Iron overload causes macrophages to produce a pro-inflammatory phenotype in the synovium of hemophiliac arthritis via the acetyl-p53 pathway.

AIM: Haemophiliac arthritis (HA) is caused by spontaneous intra-articular hemorrhage and repeated intra-articular hematomas, leading to iron overload, which, in turn, induces M1 macrophage polarisation and inflammatory cytokine secretion, resulting in synovitis. Here, we explored the mechanism by which iron overload in HA induces the polarisation of M1 macrophages, providing a new approach for the treatment of HA synovitis. METHODS: The synovium from the knee joints of normal amputees and patients with HA was collected. Pathological changes in the synovial tissues were analysed using hematoxylin and eosin staining. Iron tissue deposition was evaluated using the iron assay kit and Prussia Blue staining, while macrophage phenotype was determined using immunofluorescence. The levels of pro-inflammatory cytokines and p53 acetylation were determine using western blotting. An in vitro iron overload model was established by inducing THP-1 macrophages with ferric ammonium citrate, and the involvement of acetylated p53 in M1 macrophage polarisation was investigated. RESULTS: Compared to control samples, the iron content in the synovium of patients with HA was significantly increased. The protein levels of M1 macrophage markers, pro-inflammatory cytokines, and acetylated p53, were also significantly elevated in the synovial tissues of patients with HA. Similar results were observed in the in vitro iron overload model. Furthermore, the inhibition of p53 acetylation in vitro reversed these iron overload-induced effects. CONCLUSION: In patients with HA, iron overload induced synovial p53 acetylation, leading to macrophage polarisation toward the M1 phenotype and increased inflammatory cytokine secretion, resulting in synovitis. HIGHLIGHTS: Synovial iron overload is associated with changes in P53 acetylation in hemophiliac arthritis (HA). Acetylated p53, a known regulator of macrophage polarization, is highly expressed in HA synovium, suggesting a potential role in M1 polarization. HA synovial macrophages predominantly polarize into the pro-inflammatory M1 phenotype, secreting elevated levels of pro-inflammatory cytokines.

Iron regulates chondrocyte phenotype in haemophilic cartilage through the PTEN/PI3 K/AKT/FOXO1 pathway.

OBJECTIVE: Our previous study demonstrated that iron overload could lead to haemophilic cartilage destruction by changing chondrocyte phenotype. This change was caused by iron's effect on chondrocyte expression of FGF23 and SOX9, in addition to iron-induced chondrocyte apoptosis and cartilage extracellular matrix degradation. However, the underlying mechanisms remain unclear. This study aimed to determine the mechanism by which iron influences chondrocyte phenotype in the pathogenesis of haemophilic cartilage destruction. METHODS: The expression of the PTEN/PI3K/AKT/FOXO1 signal pathway in the articular cartilage of patients with haemophilic arthritis (HA) or osteoarthritis (OA) was determined using western blot (WB). Additionally, we quantified the expression of iron-induced PTEN, PI3K, p-PI3K, AKT, p-AKT, FOXO1, and p-FOXO1 in primary human normal chondrocyte cells (HUM-iCell-s018) using WB. RESULTS: We found that compared to that in patients with OA, the expression of PTEN, PI3K, AKT, and FOXO1 in the articular cartilage of patients with HA was up-regulated, while the expression of p-PI3K, p-AKT, and p-FOXO1 was down-regulated. Additionally, iron increased the expression of PTEN, PI3K, AKT, and FOXO1 and suppressed that of p-PI3K, p-AKT, and p-FOXO1 in chondrocytes in a dose-dependent manner. CONCLUSIONS: Our findings demonstrated that iron was involved in the pathogenesis of haemophilic cartilage destruction by affecting chondrocyte phenotype through the inhibition of the PTEN/PI3K/AKT/FOXO1 pathway.

Ferroptosis: a new target for iron overload-induced hemophilic arthropathy synovitis.

Iron deposition is closely related to developing haemophilic arthropathy (HA). Studying the relationship between ferroptosis signal expression and iron overload in HA synovium facilitates understanding the pathogenesis of joint synovial hyperplasia in bloodborne arthritis and the development of new protective methods. The knee synovium was collected from HA and osteoarthritis (OA) patients, and pathological changes were analysed by HE and Prussian blue staining. Ferroptosis phenotypes were examined by immunohistochemistry and western blotting. Moreover, ferric ammonium citrate (FAC)-induced was used to construct an in vitro iron overload model to investigate the relationship between iron overload and ferroptosis in synovial fibroblasts (FLS). Furthermore, the factors influencing ferroptosis in FLS were explored. Iron deposition, cell proliferation, and vascular proliferation in the synovium of HA were more obvious. Ferroptosis in HA synovium appears to inhibit. FLS ferroptosis increased with iron accumulation, malondialdehyde (MDA) in cells, and glutathione (GSH) depletion. TNF-α plays a protective role in this process. Blocking the action of TNF-α and inducing ferroptosis significantly reduced synovial proliferation. TNF-α inhibitors combined with a ferroptosis inducer may be a new therapeutic method for HA synovitis.

IL-6, IL-1ß and TNF-α regulation of the chondrocyte phenotype: a possible mechanism of haemophilic cartilage destruction.

OBJECTIVE: Proinflammatory cytokines are considered to be one of the key causes of haemophilic cartilage destruction by inducing chondrocyte apoptosis and extracellular matrix degradation. However, few studies have focused on how proinflammatory cytokines regulate the phenotypic changes of chondrocytes, which may be an important factor in haemophilic cartilage degradation pathogenesis. More understanding is needed about the effect of proinflammatory cytokines on phenotypic changes of the chondrocyte. The objective of this study was to examine how IL-6, TNF-α and IL-1ß regulate the chondrocyte phenotype, which may be an important factor in haemophilic cartilage degradation pathogenesis. METHODS: HUM-iCell-s018 chondrocytes were treated with increasing concentrations of TNF-α, IL-6 or IL-1ß (0, 1, 5, 10 ng/ml) for 24 h, then FGF23 and SOX9 expression was determined by qRT-PCR and WB, respectively. RESULTS: We found that TNF-α, IL-6 and IL-1ß induced FGF23 and suppressed SOX9 expression in chondrocytes in a dose-dependent manner. IL-1ß had a stronger regulatory effect on FGF23, while TNF-α and IL-6 had stronger regulatory effects on SOX9. CONCLUSIONS: These findings suggest that IL-6, IL-1ß and TNF-α may be involved in haemophilic cartilage destruction pathogenesis by altering the chondrocyte phenotype through modulation of FGF23 and SOX9 gene expression.

A Digital Microfluidic RT-qPCR Platform for Multiple Detections of Respiratory Pathogens.

The coronavirus disease 2019 pandemic has spread worldwide and caused more than six million deaths globally. Therefore, a timely and accurate diagnosis method is of pivotal importance for controlling the dissemination and expansions. Nucleic acid detection by the reverse transcription-polymerase chain reaction (RT-PCR) method generally requires centralized diagnosis laboratories and skilled operators, significantly restricting its use in rural areas and field settings. The digital microfluidic (DMF) technique provides a better option for simultaneous detections of multiple pathogens with fewer specimens and easy operation. In this study, we developed a novel digital microfluidic RT-qPCR platform for multiple detections of respiratory pathogens. This method can simultaneously detect eleven respiratory pathogens, namely, mycoplasma pneumoniae (MP), chlamydophila pneumoniae (CP), streptococcus pneumoniae (SP), human respiratory syncytial virus A (RSVA), human adenovirus (ADV), human coronavirus (HKU1), human coronavirus 229E (HCoV-229E), human metapneumovirus (HMPV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (FLUA) and influenza B virus (FLUB). The diagnostic performance was evaluated using positive plasmids samples and clinical specimens compared with off-chip individual RT-PCR testing. The results showed that the limit of detections was around 12 to 150 copies per test. The true positive rate, true negative rate, positive predictive value, negative predictive value, and accuracy of DMF on-chip method were 93.33%, 100%, 100%, 99.56%, and 99.85%, respectively, as validated by the off-chip RT-qPCR counterpart. Collectively, this study reported a cost-effective, high sensitivity and specificity on-chip DMF RT-qPCR system for detecting multiple respiratory pathogens, which will greatly contribute to timely and effective clinical management of respiratory infections in medical resource-limited settings.

FGF23 and SOX9 expression in haemophilic cartilage: In vitro studies of the effects of iron.

INTRODUCTION: Clarifying the links between iron and FGF23, SOX9 expression in chondrocytes would be helpful for comprehending articular cartilage degradation pathogenesis in blood-induced arthritis and exploring new protective methods. AIM: The purpose of this study was to determine iron regulation of fibroblast growth factor 23 (FGF23) and SRY-box 9 (SOX9) in human chondrocytes, an area which is unexplored in blood-induced arthritis cartilage degradation pathogenesis. METHODS: Expression of FGF23, SOX9, MMP13 and collagen Ⅱ in articular cartilage of patients with osteoarthritis (OA) or haemophilic arthritis (HA) was determined by western blot (WB). Iron-induced FGF23 and SOX9 mRNA and protein expression in primary human normal chondrocyte cells (HUM-iCell-s018) was quantified by qRT-PCR and WB, respectively. RESULTS: We found that compared with OA patients, the expression of FGF23, MMP13 in articular cartilage of patients with HA was up-regulated, while the expression of SOX9, collagen Ⅱ was down-regulated. Iron-induced FGF23 and suppressed SOX9 expression in chondrocytes in a dose-dependent manner. CONCLUSIONS: These findings demonstrated that iron was involved in hemophilic cartilage lesion directly via changing cartilage phenotype through regulation of FGF23 and SOX9 expression in chondrocytes.

Study on the morphological characteristics and rotational alignment axis of placement plane of the tibial component in total knee arthroplasty for hemophilia-related knee arthritis.

BACKGROUND: Abnormal epiphyseal growth plate development of the proximal tibia in hemophilia patients leads to notable morphological changes in the mature knee joint. This study aimed to compare the morphological characteristics of tibial component placement cut surface in patients with hemophilic arthritis (HA) and osteoarthritis (OA) and to determine the tibial component rotational alignment axis' best position for HA patients. METHODS: Preoperative computed tomography scans of 40 OA and 40 HA patients who underwent total knee arthroplasty were evaluated using a three-dimensional (3D) software. The tibial component's placement morphological parameters were measured. The tibial component's rotational mismatch angles were evaluated, and the most appropriate 0°AP axis position for HA patients was investigated. RESULTS: In the two groups, the morphology was significantly different in some of the parameters (p < 0.05). The tibial component rotational mismatch angles were significantly different between both groups (p < 0.05). The medial 9.26° of the medial 1/3 of the patellar tendon was the point through which 0°AP axis passed for the HA patients. Similarly, the medial 13.02° of the medial 1/3 of the tibial tubercle was also the point through which the 0°AP axis passed. CONCLUSIONS: The ratio of the anteroposterior length to the geometric transverse length of the placement section of the tibial component in HA patients was smaller than that in OA patients. The medial 9.26° of the medial 1/3 of the patellar tendon or the medial 13.02° of the medial 1/3 of the tibial tubercle seem to be an ideal reference position of the rotational alignment axis of the tibial component for HA patients.

Pathological changes and expression of lysine oxidases and matrix metalloproteinases -1, -2, and -3 in ligaments of patients with haemophilic arthritis.

INTRODUCTION: Studying the pathological changes of ligaments in patients with haemophilic arthritis (HA) has important significance for guiding the release of ligaments during total knee arthroplasty (TKA) and exploring interventions to prevent ligament lesions. AIM: This study was conducted to show the pathological changes and investigate the lysine oxidase (LOX) and matrix metalloproteinase (MMP)-1, -2, and -3 levels in the ligaments of patients with HA compared with those of patients with osteoarthritis (OA). METHODS: Ligaments obtained during the TKA were stained with Masson trichrome, Verhoeff-Van Gieson and haematoxylin and eosin to show the basic pathological changes. Collagen I, elastin, LOXs and MMP-1, -2, and -3 expression levels were detected via western blot. LOX and MMP-1, -2, and -3 mRNA expression levels were analysed via quantitative real-time PCR. RESULTS: Compared with OA ligaments, HA ligaments were constructed more loosely with wider gaps, more breaks, haemocytodeposition and local hypertrophy among the fibres. LOXs and MMP mRNA expression levels were upregulated in the HA tissues, which was consistent with the western blot results. Collagen I and elastin levels were also higher in patients with HA. CONCLUSIONS: The metabolism of the ligaments in patients with HA is more complex than in those with OA, and the ligaments of patients with HA have stronger healing and destruction processes. This pathology is related to iron overload and imbalanced inflammatory factors due to repeated intra-articular bleeding.

[Applicability of lives saved tool in projecting effects of scaling up interventions on reducing maternal mortality rates in the rural area of Guangxi province in China].

OBJECTIVE: To evaluate applicability of lives saved tool (LiST) in projecting effects of maternal health interventions on reducing maternal mortality in the rural area of Guangxi Zhuang Autonomous Region in China, and provide evidence for promoting LiST in China. METHODS: By using maternal intervention coverage and other information collected through the cross-sectional household survey, literature review and expert consultation, LiST projection was performed and modeled. The maternal mortality reduction and causes of death were measured and compared, and the differences were analyzed. SPSS 19.0 was used in the household survey data analysis. RESULTS: Coverage of calcium supplementation, MgSO4-management of pre-eclampsia and institutional delivery reached 51.9%, 99.0% and 98.4% respectively in rural Guangxi in 2011. The LiST captured the general trend of maternal mortality in rural Guangxi. The modeled maternal mortality rate was 4.71%, lower than the measured in 2009 and 10.43% higher in 2010. Maternal mortality rate would decreased to 18/100 000 in 2015 assuming all relevant interventions reached full coverage, and 90% of the maternal morality reduction was attributed to the labor and delivery management. CONCLUSION: LiST can be applied to project effects of maternal health interventions on reducing the maternal mortality in rural Guangxi, but its accuracy was limited by the fact that the effect of relevant interventions on some major causes of maternal death, such as amniotic embolism, was not calculated in LiST and maternal deaths caused by those causes varied by the year in the area. Based on the LiST projection, labor and delivery management was found to be the priority intervention in improving maternal health in rural Guangxi. Improving the quality of obstetric care in township hospitals and facilitating referral of high-risk pregnant women were highly recommended.