Exogenous pentraxin-3 inhibits the reactive oxygen species-mitochondrial and apoptosis pathway in acute kidney injury

Senescence Biomarkers CKAP4 and PTX3 Stratify Severe Kidney Disease Patients

INTRODUCTION

Cellular senescence is the irreversible growth arrest subsequent to oncogenic mutations, DNA damage, or metabolic insult. Senescence is associated with ageing and chronic age associated diseases such as cardiovascular disease and diabetes. The involvement of cellular senescence in acute kidney injury (AKI) and chronic kidney disease (CKD) is not fully understood. However, recent studies suggest that such patients have a higher-than-normal level of cellular senescence and accelerated ageing.

METHODS

This study aimed to discover key biomarkers of senescence in AKI and CKD patients compared to other chronic ageing diseases in controls using OLINK proteomics.

RESULTS

We show that senescence proteins CKAP4 (p-value < 0.0001) and PTX3 (p-value < 0.0001) are upregulated in AKI and CKD patients compared with controls with chronic diseases, suggesting the proteins may play a role in overall kidney disease development.

CONCLUSIONS

CKAP4 was found to be differentially expressed in both AKI and CKD when compared to UHCs; hence, this biomarker could be a prognostic senescence biomarker of both AKI and CKD.

Pediatric nephrotic syndrome: The interplay of oxidative stress and inflammation

Background

The pathophysiological mechanisms crucial in the development of nephrotic syndrome (NS) in the pediatric population are still not fully understood. This study aimed to investigate the relationship between hypertension, oxidative stress, and inflammation in pediatric patients during the acute phase of the disease.

Methods

The study included 33 children, aged 2 to 9 years, with nephrotic syndrome. Blood samples were collected during the acute phase and remission. Parameters of oxidative status were determined, including total oxidative status (TOS), advanced oxidation protein products (AOPP), prooxidant-antioxidant balance (PAB), sulfhydryl groups (-SH), paraoxonase 1 (PON1), and total antioxidant status (TAS) in serum, measured spectrophotometrically. Inflam - matory parameters such as pentraxin 3 (PTX3), leptin, program med cell death ligand 1 (PD-L1), and E-cadherin were determined using enzyme-linked immunosorbent assay (ELISA).

Results

Patients with nephrotic syndrome and hypertension had significantly higher levels of advanced oxidation protein products and total antioxidant status (p=0.029 and p=0.003, respectively). During the acute phase of the disease, lower activity of sulfhydryl groups and paraoxonase 1 was observed compared to remission (p<0.001, for both). Pentraxin 3 levels were higher, while leptin levels were lower during the acute phase (p<0.001, for both). Pentraxin 3 correlated with advanced oxidation protein products and total antioxidant status during the acute phase but not in remission (rs=0.42, p=0.027 and rs=0.43, p=0.025, respectively). A negative correlation between Advanced oxidation protein products and leptin was observed during the acute phase, which disappeared in remission (rs=-0.42, p=0.028).

Conclusions

Results of this study show that hypertension influences oxidative stress markers, and decreased antioxidant capacity may contribute to nephrotic syndrome development. Pentraxin 3 appears as a potential disease activity marker, indicating a dynamic connection between inflammation and oxidative stress. Leptin may also play a role in oxidative stress in nephrotic syndrome.

Role of the mitophagy-apoptosis axis in the pathogenesis of polycystic ovarian syndrome

AIM

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by menstrual irregularities, androgen excess, and polycystic ovarian morphology, but its pathogenesis remains largely unknown. This review focuses on how androgen excess influences the molecular basis of energy metabolism, mitochondrial function, and mitophagy in granulosa cells and oocytes, summarizes our current understanding of the pathogenesis of PCOS, and discuss perspectives on future research directions.

METHODS

A search of PubMed and Google Scholar databases were used to identify relevant studies for this narrative literature review.

RESULTS

Female offspring born of pregnant animals exposed to androgens recapitulates the PCOS phenotype. Abnormal mitochondrial morphology, altered expression of genes related to glycolysis, mitochondrial biogenesis, fission/fusion dynamics, and mitophagy have been identified in PCOS patients and androgenic animal models. Androgen excess causes uncoupling of the electron transport chain and depletion of the cellular adenosine 5'-triphosphate pool, indicating further impairment of mitochondrial function. A shift toward mitochondrial fission restores mitochondrial quality control mechanisms. However, prolonged mitochondrial fission disrupts autophagy/mitophagy induction due to loss of compensatory reserve for mitochondrial biogenesis. Disruption of compensatory mechanisms that mediate the quality control switch from mitophagy to apoptosis may cause a disease phenotype. Furthermore, genetic predisposition, altered expression of genes related to glycolysis and oxidative phosphorylation, or a combination of these factors may also contribute to the development of PCOS.

CONCLUSION

In conclusion, fetuses exposed to a hyperandrogenemic intrauterine environment may cause the PCOS phenotype possibly through disruption of the compensatory regulation of the mitophagy-apoptosis axis.

Bolstering the secretion and bioactivities of umbilical cord MSC-derived extracellular vesicles with 3D culture and priming in chemically defined media

Human mesenchymal stem cells (hMSCs)-derived extracellular vesicles (EVs) have been known to possess the features of the origin cell with nano size and have shown therapeutic potentials for regenerative medicine in recent studies as alternatives for cell-based therapies. However, extremely low production yield, unknown effects derived from serum impurities, and relatively low bioactivities on doses must be overcome for translational applications. As several reports have demonstrated the tunability of secretion and bioactivities of EVs, herein, we introduced three-dimensional (3D) culture and cell priming approaches for MSCs in serum-free chemically defined media to exclude side effects from serum-derived impurities. Aggregates (spheroids) with 3D culture dramatically enhanced secretion of EVs about 6.7 times more than cells with two-dimensional (2D) culture, and altered surface compositions. Further modulation with cell priming with the combination of TNF-α and IFN-γ (TI) facilitated the production of EVs about 1.4 times more than cells without priming (9.4 times more than cells with 2D culture without priming), and bioactivities of EVs related to tissue regenerations. Interestingly, unlike changing 2D to 3D culture, TI priming altered internal cytokines of MSC-derived EVs. Through simulating characteristics of EVs with bioinformatics analysis, the regeneration-relative properties such as angiogenesis, wound healing, anti-inflammation, anti-apoptosis, and anti-fibrosis, for three different types of EVs were comparatively analyzed using cell-based assays. The present study demonstrated that a combinatory strategy, 3D cultures and priming MSCs in chemically defined media, provided the optimum environments to maximize secretion and regeneration-related bioactivities of MSC-derived EVs without impurities for future translational applications.

Molecular insight into pentraxin-3: Update advances in innate immunity, inflammation, tissue remodeling, diseases, and drug role

Pentraxin-3 (PTX3) is the prototype of the long pentraxin subfamily, an acute-phase protein consisting of a C-terminal pentraxin domain and a unique N-terminal domain. PTX3 was initially isolated from human umbilical vein endothelial cells and human FS-4 fibroblasts. It was subsequently found to be also produced by synoviocytes, chondrocytes, osteoblasts, smooth muscle cells, myeloid dendritic cells, epithelial cells, and tumor cells. Various modulatory factors, such as miRNAs, cytokines, drugs, and hypoxic conditions, could regulate the expression level of PTX3. PTX3 is essential in regulating innate immunity, inflammation, angiogenesis, and tissue remodeling. Besides, PTX3 may play dual (pro-tumor and anti-tumor) roles in oncogenesis. PTX3 is involved in the occurrence and development of many non-cancerous diseases, including COVID-19, and might be a potential biomarker indicating the prognosis, activity,and severity of diseases. In this review, we summarize and discuss the potential roles of PTX3 in the oncogenesis and pathogenesis of non-cancerous diseases and potential targeted therapies based on PTX3.

The Protective Role of the Long Pentraxin PTX3 in Spontaneously Hypertensive Rats with Heart Failure

Pentraxin 3 (PTX3) is synthesized locally and released into the circulation, reflecting local inflammation in the cardiovascular system. Therefore, we conducted a study to explore the effect of PTX3 in spontaneously hypertensive heart failure (SHHF) rats. Sprague Dawley (SD) and SHHF rats were treated with recombinant PTX3 protein, and the blood pressure (BP) and echocardiographic parameters were collected. Radioimmunoassay, enzyme immunoassay and enzyme-linked immunosorbent assay (ELISA) were applied to detect plasma levels of atrial/B-type natriuretic peptide (ANP/BNP) and PTX3. The pathological changes in the myocardial tissues were observed by hematoxylin and eosin (HE) and Masson stainings. The mRNA and protein expressions were detected by quantitative real-time reverse-transcription polymerase chain reaction (qPCR) and western blotting. Cardiomyocyte apoptosis was evaluated by TUNEL staining and DNA fragmentation test. Increased plasma concentrations of PTX3 were found in SHHF rats compared with SD rats, which was further enhanced by recombinant PTX3 protein. After injection with recombinant PTX3 protein, the heart function was improved in SHHF rats with the decreased systolic and diastolic BP, and the reduced plasma levels of ANP and BNP. Moreover, PTX3 improved the myocardial damage and interstitial fibrosis in SHHF rats with reduced cardiomyocyte apoptosis and decreased mRNA expressions of pro-inflammatory factors in myocardial tissues. PTX3 could decrease the BP and plasma levels of ANP and BNP in SHHF rats, as well as improve the inflammation, cardiomyocyte apoptosis, and pathological changes of myocardial tissues, suggesting it may be a useful intervention in the treatment of SHHF.

Pentraxin 3 secreted by human adipose-derived stem cells promotes dopaminergic neuron repair in Parkinson's disease via the inhibition of apoptosis

Although adipose-derived human mesenchymal stem cell (hADSC) transplantation has recently emerged as a promising therapeutic modality for Parkinson's disease (PD), its underlying mechanism of action has not been fully elucidated. This study evaluated the therapeutic effects of stereotaxic injection of hADSCs in the striatum of the 6-OHDA-induced mouse model. Furthermore, an in vitro PD model was constructed using tissue-organized brain slices. The therapeutic effect was also evaluated using a co-culture of the hADSCs and 6-OHDA-treated brain slice. The analysis of hADSC exocrine proteins using RNA-sequencing, human protein cytokine arrays, and label-free quantitative proteomics identified key extracellular factors in the hADSC secretion environment. The degeneration and apoptosis of the dopaminergic neurons were measured in the PD samples in vivo and in vitro, and the beneficial effects were evaluated using quantitative reverse transcription-polymerase chain reaction, western blotting, Fluoro-Jade C, TUNEL assay, and immunofluorescence analysis. This study found that hADSCs protected the dopaminergic neurons in the in vivo and vitro models. We identified Pentraxin 3 (PTX3) as a key extracellular factor in the hADSC secretion environment. Moreover, we found that human recombinant PTX3 (rhPTX3) treatment could rescue the pathophysiological behavior of the PD mice in vivo, prevent dopaminergic neuronal death, and increase neuronal terminals in the ventral tegmental area + substantia nigra pars compacta and striatum in the PD brain slices in vitro. Furthermore, testing of the pro-apoptotic markers in the PD mouse brain following rhPTX3 treatment revealed that rhPTX3 can prevent apoptosis and degeneration of the dopaminergic neurons. This study discovered that PTX3, a hADSC-secreted protein, potentially protected the dopaminergic neurons against apoptosis and degeneration during PD progression and improved motor performance in PD mice, indicating the possible mechanism of action of hADSC replacement therapy for PD. Thus, our study discovered potential translational implications for the development of PTX3-based therapeutics for PD.

MiR-29 regulates the function of goat granulosa cell by targeting PTX3 via the PI3K/AKT/mTOR and Erk1/2 signaling pathways

PTX3, a member of the pentraxin protein family, plays important roles in ovulation as a marker of cumulus cell-oocyte complex expansion. However, the expression and function of PTX3 in goat ovarian GCs remain unclear. We isolated GCs from small and large follicles and found that PTX3 expression was significantly decreased and miR-29 mRNA expression was significantly increased during the growth of antral follicles. MiR-29 decreased PTX3 expression by targeting its 3' untranslated. Furthermore, miR-29 promoted GC proliferation, suppressed steroidogenesis and apoptosis by targeting PTX3 via the activation of the PI3K/AKT/mTOR and Erk1/2 signaling pathways. Treatment with inhibitors also verified these results. Meanwhile, we found that PI3K/AKT/mTOR and Erk1/2 signaling pathways had different role in secretion of E2 and P4 by regulating differently various steroidogenic enzyme (CYP19A1, CYP11A1, StAR and HSD3B) expression. These outcomes indicate the potential role of PTX3 in goat follicular growth and atresia.

PTX3 Predicts Myocardial Damage and Fibrosis in Duchenne Muscular Dystrophy

Pentraxin 3 (PTX3) is a main component of the innate immune system by inducing complement pathway activation, acting as an inflammatory mediator, coordinating the functions of macrophages/dendritic cells and promoting apoptosis/necrosis. Additionally, it has been found in fibrotic regions co-localizing with collagen. In this work, we wanted to investigate the predictive role of PTX3 in myocardial damage and fibrosis of Duchenne muscular dystrophy (DMD). DMD is an X-linked recessive disease caused by mutations of the dystrophin gene that affects muscular functions and strength and accompanying dilated cardiomyopathy. Here, we expound the correlation of PTX3 cardiac expression with age and Toll-like receptors (TLRs)/interleukin-1 receptor (IL-1R)-MyD88 inflammatory markers and its modulation by the so-called alarmins IL-33, high-mobility group box 1 (HMGB1), and S100β. These findings suggest that cardiac levels of PTX3 might have prognostic value and potential in guiding therapy for DMD cardiomyopathy.

Oxidative stress regulates progenitor behavior and cortical neurogenesis

Orderly division of radial glial progenitors (RGPs) in the developing mammalian cerebral cortex generates deep and superficial layer neurons progressively. However, the mechanisms that control RGP behavior and precise neuronal output remain elusive. Here, we show that the oxidative stress level progressively increases in the developing mouse cortex and regulates RGP behavior and neurogenesis. As development proceeds, numerous gene pathways linked to reactive oxygen species (ROS) and oxidative stress exhibit drastic changes in RGPs. Selective removal of PRDM16, a transcriptional regulator highly expressed in RGPs, elevates ROS level and induces expression of oxidative stress-responsive genes. Coinciding with an enhanced level of oxidative stress, RGP behavior was altered, leading to abnormal deep and superficial layer neuron generation. Simultaneous expression of mitochondrially targeted catalase to reduce cellular ROS levels significantly suppresses cortical defects caused by PRDM16 removal. Together, these findings suggest that oxidative stress actively regulates RGP behavior to ensure proper neurogenesis in the mammalian cortex.

Baicalein protects renal tubular epithelial cells againsthypoxia-reoxygenation injury

BACKGROUND

To investigate the protective effects and mechanism of baicalein (BAI), a naturally occurring flavonoid, against hypoxia-reoxygenation (HR) injury in renal tubular epithelial cells (HK-2).

METHODS

Cultured human renal proximal tubular cell line HK-2 was exposed to 24 h of hypoxia (5% CO₂, 1% O₂, and 94% N₂), followed by 12 h of reoxygenation (5% CO₂, 21% O₂, and 74% N₂). HK-2 cells were divided into three groups: control, HR, and HR-BAI (0.3 µg/ml). Reactive oxygen species (ROS) were measured and cell apoptosis was analyzed by flow cytometry and morphology. ELISAs were performed to determine the levels of IL-1, intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1). IL-1β, ICAM-1, and MCP-1 mRNA levels were determined by real-time quantitative PCR.

RESULTS

HK-2 cells that underwent HR exhibited increases in IL-1β expression by 0.94%, ROS by 0.59%, ICAM-1 expression by 0.8%, and MCP-1 expression by 1.2%. Moreover, HK-2 cell apoptosis was increased after HR (p < .05). Compared with the HR group, BAI treatment reduced the elevation of oxidative stress (ROS) by 0.76%, as well as HR-mediated induction of IL-1β and apoptosis of HK2 cells. Protein and mRNA levels of ICAM-1 and MCP-1 were also reduced.

CONCLUSIONS

BAI protects renal tubular epithelial cells from HR injury by reducing inflammatory cytokine expression and oxidative stress.