Sonic hedgehog promotes synovial inflammation and articular damage through p38 mitogen-activated protein kinase signaling in experimental arthritis

Dapagliflozin targets the crosstalk between apoptosis, autophagy, and Hedgehog signaling pathways through AMPK activation in the adjuvant-induced arthritic rat model

Rheumatoid arthritis is a long-term autoimmune disorder, causes joint capsule, cartilage, and bone damage. Dapagliflozin, a novel antidiabetic drug, demonstrated promising effects against different disorders. Herein, we aimed to detect the dose-dependent antiarthritic impact of dapagliflozin alone and in combination with methotrexate standard treatment. Complete Freund's adjuvant-induced arthritic rats were treated with three doses of dapagliflozin (1, 5, or 10 mg/kg/day, p.o.) for 3 weeks, in which 10 mg dose showed eminent anti-arthritic effects according to gait score, paw diameter, arthritic index (AI), morphological and histological results. To reveal dapagliflozin mechanism, locomotor, biochemical, and histological measures were assessed in dapagliflozin (10 mg/kg/day) and/or methotrexate (0.75 mg/kg/week, i.p.)-treated arthritic rats. Radiography and histology confirmed the prominent anti-arthritic effect of dapagliflozin via reduced RF, MMP-1, and MMP-3, and improved gait score, ankle diameter, and AI. Anti-inflammatory impact was confirmed by the downregulation of TNF-α, IL-1β, IL-6, and NF-κb p65 expression. Upregulation of autophagy was detected through; Beclin-1, ULK-1, and ATG-7, in dapagliflozin treated arthritic rats. Furtherly, dapagliflozin stimulated apoptotic activity, by boosting articular levels of CASP-3, CASP-9, cartilage gene expression of p53, and Bax/Bcl2 ratio. Interestingly, dapagliflozin upregulates p-AMPK/t-AMPK articular activity. Additionally, dapagliflozin inhibited the Hedgehog signaling pathway, through the downregulation of cartilage Shh, ptch1, Smo, and Gli-1 expression. Dapagliflozin/methotrexate combination therapy exhibited greater anti-arthritic benefits compared to methotrexate alone. These data highlight dapagliflozin as an anti-rheumatic drug, either alone or with methotrexate.

NaHS@Cy5@MS@SP nanoparticles improve rheumatoid arthritis by inactivating the Hedgehog signaling pathway through sustained and targeted release of H2S into the synovium

BACKGROUND

Aberrant proliferation and inflammation of fibroblast-like synoviocytes (FLSs) significantly contribute to the pathogenesis of rheumatoid arthritis (RA). Deficiency of hydrogen sulfide (H2S) is a driving force for the development of RA, and the short half-life of the H2S-releasing donor sodium hydrosulfide (NaHS) limits its clinical application in RA therapy. Designing a targeted delivery system with slow-release properties for FLSs could offer novel strategies for treating RA.

METHODS

Herein, we designed a strategy to achieve slow release of H2S targeted to the synovium, which was accomplished by synthesizing NaHS-CY5@mesoporous silic@LNP targeted peptide Dil (NaHS@Cy5@MS@SP) nanoparticles.

RESULTS

Our results demonstrated that NaHS@Cy5@MS@SP effectively targets FLSs, upregulates H2S and its-producing enzyme cystathionine-γ-lyase (CSE) in the joints of arthritic mice. Overexpression of CSE inhibited the proliferation, migration, and inflammation of FLSs upon lipopolysaccharide (LPS) exposure, effects that were mimicked by NaHS@Cy5@MS@SP. In vivo studies showed that NaHS@Cy5@MS@SP achieved a threefold higher AUCinf than that of free NaHS, significantly improving the bioavailability of NaHS. Further, NaHS@Cy5@MS@SP inhibited synovial hyperplasia and reduced bone and cartilage erosion in the DBA/1J mouse model of collagen-induced arthritis (CIA), which was superior to NaHS. RNA sequencing and molecular studies validated that NaHS@Cy5@MS@SP inactivated the Hedgehog signaling pathway in FLSs, as evidenced by reductions in the protein expression of SHH, SMO, GLI1 and phosphorylated p38/MAPK.

CONCLUSION

This study highlights NaHS@Cy5@MS@SP as a promising strategy for the controlled and targeted delivery of H2S to synoviocytes, offering potential for RA management.

Immunomodulatory Tissue Factors in the Gallbladder Walls of Pediatric Patients with Chronic Calculous Cholecystitis

BACKGROUND

The rising rates of gallstones and cholecystectomy in pediatric populations underscore the increasing concern regarding chronic cholecystitis. However, the morphopathogenesis of pediatric calculous cholecystitis is still not well understood. This study aimed to determine the expression and distribution of immunomodulatory factors interleukin-12 (IL-12), interleukin-13 (IL-13), interleukin-1β (IL-1β), sonic hedgehog protein (SHH), nuclear factor NF-kappa-B p65 subunit (NFkBp65), and heat shock protein 60 (HSP60) in the gallbladder walls of pediatric patients with chronic calculous cholecystitis.

METHODS

In total, 11 gallbladder samples were collected from pediatric patients with calculous cholecystitis during cholecystectomy, while 5 healthy gallbladder samples served as controls. IL-12, IL-13, IL-1β, SHH, NFkBp65, and HSP60 were detected by immunohistochemistry. The number of positive structures in gallbladder wall epithelium, vasculature, and inflammatory infiltrate was assessed semi-quantitatively by microscopy. A Mann-Whitney U test and Spearman's rank-order correlation coefficient were calculated.

RESULTS

Statistically significant differences were observed between patient and control samples in the expression of IL-1β, SHH, and NFkBp65 in the epithelium, as well as in the expression of IL-12, SHH, and HSP60 in the blood vessels. The expression of IL-1β was stronger in the epithelium of controls, while other markers were more prominent in patient samples.

CONCLUSIONS

An increased number of NFkBp65, IL-12, and HSP60 positive cells in patient gallbladder tissue suggests a significant role of these tissue factors in driving immune modulation and sustaining the inflammation in pediatric chronic calculous cholecystitis. The noticeable expression of SHH in patient gallbladder tissue indicates its part in tissue regeneration and repair processes, as well as in modulating inflammation and vascular responses in calculous cholecystitis. The significant positive correlations between the factors studied highlight the importance of their coordinated interaction and intricate crosstalk in the morphopathogenesis of calculous cholecystitis.

L-selectin Promotes Migration, Invasion and Inflammatory Response of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via NF-kB Signaling Pathway

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by chronic inflammation of the synovium and progressive joint damage. Fibroblast-like synoviocytes (FLSs) exhibit excessive proliferative and aggressive phenotypes and play a major role in the pathophysiology of RA. Previous studies have confirmed the pathologic role of L-selectin in cell adhesion and migration. In rheumatoid arthritis models, L-selectin regulates leukocyte homing, which leads to joint inflammation. Moreover, in L-selectin knockout mice, there is a reduction in joint inflammation. However, the associations of L-selectin with FLSs in RA remain unclear. This study aims to reveal the effect of L-selectin on RA-FLSs and to investigate the molecular mechanism of L-selectin in RA. Our findings indicated that L-selectin was significantly expressed in RA synovial tissues and RA-FLSs. L-selectin silencing reduced RA-FLSs migration and invasion and attenuated the secretion of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 in vitro. Moreover, investigations into mechanisms revealed that L-selectin activated the nuclear factor kappa-B (NF-κB) signaling pathway while blocking this signaling pathway could compromise the effects of L-selectin. Finally, in vivo experiments with a collagen-induced arthritis rat model revealed that silencing L-selectin alleviated inflammatory infiltration of the synovium and cartilage destruction, and validated the NF-κB signaling pathways findings observed in vitro. In summary, we show that L-selectin enhances the migration and invasion of RA-FLSs through the activation of NF-κB signaling pathways, ultimately worsening the progression of RA.

Single-Cell Multi-Dimensional data analysis reveals the role of ARL4C in driving rheumatoid arthritis progression and Macrophage polarization dynamics

Rheumatoid arthritis (RA) is an enduring autoimmune inflammatory condition distinguished by continual joint inflammation, hyperplasia of the synovium, erosion of bone, and deterioration of cartilage.Fibroblast-like synoviocytes (FLSs) exhibiting "tumor-like" traits are central to this mechanism.ADP-ribosylation factor-like 4c (ARL4C) functions as a Ras-like small GTP-binding protein, significantly impacting tumor migration, invasion, and proliferation.However, it remains uncertain if ARL4C participates in the stimulation of RA FLSs exhibiting "tumor-like" features, thereby fostering the advancement of RA. In our investigation, we unveiled, for the inaugural instance, via the amalgamated scrutiny of single-cell RNA sequencing (scRNA-seq) and Bulk RNA sequencing (Bulk-seq) datasets, that activated fibroblast-like synoviocytes (FLSs) showcase high expression of ARL4C, and the ARL4C protein expression in FLSs derived from RA patients significantly surpasses that observed in individuals with osteoarthritis (OA) and traumatic injury (trauma).Silencing of the ARL4C gene markedly impeded the proliferation of RA FLSs by hindered the transition of cells from the G0/G1 phase to the S phase, and intensified cell apoptosis and diminished the migratory and invasive capabilities. Co-culture of ARL4C gene-silenced RA FLSs with monocytes/macrophages significantly inhibited the polarization of monocytes/macrophages toward M1 and the repolarization of M2 to M1.Furthermore, intra-articular injection of shARL4C significantly alleviated synovial inflammation and cartilage erosion in collagen-induced arthritis (CIA) rats. In conclusion, our discoveries propose that ARL4C assumes a central role in the synovial inflammation, cartilage degradation, and bone erosion associated with RA by triggering the PI3K/AKT and MAPK signaling pathways within RA FLSs.ARL4C holds promise as a prospective target for the development of pharmaceutical agents targeting FLSs, with the aim of addressing RA.

Microenvironment Responsive Hydrogel Exerting Inhibition of Cascade Immune Activation and Elimination of Synovial Fibroblasts for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a progressive autoimmune disease and drug therapy has been restricted due to poor therapeutic efficacy and adverse effects. In RA synovium, dendritic cells present self-antigens to activate cascade immune pathway. Furthermore, downstream macrophages secrete high levels of pro-inflammatory cytokines; Hyperplasia of activated synovial fibroblasts (FLS) is responsible for hypoxic synovium microenvironment, secretion of cytokines/chemokines and erosion of bone/cartilage tissues. Positive feedback loop of inflammation between macrophages and FLS independent of antigen-presentation is constructed. Herein, an injectable pH-sensitive peptide hydrogel encapsulating siRNA/Methotrexate-polyethyleneimine (siMP, including sip65MP, sip38MP, siCD86MP) and Bismuthene nanosheet/Methotrexate-polyethyleneimine (BiMP) is successfully developed. Among them, siCD86MP reduces protein level of co-stimulatory molecule CD86 while sip65MP and sip38MP separately inhibit NF-κB and MAPK-p38 pathways of macrophages and FLS to suppress secretion of cytokines and MMPs. Meanwhile, reduction in anti-apoptotic property of FLS induced by inhibition of NF-κB pathway has a synergistic effect with photodynamic therapy (PDT) and photothermal therapy (PTT) mediated by BiMP for FLS elimination, effectively ameliorating hypoxic synovium microenvironment. After being injected into synovium, hydrogel responds to acidic microenvironment and serves as a reservoir for sustained drug release and inherent retention capacity of which enables cationic nanoparticles to bypass tissue barrier for precise synovium targeting. This brand-new drug delivery system combines modulating cascade immune pathway from beginning to end by RNAi and eliminating FLS for improving synovium microenvironment by phototherapy together, providing a robust strategy for clinical RA treatment.

miRNA-148a-containing GMSC-derived EVs modulate Treg/Th17 balance via IKKB/NF-κB pathway and treat a rheumatoid arthritis model

Mesenchymal stem cells (MSCs) have demonstrated potent immunomodulatory properties that have shown promise in the treatment of autoimmune diseases, including rheumatoid arthritis (RA). However, the inherent heterogeneity of MSCs triggered conflicting therapeutic outcomes, raising safety concerns and limiting their clinical application. This study aimed to investigate the potential of extracellular vesicles derived from human gingival mesenchymal stem cells (GMSC-EVs) as a therapeutic strategy for RA. Through in vivo experiments using an experimental RA model, our results demonstrate that GMSC-EVs selectively homed to inflamed joints and recovered Treg and Th17 cell balance, resulting in the reduction of arthritis progression. Our investigations also uncovered miR-148a-3p as a critical contributor to the Treg/Th17 balance modulation via IKKB/NF-κB signaling orchestrated by GMSC-EVs, which was subsequently validated in a model of human xenograft versus host disease (xGvHD). Furthermore, we successfully developed a humanized animal model by utilizing synovial fibroblasts obtained from patients with RA (RASFs). We found that GMSC-EVs impeded the invasiveness of RASFs and minimized cartilage destruction, indicating their potential therapeutic efficacy in the context of patients with RA. Overall, the unique characteristics - including reduced immunogenicity, simplified administration, and inherent ability to target inflamed tissues - position GMSC-EVs as a viable alternative for RA and other autoimmune diseases.

Phosphorylation of human glioma-associated oncogene 1 on Ser937 regulates Sonic Hedgehog signaling in medulloblastoma

Aberrant activation of sonic hedgehog (SHH) signaling and its effector transcriptional factor GLI1 are essential for oncogenesis of SHH-dependent medulloblastoma (MBSHH) and basal cell carcinoma (BCC). Here, we show that SHH inactivates p38α (MAPK14) in a smoothened-dependent manner, conversely, p38α directly phosphorylates GLI1 on Ser937/Ser941 (human/mouse) to induce GLI1's proteasomal degradation and negates the transcription of SHH signaling. As a result, Gli1S941E loss-of-function knock-in significantly reduces the incidence and severity of smoothened-M2 transgene-induced spontaneous MBSHH, whereas Gli1S941A gain-of-function knock-in phenocopies Gli1 transgene in causing BCC-like proliferation in skin. Correspondingly, phospho-Ser937-GLI1, a destabilized form of GLI1, positively correlates to the overall survival rate of children with MBSHH. Together, these findings indicate that SHH-induced p38α inactivation and subsequent GLI1 dephosphorylation and stabilization in controlling SHH signaling and may provide avenues for future interventions of MBSHH and BCC.

Salt Behind the Scenes of Systemic Lupus Erythematosus and Rheumatoid Arthritis

PURPOSE OF REVIEW

Sodium is vital for human health. High salt intake is a global health problem and is associated with cardiovascular morbidity and mortality. Recent evidence suggests that both innate and adaptive immune systems are affected by sodium. In general, excess salt intake drives immune cells toward a pro-inflammatory phenotype. The incidence of autoimmune diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), is steadily increasing. As excess salt induces a pro-inflammatory state, increased salt intake may have impacts on autoimmune diseases. The relationship between salt intake and autoimmune diseases is most widely studied in patients with SLE or RA. This review aimed to summarize the relationship between salt intake and SLE and RA.

RECENT FINDINGS

Most, but not all, of these studies showed that high salt intake might promote SLE by M1 macrophage shift, increase in Th17/Treg cell ratio, activation of dendritic and follicular helper T cells, and increased secretion of pro-inflammatory cytokines. In RA, apart from driving immune cells toward a pro-inflammatory state, high salt intake also influences cellular signaling pathways, including receptor activator of nuclear factor κB ligand (RANKL), Rho GTPases, and MAPK (mitogen-activated protein kinase). There is now sufficient evidence that excess salt intake may be related to the development and progression of SLE and RA, although there are still knowledge gaps. More studies are warranted to further highlight the relationship between excess salt intake, SLE, and RA. Salt intake may affect cell types and pro-inflammatory cytokines and signaling pathways associated with the development and progression of systemic lupus erythematosus and rheumatoid arthritis. Bcl-6 B-cell lymphoma, 6 Erk extracellular signal-regulated kinases, IFN-γ interferon-gamma, JNK c-Jun N-terminal kinase, IL-4 interleukin 4, IL-6 interleukin 6, MAPK mitogen-activated protein kinase, STAT signal transducer and activator of transcription, Tnf-α tumor necrosis factor, Treg T regulatory cell.

Novel HIF-1α Inhibitor AMSP-30m Mitigates the Pathogenic Cellular Behaviors of Hypoxia-Stimulated Fibroblast-Like Synoviocytes and Alleviates Collagen-Induced Arthritis in Rats via Inhibiting Sonic Hedgehog Pathway

Synovial hypoxia-inducible factor 1α (HIF-1α) is a prospective therapeutic target for rheumatoid arthritis (RA). AMSP-30 m, a novel HIF-1α inhibitor, was reported to have notable anti-arthritic effects in rats with adjuvant-induced arthritis. However, its roles in inhibiting the pathogenic behaviors of fibroblast-like synoviocytes (FLS) and the involved mechanisms remain unknown. Here, AMSP-30 m inhibited proliferation and induced apoptosis in hypoxia-induced RA FLS (MH7A cell line), as evidenced by decreased cell viability, reduced Ki67-positive cells, G0/G1 phase arrest, lowered C-myc and Cyclin D1 protein levels, emergence of apoptotic nuclear fragmentation, raised apoptosis rates, and activation of caspase 3. Furthermore, AMSP-30 m prevented hypoxia-induced increases in pro-inflammatory factor production, MMP-2 activity, migration index, migrated/invasive cells, and actin cytoskeletal rearrangement. In vivo, AMSP-30 m alleviated the severity of rat collagen-induced arthritis (CIA). Mechanically, AMSP-30 m reduced HIF-1α expression and blocked sonic hedgehog (Shh) pathway activation in hypoxia-induced MH7A cells and CIA rat synovium, as shown by declines in pathway-related proteins (Shh, Smo, and Gli-1). Particularly, the combination of Shh pathway inhibitor cyclopamine enhanced AMSP-30 m's inhibitory effects on the pathogenic behaviors of hypoxia-stimulated MH7A cells, whereas the combination of Shh pathway activator SAG canceled AMSP-30 m's therapeutic effects in vitro and in CIA rats, implying a close involvement of Shh pathway inhibition in its anti-arthritic effects. We likewise confirmed AMSP-30 m's anti-proliferative role in hypoxia-induced primary CIA FLS. Totally, AMSP-30 m suppressed hypoxia-induced proliferation, inflammation, migration, and invasion of MH7A cells and ameliorated the severity of rat CIA via inhibiting Shh signaling.