IgA1 isolated from Henoch-Schönlein purpura children promotes proliferation of human mesangial cells in vitro

Knockdown of TFRC suppressed the progression of nasopharyngeal carcinoma by downregulating the PI3K/Akt/mTOR pathway

BACKGROUND

The transferrin receptor (TfR) encoded by TFRC gene is the main cellular iron importer. TfR is highly expressed in many cancers and is expected to be a promising new target for cancer therapy; however, its role in nasopharyngeal carcinoma (NPC) remains unknown.

METHODS

The TfR levels were investigated in NPC tissues and cell lines using immunohistochemistry and reverse transcription-quantitative polymerase chain reaction. Knockdown of TFRC using two siRNA to investigate the effects on intracellular iron level and biological functions, including proliferation by CKK-8 assay, colony formation, cell apoptosis and cell cycle by flow cytometry, migration and invasion, and tumor growth in vivo by nude mouse xenografts. RNA sequencing was performed to find possible mechanism after TFRC knockdown on NPC cells and further verified by western blotting.

RESULTS

TfR was overexpressed in NPC cell lines and tissues. Knockdown of TFRC inhibited cell proliferation concomitant with increased apoptosis and cell cycle arrest, and it decreased intracellular iron, colony formation, migration, invasion, and epithelial-mesenchymal transition in HK1-EBV cells. Western blotting showed that TFRC knockdown suppressed the levels of the iron storage protein FTH1, anti-apoptotic marker BCL-xL, and epithelial-mesenchymal transition markers. We confirmed in vivo that TFRC knockdown also inhibited NPC tumor growth and decreased Ki67 expression in tumor tissues of nude mouse xenografts. RNA sequencing and western blotting revealed that TFRC silencing inhibited the PI3K/Akt/mTOR signaling pathway.

CONCLUSIONS

These results indicated that TfR was overexpressed in NPC, and TFRC knockdown inhibited NPC progression by suppressing the PI3K/Akt/mTOR signaling pathway. Thus, TfR may serve as a novel biomarker and therapeutic target for NPC.

IgA vasculitis nephritis

PURPOSE OF REVIEW

The purpose of this update is to summarize current knowledge on the pathophysiology of immunglobulin A (IgA) vasculitis nephritis (IgAVN) as well as to critically review evidence for established therapeutic regimes and available biomarkers. An additional purpose is to raise the discussion what could be done to further improve our understanding of IgAVN, identify patients at risk for adverse outcome and increase the evidence for therapy recommendations.

RECENT FINDINGS

Clinical and experimental studies have established the concept of a multilevel pathogenesis. Toll-like-receptor activation, B cell proliferation, micro-RNAs and complement activation have been identified or confirmed as potential therapeutic targets which can modify the course of the disease. Currently, kidney injury molecule-1, monocyte chemotactic protein-1, N-acetyl-β-glucosaminidase, and angiotensinogen are the most promising urinary biomarkers for early diagnosis of renal involvement in IgA vasculitis.

SUMMARY

Close surveillance of all IgAV patients for renal involvement is recommended. Given the multilevel pathogenesis, early treatment of even mild cases should be initiated. Further therapeutic options should be considered in case first-line therapy (mostly corticosteroids) has no effect. The evidence supporting current therapeutic regimes is predominantly based on expert opinion. Prospective studies are needed and should involve substances inhibiting B cell proliferation and complement activation.

A Review of the Mechanism of Vascular Endothelial Injury in Immunoglobulin A Vasculitis

Immunoglobulin A (IgA) vasculitis (IgAV), also known as Henoch-Schönlein purpura, is the most common form of childhood vasculitis. It is characterized by cutaneous hemorrhage, resulting from red blood cell leakage into the skin or mucosae, possibly caused by damage to small blood vessels. These acute symptoms usually disappear without treatment. Endothelial cells are distributed on the inner surfaces of blood vessels and lymphatic vessels, and have important functions in metabolism and endocrine function, as well as being the primary targets of external stimuli and endogenous immune activity. Injury to endothelial cells is a feature of IgA vasculitis. Endothelial cell damage may be related to the deposition of immune complexes, the activation of complement, inflammatory factors, and chemokines, oxidative stress, hemodynamics, and coagulation factors. Both epigenetic mechanisms and genetic diversity provide a genetic background for endothelial cell injury. Here, research on the role of endothelial cells in allergic IgA vasculitis is reviewed.

Pathogenesis of IgA Vasculitis: An Up-To-Date Review

Immunoglobin A (IgA) vasculitis (IgAV), formerly called the Henoch-Schönlein purpura (HSP), is a small vessel vasculitis, characterized by IgA1-dominant immune deposition at diseased vessel walls. IgAV is the most common form of vasculitis in children; typical symptoms include palpable purpura, arthritis or arthralgia, abdominal pain, and hematuria or proteinuria. Galactose-deficient IgA1 is detected in the tissues of the kidney and skin in patients with IgAV; it forms immune complexes leading to subsequent immune reactions and injuries. This report provides the recent advances in the understanding of environmental factors, genetics, abnormal innate and acquired immunity, and the role of galactose-deficient IgA1 immunocomplexes in the pathogenesis of IgAV.

An Integrated Transcriptomic and Proteomic Analysis Identifies Significant Novel Pathways for Henoch-Schönlein Purpura Nephritis Progression

Background

Although Henoch-Schönlein purpura nephritis (HSPN) is characterized by glomerular deposition of aberrantly glycosylated immunoglobulin A1 (IgA1), the underlying mechanism of HSPN progression has not yet been completely elucidated. In this study, we integrated transcriptomic and proteomic analyses to explore the underlying mechanism of HSPN progression.

Methods

RNA sequencing and tandem mass tag- (TMT-) based quantitative proteomics were used to gain serum transcriptomic and proteomic profiles of patients with different types of HSPN (3 × type 1, 3 × type 2, and 3 × type 3). Student's t-tests were performed to obtain the significance of the differential gene expression. The clusterProfiler package was used to conduct the functional annotation of the DEGs for both Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways.

Results

A total of 2315 mRNAs and 30 proteins were differentially expressed between the different types of HSPN. 58 mRNAs and one protein changed continuously during HSPN development and are potential biomarkers for HSPN progression. The validation cohort (another 9 patients) confirmed the high-throughput results of the transcriptomic and proteomic analyses. A total of 385 significant pathways were related to HSPN progression, and four of them were closely related to clinical biochemical indicators and may play an important role in the progression of HSPN. Those pathways reveal that HSPN progression may be related to the inhibition of inflammation, promotion of apoptosis, and repair of renal injury.

Conclusions

Four pathways were found to be closely related to HSPN progression, and it seems that HSPN progression is mainly due to the inhibition of inflammation, promotion of apoptosis, and repair of renal injury.