Iron metabolism and arthritis: Exploring connections and therapeutic avenues.

ABSTRACT: Iron is indispensable for the viablility of nearly all living organisms, and it is imperative for cells, tissues, and organisms to acquire this essential metal sufficiently and maintain its metabolic stability for survival. Disruption of iron homeostasis can lead to the development of various diseases. There is a robust connection between iron metabolism and infection, immunity, inflammation, and aging, suggesting that disorders in iron metabolism may contribute to the pathogenesis of arthritis. Numerous studies have focused on the significant role of iron metabolism in the development of arthritis and its potential for targeted drug therapy. Targeting iron metabolism offers a promising approach for individualized treatment of arthritis. Therefore, this review aimed to investigate the mechanisms by which the body maintains iron metabolism and the impacts of iron and iron metabolism disorders on arthritis. Furthermore, this review aimed to identify potential therapeutic targets and active substances related to iron metabolism, which could provide promising research directions in this field.

Preosteoclast plays a pathogenic role in syndesmophyte formation of ankylosing spondylitis through the secreted PDGFB - GRB2/ERK/RUNX2 pathway.

OBJECTIVES: Ankylosing spondylitis (AS) is a chronic inflammatory disease that mainly affects the sacroiliac joint and spine. However, the real mechanisms of immune cells acting on syndesmophyte formation in AS are not well identified. We aimed to find the key AS-associated cytokine and assess its pathogenic role in AS. METHODS: A protein array with 1000 cytokines was performed in five AS patients with the first diagnosis and five age- and gender-matched healthy controls to discover the differentially expressed cytokines. The candidate differentially expressed cytokines were further quantified by multiplex protein quantitation (3 AS-associated cytokines and 3 PDGF-pathway cytokines) and ELISA (PDGFB) in independent samples (a total of 140 AS patients vs 140 healthy controls). The effects of PDGFB, the candidate cytokine, were examined by using adipose-derived stem cells (ADSCs) and human fetal osteoblast cell line (hFOB1.19) as in vitro mesenchymal cell and preosteoblast models, respectively. Furthermore, whole-transcriptome sequencing and enrichment of phosphorylated peptides were performed by using cell models to explore the underlying mechanisms of PDGFB. The xCELLigence system was applied to examine the proliferation, chemotaxis, and migration abilities of PDGFB-stimulated or PDGFB-unstimulated cells. RESULTS: The PDGF pathway was observed to have abnormal expression in the protein array, and PDGFB expression was further found to be up-regulated in 140 Chinese AS patients. Importantly, PDGFB expression was significantly correlated with BASFI (Pearson coefficient/p value = 0.62/6.70E - 8) and with the variance of the mSASSS score (mSASSS 2 years - baseline, Pearson coefficient/p value = 0.76/8.75E - 10). In AS patients, preosteoclasts secreted more PDGFB than the healthy controls (p value = 1.16E - 2), which could promote ADSCs osteogenesis and enhance collagen synthesis (COLI and COLIII) of osteoblasts (hFOB 1.19). In addition, PDGFB promoted the proliferation, chemotaxis, and migration of ADSCs. Mechanismly, in ADSCs, PDGFB stimulated ERK phosphorylation by upregulating GRB2 expression and then increased the expression of RUNX2 to promote osteoblastogenesis of ADSCs. CONCLUSION: PDGFB stimulates the GRB2/ERK/RUNX2 pathway in ADSCs, promotes osteoblastogenesis of ADSCs, and enhances the extracellular matrix of osteoblasts, which may contribute to pathological bone formation in AS.

Reducing the risk of gestational diabetes mellitus in chronic hepatitis B virus carriers via more strict control of gestational weight gain.

OBJECTIVE: To explore the association between gestational weight gain (GWG) and gestational diabetes mellitus (GDM) in hepatitis B surface antigen (HBsAg) -positive women using a retrospective cohort study to provide advice on the management of GWG. METHODS: Our study included 39 539 pregnant women who gave birth at the Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. Patients were divided into two groups: the HBsAg-negative and HBsAg-positive groups, comprising 36 500 and 3039 participants, respectively. We used univariate and multivariable logistic regression analyses to explore the association between GWG and GDM in maternal hepatitis B virus (HBV) carrier women. RESULTS: Being HBsAg positive and excessive GWG were independent risk factors for GDM. Excessive GWG was associated with a higher risk of GDM in HBsAg-positive women. Among pre-pregnancy women of normal weight, HBsAg-positive women with adequate GWG had a higher risk of GDM than HBsAg-negative women, whereas HBsAg-positive women with inadequate GWG had a lower risk of GDM. CONCLUSIONS: The optimal GWG ranges for pre-pregnancy normal-weight HBsAg-positive pregnancies might be lower than the US Institute of Medicine recommendations. HBsAg-positive women should strictly control GWG to reduce the risk of GDM.

Heterogeneity induced splay state of amplitude envelope in globally coupled oscillators.

Splay states of the amplitude envelope are stably observed as a heterogenous node is introduced into the globally coupled identical oscillators with repulsive coupling. With the increment of the frequency mismatches between the heterogenous nodes and the rest identical globally coupled oscillators, the formal stable splay state based on the time series becomes unstable, while a splay state based on the new-born amplitude envelopes of time series is stably observed among the rest identical oscillators. The characteristics of the splay state based on the amplitude envelope are numerically and theoretically presented for different parameters of the coupling strength ϵ and the frequency mismatches Δω for small coupling strength and large frequency mismatches. We expect that all these results could reveal the generality of splay states in coupled nonidentical oscillators and help to understand the rich dynamics of amplitude envelopes in multidisciplinary fields.

Association between maternal hepatitis B virus carrier and gestational diabetes mellitus: a retrospective cohort analysis.

INTRODUCTION: Given that many pregnant women have chronic hepatitis B virus (HBV) infection and that gestational diabetes mellitus (GDM) is linked to poor maternal and neonatal outcomes, we looked into the relationship between the hepatitis B surface antigen (HBsAg) and GDM to see if a high HBV DNA load is linked to a higher risk of GDM in chronic maternal HBsAg carriers. MATERIALS AND METHODS: Our study included 39,539 pregnant women who gave birth at the Third Affiliated Hospital of Guangzhou Medical University in Guangzhou, China, between January 1, 2009, and December 31, 2019. The patients were divided into two groups: HBsAg negative (36,500) and positive (3039). The viral load levels of 1250 HBsAg-positive women who had tested their HBV DNA load during pregnancy were separated into three groups. We utilized univariate and multivariable logistical regression analysis to determine the relationship between maternal chronic HBsAg carrier and GDM. RESULTS: Being HBsAg positive was discovered to be an independent risk factor for GDM.Pre-pregnancy Obesity and advanced age were linked to an increased incidence of GDM. Those with a high HBV DNA load (> 106 IU/mL) had a higher risk of GDM than HBsAg-positive women with a low viral load (< 103 IU/mL). Pre-eclampsia and intrahepatic cholestasis of pregnancy (ICP) appeared to be more common in HBsAg-positive women than in uninfected women. CONCLUSIONS: Being HBsAg positive, advanced age, and pre-pregnancy obesity were all revealed to be independent risk factors for GDM in our study. In HBsAg carrier, pregnant women, a high HBV DNA burden was linked to a greater risk of GDM. Furthermore, being an HBsAg carrier during pregnancy raised the risk of ICP and pre-eclampsia.

A DNA Inversion System in Eukaryotes Established via Laboratory Evolution.

DNA inversion is a type of site-specific recombination system that plays an important role in the generation of genetic diversity and phenotypic adaptation by programmed rearrangements in bacteria. However, no such inversion system exhibiting a strong directionality bias has been identified or developed in eukaryotes yet. Here, using directed evolution of Rci recombinase, a tyrosine recombinase from a bacterial DNA inversion system, we identified a mutant Rci8 with a ratio of inversion/deletion up to ∼4320 in yeast. Based on Rci8 recombinase and sfxa101 sites, we have established a DNA inversion system in yeast and mammalian cells, enabling specificity for DNA inversions between inverted sites over deletions between directly repeated sites. Our results validated that the reversible DNA inversion system can act as an on/off transcriptional switch. Moreover, we demonstrate that the inversion system can also work on linear chromosomes. The eukaryotic DNA inversion system would provide a new tool for fields of genetic circuits, cellular barcoding, and synthetic genomes.