Hypoxia--a key regulator of angiogenesis and inflammation in rheumatoid arthritis

Synergistic rheumatoid arthritis therapy by interrupting the detrimental feedback loop to orchestrate hypoxia M1 macrophage polarization using an enzyme-catalyzed nanoplatform

A detrimental feedback loop between hypoxia and oxidative stress consistently drives macrophage polarization toward a pro-inflammatory M1 phenotype, thus persistently aggravating rheumatoid arthritis (RA) progression. Herein, an enzyme-catalyzed nanoplatform with synergistic hypoxia-relieving and reactive oxygen species (ROS)-scavenging properties was developed using bovine serum albumin-bilirubin-platinum nanoparticles (BSA-BR-Pt NPs). Bilirubin was employed to eliminate ROS, while platinum exhibited a synergistic effect in scavenging ROS and simultaneously generated oxygen. In mice RA model, BSA-BR-Pt NPs treatment exhibited superior effects, resulting in significant improvements in joint inflammation, cartilage damage, and bone erosion, compared to methotrexate, the most widely used antirheumatic drug. Mechanistically, RNA-sequencing data and experimental results elucidated that BSA-BR-Pt NPs induced a re-polarization of hypoxic M1 macrophages to M2 macrophages via switching glycolysis to oxidative phosphorylation through the inhibition of HIF-1α pathway. Collectively, this research for the first time elaborated the underlying mechanism of enzyme-catalyzed nanoplatform in orchestrating macrophage polarization, and identified a novel therapeutic strategy for RA and other inflammatory disorders.

RNA-seq Based Transcriptome Analysis Reveals Role of Myoglobin in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease which manifests as joint destruction and bone erosion, could be caused by both genetic and environmental factors. Currently, the causes of RA are unknown, and targeted therapies are often associated with side effects and contraindications. The detection rate of RA in women is higher than men (3:1), however, there is still a lack of comprehensive understanding of the relationship between sex and RA. We hypothesized gender differences in RA prevalence and their associated mechanisms by performing genome-wide transcriptome analysis of synovial biopsy samples. The results indicated that myoglobin (MB) was differentially expressed between males and females, with higher expression in males than females in healthy populations, while the opposite was observed in RA patients. MB interacted with HLA class II histocompatibility antigen, DM beta (HLA-DMB) and the inflammatory factor interleukin 6 (IL-6) in the human synovial cell line MH7A.

A novel low-background nitroreductase fluorescent probe for real-time fluorescence imaging and surgical guidance of thyroid cancer resection

Thyroid cancer always appears insidiously with few noticeable clinical symptoms. Due to its limitations, conventional ultrasound imaging can lead to missed or misdiagnosed cases. Surgery is still the primary treatment method of thyroid cancer, but removal of surrounding healthy tissues to minimize recurrence leads to overtreatment and added patient suffering. To address this challenge, herein, a nitroreductase (NTR) fluorescent probe, Ox-NTR, has been developed for detecting thyroid cancer and tracking the surgical removal of thyroid tumors by fluorescence imaging. The conjugated structure of oxazine 1 was disrupted, significantly reducing the issue of high background signals, thus effectively achieving low background fluorescence. Under hypoxic conditions, the nitro group of Ox-NTR can be reduced to an amine and subsequently decomposed into oxazine 1, emitting intense red fluorescence. Ox-NTR has a low detection limit of 0.09 μg/mL for NTR with excellent photostability and selectivity. Cellular studies show that Ox-NTR can effectively detect NTR levels in hypoxic thyroid cancer cells. Moreover, the ability of Ox-NTR of rapid response to thyroid cancer in vivo is confirmed by fluorescence imaging in mice, distinguishing tumors from normal tissues due to its superior low background fluorescence. Utilizing this fluorescence imaging method during surgical resection can guide the removal of tumors, preventing both missed tumor tissues and accidental removal of healthy tissue. In summary, the novel Ox-NTR offers precise detection capabilities that provide significant advantages over traditional imaging methods for thyroid cancer diagnosis and treatment, making it a valuable tool to guide tumor removal in surgical procedures.

Oral administration of Robinia pseudoacacia L. flower exosome-like nanoparticles attenuates gastric and small intestinal mucosal ferroptosis caused by hypoxia through inhibiting HIF-1α- and HIF-2α-mediated lipid peroxidation

The prevention and treatment of gastrointestinal mucosal injury caused by a plateau hypoxic environment is a clinical conundrum due to the unclear mechanism of this syndrome; however, oxidative stress and microbiota dysbiosis may be involved. The Robinia pseudoacacia L. flower, homologous to a functional food, exhibits various pharmacological effects, such as antioxidant, antibacterial, and hemostatic activities. An increasing number of studies have revealed that plant exosome-like nanoparticles (PELNs) can improve the intestinal microbiota and exert antioxidant effects. In this study, the oral administration of Robinia pseudoacacia L. flower exosome-like nanoparticles (RFELNs) significantly ameliorated hypoxia-induced gastric and small intestinal mucosal injury in mice by downregulating hypoxia-inducible factor-1α (HIF-1α) and HIF-2α expression and inhibiting hypoxia-mediated ferroptosis. In addition, oral RFELNs partially improved hypoxia-induced microbial and metabolic disorders of the stomach and small intestine. Notably, RFELNs displayed specific targeting to the gastrointestinal tract. In vitro experiments using gastric and small intestinal epithelial cell lines showed that cell death caused by elevated HIF-1α and HIF-2α under 1% O2 mainly occurred via ferroptosis. RFELNs obviously inhibited HIF-1α and HIF-2α expression and downregulated the expression of NOX4 and ALOX5, which drive reactive oxygen species production and lipid peroxidation, respectively, suppressing ferroptosis under hypoxia. In conclusion, our findings underscore the potential of oral RFELNs as novel, naturally derived agents targeting the gastrointestinal tract, providing a promising therapeutic approach for hypoxia-induced gastric and small intestinal mucosal ferroptosis.

Investigating Expression Dynamics of miR-21 and miR-10b in Glioblastoma Cells In Vitro: Insights into Responses to Hypoxia and Secretion Mechanisms

Glioblastoma poses significant challenges in oncology, with bevacizumab showing promise as an antiangiogenic treatment but with limited efficacy. microRNAs (miRNAs) 10b and 21 have emerged as potential biomarkers for bevacizumab response in glioblastoma patients. This study delves into the expression dynamics of miR-21 and miR-10b in response to hypoxia and explores their circulation mechanisms. In vitro experiments exposed glioma cells (A172, U87MG, U251) and human umbilical vein endothelial cells (HUVEC) to hypoxic conditions (1% oxygen) for 24 h, revealing heightened levels of miR-10b and miR-21 in glioblastoma cells. Manipulating miR-10b expression in U87MG, demonstrating a significant decrease in VEGF alpha (VEGFA) following miR-10b overexpression under hypoxic conditions. Size exclusion chromatography illustrated a notable shift towards miR-21 and miR-10b exosomal packaging during hypoxia. A proposed model suggests that effective bevacizumab treatment reduces VEGFA levels, heightening hypoxia and subsequently upregulating miR-21 and miR-10b expression. These miRNAs, released via exosomes, might impact various cellular processes, with miR-10b notably contributing to VEGFA level reduction. However, post-treatment increases in miR-10b and miR-21 could potentially restore cells to normoxic conditions through the downregulation of VEGF. This study highlights the intricate feedback loop involving miR-10b, miR-21, and VEGFA in glioblastoma treatment, underscoring the necessity for personalized therapeutic strategies. Further research should explore clinical implications for personalized glioma treatments.

Progress and prospects of biomarker-based targeted therapy and immune checkpoint inhibitors in advanced gastric cancer

Gastric cancer and gastroesophageal junction cancer represent the leading cause of tumor-related death worldwide. Although advances in immunotherapy and molecular targeted therapy have expanded treatment options, they have not significantly altered the prognosis for patients with unresectable or metastatic gastric cancer. A minority of patients, particularly those with PD-L1-positive, HER-2-positive, or MSI-high tumors, may benefit more from immune checkpoint inhibitors and/or HER-2-directed therapies in advanced stages. However, for those lacking specific targets and unique molecular features, conventional chemotherapy remains the only recommended effective and durable regimen. In this review, we summarize the roles of various signaling pathways and further investigate the available targets. Then, the current results of phase II/III clinical trials in advanced gastric cancer, along with the superiorities and limitations of the existing biomarkers, are specifically discussed. Finally, we will offer our insights in precision treatment pattern when encountering the substantial challenges.

A Review of Advances in Molecular Imaging of Rheumatoid Arthritis: From In Vitro to Clinic Applications Using Radiolabeled Targeting Vectors with Technetium-99m

Rheumatoid arthritis (RA) is a systemic autoimmune disorder caused by inflammation of cartilaginous diarthrodial joints that destroys joints and cartilage, resulting in synovitis and pannus formation. Timely detection and effective management of RA are pivotal for mitigating inflammatory arthritis consequences, potentially influencing disease progression. Nuclear medicine using radiolabeled targeted vectors presents a promising avenue for RA diagnosis and response to treatment assessment. Radiopharmaceutical such as technetium-99m (99mTc), combined with single photon emission computed tomography (SPECT) combined with CT (SPECT/CT), introduces a more refined diagnostic approach, enhancing accuracy through precise anatomical localization, representing a notable advancement in hybrid molecular imaging for RA evaluation. This comprehensive review discusses existing research, encompassing in vitro, in vivo, and clinical studies to explore the application of 99mTc radiolabeled targeting vectors with SPECT imaging for RA diagnosis. The purpose of this review is to highlight the potential of this strategy to enhance patient outcomes by improving the early detection and management of 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.

Bridging the gap in rheumatoid arthritis treatment with hyaluronic acid-based drug delivery approaches

Rheumatoid Arthritis (RA) is a chronic, inflammatory, auto-immune disease that is majorly associated with the degradation of the synovial linings of the joints. It is a progressive disease that reduces the life span in affected individuals. Nanoparticles involving hyaluronic acid (HA) have gained the limelight for designing target-specific and more effective drug delivery options for RA. HA is found abundantly in the synovial fluid and acts as a natural ligand for the CD44 receptors. The targeted delivery approach using CD44 as the target can help in minimizing off-target drug distribution. These HA-based surface-decorated nanocarriers, hydrogels, and MNs are cutting-edge strategies that promise tailored delivery, fewer side effects, and more patient adherence to address the common issues associated with RA therapy. Considering the above facts, this review attempts to discuss the role of HA in making more effective formulations for therapeutic delivery in treating RA. Additionally, it provides a comprehensive overview of the potential advancements, mainly in treating RA by HA-based topical, transdermal, and parenteral drug delivery systems, with relevant case studies. The existing difficulties and potential paths for future research on HA-based non-conventional formulations for the management of RA are also discussed.

The protective effect of natural medicines in rheumatoid arthritis via inhibit angiogenesis

Rheumatoid arthritis is a chronic immunological disease leading to the progressive bone and joint destruction. Angiogenesis, accompanied by synovial hyperplasia and inflammation underlies joint destruction. Delaying or even blocking synovial angiogenesis has emerged as an important target of RA treatment. Natural medicines has a long history of treating RA, and numerous reports have suggested that natural medicines have a strong inhibitory activity on synovial angiogenesis, thereby improving the progression of RA. Natural medicines could regulate the following signaling pathways: HIF/VEGF/ANG, PI3K/Akt pathway, MAPKs pathway, NF-κB pathway, PPARγ pathway, JAK2/STAT3 pathway, etc., thereby inhibiting angiogenesis. Tripterygium wilfordii Hook. f. (TwHF), sinomenine, and total glucoside of Paeonia lactiflora Pall. Are currently the most representative of all natural products worthy of development and utilization. In this paper, the main factors affecting angiogenesis were discussed and different types of natural medicines that inhibit angiogenesis were systematically summarized. Their specific anti-angiogenesis mechanisms are also reviewed which aiming to provide new perspective and options for the management of RA by targeting angiogenesis.

Chondroitin sulfate-modified tragacanth gum-gelatin composite nanocapsules loaded with curcumin nanocrystals for the treatment of arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease of yet undetermined etiology that is accompanied by significant oxidative stress, inflammatory responses,  and damage to joint tissues. In this study, we designed chondroitin sulfate (CS)-modified tragacanth gum-gelatin composite nanocapsules (CS-Cur-TGNCs) loaded with curcumin nanocrystals (Cur-NCs), which rely on the ability of CS to target CD44 to accumulate drugs in inflamed joints. Cur was encapsulated in the form of nanocrystals into tragacanth gum-gelatin composite nanocapsules (TGNCs) by using an inborn microcrystallization method, which produced CS-Cur-TGNCs with a particle size of approximately 80 ± 11.54 nm and a drug loading capacity of 54.18 ± 5.17%. In an in vitro drug release assay, CS-Cur-TGNCs showed MMP-2-responsive properties. During the treatment of RA, CS-Cur-TGNCs significantly inhibited oxidative stress, promoted the polarization of M2-type macrophages to M1-type macrophages, and decreased the expression of inflammatory factors (TNF-α, IL-1β, and IL-6). In addition, it also exerted excellent anti-inflammatory effects, and significantly alleviated the swelling of joints during the treatment of gouty arthritis (GA). Therefore, CS-Cur-TGNCs, as a novel drug delivery system, could lead to new ideas for clinical therapeutic regimens for RA and GA.

Discovery of novel diaryl substituted isoquinolin-1(2H)-one derivatives as hypoxia-inducible factor-1 signaling inhibitors for the treatment of rheumatoid arthritis

Since synovial hypoxic microenvironment significantly promotes the pathological progress of rheumatoid arthritis (RA), hypoxia-inducible factor 1 (HIF-1) has been emerged as a promising target for the development of novel therapeutic agents for RA treatment. In this study, we designed and synthesized a series of diaryl substituted isoquinolin-1(2H)-one derivatives as HIF-1 signaling inhibitors using scaffold-hopping strategy. By modifying the substituents on N-atom and 6-position of isoquinolin-1-one, we discovered compound 17q with the most potent activities against HIF-1 (IC50 = 0.55 μM) in a hypoxia-reactive element (HRE) luciferase reporter assay. Further pharmacological studies revealed that 17q concentration-dependently blocked hypoxia-induced HIF-1α protein accumulation, reduced inflammation response, inhibited cellular invasiveness and promoted VHL-dependent HIF-1α degradation in human RA synovial cell line. Moreover, 17q improved the pathological injury of ankle joints, decreased angiogenesis and attenuated inflammation response in the adjuvant-induced arthritis (AIA) rat model, indicating the promising therapeutic potential of compound 17q as an effective HIF-1 inhibitor for RA therapy.

Synovium microenvironment-responsive injectable hydrogel inducing modulation of macrophages and elimination of synovial fibroblasts for enhanced treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a progressive autoimmune disease accompanied by joint swelling, cartilage erosion and bone damage. Drug therapy for RA has been restricted due to poor therapeutic effect, recurrence and adverse effects. Macrophages and synovial fibroblasts both play important roles in the pathology of RA. Macrophages secrete large amount of pro-inflammatory cytokines, while synovial fibroblasts are tightly correlated with hypoxia synovium microenvironment, cytokine release, recruitment of pro-inflammatory cells, bone and cartilage erosion. Therefore, in this timely research, an injectable and pH-sensitive peptide hydrogel loading methotrexate (MTX) and bismuthene nanosheet/polyethyleneimine (BiNS/PEI) has been developed to reduce the activity of macrophages and eliminate over-proliferated synovial fibroblasts simultaneously. MTX can reduce the cytokine secretion of macrophages/anti-apoptosis property of synovial fibroblasts and BiNS/PEI can eliminate synovial fibroblasts via photodynamic therapy (PDT) and photothermal therapy (PTT) routes. The hydrogel was injected into the acidic inflammatory synovium for precise targeting and served as a drug reservoir for pH responsive and sustained drug release, while improving the bioavailability and reducing the toxicity of MTX. Excellent therapeutic efficacy has been achieved in both in vivo and in vitro studies, and this unique drug delivery system provides a new and robust strategy to eliminate synovial fibroblasts and modulate immune system for RA treatment in clinical.

Mechanisms of vascular invasion after cartilage injury and potential engineering cartilage treatment strategies

Articular cartilage injury is one of the most common diseases in orthopedic clinics. Following an articular cartilage injury, an inability to resist vascular invasion can result in cartilage calcification by newly formed blood vessels. This process ultimately leads to the loss of joint function, significantly impacting the patient's quality of life. As a result, developing anti-angiogenic methods to repair damaged cartilage has become a popular research topic. Despite this, tissue engineering, as an anti-angiogenic strategy in cartilage injury repair, has not yet been adequately investigated. This exhaustive literature review mainly focused on the process and mechanism of vascular invasion in articular cartilage injury repair and summarized the major regulatory factors and signaling pathways affecting angiogenesis in the process of cartilage injury. We aimed to discuss several potential methods for engineering cartilage repair with anti-angiogenic strategies. Three anti-angiogenic tissue engineering methods were identified, including administering angiogenesis inhibitors, applying scaffolds to manage angiogenesis, and utilizing in vitro bioreactors to enhance the therapeutic properties of cultured chondrocytes. The advantages and disadvantages of each strategy were also analyzed. By exploring these anti-angiogenic tissue engineering methods, we hope to provide guidance for researchers in related fields for future research and development in cartilage repair.

Microneedles loaded with cerium-manganese oxide nanoparticles for targeting macrophages in the treatment of rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a prevalent inflammatory autoimmune disease characterised by persistent inflammation and joint damage with elevated levels of reactive oxygen species (ROS). Current treatment modalities for RA have significant limitations, including poor bioavailability, severe side effects, and inadequate targeting of inflamed joints. Herein, we synthesised cerium/manganese oxide nanoparticles (NPs) as efficient drug carriers with antioxidant and catalytic-like functions that can eliminate ROS to facilitate the polarization of macrophages phenotype from M1 to M2 and alleviate inflammation. Methotrexate (MTX), a first-line RA medication, was loaded into the NPs, which were further modified with bovine serum albumin (BSA) and integrated into dissolving hyaluronic acid-based microneedles (MNs) for transdermal delivery.

RESULT

This innovative approach significantly enhanced drug delivery efficiency, reduced RA inflammation, and successfully modulated macrophage polarization toward an anti-inflammatory phenotype.

CONCLUSION

This research not only presents a promising drug delivery strategy for RA but also contributes broadly to the field of immune disease treatment by offering an advanced approach for macrophage phenotypic reprogramming.

Tetramethylpyrazine alleviates hypoxia-induced proliferation, migration, and inflammatory response of fibroblast-like synoviocytes via inhibiting the HIF-1α- circCDC42BPB pathway

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, which might trigger cartilage, bone damage, and disability. Recent studies have suggested that Tetramethylpyrazine (TMP), an alkaloid monomer isolated from the rhizome of the traditional herbal medicine Ligusticum wallichii Franch, exerts a broad spectrum of pharmacological properties, containing anti-inflammatory. This study aimed to analyze the role and underlying mechanism of TMP in RA.

METHODS

Under Hypoxia condition, RA-Fibroblast-like synoviocyte (FLS) were treated with TMP at different doses. Cell viability, proliferation, cell cycle progression, and migration were detected using Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry assay, wound healing assay, and transwell assay. Cyclin D1, Proliferating cell nuclear antigen (PCNA), Matrix metalloproteinase-2 (MMP2), MMP9, and hypoxia-inducible factor-1α (HIF-1α) protein levels were measured using western blot assay. Interleukin-6 (IL-6) and IL-8 were evaluated using ELISA. Circular RNA (circRNA) hsa_circ_0005178 (circCDC42BPB), CDC42BPB, and HIF-1α expression were determined using real-time quantitative polymerase chain reaction (RT-qPCR). Binding between HIF-1α and CDC42BPB promoter was predicted by JASPAR and verified using dual-luciferase reporter and Chromatin immunoprecipitation (ChIP) assays.

RESULTS

TMP might hinder FLS proliferation, cycle progression, migration, and inflammatory response under hypoxic conditions. CircCDC42BPB expression was increased in RA patients and RA-FLSs treated with hypoxia, while its level was obviously reduced in RA-FLSs treated with hypoxia and TMP. TMP might abolish hypoxia-induced circCDC42BPB expression. Upregulation of circCDC42BPB might partially overturn the repression of TMP on hypoxia-caused RA-FLS damage. TMP might regulate circCDC42BPB level via HIF-1α in RA-FLSs under hypoxic conditions.

CONCLUSION

TMP might block RA-FLS injury partly via regulating the HIF-1α- circCDC42BPB pathway, providing a promising therapeutic target for RA.

Alleviated NCOA4-mediated ferritinophagy protected RA FLSs from ferroptosis in lipopolysaccharide-induced inflammation under hypoxia

OBJECTIVE

Ferroptosis is a reactive oxygen species (ROS)- and iron-dependent form of non-apoptotic cell death process. Previous studies have demonstrated that ferroptosis participates in the development of inflammatory arthritis. However, the role of ferroptosis in rheumatoid arthritis (RA) inflammatory hypoxic joints remains unclear. This study sought to explore the underlying mechanism of ferroptosis on lipopolysaccharide (LPS)-induced RA fibroblast-like synoviocytes (FLSs).

METHODS

FLSs, isolated from patients with RA, were treated with LPS and ferroptosis inducer (erastin and RSL-3), and ferroptosis inhibitor (Fer-1 and DFO), respectively. The cell viability was measured by CCK-8. The cell death was detected by flow cytometer. The proteins level were tested by Western blot. The cytosolic ROS and lipid peroxidation were determined using DCFH-DA and C11-BODIPY581/591 fluorescence probes, respectively. The small interfering RNA (siRNA) was used to knock down related proteins. The levels of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), iron, inflammatory cytokines (IL6 and IL8), and LDH were analyzed by commercial kits.

RESULTS

Ferroptosis was activated by LPS in RA FLS with increased cellular damage, ROS and lipid peroxidation, intracellular Fe and IL8, which can be further amplified by ferroptosis inducer (erastin and RSL-3) and inhibited by ferroptosis inhibitor (Fer-1 and DFO). Mechanistically, LPS triggered ferroptosis via NCOA4-mediated ferritinophagy in RA FLSs, and knockdown of NCOA4 strikingly prevent the process of ferroptosis. Intriguingly, LPS-induced RA FLSs became insensitive to ferroptosis and NCOA4-mediated ferritinophagy under hypoxia compared with normoxia. Knockdown of HIF-1α reverted ferroptosis and ferritinophagy evoking by LPS-induced RA FLSs inflammation under hypoxia. In addition, low dose of auranofin (AUR) induced re-sensitization of ferroptosis and ferritinophagy through inhibiting the expression of HIF-1α under hypoxia.

CONCLUSIONS

NCOA4-mediated ferritinophagy was a key driver of ferroptosis in inflammatory RA FLSs. The suppression of NCOA4-mediated ferritinophagy protected RA FLSs from ferroptosis in LPS-induced inflammation under hypoxia. Targeting HIF-1α/NCOA4 and ferroptosis could be an effective and valuable therapeutic strategy for synovium hyperplasia in the patients with RA.

Impact of C-reactive protein on the effect of Roxadustat for the treatment of anemia in chronic kidney disease: a systematic review of randomized controlled trials

BACKGROUND

Chronic inflammation, reflected by an increased blood C-reactive protein (CRP) level, is common in patients with chronic kidney disease (CKD) and is involved in the development of renal anemia. This systematic review aims to investigate the impacts of CRP on the efficacy of hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) in the treatment of renal anemia in patients with CKD.

METHODS

We conducted a comprehensive search of electronic databases including Pubmed, Web of Science, Embase, Cochrane Library, CNKI, Wanfang, and the International Clinical Trials Registry Platform (ICTRP), from their inception to May 19, 2022. We systematically reviewed evidence from randomized controlled trials using HIF-PHIs for renal anemia treatment. The mean difference (MD) in changes in hemoglobin concentration (∆Hb) before and after treatment served as the meta-analysis outcome, utilizing a random-effects model. We compared groups with CRP levels greater than or equal to the upper limit of normal (ULN) and less than the ULN. Additionally, further analysis was conducted in the CRP ≥ ULN group comparing HIF-PHIs and erythropoiesis-stimulating agents (ESA).

RESULTS

A total of 7 studies from 6 publications were included in the analysis. In the comparison between the CRP ≥ ULN group and the CRP < ULN group, 524 patients from 4 studies were incorporated into the analysis. All patients received roxadustat as the primary intervention. The pooled results revealed no significant difference in ΔHb between patients with CRP ≥ ULN and CRP < ULN at baseline (Mean Difference: 0.00, 95% Confidence Interval: -0.32 to 0.33, P = 0.99). Moreover, within the CRP ≥ ULN group, three studies involving 1399 patients compared the efficacy of roxadustat and erythropoiesis-stimulating agents (ESAs). The results indicated no significant difference in ΔHb between patients treated with ESAs and HIF-PHIs (Mean Difference: 0.24, 95% Confidence Interval: -0.08 to 0.56, P = 0.14). In terms of medication dosage, an increase in ESA dose over time was observed across various studies, particularly evident in the CRP ≥ ULN group, while the dose of roxadustat remains constant over time and is not influenced by the baseline levels of CRP.

CONCLUSIONS

Our systematic review demonstrates that roxadustat exhibits similar efficacy across different CRP levels. Moreover, within the CRP ≥ ULN group, roxadustat can maintain efficacy comparable to ESA without the necessity for dose escalation.

TRIAL REGISTRATION

CRD42023396704.

Network pharmacology and experimental validation to study the potential mechanism of Tongguanteng injection in regulating apoptosis in osteosarcoma

OBJECTIVE

The main objectives of this study were to identify the active components of Tongguanteng injection (TGT) and investigate the preclinical efficacy and mechanism of TGT on osteosarcoma using a combination of network pharmacology and experimental validation.

METHODS

To identify the active constituents and targets of TGT against osteosarcoma using network pharmacology, we constructed a network consisting of an 'active ingredient-disease-target-pathway' and a protein-protein interaction (PPI) network. The target organ network was utilized to investigate the distribution of core targets in tissues. Afterwards, the core targets underwent Gene ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The binding energy between receptors and ligands was compared using molecular docking. In addition, SwissADME was employed to forecast the pharmacokinetic characteristics of the substances. Finally, real-time polymerase chain reaction (RT-PCR), cell proliferation assay, morphological analysis, apoptosis assay, mitochondrial membrane potential (MMP) detection, and Western blotting were utilized to confirm the potential mechanisms of TGT treatment in osteosarcoma cell lines 143B and SAOS2.

RESULTS

A total of 54 chemical constituents of TGT and 71 targets associated with osteosarcoma were acquired. Through the molecular docking technology, Tenacigenin B, Marsdekoiside, Taraxasterol, Tenacissoside G, Tenacissoside L, and Tenacissoside J were identified as the primary active components of TGT among the various compounds. Analysis of target organs suggests that TGT may play an anti-osteosarcoma role through immune regulation. The GO and KEGG enrichment analysis revealed that TGT could trigger osteosarcoma cell apoptosis by inhibiting the HIF-1 signalling pathway and modulating PD-1 expression and the PD-1 checkpoint pathway in cancer. SwissADME database predicted that Tenacigenin B and Taraxasterol had the best drug-likeness. In vitro studies also demonstrated that TGT suppressed the activity and induced alterations in the morphology of osteosarcoma cells. It decreased MMP levels, triggered apoptosis by increasing Bax expression and Caspase-3 activity, and decreased Bcl-2 expression, thereby exerting an anti-osteosarcoma effect. In the meantime, RT-PCR tests demonstrated that TGT could control immune response against tumors and hinder the proliferation and spread of cancerous cells by impacting the levels of critical factors, including JUN, HSP90AA1, HDAC1, and CDK1.

CONCLUSION

The study accurately anticipated the active components, targets, and pathways of TGT in the management of osteosarcoma. The molecular mechanism of TGT-induced apoptosis in osteosarcoma cells was demonstrated by in vitro experiments. These results provide theoretical and technical support for TGT as a clinical adjuvant drug for osteosarcoma.

Current situation and trend of non-coding RNA in rheumatoid arthritis: a review and bibliometric analysis

Background

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that affects multiple joints and has adverse effects on various organs throughout the body, often leading to a poor prognosis. Recent studies have shown significant progress in the research of non-coding RNAs (ncRNAs) in RA. Therefore, this study aims to comprehensively assess the current status and research trends of ncRNAs in RA through a bibliometric analysis.

Methods

This study retrieved articles relevant to ncRNAs and RA from the Science Citation Index Expanded Database of the Web of Science Core Collection between January 1st, 2003, and July 31st, 2023. The relevant articles were screened based on the inclusion criteria. VOSviewer and CiteSpace are utilized for bibliometric and visual analysis.

Results

A total of 1697 publications were included in this study, and there was a noticeable increase in annual publications from January 1st, 2003, to July 31st, 2023. China, the United States, and the United Kingdom were the most productive countries in this field, contributing to 43.81%, 13.09%, and 3.87% of the publications. Anhui Medical University and Lu Qianjin were identified as the most influential institution and author. Frontiers In Immunology stood out as the most prolific journal, while Arthritis & Rheumatology was the most co-cited journal. Additionally, the research related to "circular RNA", "oxidative stress", "proliferation", and "migration" have emerged as new hotspots in the field.

Conclusion

In this study, we have summarized the publication characteristics related to ncRNA and RA and identified the most productive countries, institutions, authors, journals, hot topics, and trends.

2-Deoxy-D-glucose ameliorates inflammation and fibrosis in a silicosis mouse model by inhibiting hypoxia-inducible factor-1α in alveolar macrophages

Inhaling silica causes the occupational illness silicosis, which mostly results in the gradual fibrosis of lung tissue. Previous research has demonstrated that hypoxia-inducible factor-1α (HIF-1α) and glycolysis-related genes are up-regulated in silicosis. The role of 2-deoxy-D-glucose (2-DG) as an inhibitor of glycolysis in silicosis mouse models and its molecular mechanisms remain unclear. Therefore, we used 2-DG to observe its effect on pulmonary inflammation and fibrosis in a silicosis mouse model. Furthermore, in vitro cell experiments were conducted to explore the specific mechanisms of HIF-1α. Our study found that 2-DG down-regulated HIF-1α levels in alveolar macrophages induced by silica exposure and reduced the interleukin-1β (IL-1β) level in pulmonary inflammation. Additionally, 2-DG reduced silica-induced pulmonary fibrosis. From these findings, we hypothesize that 2-DG reduced glucose transporter 1 (GLUT1) expression by inhibiting glycolysis, which inhibits the expression of HIF-1α and ultimately reduces transcription of the inflammatory cytokine, IL-1β, thus alleviating lung damage. Therefore, we elucidated the important regulatory role of HIF-1α in an experimental silicosis model and the potential defense mechanisms of 2-DG. These results provide a possible effective strategy for 2-DG in the treatment of silicosis.

Association analysis of Vascular Endothelial Growth Factor-A (VEGF-A) polymorphism in rheumatoid arthritis using computational approaches

Rheumatoid arthritis (RA), is marked by joint inflammation leading to pannus formation which results in cartilage destruction promoting bone erosion. The pathological hallmark of RA includes synovial hyperplasia and synovial angiogenesis. Active tissue neovascularization is observed in RA. Vascular endothelial Growth factor A (VEGFA), an endothelial cell-specific proangiogenic molecule is triggered by hypoxic cells and its levels are upregulated in RA. The aim of this study was to investigate functional and pathogenic VEGFA variants and to identify the impact of point mutation in VEGFA's interaction with VEGFR2 and how these polymorphisms affect the susceptibility and severity of RA. We investigated impact of these point mutations on the stability of VEGFA using various computational tools. These mutations were further identified by conservational profile as they are highly involved as structural and functional mutations. Furthermore, these selected variants were modelled and docked against targeted domain regions IGD2 and IGD3 of VEGFR2. Further molecular dynamic simulations were performed using Gromacs. Out of 168 nsSNPS, 19 were highlighted as highly pathogenic using insilico prediction tools. InterPro and ConSurf revealed domains and conserved variants respectively. After stability analysis, we concluded that almost all the mutations were responsible for decreasing the protein stability. HOPE predicted that all the selected damaging nsSNPs were present in the domain which is essential for the functioning of VEGFA protein. Constructed Ramachandran plot and ERRAT validated the quality of all the models. Based on the interactions predicted by STRING database, we performed Protein-Protein docking between VEGFA and VEGFR2. We found few conserved interactions and new polar contacts among wild-type and mutants with VEGFR2. From the simulations, we concluded that mutant R108Q was the most stabilizing mutant among all others whereas R82Q, C86Y, and R108W complexed with VEGFR2 were comparatively less stabilizing as compared to the wild type. This study provides insight into pathogenic nsSNPs that can affect VEGFA protein structure and function. These high-risk variants must be taken into consideration for genetic screening of patients suffering from RA.

Examining the functions of the vascular endothelial growth factor/hypoxia-inducible factor signaling pathway in psoriatic arthritis

Objectives

The present study aimed to examine the roles of the vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF), and heme oxygenase-1 (HO-1) in psoriatic arthritis (PsA).

Patients and methods

In this cross-sectional study conducted between November 2020 and May 2021, 64 patients (43 female, 21 male; mean age: 43.2±10.4 years; range, 22 to 60 years) with active PsA were included in the patient group, and 64 healthy volunteers (43 female, 21 male; mean age: 42.8±10.5 years; range, 23 to 61 years) were included in the control group. The demographic features of all cases were recorded. The following indices were used to assess the activity of PsA: Bath Ankylosing Spondylitis Disease Activity Index, Disease Activity Score in 28 joints (DAS28), and Visual Analog Scale. Additionally, Disease Activity in Psoriatic Arthritis (DAPSA) and Psoriasis Area and Severity Index (PASI) were used to evaluate the patients. The biochemical parameters of the patients were calculated. The serum levels of VEGF, HIF, and HO-1 were determined using an enzyme-linked immunosorbent assay.

Results

When the molecule levels and clinical features of the groups were evaluated, it was found that the VEGF and HIF-1 levels were higher in the patient group compared to the control group (p<0.05). No difference was observed in the comparison of the HO-1 levels of the patient group and the control group (p<0.05). A positive correlation was found between VEGF, HIF-1, and HO-1 (p<0.05). A positive relationship was found between VEGF and HIF-1 and erythrocyte sedimentation rate, C-reactive protein, DAPSA score, and PASI score (p<0.05). It was also determined that there was a positive relationship between the HIF molecule and DAS28 (p<0.05).

Conclusion

According to the results obtained in the present study, VEGF and HIF play a role in the etiology of PsA, and the observation of intermolecular correlation suggests that these molecules move together in pathogenesis.

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.

Ferrihydrite Nanoparticles Alleviate Rheumatoid Arthritis by Nanocatalytic Antioxidation and Oxygenation

Oxidative stress and hypoxia are two key biochemical factors in the development of rheumatoid arthritis (RA). As both reactive oxygen species (ROS) and oxygen gas (O2) are oxygen-related chemicals, we suggest that a redox reaction converting ROS into O2 can mitigate oxidative stress and hypoxia concurrently, synergistically modulating the inflammatory microenvironment. In this work, ferrihydrite, a typical iron oxyhydroxide, is prepared in nanodimensions in which tetrahedrally coordinated Fe can form a composite catalytic center by coupling with an adjacent hydroxyl group, cooperatively facilitating H2O2 decomposition and O2 generation, presenting a high catalase-like activity. In the RA region, the nanomaterial catalyzes the conversion of excess H2O2 into O2, achieving both antioxidation and oxygenation favoring the alleviation of inflammation. Both cellular and in vivo experiments demonstrate the desirable efficacy of ferrihydrite nanoparticles for RA treatment. This work provides a methodology for the catalytic therapy of inflammatory diseases featuring both oxidative stress and hypoxia.

Role of mitochondria-bound HK2 in rheumatoid arthritis fibroblast-like synoviocytes

Background

Glucose metabolism, specifically, hexokinase 2 (HK2), has a critical role in rheumatoid arthritis (RA) fibroblast-like synoviocyte (FLS) phenotype. HK2 localizes not only in the cytosol but also in the mitochondria, where it protects mitochondria against stress. We hypothesize that mitochondria-bound HK2 is a key regulator of RA FLS phenotype.

Methods

HK2 localization was evaluated by confocal microscopy after FLS stimulation. RA FLSs were infected with Green fluorescent protein (GFP), full-length (FL)-HK2, or HK2 lacking its mitochondrial binding motif (HK2ΔN) expressing adenovirus (Ad). RA FLS was also incubated with methyl jasmonate (MJ; 2.5 mM), tofacitinib (1 µM), or methotrexate (1 µM). RA FLS was tested for migration and invasion and gene expression. Gene associations with HK2 expression were identified by examining single-cell RNA sequencing (scRNA-seq) data from murine models of arthritis. Mice were injected with K/BxN serum and given MJ. Ad-FLHK2 or Ad-HK2ΔN was injected into the knee of wild-type mice.

Results

Cobalt chloride (CoCl2) and platelet-derived growth factor (PDGF) stimulation induced HK2 mitochondrial translocation. Overexpression of the HK2 mutant and MJ incubation reversed the invasive and migrative phenotype induced by FL-HK2 after PDGF stimulation, and MJ also decreased the expression of C-X-C Motif Chemokine Ligand 1 (CXCL1) and Collagen Type I Alpha 1 Chain (COL1A1). Of interest, tofacitinib but not methotrexate had an effect on HK2 dissociation from the mitochondria. In murine models, MJ treatment significantly decreased arthritis severity, whereas HK2FL was able to induce synovial hypertrophy as opposed to HK2ΔN.

Conclusion

Our results suggest that mitochondrial HK2 regulates the aggressive phenotype of RA FLS. New therapeutic approaches to dissociate HK2 from mitochondria offer a safer approach than global glycolysis inhibition.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Hypoxia-inducible factor-1α regulates the interleukin-6 production by B cells in rheumatoid arthritis

Objectives

Rheumatoid arthritis (RA) is a disease characterised by bone destruction and systemic inflammation, and interleukin-6 (IL-6) is a therapeutic target for treating it. The study aimed at investigating the sources of IL-6 and the influence of hypoxia-inducible factor-1α (HIF-1α) on IL-6 production by B cells in RA patients.

Methods

The phenotype of IL-6-producing cells in the peripheral blood of RA patients was analysed using flow cytometry. Bioinformatics, real-time polymerase chain reaction, Western blot and immunofluorescence staining were used to determine the IL-6 production and HIF-1α levels in B cells. A dual-luciferase reporter assay and chromatin immunoprecipitation were used to investigate the regulatory role of HIF-1α on IL-6 production in human and mouse B cells.

Results

Our findings revealed that B cells are major sources of IL-6 in the peripheral blood of RA patients, with the proportion of IL-6-producing B cells significantly correlated with RA disease activity. The CD27-IgD+ naïve B cell subset was identified as the typical IL-6-producing subset in RA patients. Both HIF-1α and IL-6 were co-expressed by B cells in the peripheral blood and synovium of RA patients, and HIF-1α was found to directly bind to the IL6 promoter and enhance its transcription.

Conclusion

This study highlights the role of B cells in producing IL-6 and the regulation of this production by HIF-1α in patients with RA. Targeting HIF-1α might provide a new therapeutic strategy for treating RA.

Hypoxia regulates adipose mesenchymal stem cells proliferation, migration, and nucleus pulposus-like differentiation by regulating endoplasmic reticulum stress via the HIF-1α pathway

OBJECTIVE

Hypoxia can promote stem cell proliferation and migration through HIF-1α. Hypoxia can regulate cellular endoplasmic reticulum (ER) stress. Some studies have reported the relationship among hypoxia, HIF-α, and ER stress, however, while little is known about HIF-α and ER stress in ADSCs under hypoxic conditions. The purpose of the study was to investigate the role and relationship of hypoxic conditions, HIF-1α and ER stress in regulating adipose mesenchymal stem cells (ADSCs) proliferation, migration, and NPC-like differentiation.

METHOD

ADSCs were pretreated with hypoxia, HIF-1α gene transfection, and HIF-1α gene silence. The ADSCs proliferation, migration, and NPC-like differentiation were assessed. The expression of HIF-1α in ADSCs was regulated; then, the changes of ER stress level in ADSCs were observed to investigate the relationship between ER stress and HIF-1α in ADSCs under hypoxic conditions.

RESULT

The cell proliferation and migration assay results show that hypoxia and HIF-1α overexpression can significantly increase the ADSCs proliferation and migration, while HIF-1α inhibition can significantly decrease the ADSCs proliferation and migration. The HIF-1α and co-cultured with NPCs played an important role in the directional differentiation of ADSCs into NPCs. The hypoxia-regulated ER stress in ADSCs through the HIF-1α pathway, thereby regulating the cellular state of ADSCs, was also observed.

CONCLUSION

Hypoxia and HIF-1α play important roles in proliferation, migration, and NPC-like differentiation of ADSCs. This study provides preliminary evidence that HIF-1α-regulated ER stress thus affects ADSCs proliferation, migration, and differentiation. Therefore, HIF-1α and ER may serve as key points to improve the efficacy of ADSCs in treating disc degeneration.

A Metabolic Driven Bio-Responsive Hydrogel Loading Psoralen for Therapy of Rheumatoid Arthritis

Overexpressed matrix metalloproteinases, hypoxia microenvironment, and metabolic abnormality are important pathological signs of rheumatoid arthritis (RA). Designing a delivery carrier according to the pathological characteristics of RA that can control drug release in response to disease severity may be a promising treatment strategy. Psoralen is the main active ingredient isolated from Psoralea corylifolia L. and possesses excellent anti-inflammatory activities as well as improving bone homeostasis. However, the specific underlying mechanisms, particularly the possible relationships between the anti-RA effects of psoralen and related metabolic network, remain largely unexplored. Furthermore, psoralen shows systemic side effects and has unsatisfactory solubility. Therefore, it is desirable to develop a novel delivery system to maximize psoralen's therapeutic effect. In this study, a self-assembled degradable hydrogel platform is developed that delivers psoralen and calcium peroxide to arthritic joints and controls the release of psoralen and oxygen according to inflammatory stimulation, to regulate homeostasis and the metabolic disorder of the anoxic arthritic microenvironment. Therefore, the hydrogel drug delivery system based on the responsiveness of the inflammatory microenvironment and regulation of metabolism provides a new therapeutic strategy for RA treatment.

Computational Fluid Dynamics (CFD) Model for Analysing the Role of Shear Stress in Angiogenesis in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterised by an attack on healthy cells in the joints. Blood flow and wall shear stress are crucial in angiogenesis, contributing to RA's pathogenesis. Vascular endothelial growth factor (VEGF) regulates angiogenesis, and shear stress is a surrogate for VEGF in this study. Our objective was to determine how shear stress correlates with the location of new blood vessels and RA progression. To this end, two models were developed using computational fluid dynamics (CFD). The first model added new blood vessels based on shear stress thresholds, while the second model examined the entire blood vessel network. All the geometries were based on a micrograph of RA blood vessels. New blood vessel branches formed in low shear regions (0.840-1.260 Pa). This wall-shear-stress overlap region at the junctions was evident in all the models. The results were verified quantitatively and qualitatively. Our findings point to a relationship between the development of new blood vessels in RA, the magnitude of wall shear stress and the expression of VEGF.

Bioactive Compounds and Signaling Pathways of Wolfiporia extensa in Suppressing Inflammatory Response by Network Pharmacology

Wolfiporia extensa (WE) is a medicinal mushroom and an excellent source of naturally occurring anti-inflammatory substances. However, the particular bioactive compound(s) and mechanism(s) of action against inflammation have yet to be determined. Here, we studied anti-inflammatory bioactive compounds and their molecular mechanisms through network pharmacology. Methanol (ME) extract of WE (MEWE) was used for GC-MS analysis to identify the bioactives, which were screened by following Lipinski’s rules. Public databases were used to extract selected bioactives and inflammation-related targets, and Venn diagrams exposed the common targets. Then, STRING and Cytoscape tools were used to construct protein-protein (PPI) network and mushroom-bioactives-target (M-C-T) networks. Gene Ontology and KEGG pathway analysis were performed by accessing the DAVID database and molecular docking was conducted to validate the findings. The chemical reactivity of key compounds and standard drugs was explored by the computational quantum mechanical modelling method (DFT study). Results from GC-MS revealed 27 bioactives, and all obeyed Lipinski’s rules. The public databases uncovered 284 compound-related targets and 7283 inflammation targets. A Venn diagram pointed to 42 common targets which were manifested in the PPI and M-C-T networks. KEGG analysis pointed to the HIF-1 signaling pathway and, hence, the suggested strategy for preventing the onset of inflammatory response was inhibition of downstream NFKB, MAPK, mTOR, and PI3K-Akt signaling cascades. Molecular docking revealed the strongest binding affinity for “N-(3-chlorophenyl) naphthyl carboxamide” on five target proteins associated with the HIF-1 signaling pathway. Compared to the standard drug utilized in the DFT (Density Functional Theory) analysis, the proposed bioactive showed a good electron donor component and a reduced chemical hardness energy. Our research pinpoints the therapeutic efficiency of MEWE and this work suggests a key bioactive compound and its action mechanism against inflammation.

Redox Homeostasis Strategy for Inflammatory Macrophage Reprogramming in Rheumatoid Arthritis Based on Ceria Oxide Nanozyme-Complexed Biopolymeric Micelles

The synovial tissues under rheumatoid arthritis conditions are usually infiltrated by inflammatory cells, particularly M1 macrophages with aberrant redox homeostasis, which causes rapid deterioration of articular structure and function. Herein, we created an ROS-responsive micelle (HA@RH-CeO_X) through the in situ host-guest complexation between ceria oxide nanozymes and hyaluronic acid biopolymers, which precisely delivered nanozyme and clinically approved rheumatoid arthritis drug Rhein (RH) to proinflammatory M1 macrophage populations in inflamed synovial tissues. The abundant cellular ROS could cleave the thioketal linker to trigger the release of RH and Ce. Specifically, the Ce³⁺/Ce⁴⁺ redox pair could present SOD-like enzymatic activity to rapidly decompose ROS and alleviate the oxidative stress in M1 macrophages, while RH could inhibit the TLR4 signaling in M1 macrophages, both of which could act in a concerted manner to induce their repolarization into anti-inflammatory M2 phenotype to ameliorate local inflammation and promote cartilage repair. Notably, rats bearing rheumatoid arthritis showed a drastic increase in the M1-to-M2 macrophage ratio from 1:0.48 to 1:1.91 in the inflamed tissue and significantly reduced inflammatory cytokine levels including TNF-α and IL-6 following the intra-articular injection of HA@RH-CeO_X, accompanied by efficient cartilage regeneration and restored articular function. Overall, this study revealed an approach to in situ modulate the redox homeostasis in inflammatory macrophages and reprogram their polarization states through micelle-complexed biomimetic enzymes, which offers alternative opportunities for the treatment of rheumatoid arthritis.

A novel analytical approach for outcome prediction in newly diagnosed NSCLC based on [18F]FDG PET/CT metabolic parameters, inflammatory markers, and clinical variables

OBJECTIVES

To develop a novel analytical approach based on ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography (PET) metabolic parameters, serum inflammatory markers, and clinical variables to improve the outcome prediction in NSCLC.

METHODS

A total of 190 newly diagnosed NSCLC patients who underwent pretreatment [¹⁸F]FDG PET/CT were retrospectively enrolled and divided into a training cohort (n = 127) and a test cohort (n = 63). Cox regression analysis was used to investigate the predictive values of PET metabolic parameters, inflammation markers, and clinical variables for progression-free survival (PFS) and overall survival (OS). Based on the results of multivariate analysis, PET-based, clinical, and combined models were constructed. The predictive performance of different models was evaluated using time-dependent ROC curve analysis, Harrell concordance index (C-index), calibration curve, and decision curve analysis.

RESULTS

The combined models incorporating SULmax, MTV, NLR, and ECOG PS demonstrated significant prognostic superiority over PET-based models, clinical models, and TNM stage in terms of both PFS (C-index: 0.813 vs. 0.786 vs. 0.776 vs. 0.678, respectively) and OS (C-index: 0.856 vs. 0.792 vs. 0.781 vs. 0.674, respectively) in the training cohort. Similar results were observed in the test cohort for PFS (C-index: 0.808 vs. 0.764 vs. 0.748 vs. 0.679, respectively) and OS (C-index: 0.836 vs. 0.785 vs. 0.726 vs. 0.660, respectively) prediction. The combined model calibrated well in two cohorts. Decision curve analysis supported the clinical utility of the combined model.

CONCLUSIONS

We reported a novel analytical approach combining PET metabolic information with inflammatory biomarker and clinical characteristics, which could significantly improve outcome prediction in newly diagnosed NSCLC.

KEY POINTS

• The nomogram incorporating SULmax, MTV, NLR, and ECOG PS outperformed the TNM stage for outcome prediction in patients with newly diagnosed NSCLC. • The established nomogram could provide refined prognostic stratification.

Role of reactive oxygen species and mitochondrial damage in rheumatoid arthritis and targeted drugs

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation, pannus formation, and bone and cartilage damage. It has a high disability rate. The hypoxic microenvironment of RA joints can cause reactive oxygen species (ROS) accumulation and mitochondrial damage, which not only affect the metabolic processes of immune cells and pathological changes in fibroblastic synovial cells but also upregulate the expression of several inflammatory pathways, ultimately promoting inflammation. Additionally, ROS and mitochondrial damage are involved in angiogenesis and bone destruction, thereby accelerating RA progression. In this review, we highlighted the effects of ROS accumulation and mitochondrial damage on inflammatory response, angiogenesis, bone and cartilage damage in RA. Additionally, we summarized therapies that target ROS or mitochondria to relieve RA symptoms and discuss the gaps in research and existing controversies, hoping to provide new ideas for research in this area and insights for targeted drug development in RA.

Cell-Based Drug Delivery Systems with Innate Homing Capability as a Novel Nanocarrier Platform

Nanoparticle-based drug delivery systems have been designed to treat various diseases. However, many problems remain, such as inadequate tumor targeting and poor therapeutic outcomes. To overcome these obstacles, cell-based drug delivery systems have been developed. Candidates for cell-mediated drug delivery include blood cells, immune cells, and stem cells with innate tumor tropism and low immunogenicity; they act as a disguise to deliver the therapeutic payload. In drug delivery systems, therapeutic agents are encapsulated intracellularly or attached to the surface of the plasma membrane and transported to the desired site. Here, we review the pros and cons of cell-based therapies and discuss their homing mechanisms in the tumor microenvironment. In addition, different strategies to load therapeutic agents inside or on the surface of circulating cells and the current applications for a wide range of disease treatments are summarized.

Acupotomy Improves Synovial Hypoxia, Synovitis and Angiogenesis in KOA Rabbits

Purpose

Knee osteoarthritis (KOA) is a chronic inflammatory disease highly associated with intra-articular hypertension, hypoxia and angiogenesis of synovial tissue. Our previous studies showed that acupotomy could treat KOA in a variety of ways, including reducing cartilage deterioration and enhancing biomechanical qualities. However, the mechanism of hypoxia and angiogenesis induced by acupotomy in KOA synovium remains unclear. This study looked for the benign intervention of acupotomy in synovial pathology.

Methods

The rabbits were divided into 3 groups, Normal group, KOA group, and KOA + Acupotomy (Apo) group, with 11 rabbits in each group. The KOA rabbit model was established by the modified Videman method with six weeks. The KOA + Apo group performed the intervention. The tendon insertion of vastus medialis, vastus lateralis, rectus femoris, biceps femoris, and anserine bursa were selected as treatment points in rabbits. Rabbits were treated once every 7 days for 3 weeks. We observed the intra-articular pressure and oxygen partial pressure (BOLD MRI). The synovial morphology was monitored by Hematoxylin-Eosin Staining (HE Staining). The expression of hypoxia-inducible transcription factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) was detected using Immunohistochemical (IHC), Western Blot and Enzyme-Linked Immunosorbent Assay (ELISA).

Results

Acupotomy reduced intra-articular hypertension and improved the synovial oxygen situation, synovial inflammatory and angiogenesis. HIF-1α, VEGF, IL-1β and TNF-α expression were downregulated by acupotomy.

Conclusion

Acupotomy may reduce inflammation and angiogenesis in KOA rabbit by reducing abnormally elevated intra-articular pressure and improving synovial oxygen environment. The above may provide a new theoretical foundation for acupotomy treatment of KOA.

Targeted inhibition of the GRK2/HIF-1α pathway is an effective strategy to alleviate synovial hypoxia and inflammation

G-protein coupled receptor (GPCR) kinases (GRKs) and hypoxia-inducible factor-1α (HIF-1α) play key roles in rheumatoid arthritis (RA). Several studies have demonstrated that HIF-1α expression is positively regulated by GRK2, suggesting its posttranscriptional effects on HIF-1α. In this study, we review the role of HIF-1α and GRK2 in RA pathophysiology, focusing on their proinflammatory roles in immune cells and fibroblast-like synoviocytes (FLS).We then introduce several drugs that inhibit GRK2 and HIF-1α, and briefly outline their molecular mechanisms. We conclude by presenting gaps in knowledge and our prospects for the pharmacological potential of targeting these proteins and the relevant downstream signaling pathways.Future research is warranted and paramount for untangling these novel and promising roles for GRK2 and HIF-1α in RA.

Targeting hypoxia-inducible factors for breast cancer therapy: A narrative review

Hypoxia-inducible factors (HIFs), central regulators for cells to adapt to low cellular oxygen levels, are often overexpressed and activated in breast cancer. HIFs modulate the primary transcriptional response of downstream pathways and target genes in response to hypoxia, including glycolysis, angiogenesis and metastasis. They can promote the development of breast cancer and are associated with poor prognosis of breast cancer patients by regulating cancer processes closely related to tumor invasion, metastasis and drug resistance. Thus, specific targeting of HIFs may improve the efficiency of cancer therapy. In this review, we summarize the advances in HIF-related molecular mechanisms and clinical and preclinical studies of drugs targeting HIFs in breast cancer. Given the rapid progression in this field and nanotechnology, drug delivery systems (DDSs) for HIF targeting are increasingly being developed. Therefore, we highlight the HIF related DDS, including liposomes, polymers, metal-based or carbon-based nanoparticles.

Photoacoustic image-guided biomimetic nanoparticles targeting rheumatoid arthritis

The high level of reactive oxygen species (ROS) in the rheumatoid arthritis (RA) microenvironment (RAM) and its persistent inflammatory nature can promote damage to joints, bones, and the synovium. Targeting strategies that integrate effective RAM regulation with imaging-based monitoring could lead to improvements in the diagnosis and treatment of RA. Here, we report the combined use of small interfering RNAs (siRNAs^T/I) and Prussian blue nanoparticles (PBNPs) to silence the expression of proinflammatory cytokines TNF-α/IL-6 and scavenge the ROS associated with RAM. To enhance the in vitro and in vivo biological stability, biocompatibility, and targeting capability of the siRNAs^T/I and PBNPs, macrophage membrane vesicles were used to prepare biomimetic nanoparticles, M@P-siRNAs^T/I. The resulting constructs were found to suppress tumor necrosis factor-α/interleukin-6 expression and overcome the hypoxic nature of RAM, thus alleviating RA-induced joint damage in a mouse model. The M@P-siRNAs^T/I of this study could be monitored via near-infrared photoacoustic (PA) imaging. Moreover, multispectral PA imaging without the need for labeling permitted the real-time evaluation of M@P-siRNAs^T/I as a putative RA treatment. Clinical microcomputed tomography and histological analysis confirmed the effectiveness of the treatment. We thus suggest that macrophage-biomimetic M@P-siRNAs^T/I and their analogs assisted by PA imaging could provide a new strategy for RA diagnosis, treatment, and monitoring.

Cationic amino acid transporter-1 (CAT-1) promotes fibroblast-like synoviocyte proliferation and cytokine secretion by taking up L-arginine in rheumatoid arthritis

Background

Abnormal proliferation of fibroblast-like synoviocytes (FLSs) in the synovial lining layer is the primary cause of synovial hyperplasia and joint destruction in rheumatoid arthritis (RA). Currently, the relationship between metabolic abnormalities and FLS proliferation is a new focus of investigation. However, little is known regarding the relationship between amino acid metabolism and RA.

Methods

The concentrations of amino acids and cytokines in the synovial fluid of RA (n = 9) and osteoarthritis (OA, n = 9) were detected by LC–MS/MS and CBA assay, respectively. The mRNA and protein expression of cationic amino acid transporter-1 (CAT-1) were determined in FLSs isolated from RA and OA patients by real-time PCR and western blotting. MTT assay, cell cycle, apoptosis, invasion, and cytokine secretion were determined in FLSs knocked down of CAT-1 using siRNA or treated with D-arginine under normoxic and hypoxic culture conditions. A mouse collagen-induced arthritis (CIA) model was applied to test the therapeutic potential of blocking the uptake of L-arginine in vivo.

Results

L-rginine was upregulated in the synovial fluid of RA patients and was positively correlated with the elevation of the cytokines IL-1β, IL-6, and IL-8. Further examination demonstrated that CAT-1 was the primary transporter for L-arginine and was overexpressed on RA FLSs compared to OA FLSs. Moreover, knockdown of CAT-1 using siRNA or inhibition of L-arginine uptake using D-arginine significantly suppressed L-arginine metabolism, cell proliferation, migration, and cytokine secretion in RA FLSs under normoxic and hypoxic culture conditions in vitro but increased cell apoptosis in a dose-dependent manner. Meanwhile, in vivo assays revealed that an L-arginine-free diet or blocking the uptake of L-arginine using D-arginine suppressed arthritis progression in CIA mice.

Conclusion

CAT-1 is upregulated and promotes FLS proliferation by taking up L-arginine, thereby promoting RA progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02921-8.

Monitoring mitochondrial nitroreductase activity in tumors and a hind-limb model of ischemia in mice using a novel activatable NIR fluorescent probe

We report a mitochondria-targeted nitroreductase (NTR)-activated near-infrared fluorescent probe: CS-NO2. Overexpressed NTR in mitochondria was measured with high sensitivity. More importantly, the probe CS-NO2 successfully monitored NTR activity in solid tumors and a hind-limb model of ischemia in mice. This novel finding indicates the promising function of our probe for the diagnosis of solid tumors and hypoxia-associated diseases.

Harnessing immune response using reactive oxygen Species-Generating/Eliminating inorganic biomaterials for disease treatment

With the increasing understanding of various biological functions mediated by reactive oxygen species (ROS) in the immune system, a number of studies have been designed to develop ROS-generating/eliminating strategies to selectively modulate immunogenicity for disease treatment. These strategies potentially exploit ROS-modulating inorganic biomaterials to harness host immunity to maximize the therapeutic potency by eliciting a favorable immune response. Inorganic biomaterial-guided in vivo ROS scavenging can exhibit several effects to: i) reduce the secretion of pro-inflammatory factors, ii) induce the phenotypic transition of macrophages from inflammatory M1 to immunosuppressive M2 phase, iii) minimize the recruitment and infiltration of immune cells. and/or iv) suppress the activation of nuclear factor kappa-B (NF-κB) pathway. Inversely, ROS-generating inorganic biomaterials have been found to be capable of: i) inducing immunogenic cell death (ICD), ii) reprograming tumor-associated macrophages from M2 to M1 phenotypes, iii) activating inflammasomes to stimulate tumor immunogenicity, and/or iv) recruiting phagocytes for antimicrobial therapy. This review provides a systematic and up-to-date overview on the progress related to ROS-nanotechnology mediated immunomodulation. We highlight how the ROS-generating/eliminating inorganic biomaterials can converge with immunomodulation and ultimately elicit an effective immune response against inflammation, autoimmune diseases, and/or cancers. We expect that contents presented in this review will be beneficial for the future advancements of ROS-based nanotechnology and its potential applications in this evolving field.

Systematic Review: Targeted Molecular Imaging of Angiogenesis and Its Mediators in Rheumatoid Arthritis

Extensive angiogenesis is a characteristic feature in the synovial tissue of rheumatoid arthritis (RA) from a very early stage of the disease onward and constitutes a crucial event for the development of the proliferative synovium. This process is markedly intensified in patients with prolonged disease duration, high disease activity, disease severity, and significant inflammatory cell infiltration. Angiogenesis is therefore an interesting target for the development of new therapeutic approaches as well as disease monitoring strategies in RA. To this end, nuclear imaging modalities represent valuable non-invasive tools that can selectively target molecular markers of angiogenesis and accurately and quantitatively track molecular changes in multiple joints simultaneously. This systematic review summarizes the imaging markers used for single photon emission computed tomography (SPECT) and/or positron emission tomography (PET) approaches, targeting pathways and mediators involved in synovial neo-angiogenesis in RA.

YWHAH Genetic Variants are Associated with Increased Hypoxia Inducible Factor-1α/Vascular Endothelial Growth Factor in Egyptian Rheumatoid Arthritis Patients

The 14-3-3 Eta (14-3-3 η) biomarker platform is a relatively recent discovery with the potential to significantly address the diagnosis and prognosis of rheumatoid arthritis (RA) disease. Hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) have been implicated in inflammatory mechanisms in RA. We hypothesized a molecular association of the coding YWHAH gene and its expressed protein 14-3-3 η with hypoxia and angiogenesis in RA. One hundred healthy subjects and 100 RA patients were enrolled in the study. YWHAH gene expression was determined using quantitative PCR, and its gene polymorphism rs2858750 was assessed by Taqman genotyping assay. Serum levels of 14-3-3 η, HIF-1α, and VEGF were measured using the ELISA technique, and clinical parameters were routinely examined. In RA patients, significant positive correlations were found between 14-3-3 η, HIF-1α (r = 0.84), and VEGF (r = 0.85). YWHAH gene expression was upregulated 10.8 fold (CI 95% 10.1-11.5) in RA patients and significantly correlated with all disease activity parameters, ACPA, and levels of 14-3-3 η, HIF-1α, and VEGF. RA patients showed a higher frequency of YWHAH rs2858750 A allele than healthy subjects (p = 0.02). The risk A allele carriers showed higher disease activity parameters, ACPA, YWHAH gene expression, and increased serum levels of 14-3-3 η (p < 0.001), HIF-1α (p = 0.002), and VEGF (p = 0.001) than the G allele. Serum 14-3-3 η and its rs2858750 genetic variant are associated with increased hypoxia and angiogenesis in RA and activity, and severity of the disease.

Hypoxia-Inducible Factor-2 Alpha Regulates the Migration of Fibroblast-like Synoviocytes via Oxidative Stress-Induced CD70 Expression in Patients with Rheumatoid Arthritis

This study aimed to examine the role of CD70, which is highly expressed on fibroblast-like synoviocytes (FLS), in rheumatoid arthritis (RA) patients. FLS isolated from RA (n = 14) and osteoarthritis (OA, n = 4) patients were stimulated with recombinant interleukin-17 (IL-17; 5 ng/mL) and tumor necrosis factor alpha (TNF-α; 5 ng/mL) for 24 h. Expression of CD70, CD27/soluble CD27 (sCD27), and hypoxia-inducible factor-2 alpha (HIF-2α) was analyzed by RT-qPCR, flow cytometry, and ELISA assays, respectively. Reactive oxygen species (ROS) expression and cell migration were also examined. The HIF-2α inhibitor PT-2385 and CD70 inhibitor BU69 were used to specifically suppress these pathways. Stimulation with IL-17 and TNF-α significantly induced CD70 expression in RA FLS. Although the synovial fluids from patients with RA contained high levels of sCD27, surface expression of CD27, a ligand of CD70, was rarely detected in RA FLS. Cytokine-induced CD70 expression was significantly decreased following antioxidant treatment. Following HIF-2α inhibition, RA FLS had decreased expression of CD70 and ROS levels. Migration of RA FLS was also inhibited by inhibition of CD70 or HIF-2α. The surface expression of CD70 is regulated by HIF-2α and ROS levels and is a key contributor to cytokine-enhanced migration in RA FLS.

Fractal analysis of perfusion imaging in synovitis: a novel imaging biomarker for grading inflammatory activity based on assessing angiogenesis

Objectives

The mutual and intertwined dependence of inflammation and angiogenesis in synovitis is widely acknowledged. However, no clinically established tool for objective and quantitative assessment of angiogenesis is routinely available. This study establishes fractal analysis as a novel method to quantitatively assess inflammatory activity based on angiogenesis in synovitis.

Methods

First, we established a pathophysiological framework for synovitis including fractal analysis of software perfusion phantoms, which allowed to derive explainability with a known and controllable reference standard for vascular structure. Second, we acquired MRI datasets of patients with suspected rheumatoid arthritis of the hand, and three imaging experts independently assessed synovitis analogue to Rheumatoid Arthritis MRI Scoring (RAMRIS) criteria. Finally, we performed fractal analysis of dynamic first-pass perfusion MRI in vivo to evaluate angiogenesis in relation to inflammatory activity with RAMRIS as reference standard.

Results

Fractal dimension (FD) achieved highly significant discriminability for different degrees of inflammatory activity (p<0.01) in software phantoms with known ground-truth of angiogenic structure. FD indicated increasingly chaotic perfusion patterns with increasing grades of inflammatory activity (Spearman’s ρ=0.94, p<0.001). In 36 clinical patients, fractal analysis quantitatively and objectively discriminated individual RAMRIS scores (p≤0.05). Area under the receiver-operating curve was 0.84 (95% CI 0.7 to 0.89) for fractal analysis when considering RAMRIS as ground-truth. Fractal analysis additionally identified angiogenesis in cases where RAMRIS underestimated inflammatory activity.

Conclusions

Based on angiogenesis and perfusion pathophysiology, fractal analysis non-invasively enables comprehensive, objective and quantitative characterisation of inflammatory angiogenesis with subjective and qualitative RAMRIS as reference standard. Further studies are required to establish the clinical value of fractal analysis for diagnosis, prognostication and therapy monitoring in inflammatory arthritis.

CaP-based anti-inflammatory HIF-1α siRNA-encapsulating nanoparticle for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a common inflammatory disease and its treatment is largely limited by drug ineffectiveness or severe side effects. In RA progression, multiple signalling pathways, such as hypoxia-inducible factor (HIF)-1α, nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways, act synergistically to maintain the inflammatory response. To downregulate HIF-1α, NF-κB, and MAPK expression, we proposed HIF-1α siRNA-loaded calcium phosphate nanoparticles encapsulated in apolipoprotein E3-reconstituted high-density lipoprotein (HIF-CaP-rHDL) for RA therapy. Here, we evaluated the potential of CaP-rHDL nanoparticles in RA therapy using a murine macrophage line (RAW 264.7) and a collagen-induced arthritis (CIA) mouse model. The CaP-rHDL nanoparticles showed significant anti-inflammatory effects along with HIF-1α knockdown and NF-κB and MAPK signalling pathway inhibition in lipopolysaccharide-activated macrophages. Moreover, they inhibited receptor activator of NF-κB ligand (RANKL)-induced osteoclast formation. In CIA mice, their intravenous administration resulted in high accumulation at the arthritic joint sites, and HIF-CaP-rHDL effectively suppressed inflammatory cytokine secretion and relieved bone erosion, cartilage damage, and osteoclastogenesis. Thus, HIF-CaP-rHDL demonstrated great potential in RA precision therapy by inhibiting multiple inflammatory signalling pathways.