DNA induction of MDM2 promotes proliferation of human renal mesangial cells and alters peripheral B cells subsets in pediatric systemic lupus erythematosus

Intranasal PAMAM-G3 scavenges cell-free DNA attenuating the allergic airway inflammation

Allergic airway inflammation (AAI), including allergic rhinitis (AR) and allergic asthma, is driven by epithelial barrier dysfunction and type 2 inflammation. However, the underlying mechanism remains uncertain and available treatments are constrained. Consequently, we aim to explore the role of cell-free DNA (cfDNA) in AAI and assess the potential alleviating effects of cationic polymers (CPs) through cfDNA elimination. Levels of cfDNA were evaluated in AR patients, allergen-stimulated human bronchial epithelium (BEAS-2B cells) and primary human nasal epithelium from both AR and healthy control (HC), and AAI murine model. Polyamidoamine dendrimers-generation 3 (PAMAM-G3), a classic type of cationic polymers, were applied to investigate whether the clearance of cfDNA could ameliorate airway epithelial dysfunction and inhibit AAI. The levels of cfDNA in the plasma and nasal secretion from AR were higher than those from HC (P < 0.05). Additionally, cfDNA levels in the exhaled breath condensate (EBC) were positively correlated with Interleukin (IL)-5 levels in EBC (R = 0.4191, P = 0.0001). Plasma cfDNA levels negatively correlated with the duration of allergen immunotherapy treatment (R = -0.4297, P = 0.006). Allergen stimulated cfDNA secretion in vitro (P < 0.001) and in vivo (P < 0.0001), which could be effectively scavenged with PAMAM-G3. The application of PAMAM-G3 inhibited epithelial barrier dysfunction in vitro and attenuated the development of AAI in vivo. This study elucidates that cfDNA, a promising biomarker for monitoring disease severity, aggravates AAI and the application of intranasal PAMAM-G3 could potentially be a novel therapeutic intervention for AAI. Allergen stimulates the secretion of cell-free DNA (cfDNA) in both human and mouse airway. Intranasal polyamidoamine dendrimers-generation 3 (PAMAM-G3) scavenges cfDNA and alleviates allergic airway inflammation.

RNA sequencing and bioinformatics analysis of differentially expressed genes in the peripheral serum of ankylosing spondylitis patients

BACKGROUND

Ankylosing spondylitis (AS) is a chronic progressive autoimmune disease characterized by spinal and sacroiliac arthritis, but its pathogenesis and genetic basis are largely unclear.

METHODS

We randomly selected three serum samples each from an AS and a normal control (NC) group for high-throughput sequencing followed by using edgeR to find differentially expressed genes (DEGs). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes, Reactome pathway analyses, and Gene Set Enrichment Analysis were used to comprehensively analyze the possible functions and pathways involved with these DEGs. Protein-protein interaction (PPI) networks were constructed using the STRING database and Cytoscape. The modules and hub genes of these DEGs were identified using MCODE and CytoHubba plugins. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to validate the expression levels of candidate genes in serum samples from AS patients and healthy controls.

RESULTS

We successfully identified 100 significant DEGs in serum. When we compared them with the NC group, 49 of these genes were upregulated in AS patients and 51 were downregulated. GO function and pathway enrichment analysis indicated that these DEGs were mainly enriched in several signaling pathways associated with endoplasmic reticulum stress, including protein processing in the endoplasmic reticulum, unfolded protein response, and ubiquitin-mediated proteolysis. We also constructed a PPI network and identified the highly connected top 10 hub genes. The expression levels of the candidate hub genes PPARG, MDM2, DNA2, STUB1, UBTF, and SLC25A37 were then validated by RT-qPCR analysis. Finally, receiver operating characteristic curve analysis suggested that PPARG and MDM2 may be the potential biomarkers of AS.

CONCLUSIONS

These findings may help to further elucidate the pathogenesis of AS and provide valuable potential gene biomarkers or targets for the diagnosis and treatment of AS.

p53 and Myofibroblast Apoptosis in Organ Fibrosis

Organ fibrosis represents a dysregulated, maladaptive wound repair response that results in progressive disruption of normal tissue architecture leading to detrimental deterioration in physiological function, and significant morbidity/mortality. Fibrosis is thought to contribute to nearly 50% of all deaths in the Western world with current treatment modalities effective in slowing disease progression but not effective in restoring organ function or reversing fibrotic changes. When physiological wound repair is complete, myofibroblasts are programmed to undergo cell death and self-clearance, however, in fibrosis there is a characteristic absence of myofibroblast apoptosis. It has been shown that in fibrosis, myofibroblasts adopt an apoptotic-resistant, highly proliferative phenotype leading to persistent myofibroblast activation and perpetuation of the fibrotic disease process. Recently, this pathological adaptation has been linked to dysregulated expression of tumour suppressor gene p53. In this review, we discuss p53 dysregulation and apoptotic failure in myofibroblasts and demonstrate its consistent link to fibrotic disease development in all types of organ fibrosis. An enhanced understanding of the role of p53 dysregulation and myofibroblast apoptosis may aid in future novel therapeutic and/or diagnostic strategies in organ fibrosis.

The Value of Cell-Free Circulating DNA Profiling in Patients with Skin Diseases

Liquid biopsy, also known as fluid biopsy or fluid-phase biopsy, is the sampling and analysis of the blood, cerebrospinal fluid, saliva, pleural fluid, ascites, and urine. Compared with tissue biopsy, liquid biopsy technology has the advantages of being noninvasive, having strong repeatability, enabling early diagnosis, dynamic monitoring, and overcoming tumor heterogeneity. However, interest in cfDNA and skin diseases has not expanded until recently. In this review, we present an overview of the literature related to the basic biology of cfDNA in the field of dermatology as a biomarker for early diagnosis, monitoring disease activity, predicting progression, and treatment response.

Mesangial cell: A hub in lupus nephritis

Lupus nephritis (LN) is a severe renal disease caused by the massive deposition of the immune complexes (ICs) in renal tissue, acting as one of the significant organ manifestations of systemic lupus erythematosus (SLE) and a substantial cause of death in clinical patients. As mesangium is one of the primary sites for IC deposition, mesangial cells (MCs) constantly undergo severe damage, resulting in excessive proliferation and increased extracellular matrix (ECM) production. In addition to playing a role in organizational structure, MCs are closely related to in situ immunomodulation by phagocytosis, antigen-presenting function, and inflammatory effects, aberrantly participating in the tissue-resident immune responses and leading to immune-mediated renal lesions. Notably, such renal-resident immune responses drive a second wave of MC damage, accelerating the development of LN. This review summarized the damage mechanisms and the in situ immune regulation of MCs in LN, facilitating the current drug research for exploring clinical treatment strategies.

Mesangial Cells in Lupus Nephritis

PURPOSE OF REVIEW

Mesangial cells are critical for the proper function of the glomerulus, playing roles in structural support and injury repair. However, they are also early responders to glomerular immune complex deposition and contribute to inflammation and fibrosis in lupus nephritis. This review highlights recent studies identifying signaling pathways and mediators in mesangial cell response to lupus-relevant stimuli.

RECENT FINDINGS

Anti-dsDNA antibodies, serum, or plasma from individuals with lupus nephritis, or specific pathologic factors activated multiple signaling pathways. These pathways largely included JAK/STAT/SOCS, PI3K/AKT, and MAPK and led to induction of proliferation and expression of multiple proinflammatory cytokines, growth factors, and profibrotic factors. NFκB activation was a common mediator of response. Mesangial cells proliferate and express a wide array of proinflammatory/profibrotic factors in response to a variety of lupus-relevant pathologic stimuli. While some of the responses are similar, the mechanisms involved appear to be diverse depending on the stimulus. Future studies are needed to fully elucidate these mechanisms with respect to the diverse milieu of stimuli.

IFN-I Mediates Lupus Nephritis From the Beginning to Renal Fibrosis

Lupus nephritis (LN) is a common complication of systemic lupus erythematosus (SLE) and a major risk factor for morbidity and mortality. The abundant cell-free nucleic (DNA/RNA) in SLE patients, especially dsDNA, is a key substance in the pathogenesis of SLE and LN. The deposition of DNA/RNA-immune complexes (DNA/RNA-ICs) in the glomerulus causes a series of inflammatory reactions that lead to resident renal cell disturbance and eventually renal fibrosis. Cell-free DNA/RNA is the most effective inducer of type I interferons (IFN-I). Resident renal cells (rather than infiltrating immune cells) are the main source of IFN-I in the kidney. IFN-I in turn damages resident renal cells. Not only are resident renal cells victims, but also participants in this immunity war. However, the mechanism for generation of IFN-I in resident renal cells and the pathological mechanism of IFN-I promoting renal fibrosis have not been fully elucidated. This paper reviews the latest epidemiology of LN and its development process, discusses the mechanism for generation of IFN-I in resident renal cells and the role of IFN-I in the pathogenesis of LN, and may open a new perspective for the treatment of LN.

Altered expression of miR-142, miR-155, miR-499a and of their putative common target MDM2 in systemic lupus erythematosus

Aim: To evaluate genetic and expression variability of three miRNAs potentially involved in systemic lupus erythematosus (SLE) and to identify any miRNA's target gene. Materials & methods: Gene polymorphisms and expression levels of three miRNAs have been evaluated in a cohort of SLE patients and controls. Results: miR-142 and miR-499a were significantly down-expressed in patients (p = 0.005 and p = 0.02, respectively). A trend for down-expression of miR-155 was also observed (p = 0.07). The lower expression of miR-142 was associated with the rs2632516 polymorphism variant allele (p = 0.002). Predictive analyses identified a target gene common to the three miRNAs, MDM2, whose higher expression was seen in patients compared with controls (p = 0.03). Conclusion: The three miRNAs and MDM2 might be involved in SLE.

Combined use of murine double minute-2 promoter methylation and serum AFP improves diagnostic efficiency in hepatitis B virus-related hepatocellular carcinoma

Objective: Hepatocellular carcinoma (HCC) accounts for approximately 85% of all cases of liver cancer. In China, chronic hepatitis B virus-related HCC (HBV-related HCC) is the most common type of HCC. However, the majority of HBV-related HCC patients are asymptomatic, and the best opportunities for treating these patients are missed. The precise diagnosis of HBV-related HCC is crucial. The main purpose of this study was to evaluate the diagnostic value of murine double minute-2 (MDM2) promoter methylation in HBV-related HCC patients. Methods: The methylation status of the MDM2 promoter was detected by methylation-specific PCR. The MDM2 expression levels were validated by quantitative real-time PCR. Enzyme-linked immunosorbent assay was used to determine the levels of interleukin-6 (IL-6) and tumor-necrosis factor-α (TNF-α) in plasma. Results: The methylation frequency of the MDM2 promoter was decreased in HBV-related HCC patients. The MDM2 mRNA levels of patients with HBV-related HCC were higher than those of patients with liver cirrhosis and chronic hepatitis B. The plasma levels of IL-6 and TNF-α were significantly higher in HBV-related HCC patients than that in liver cirrhosis and chronic hepatitis B patients. The TNF-α levels were higher in the unmethylated MDM2 promoter group than in the methylated MDM2 promoter group in HBV-related HCC patients. Moreover, the combination of MDM2 promoter methylation and alpha-fetoprotein (AFP) improved the diagnosis of HBV-related HCC. Conclusions: Our study indicates, for the first time, that MDM2 promoter hypomethylation is present in HBV-related HCC patients. The combination of MDM2 promoter methylation and AFP can greatly improve diagnostic efficiency in HBV-related HCC, which might provide a new method for HBV-related HCC diagnosis.

Targeting MDM2 for novel molecular therapy: Beyond oncology

The murine double minute 2 (MDM2) oncogene exerts major oncogenic activities in human cancers; it is not only the best-documented negative regulator of the p53 tumor suppressor, but also exerts p53-independent activities. There is an increasing interest in developing MDM2-based targeted therapies. Several classes of MDM2 inhibitors have been evaluated in preclinical models, with a few entering clinical trials, mainly for cancer therapy. However, noncarcinogenic roles for MDM2 have also been identified, demonstrating that MDM2 is involved in many chronic diseases and conditions such as inflammation and autoimmune diseases, dementia and neurodegenerative diseases, heart failure and cardiovascular diseases, nephropathy, diabetes, obesity, and sterility. MDM2 inhibitors have been shown to have promising therapeutic efficacy for treating inflammation and other nonmalignant diseases in preclinical evaluations. Therefore, targeting MDM2 may represent a promising approach for treating and preventing these nonmalignant diseases. In addition, a better understanding of how MDM2 works in nonmalignant diseases may provide new biomarkers for their diagnosis, prognostic prediction, and monitoring of therapeutic outcome. In this review article, we pay special attention to the recent findings related to the roles of MDM2 in the pathogenesis of several nonmalignant diseases, the therapeutic potential of its downregulation or inhibition, and its use as a biomarker.

Association of GTF2I gene polymorphisms with renal involvement of systemic lupus erythematosus in a Chinese population

The purposes of the study was to validate the relationship between General transcription factor II-I (GTF2I) genetic variants and kidney involvements of systemic lupus erythematosus (SLE) patients in a Chinese Han population.Samples from 400 SLE patients and 400 age- and sex-matched healthy controls were collected and genotyped by improved multiplex ligation detection reaction technique. The relationship between gene polymorphism of rs117026326, rs73366469, and susceptibility, progression of SLE were analyzed.The present study provided evidence that rs117026326 and rs73366469 were both associated with SLE susceptibility (both C vs T: P < .001). The analysis of dominant, recessive disease model provided us with further validation (P < .001). Both gene polymorphisms are associated with a triad of disease manifestations among SLE patients. Patients carrying genotype TT of rs117026326 had lower 24-hour urinary total protein (24 hours UTP, g/24 hours), 24-hour urinary protein level (g/L·24 hours), lower frequency of the proteinuria and lupus nephritis (LN). Patients carrying genotype TT at rs73366469 had higher 24-hour urinary protein level, higher frequency of the proteinuria, LN and positive anti-dsDNA than those with other genotypes.This study identified the involvement of GTF2I gene polymorphisms in development of SLE, particularly in renal involvement.

Evaluating the diagnostic and prognostic value of lone anti-Sm for autoimmune diseases using Euroimmun line immunoassays

To investigate the value of lone anti-Smith antibody (anti-Sm) using Euroimmun line immunoassay (LIA) in a Chinese population. One thousand two hundred eight of 39,766 patients who were analyzed for anti-Sm had positive anti-Sm, and were divided into true group (having both positive Sm and nRNP/Sm bands) and lone group (only having Sm band without nRNP/Sm band). The proportions of clinical diagnosis of autoimmune diseases (AIDs), non-autoimmune diseases (NAIDs), concentration of C3, C4, and rheumatoid factor (RF), positive rate of autoantibodies of antinuclear antibody (ANA) profile, and titer of anti-Sm and ANA in systemic lupus erythematosus (SLE) patients were analyzed. Lone anti-Sm was evident in 271/1208 (22.42%) of all positive cases. One hundred seventy-five of them had definitive diagnoses with AIDs being the most prominent (69.71%, 122/175). Compared to the true group, SLE patients in the lone group showed significantly lower ANA and anti-Sm titers (both P < 0.001). There was no difference in frequency of other autoantibodies or C3, C4, and RF levels of SLE patients between the two groups. In NAIDs patients, lone anti-Sm indicates less incidence of kidney injury than true anti-Sm (P = 0.05). Lone anti-Sm has great diagnostic value in AIDs, especially SLE. Lone anti-Sm has relationship with mild kidney impairment. Positive anti-Sm patients with no clinical findings or SLE diagnosis should be submitted to new testing to identify changes in anti-Sm, because turning of lone anti-Sm to true anti-Sm indicates evolving kidney injury.