and liquid chromatography mass spectrometry (LC-MS/MS) based proteomics were performed to identify FeL and FeH in BM and sera, respectively, in the same patients. Macrophages were stimulated with ferritin, FeH, and FeL to assess pro-inflammatory effects by RT-PCR and western blot. The proliferation of co-cultured PBMCs with FeH-stimulated macrophages was tested. Immunofluorescence showed an increased FeH expression in BMs, whereas LC-MS/MS identified that FeL was mainly represented in sera. FeH induced a significant increase of gene expressions of IL-1β, IL-6, IL-12, and TNF-α, more marked with FeH, which also stimulated NLRP3. FeH-stimulated macrophages enhanced the proliferation of PBMCs. The ELISA assays showed that mature form of IL-1β and IL-12p70 were increased, in extracellular compartments of FeH-stimulated macrophages. Our results showed FeH in BM biopsies of MAS patients, whereas, LC-MS/MS identified FeL in the sera. FeH showed pro-inflammatory effects on macrophages, stimulated NLRP3, and increased PBMCs proliferation.

Nanoparticle-siRNA: A potential strategy for rheumatoid arthritis therapy?

Rheumatoid arthritis (RA) is a common clinical inflammatory disease of the autoimmune system manifested by persistent synovitis, cartilage damage and even deformities. Despite significant progress in the clinical treatment of RA, long-term administration of anti-rheumatic drugs can cause a series of problems, including infections, gastrointestinal reactions, and abnormal liver and kidney functions. The emergence of RNA interference (RNAi) drugs has brought new hope for the treatment of RA. Designing a reasonable vector for RNAi drugs will greatly expand the application prospects of RNAi. Nanoparticles as a promising drug carrier provide reliable support for RNAi drugs. The review summarizes the pathogenesis of RA as a possible target for small interference RNA (siRNA) design. At the same time, the review also analyzes the nanoparticles used in siRNA carriers in recent years, laying the foundation and prospect for the next step in the development of intelligent nanocarriers.

Ciprofloxacin promotes polarization of CD86+CD206‑ macrophages to suppress liver cancer

Gut microbiota can promote tumor development by producing toxic metabolites and inhibiting the function of immune cells. Previous studies have demonstrated that gut microbiota can reach the liver through the circulation and promote the occurrence of liver cancer. Ciprofloxacin, an effective broad‑spectrum antimicrobial agent, can promote cell apoptosis and regulate the function of immune cells. As an important part of the tumor microenvironment, macrophages play an important role in tumor regulation. The present study demonstrated that the treatment of macrophages with ciprofloxacin was able to promote the production of interleukin‑1β, tumor necrosis factor‑α and the polarization of CD86+CD206‑ macrophages, while inhibiting the polarization of CD86‑CD206+ macrophages. This transformation may help macrophages promote tumor cell apoptosis, inhibit tumor cell proliferation, reduce metastasis and downregulate the phosphoinositide 3‑kinase/AKT signaling pathway in liver cancer cell lines. In vivo experiments demonstrated that macrophages treated with ciprofloxacin inhibited the growth of subcutaneous implanted tumors in nude mice. In conclusion, the findings of the present study indicated that ciprofloxacin may inhibit liver cancer by upregulating the expression of CD86+CD206‑ macrophages. This study further revealed the biological mechanism underlying the potential value of ciprofloxacin in antitumor therapy and provided new targets for the treatment of liver cancer.

Glaucoma is an autoimmune disease

Glaucoma is characterized by retinal ganglion cell (RGC) neurodegeneration. Elevated intraocular pressure (IOP) is a major risk factor however, mechanisms independent of IOP play a role in RGC pathology. Both antibodies and CD4 T-cells as well as microbiota take part in the pathogenesis of both glaucoma and rheumatoid arteritis (RA).Heat shock proteins (HSPs) which originate in bacteria cross-react with RCG epitopes and were involved in rat model of retinal injury. Enhanced expression of HSPs in the retina was associated with glaucoma-like neuropathology and previous studies have also suggested a pathogenic role for HSPs in RA. In view of these data we suggest that glaucoma should be included in the spectrum of autoimmune diseases and that proven medications for RA should be adopted as an innovative IOP -independent therapeutic strategy for glaucoma.

Sensing Peroxynitrite in Different Organelles of Murine RAW264.7 Macrophages With Coumarin-Based Fluorescent Probes

The elucidation of biological processes involving reactive oxygen species (ROS) facilitates a better understanding of the underlying progression of non-communicable diseases. Fluorescent probes are a powerful tool to study various ROS and have the potential to become essential diagnostic tools. We have developed a series of coumarin fluorescent probes for the selective and sensitive detection of peroxynitrite (ONOO-), a key ROS. Coumarin based probes exhibit good photostability, large Stokes shift and high quantum yields. The three ratiometric probes all contain a boronate ester motif for the detection of ONOO- and a distinctive organelle targeting group. The study of ONOO- generation in a particular organelle will allow more precise disease profiling. Hence, targeting groups for the mitochondria, lysosome and endoplasmic reticulum were introduced into a coumarin scaffold. The three ratiometric probes displayed sensitive and selective detection of ONOO- over other ROS species. All three coumarin probes were evaluated in murine RAW264.7 macrophages for detection of basal and stimulated ONOO- formation.

Dual Role of Chondrocytes in Rheumatoid Arthritis: The Chicken and the Egg

Rheumatoid arthritis (RA) is one of the inflammatory joint diseases that display features of articular cartilage destruction. The underlying disturbance results from immune dysregulation that directly and indirectly influence chondrocyte physiology. In the last years, significant evidence inferred from studies in vitro and in the animal model offered a more holistic vision of chondrocytes in RA. Chondrocytes, despite being one of injured cells in RA, also undergo molecular alterations to actively participate in inflammation and matrix destruction in the human rheumatoid joint. This review covers current knowledge about the specific cellular and biochemical mechanisms that account for the chondrocyte signatures of RA and its potential applications for diagnosis and prognosis in RA.

The impact of PARPs and ADP-ribosylation on inflammation and host-pathogen interactions

Poly-adenosine diphosphate-ribose polymerases (PARPs) promote ADP-ribosylation, a highly conserved, fundamental posttranslational modification (PTM). PARP catalytic domains transfer the ADP-ribose moiety from NAD⁺ to amino acid residues of target proteins, leading to mono- or poly-ADP-ribosylation (MARylation or PARylation). This PTM regulates various key biological and pathological processes. In this review, we focus on the roles of the PARP family members in inflammation and host-pathogen interactions. Here we give an overview the current understanding of the mechanisms by which PARPs promote or suppress proinflammatory activation of macrophages, and various roles PARPs play in virus infections. We also demonstrate how innovative technologies, such as proteomics and systems biology, help to advance this research field and describe unanswered questions.

A Clinical Approach for the Use of VIP Axis in Inflammatory and Autoimmune Diseases

The neuroendocrine and immune systems are coordinated to maintain the homeostasis of the organism, generating bidirectional communication through shared mediators and receptors. Vasoactive intestinal peptide (VIP) is the paradigm of an endogenous neuropeptide produced by neurons and endocrine and immune cells, involved in the control of both innate and adaptive immune responses. Exogenous administration of VIP exerts therapeutic effects in models of autoimmune/inflammatory diseases mediated by G-protein-coupled receptors (VPAC1 and VPAC2). Currently, there are no curative therapies for inflammatory and autoimmune diseases, and patients present complex diagnostic, therapeutic, and prognostic problems in daily clinical practice due to their heterogeneous nature. This review focuses on the biology of VIP and VIP receptor signaling, as well as its protective effects as an immunomodulatory factor. Recent progress in improving the stability, selectivity, and effectiveness of VIP/receptors analogues and new routes of administration are highlighted, as well as important advances in their use as biomarkers, contributing to their potential application in precision medicine. On the 50th anniversary of VIP's discovery, this review presents a spectrum of potential clinical benefits applied to inflammatory and autoimmune diseases.

The Role of Maresins in Inflammatory Pain: Function of Macrophages in Wound Regeneration

Although acute inflammatory responses are host-protective and generally self-limited, unresolved and delayed resolution of acute inflammation can lead to further tissue damage and chronic inflammation. The mechanism of pain induction under inflammatory conditions has been studied extensively; however, the mechanism of pain resolution is not fully understood. The resolution of inflammation is a biosynthetically active process, involving specialized pro-resolving mediators (SPMs). In particular, maresins (MaRs) are synthesized from docosahexaenoic acid (DHA) by macrophages and have anti-inflammatory and pro-resolving capacities as well as tissue regenerating and pain-relieving properties. A new class of macrophage-derived molecules—MaR conjugates in tissue regeneration (MCTRs)—has been reported to regulate phagocytosis and the repair and regeneration of damaged tissue. Macrophages not only participate in the biosynthesis of SPMs, but also play an important role in phagocytosis. They exhibit different phenotypes categorized as proinflammatory M1-like phenotypes and anti-inflammatory M2 phenotypes that mediate both harmful and protective functions, respectively. However, the signaling mechanisms underlying macrophage functions and phenotypic changes have not yet been fully established. Recent studies report that MaRs help resolve inflammatory pain by enhancing macrophage phagocytosis and shifting cytokine release to the anti-inflammatory M2 phenotypes. Consequently, this review elucidated the characteristics of MaRs and macrophages, focusing on the potent action of MaRs to enhance the M2 macrophage phenotype profiles that possess the ability to alleviate inflammatory pain.