Potential signal pathway between all-trans retinoic acid and LMX1B in hypoxia-induced renal tubular epithelial cell injury

Non-dialyzable uremic toxins and renal tubular cell damage in CKD patients: a systems biology approach

BACKGROUND

Chronic kidney disease presents global health challenges, with hemodialysis as a common treatment. However, non-dialyzable uremic toxins demand further investigation for new therapeutic approaches. Renal tubular cells require scrutiny due to their vulnerability to uremic toxins.

METHODS

In this study, a systems biology approach utilized transcriptomics data from healthy renal tubular cells exposed to healthy and post-dialysis uremic plasma.

RESULTS

Differential gene expression analysis identified 983 up-regulated genes, including 70 essential proteins in the protein-protein interaction network. Modularity-based clustering revealed six clusters of essential proteins associated with 11 pathological pathways activated in response to non-dialyzable uremic toxins.

CONCLUSIONS

Notably, WNT1/11, AGT, FGF4/17/22, LMX1B, GATA4, and CXCL12 emerged as promising targets for further exploration in renal tubular pathology related to non-dialyzable uremic toxins. Understanding the molecular players and pathways linked to renal tubular dysfunction opens avenues for novel therapeutic interventions and improved clinical management of chronic kidney disease and its complications.

Management of Pediatric Urolithiasis in an Italian Tertiary Referral Center: A Retrospective Analysis

Background and Objectives: In recent years, the prevalence of pediatric urolithiasis has increased in North America and Western countries, though it is endemic in developing countries. The aim of this study is to describe the experience of a tertiary pediatric referral center in the surgical management of pediatric urolithiasis. Materials and Methods: We retrospectively reviewed the experience of patients ≤ 16 years old affected by urinary stones who underwent surgery. Results: From April 2021 to September 2023, 31 pediatric patients underwent surgical procedures for stone diseases at our department: 13 preschool-aged (1-5 years) and 18 school-aged (6-16 years) children. During this period, 12 URSs, 17 RIRSs, and 2 PCNLs were recorded. Five patients had residual fragments at first, so three of them underwent a second endourological lithotripsy (2 RIRSs and 1 URS). Complete clearance was finally achieved in 27 patients. The stone composition was evaluated in 25 cases. Conclusions: Numerous innovations in the surgical treatment of pediatric urolithiasis have resulted from the development of smaller devices and new technology. Our results show how, in experienced centers, retrograde and percutaneous lithotripsy are safe and effective procedures for use in pediatric populations.

Melatonin relieves sepsis-induced myocardial injury via regulating JAK2/STAT3 signaling pathway

BACKGROUND

To study the effect of melatonin on myocardial injury of septic rats through regulating the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway.

METHODS

Healthy rats were selected as the samples and divided into blank group, sepsis group and sepsis + melatonin group. The difference in the myocardial tissue structure in the three groups of rats was observed via hematoxylin-eosin (HE) staining, and the messenger ribonucleic acid (mRNA) expression levels of JAK2 and STAT3 in myocardium were compared among groups through fluorescence quantitative polymerase chain reaction (qPCR). Western blotting was applied to detect the protein expressions of JAK2, phosphorylated (p)-JAK2, STAT3 and p-STAT3, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was utilized to determine the cell apoptosis in myocardial tissues. Moreover, the activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) in myocardial tissues as well as the activity of serum creatine kinase (CK) and lactate dehydrogenase (LDH) were measured and compared.

RESULTS

There were inflammatory cells in the myocardium in sepsis group, and the pathological changes were milder in sepsis + melatonin group. The mRNA expressions of JAK2 and STAT3 and the protein expressions of JAK2, STAT3, p-JAK2 and p-STAT3 were raised remarkably in sepsis group compared with those in blank group and sepsis + melatonin group. The apoptosis rate in tissues was significantly different among the three groups, and it was the highest in sepsis group, followed by that in sepsis + melatonin group and blank group. There were significant differences in SOD activity and MDA content in myocardial tissues among the three groups, of which the SOD activity was the strongest in blank group, followed by that in sepsis + melatonin group and sepsis group, and the MDA content was the highest in sepsis group, followed by that in sepsis + melatonin group and blank group. Sepsis group had extremely notably increased activity of CK and LDH compared with blank group, while sepsis + melatonin group exhibited evidently decreased activity of CK and LDH in comparison with sepsis group.

CONCLUSIONS

The JAK2/STAT3 signaling pathway is associated with sepsis-induced myocardial injury, and melatonin can relieve sepsis-induced myocardial injury by regulating the JAK2/STAT3 signaling pathway.

All‑trans retinoic acid promotes macrophage phagocytosis and decreases inflammation via inhibiting CD14/TLR4 in acute lung injury

Acute lung injury (ALI) is a common clinical emergency and all-trans retinoic acid (ATRA) can alleviate organ injury. Therefore, the present study investigated the role of ATRA in ALI. Lipopolysaccharide (LPS)-induced ALI rats were treated with ATRA and the arterial partial pressure of oxygen (PaO₂), lung wet/dry weight (W/D) ratio and protein content in the bronchial alveolar lavage fluid (BALF) were measured to evaluate the effect of ATRA on ALI rats. Alveolar macrophages were isolated from the BALF. The phagocytic function of macrophages was detected using the chicken erythrocyte phagocytosis method and flow cytometry. The viability of macrophages was measured using a Cell Counting Kit-8 assay, and apoptosis was analyzed using a TUNEL assay and flow cytometry. The expression levels of Toll-like receptor 4 (TLR4) and cluster of differentiation (CD)14 on the macrophage membrane were detected by immunofluorescence staining. The protein levels of TLR4, CD14, phosphorylated (p)-65, p65, p-IκBα and IκBα were analyzed using western blotting. The concentrations of IL-6, IL-1β and macrophage inflammatory protein-2 in the plasma of rats were detected by ELISA. Macrophages were treated with IAXO-102 (TLR4 inhibitor) to verify the involvement of CD14/TLR4 in the effect of ATRA on ALI. ATRA provided protection against LPS-induced ALI, as evidenced by the increased PaO₂ and reduced lung W/D ratio and protein content in the BALF. ATRA enhanced macrophage phagocytosis and viability and reduced apoptosis and inflammation in ALI rats. Mechanically, ATRA inhibited CD14 and TLR4 expression and NF-κB pathway activation. ATRA enhanced macrophage phagocytosis and reduced inflammation by inhibiting the CD14/TLR4-NF-κB pathway in LPS-induced ALI. In summary, ATRA inactivated the NF-κB pathway by inhibiting the expression of CD14/TLR4 receptor in the alveolar macrophages of rats, thus enhancing the phagocytic function of macrophages in ALI rats, improving the activity of macrophages, inhibiting apoptosis, reducing the levels of inflammatory factors, and consequently playing a protective role in ALI model rats. This study may offer novel insights for the clinical management of ALI.

Metabolomics analysis of the serum from children with urolithiasis using UPLC-MS

Pediatric urolithiasis is a common urologic disease with high morbidity and recurrence rates. Recent studies have shown that metabolic dysfunction plays a vital role in the pathogenesis of urolithiasis, especially in children, but the specific mechanism is still unclear. Metabolomics is an ideal technology for exploring the mechanism of metabolic disorders in urolithiasis. In the present study, a serum metabolomics based on ultra‐performance liquid chromatography mass spectrometry was performed. A total of 50 children subjects were recruited for the study, including 30 patients with kidney stones and 20 normal controls (NCs). Principal component analysis and orthogonal partial least‐squares determinant analysis were carried, and 40 metabolites were found to be significantly altered in patients with kidney stones, mainly involving retinol metabolism, steroid hormone biosynthesis, and porphyrin and chlorophyll metabolism. The kidney stone group appeared to have a lower serum level of bilirubin, but a relative higher level of retinal, all‐transretinoic acid, progesterone, and prostaglandin E2 compared with those of the NC group. All the findings suggest that patients with urolithiasis have several metabolic characteristics, which are related to stone formation or compensation. These metabolites and pathways are very likely associated with development of kidney stones and should be considered as potential novel targets for treatment and prevention.