Structure of the Bacteriophage PhiKZ non-virion RNA Polymerase transcribing from its promoter p119L.

Bacteriophage ΦKZ (phiKZ) is the founding member of a family of giant bacterial viruses. It has potential as a therapeutic as its host, Pseudomonas aeruginosa, kills tens of thousands of people worldwide each year. ΦKZ infection is independent of the host transcriptional apparatus; the virus forms a "nucleus", producing a proteinaceous barrier around the ΦKZ genome that excludes the host immune systems. It expresses its own non-canonical multi-subunit non-virion RNA polymerase (nvRNAP), which is imported into its "nucleus" to transcribe viral genes. The ΦKZ nvRNAP is formed by four polypeptides representing homologues of the eubacterial ß/ß' subunits, and a fifth that is likely to have evolved from an ancestral homologue to σ-factor. We have resolved the structure of the ΦKZ nvRNAP initiating transcription from its cognate promoter, p119L, including previously disordered domains and regions. Our results shed light on the similarities and differences between ΦKZ nvRNAP mechanisms of transcription and those of canonical eubacterial RNAPs and the related non-canonical nvRNAP of bacteriophage AR9.

Clinical significance of massive proteinuria in primary IgA nephropathy with and without nephrotic syndrome: a single center cohort study.

BACKGROUND: Both primary IgA nephropathy (IgAN) with and without nephrotic syndrome (NS) can present massive proteinuria (24-h urinary protein ≥3.5 g/d). The clinical significance of massive proteinuria may be different in the two entities and needs further research. METHODS: Data of 1870 patients with biopsy-proven IgAN in our hospital from January 2011 to December 2022 was retrospectively reviewed. A total of 242 IgAN patients with massive proteinuria were enrolled. Patients who presented with nephrotic syndrome at renal biopsy were included in the IgAN with NS cohort (IgAN-NS). The IgAN with nephrotic-range proteinuria cohort (IgAN-NR) consisted of 1:1 matched cases from the remaining according to age, gender, estimated glomerular filtration rate (eGFR) at baseline, and follow-up time. The clinical and pathological characteristics between the two cohorts were analyzed. RESULTS: The IgAN-NS had a significantly higher proteinuria level than the IgAN-NR (p < .001). Cluster analysis revealed that proteinuria was associated with lipids in IgAN-NS, while it was associated with inflammatory indicators in IgAN-NR. When the complete remission of proteinuria (CR) was not achieved, the Kaplan-Meier analysis showed the prognosis of IgAN-NS was significantly worse than that of IgAN-NR (p = .04). Then, our GLMM model and line chart showed that the serum albumin level of the IgAN-NR was always evidently higher than that of the IgAN-NS while the significant difference in urinary albumin/creatinine ratio between the two cohorts gradually disappeared during the short-term follow-up (1 year). Moreover, the Cox regression analysis showed that the increased serum albumin was an independent protective factor for the poor outcomes (eGFR decreased from the baseline ≥ 30% continuously or reached end-stage renal disease [ESRD]). CONCLUSION: The IgAN-NS had poorer clinicopathologic manifestation than IgAN-NR, including severer massive proteinuria. When the CR was not achieved, the prognosis of IgAN-NS was inferior to that of the IgAN-NR.

Role of crescents for lupus nephritis in clinical, pathological and prognosis: a single-center retrospective cohort study.

BACKGROUND: Referring to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2018 pathological classification, we aim to reveal the significance of cellular/fibrocellular crescents in lupus nephritis (LN) patients. METHODS: Patients with LN proven by renal biopsy at the First Affiliated Hospital of Wenzhou Medical University from December 2001 to November 2017 were identified, and eligible cases were divided into two groups according to the presence or absence of cellular/fibrocellular crescents in renal biopsy tissues. RESULTS: A total of 401 LN patients were identified from our follow-up database, and 296 eligible LN patients were enrolled in the study. Of these patients, 146 patients in the group without cellular/fibrocellular crescents (non-crescent group) and 150 patients in the group with cellular/fibrocellular crescents (Crescent group). The median follow-up time of patients was 47 months, and a total of 54 patients progressed to the composite endpoint. Crescent group had higher serum creatinine, lower serum albumin, higher systemic lupus erythematosus (SLE) disease activity index, and higher activity index of renal tissue. The interaction between cellular/fibrocellular crescents and proteinuria at baseline was associated with the prognostic risk of LN (P = 0.006). In the group with proteinuria < 3.5 g/24 h, the prognosis of crescent group was significantly worse than of non-crescent group (P < 0.001), while in the group with proteinuria ≥ 3.5 g/24 h, there was no significant relationship between crescents and prognosis (p = 0.452). By multivariable Cox hazard analysis, positive anti-dsDNA, chronic index of renal biopsy tissue, cellular/fibrocellular crescents and its interaction with 24 h proteinuria were independent risk factors for poor prognosis of LN. CONCLUSIONS: LN patients with cellular/fibrocellular crescents had more severe and active disease features, and cellular/fibrocellular crescents is a risk factor for poor prognosis of LN. There was an interaction between cellular/fibrocellular crescents and proteinuria in predicting poor prognosis, and among patients with low levels of proteinuria at the time of renal biopsy, those with crescents had a worse long-term prognosis than those without crescents.

Clinical significance of intrarenal vascular lesions in non-hypertensive patients with IgA nephropathy.

BACKGROUND: The clinical significance of intrarenal vascular lesions has not been elucidated in primary IgA nephropathy (IgAN), especially in non-hypertensive subjects. METHODS: From January 2003 to December 2020, data of 3435 patients with biopsy-proven IgAN were reviewed. Two hundred-forty non-hypertensive patients who met the criteria for IgAN and had intrarenal vascular lesions (IgAN-vas) were selected. The control cohort was constructed with 1:1 matched cases of non-hypertensive IgAN patients without vascular lesions according to age, gender, estimated glomerular filtration rate (eGFR) and follow-up time. RESULTS: The IgAN-vas cohort had significantly higher serum uric acid levels than the control IgAN cohort (P < 0.05); glomerulosclerosis was more common in IgAN-vas patients. Moreover, cluster analysis indicated that the serum uric acid level was associated with serum creatinine (s-Cr) levels in IgAN-vas while it was associated with serum lactate dehydrogenase (LDH) levels in control cases with IgAN. Both Kaplan-Meier analysis and generalized linear mixed-effects models revealed that the prognosis of the IgAN-vas cohort was significantly worse than that of the IgAN cohort after > 5 years of follow-up. Intimal thickening was an independent risk factor associated with reaching the endpoint (eGFR decrease ≥ 30% from the baseline or reaching end-stage renal disease [ESRD] or death). CONCLUSIONS: The prognosis of non-hypertensive patients with IgAN-vas was worse than that of matched individuals with IgAN. The clinicopathologic manifestation of IgAN-vas was more severe, and included a higher proportion of glomerulosclerosis, and a higher serum uric acid level correlated with renal function impairment.

Clinicopathologic and Prognostic Study of Primary IgA Nephropathy With Light Chain λ Restriction in the Mesangial Deposits.

Introduction: Primary IgA nephropathy (IgAN) with light chain λ restriction in the mesangial deposits (IgAN-λ) has unique immunofluorescence (IF) features. Nevertheless, its clinicopathology and prognosis are still ambiguous. Methods: From January 2002 to December 2020, the clinical and pathologic data of 3872 patients who were diagnosed with having primary IgAN by renal biopsy in our hospital were reviewed. A total of 187 patients who met the selection criteria for IgAN-λ were enrolled to conduct a retrospective single-center study. The selection criteria were that IF features conform to light chain λ restriction in the mesangial deposits. According to age, sex, renal function (estimated glomerular filtration rate [eGFR]), and follow-up time, the control group was constructed with 1:3 matched cases of IgAN. The clinicopathologic and prognostic differences between the 2 groups were analyzed. Results: Compared with that in the IgAN group, the serum fibrinogen level in the IgAN-λ group was significantly higher (P < 0.001). Furthermore, cluster analysis indicated the different clusters involved in fibrinogen between the IgAN-λ and IgAN groups and that fibrinogen is associated with factors reflecting renal function in IgAN-λ but proteinuria levels in IgAN. The light chain λ deposit in the mesangium is associated with the formation of crescents in those with IgAN-λ, but complement C3 deposition in those with IgAN. Our Kaplan-Meier analysis revealed that the prognosis of the IgAN-λ group was significantly worse than that of the IgAN group within >6 years of follow-up (P = 0.02). The multi-Cox analysis revealed that the light chain λ restriction in the mesangial deposits was an independent risk factor for poor outcomes (eGFR decreased from the baseline ≥ 30% continuously or reached end-stage renal disease [ESRD] or died). Conclusion: The prognosis of those with IgAN-λ was worse than that of those with IgAN, which may be attributed to the light chain λ restriction in the mesangial deposits inducing a significant systemic inflammation manifested as severe clinical features and frequent crescent.

Transcriptional Landscape of Enhancer RNAs in Peripheral Blood Mononuclear Cells from Patients with Systemic Lupus Erythematosus.

OBJECTIVE: Enhancer RNAs (eRNAs), a class of non-coding RNAs, play indispensable roles in regulating target gene transcription and maintaining cell identity in cooperation with promoters. In this study, we investigated the transcriptional landscape and potential functions of eRNAs in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). METHODS: PBMCs from five patients with stable SLE, five patients with active SLE, and ten healthy individuals (HCs) were subjected to RNA-sequencing. Putative regulators, differential expression, and pathways were analyzed. eRNAs that were significantly upregulated were first validated by RT-qPCR in 12 samples. Then, candidate eRNAs were confirmed in a validation cohort of 45 samples. We conducted comprehensive pathway analyses to explore the correlations between the candidate eRNAs and SLE pathology. RESULTS: By analyzing eRNA transcript data from PBMCs from SLE patients and HCs, we identified various eRNAs and functional super-enhancers potentially related with SLE. The SLE-specificity of eRNAs seemed to be largely driven by SLE-specific transcription factors (TFs). A Venn diagram of eRNAs differentially expressed in stable, active, and total SLE vs HCs revealed that 13 and 23 eRNAs were commonly upregulated and downregulated, respectively, in patients with stable SLE and those with active SLE. The commonly upregulated eRNAs participate in regulating SLE-related pathways. Only eRNA TCONS_00034326 was significantly (P < 0.05) upregulated in PBMCs of patients with SLE when compared with those of HCs as indicated by RT-qPCR. The area under the receiver-operating curve of TCONS_00034326 for distinguishing SLE patients from HCs was 0.691. Through its putative SLE-related master TF, TCONS_00034326 is involved in multiple SLE-relevant signaling pathways, especially tumor necrosis factor signaling. CONCLUSION: This study unraveled the transcriptional landscape of eRNAs, eRNA-related TFs, and super-enhancers in PBMCs from SLE patients and HCs. We identified a panel of SLE-relevant eRNAs, providing potential targets in SLE pathogenesis.

Clinicopathological and prognostic study of IgA-dominant postinfectious glomerulonephritis.

BACKGROUND: The clinicopathological and prognostic features of IgA-dominant postinfectious glomerulonephritis and its difference from the primary IgA nephropathy remains to be investigated. METHODS: The clinical and pathological data of 6542 patients who underwent renal biopsy from 2009 to 2020 in our hospital were reviewed and 50 patients who met the selection criteria of IgA-dominant postinfectious glomerulonephritis were enrolled to conduct a retrospective and observational single-center study. The selection criteria were: meet the characteristics of IgA dominance or codominance in immunofluorescence, and conform to 3 of the following 5 criteria: 1.Clinical or laboratory evidence show that there is infection before or at the onset of glomerulonephritis; 2.The level of serum complement decreased; 3.Renal pathology is consistent with endocapillary proliferative glomerulonephritis; 4. Glomerular immunofluorescence staining showed complement C3 dominance or codominance; 5. Hump-like subepithelial immune complex deposition was observed under electron microscopy. According to age, sex, renal function (estimated glomerular filtration rate, eGFR) and follow-up time, the control group was constructed with 1:3 matched cases of primary IgA nephropathy. The clinicopathological and prognostic differences between the two groups were analyzed. RESULTS: The most common histological pattern of IgA-dominant postinfectious glomerulonephritis was acute endocapillary proliferative glomerulonephritis and exudative glomerulonephritis. Immunofluorescence showed mainly IgA deposition or IgA deposition only, mainly deposited in the mesangial area (deposition rate 100 %), with typical C3 high-intensity staining (intensity++~+++), mainly deposited in the mesangial area (deposition rate 92.0 %). The fluorescence intensity of kappa is usually not weaker than lambda. The probability of the appearance of typical hump-like electron deposition under electron microscopy is low. Compared to primary IgA nephropathy, patients with IgA-dominant postinfectious glomerulonephritis had higher proportion of crescents (p = 0. 005) and endocapillary hypercellularity (p < 0.001) in pathological manifestations. Using serum creatinine level doubled of the baseline or reached end-stage renal disease as the endpoint, the prognosis of IgA-dominant postinfectious glomerulonephritis patients was worse than that of primary IgA nephropathy patients (p = 0.013). CONCLUSIONS: The clinicopathological features of patients with IgA-dominant postinfectious glomerulonephritis was different from that of primary IgA nephropathy, and the prognosis was worse.

Role of clinicopathological features for the early prediction of prognosis in lupus nephritis.

Ambiguities remain regarding the role of clinicopathological characteristics in the early prediction of the prognosis of lupus nephritis (LN). Systemic lupus erythematosus (SLE) patients who completed routine follow-up were identified and retrospectively reviewed for eligible cases. Poor prognosis was defined as all-cause mortality or a persistent decrease of eGFR greater than half the baseline level or progression to end-stage renal disease (ESRD). An optimal Cox regression model was constructed for the early prediction of a poor prognosis for LN. Among the 2163 SLE patients, 376 eligible LN cases were enrolled in the study, with a median follow-up time of 55 [27.0, 87.0] months. The male-to-female ratio was 1:7.2, and 37 patients (9.8%) progressed to the composite endpoint. The ISN/RPS class was significantly associated with proteinuria levels (P-value < 0.001), and class IV/IV + V patients, but not class V patients, had the most severe proteinuria. Our optimal multivariate Cox regression model indicated that sex, ISN/RPS class, tubular atrophy/interstitial fibrosis, serum albumin, tertiles of proteinuria, and their interaction were independently associated with a poor prognosis. ROC analysis and external validation demonstrated that our model was efficient and robust for distinguishing LN patients with a poor prognosis. Our study constructed a robust and early predictive model for convenience in clinical practice to identify poor prognosis in LN patients. We found a significant interaction effect between proteinuria and serum albumin for the prediction of poor prognosis. LN patients with low-level proteinuria and hypoalbuminemia exhibit an increased hazard of progression to poor outcomes.

Empagliflozin, a sodium glucose cotransporter-2 inhibitor, ameliorates peritoneal fibrosis via suppressing TGF-ß/Smad signaling.

Sodium glucose cotransporter-2 (SGLT-2) inhibitor has been reported to exert a glucose-lowering effect in the peritoneum exposed to peritoneal dialysis solution. However, whether SGLT-2 inhibitors can regulate peritoneal fibrosis by suppressing TGF-ß/Smad signaling is unclear. We aimed to (i) examine the effect of the SGLT-2 inhibitor empagliflozin in reducing inflammatory reaction and preventing peritoneal dialysis solution-induced peritoneal fibrosis and (ii) elucidate the underlying mechanisms. High-glucose peritoneal dialysis solution or transforming growth factor ß1 (TGF-ß1) was used to induce peritoneal fibrosis in vivo, in a mouse peritoneal dialysis model (C57BL/6 mice) and in human peritoneal mesothelial cells in vitro, to stimulate extracellular matrix accumulation. The effects of empagliflozin and adeno-associated virus-RNAi, which is used to suppress SGLT-2 activity, on peritoneal fibrosis and extracellular matrix were evaluated. The mice that received chronic peritoneal dialysis solution infusions showed typical features of peritoneal fibrosis, including markedly increased peritoneal thickness, excessive matrix deposition, increased peritoneal permeability, and upregulated α-smooth muscle actin and collagen I expression. Empagliflozin treatment or downregulation of SGLT-2 expression significantly ameliorated these pathological changes. Inflammatory cytokines (TNF-α, IL-1ß, IL-6) and TGF-ß/Smad signaling-associated proteins, such as TGF-ß1 and phosphorylated Smad (p-Smad3), decreased in the empagliflozin-treated and SGLT-2 downregulated groups. In addition, empagliflozin treatment and downregulation of SGLT-2 expression reduced the levels of inflammatory cytokines (TNF-α, IL-1ß, IL-6), TGF-ß1, α-smooth muscle actin, collagen I, and p-Smad3 accumulation in human peritoneal mesothelial cells. Collectively, these results indicated that empagliflozin exerted a clear protective effect on high-glucose peritoneal dialysis-induced peritoneal fibrosis via suppressing TGF-ß/Smad signaling.

Tuberculosis spondylitis in patients on hemodialysis: Clinical features, risk factors, and outcomes in 12 patients.

The aim of this study was to investigate the clinical features, risk factors and outcomes of tuberculosis spondylitis (TBS) in patients on hemodialysis (HD). We systematically reviewed medical records from 12 HD patients with TBS admitted to our hospital from April 2008 to April 2018. A total of 120 age- and sex-matched HD patients without infections were randomly selected as controls. The incidence of TBS in our patient group was 1.5/1000 per year. The average duration from initial symptoms to diagnosis was 45.4 days (range, 11-180 days). Neurosurgery was performed in 4 (33.3%) patients. TBS was cured or improved in 11 (91.7%) patients. HD patients with TBS had significantly lower albumin and Hb levels than controls (P = .03 and P = .01). These findings indicated that lower albumin and Hb levels were possible risk factors for TBS in patients on HD, most HD patients with TBS had a good outcome after anti-TB therapy with or without surgery.

Inhibition of proliferation-linked signaling cascades with atractylenolide I reduces myofibroblastic phenotype and renal fibrosis.

Renal fibrosis is a frequent axis contributing to the occurrence of end-stage nephropathy. Previously, it has been reported that atractylenolide Ⅰ (ATL-1), a natural compound extracted from Atractylodes macrocephala, has anti-cancer and antioxidant effects. However, the renal anti-fibrotic effects of action remain unclear. In this study, the anti-fibrotic effects of ATL-1 were examined in fibroblasts, tubular epithelial cells (TECs) triggered by TGF-ß1 in vitro, and using a unilateral ureteral obstruction (UUO) mouse model in vivo. We found that ATL-1 represses the myofibroblastic phenotype and fibrosis development in UUO kidneys by targeting the fibroblast-myofibroblast differentiation (FMD), as well as epithelial-mesenchymal transition (EMT). The anti-fibrotic effects of ATL-1 were associated with reduced cell growth in the interstitium and tubules, leading to suppression of the proliferation-linked cascades activity consisting of JAK2/STAT3, PI3K/Akt, p38 MAPK, and Wnt/ß-catenin pathways. Besides, ATL-1 treatment repressed TGF-ß1-triggered FMD and the myofibroblastic phenotype in fibroblasts by antagonizing the activation of proliferation-linked cascades. Likewise, TGF-ß1-triggered excessive activation of the proliferation-linked signaling in TECs triggered EMT. The myofibroblastic phenotype was repressed by ATL-1. The anti-fibrotic and anti-proliferative effects of ATL-1 were linked to the inactivation of Smad2/3 signaling, partially reversing FMD, as well as EMT and the repression of the myofibroblastic phenotype. Thus, the inhibition of myofibroblastic phenotype and fibrosis development in vivo and in vitro through proliferation-linked cascades of ATL-1 makes it a prospective therapeutic bio-agent to prevent renal fibrosis.

Polyphyllin I attenuates cognitive impairments and reduces AD-like pathology through CIP2A-PP2A signaling pathway in 3XTg-AD mice.

Polyphyllin I (PPI) is a natural phytochemical drug isolated from plants which can inhibit the proliferation of cancer cells. One of the PPI tumor-inhibitory effects is through downregulating the expression of Cancerous Inhibitor of PP2A (CIP2A), the latter, is found upregulated in Alzheimer's disease (AD) brains and participates in the development of AD. In this study, we explored the application of PPI in experimental AD treatment in CIP2A-overexpressed cells and 3XTg-AD mice. In CIP2A-overexpressed HEK293 cells or primary neurons, PPI effectively reduced CIP2A level, activated PP2A, and decreased the phosphorylation of tau/APP and the level of Aß. Furthermore, synaptic protein levels were restored by PPI in primary neurons overexpressing CIP2A. Animal experiments in 3XTg-AD mice revealed that PPI treatment resulted in decreased CIP2A expression and PP2A re-activation. With the modification of CIP2A-PP2A signaling, the hyperphosphorylation of tau/APP and Aß overproduction were prevented, and the cognitive impairments of 3XTg-AD mice were rescued. In summary, PPI ameliorated AD-like pathology and cognitive impairment through modulating CIP2A-PP2A signaling pathway. It may be a potential drug candidate for the treatment of AD.

Long-term predictive value of acute kidney injury classification in diffuse proliferative lupus nephritis with acute kidney injury.

BACKGROUND: The long-term predictive ability of acute kidney injury (AKI) classification based on "Kidney Disease: Improving Global Outcomes"(KDIGO) AKI diagnosis criteria has not been clinically validated in diffuse proliferative lupus nephritis (DPLN) patients with AKI. Our objective was to assess the long-term predictive value of KDIGO AKI classification in DPLN patients with AKI. METHODS: Retrospective cohort study was conducted by reviewing medical records of biopsy-proven DPLN patients with AKI from the First Affiliated Hospital of Wenzhou Medical University between Jan 1, 2000 and Dec 31, 2014. Multivariate Cox regression and survival analysis were performed. RESULTS: One hundred sixty-seven DPLN patients were enrolled,82(49%) patients were normal renal function (No AKI), 40(24%) patients entered AKI-1 stage (AKI-1), 26(16%) patients entered AKI-2 stage (AKI-2) and 19(16%) patients entered AKI-3 stage (AKI-3). The mean follow-up of all patients was 5.1 ± 3.8 years. The patient survival without ESRD of all patients was 86% at 5 years and 79% at 10 years. The patient survival rate without ESRD at 10 yr was 94.5% for No AKI patients, 81.8% for AKI-1 patients, 44.9% for AKI-2 patients and 14.6% for AKI-3 patients. The area under the ROC curve for KDIGO AKI classification to predict the primary end point was 0.83 (95% CI: 0.73-0.93) (P < 0.001). In Cox regression analysis, AKI stage was independently associated with primary endpoint, with an adjusted hazard ratio (HR) of 3.8(95% CI 2.1-6.7, P < 0.001). CONCLUSION: Severity of AKI based on KDIGO AKI category was associated with progression to ESRD in DPLN patients. Analytical data also confirmed the good discriminative power of the KDIGO AKI classification system for predicting long-term prognosis of DPLN patients with AKI.

Effect of ATM on inflammatory response and autophagy in renal tubular epithelial cells in LPS-induced septic AKI.

The aim of the present study was to explore the role of ataxia-telangiectasia mutated (ATM) in lipopolysaccharide (LPS)-induced in vitro model of septic acute kidney injury (AKI) and the association between ATM, tubular epithelial inflammatory response and autophagy. The renal tubular epithelial cell HK-2 cell line was cultured and passaged, with HK-2 cell injury induced by LPS. The effects of LPS on HK-2 cell morphology, viability, ATM expression and inflammation were observed. Lentiviral vectors encoding ATM shRNA were constructed to knock down ATM expression in HK-2 cells. The efficiency of ATM knockdown in HK-2 cells was detected by western blot analysis and reverse transcription-quantitative PCR (RT-qPCR). HK-2 cells transfected with the ATM shRNA lentivirus were used for subsequent experiments. Following ATM knockdown, corresponding controls were set up, and the effects of ATM on inflammation and autophagy were detected in HK-2 cells using RT-qPCR, western blotting and ELISA. After LPS stimulation, the HK-2 cells were rounded into a slender or fusiform shape with poorly defined outlines. LPS treatment reduced cell viability in a partly dose-dependent manner. LPS increased the expression of tumor necrosis factor-α, interleukin (IL)-1ß and IL-6, with the levels reaching its highest value at 10 µg/ml. IL-6 and IL-1ß expression increased with increasing LPS concentration. These findings suggest that LPS reduced HK-2 cell viability whilst increasing the expression of inflammatory factors. Following transfection with ATM shRNA, expression levels of key autophagy indicators microtubule associated protein 1 light chain 3α I/II ratio and beclin-1 in the two ATM shRNA groups were also significantly reduced compared with the NC shRNA group. In summary, downregulation of ATM expression in HK-2 cells reduced LPS-induced inflammation and autophagy in sepsis-induced AKI in vitro, suggesting that LPS may induce autophagy in HK-2 cells through the ATM pathway leading to the upregulation of inflammatory factors.

MicroRNA-155 Mediates Obesity-Induced Renal Inflammation and Dysfunction.

Chronic inflammation is a major contributor to obesity-related renal damage. Recent studies have demonstrated that microRNA (miR)-155 is closely associated with hyperglycemia-induced nephropathy, but whether renal miR-155 participates in the inflammatory response and development of obesity-related nephropathy is unknown. In present study, we investigated the pathophysiological role of renal miR-155 in palmitic acid (PA)-treated endothelial cell and high-fat-diet (HFD)-fed mouse models by specific miR-155 sponge. Mice fed with HFD exhibited higher levels of renal miR-155, which positively correlated with urine microalbumin and blood urea nitrogen. In vitro study, mouse renal vascular endothelial cells stimulated with PA also showed higher miR-155 levels, accompanied with increased inflammatory response. Suppression of renal miR-155 effectively attenuated HFD-induced renal structural damages and dysfunction. MiR-155 sponge treatment also significantly decreased NF-κB signaling and downstream gene expression in vitro and in vivo. The obesity-increased macrophage infiltration and lipotoxicity was decreased in mouse kidney after miR-155 sponge treatment. Mechanistically, miR-155 directly targeted 3'-UTR of SHIP1/INPP5D and suppressed its expression in vitro and in vivo, whereas silence of SHIP1/INPP5D abolished the renal protective benefits of miR-155 sponge in obese mice. Taken together, present findings for the first time provided evidence for the potential role of miR-155 in obesity-related nephropathy and clarified that SHIP1/NF-κB signaling was a potential molecular mechanism.

NovelmiRNA-25 inhibits AMPD2 in peripheral blood mononuclear cells of patients with systemic lupus erythematosus and represents a promising novel biomarker.

BACKGROUND: Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease with various clinical manifestations. MicroRNAs (miRNAs) and immunometabolism are recognized as key elements in SLE pathogenesis; however, the relationship between miRNAs in peripheral blood mononuclear cells (PBMCs) and metabolism in SLE remains unclear. METHODS: We detected PBMC miRNA and mRNA profiles from 3 pooled SLE patients and 3 healthy controls (HCs) using next-generation sequencing, predicted miRNA targets in dysregulated mRNAs, predicted functions and interactions of differentially expressed genes using bioinformatics analysis, validated candidate miRNAs using qRT-PCR, and investigated the association between the expression of candidate miRNAs and SLE clinical characteristics. Moreover, we validated the direct and transcriptional regulatory effect of NovelmiRNA-25 on adenosine monophosphate deaminase 2 (AMPD2) using a dual-luciferase reporter assay and western blot and confirmed AMPD2 mRNA and protein expression in PBMCs using qRT-PCR and western blot, respectively. RESULTS: Multilayer integrative analysis of microRNA and mRNA regulation showed that 10 miRNAs were down-regulated and 19 miRNAs were up-regulated in SLE patient PBMCs compared with HCs. Bioinformatics analysis of regulatory networks between miRNAs and mRNAs showed that 19 miRNAs were related to metabolic processes. Two candidate miRNAs, NovelmiRNA-25 and miR-1273h-5p, which were significantly increased in the PBMCs of SLE patients (P < 0.05), represented diagnostic biomarkers with sensitivities of 94.74% and 89.47%, respectively (area under the curve = 0.574 and 0.788, respectively). NovelmiRNA-25 expression in PBMCs was associated with disease activity in SLE patients, in both active and stable groups (P < 0.05). NovelmiRNA-25 overexpression downregulated AMPD2 expression in HEK293T cells through direct targeting of the AMPD2 3'UTR (P < 0.01), while inhibition of NovelmiRNA-25 activity led to increased AMPD2 expression (P < 0.01). NovelmiRNA-25 overexpression also downregulated AMPD2 protein expression in HEK293T cells; AMPD2 protein expression in SLE patient PBMCs was decreased. Our results show that differentially expressed miRNAs play an important role in SLE. CONCLUSIONS: Our data demonstrate a novel mechanism in SLE development that involves the targeting of AMPD2 expression by NovelmiRNA-25. miRNAs may serve as novel biomarkers for the diagnosis and evaluation of disease activity of SLE and represent potential therapeutic targets for this disease.

Serum C3/C4 ratio is a novel predictor of renal prognosis in patients with IgA nephropathy: a retrospective study.

IgA nephropathy (IgAN) is an autoimmune disease associated with complement activation. It is unclear whether the ratio of serum C3 and C4 concentrations (C3/C4 ratio) can predict renal outcomes in IgAN patients. A total of 1503 patients diagnosed with IgAN via renal biopsy were recorded in this study. Poor renal outcomes were defined as > 50% decrease in the baseline estimated glomerular filtration rate (eGFR) or development of end-stage renal disease (ESRD) during follow-up. In total, 712 patients meeting the exclusion/inclusion criteria were selected, and the mean follow-up period was 40.6 (12.34) months. Patients with decreased C3/C4 ratios displayed significantly more severe clinical characteristics and renal pathological features and a higher proportion of poor renal outcomes and ESRD. The optimal multivariate Cox regression models identified the C3/C4 ratio (hazard ratio (HR) 0.63, 95% CI 0.5-0.9), serum uric acid (HR 1.58, 95% CI 1.2-2.2), serum creatinine (HR 1.3, 95% CI 1.1-1.6), systolic blood pressure (HR 1.57, 95% CI 1.2-2.0) and T score (relative to T0, T1: HR 1.96, 95% CI 1.1-3.7, T2: HR 3.03, 95% CI 1.6-5.9) as strong predictors of poor renal outcomes. Subgroup analysis showed that patients with low C3/C4 ratios benefited from glucocorticoids or other immunosuppressive agents (hazard ratio 0.30 and 0.18, 95% CI 0.13-0.72 and 0.07-0.46, respectively). Serum C3/C4 ratios may be an independent novel predictor of renal outcomes in IgAN patients. Decreased C3/C4 ratios suggest poor renal outcomes and the potential to benefit from aggressive immunosuppressive therapies.

Renal outcomes in primary IgA nephropathy patients with segmental glomerular necrosis: a case-control study.

The renal prognosis and treatment of primary IgA nephropathy (IgAN) patients with segmental glomerular necrosis (SGN) remain controversial. Patients with primary IgAN confirmed by renal biopsy were enrolled. Patients with SGN on renal biopsy were selected as the necrosis group, and a propensity score matching method was used to match a control group according to age, gender, weight, height and follow-up time. A total of 825 IgAN patients were enrolled in the present study. Seventy-three (8.8%) patients with SGN were selected as the necrosis group, and 292 patients without SGN were matched as the control group. Compared to the control group, a significantly increased serum fibrinogen level (3.97 g/L vs 3.54 g/L, P=.002) and proportion of patients with macroscopic hematuria (35.6% vs 14.7%, P<.001) was observed in the necrosis group. According to the new IgA pathological classification system, crescent formation was more pronounced in the necrosis group (P=.001). The average estimated glomerular filtration rate was obviously higher in the necrosis group and decreased more slowly during follow-up. However, the time-averaged urine protein-to-creatinine ratio remained low in the necrotic group, whereas it gradually increased in the control group. SGN suggests an active renal inflammatory state, but it was not an independent risk factor for a poor renal outcome in patients treated with immunosuppressive therapy. Furthermore, patients with SGN had a more stable renal function and low urinary protein excretion during follow-up, which may be attributable to aggressive immunotherapy.

The cytomegalovirus protein US31 induces inflammation through mono-macrophages in systemic lupus erythematosus by promoting NF-κB2 activation.

It has been hypothesized that human cytomegalovirus (HCMV) infection, especially in monocyte and CD34 (+) myeloid cells, acts as a important regulator of immune system to promote inflammation in multiple autoimmune diseases. The aim of this study was to elucidate the HCMV gene expression profiles in the peripheral blood mononuclear cells (PBMCs) of SLE patients and demonstrate the effect and mechanism of viral gene associated with SLE in mono-macrophages functions. Using two RNA-Seq techniques in combination with RT-PCR, 11 viral genes mainly associated with latent HCMV infection were identified in the PBMCs of SLE patients. Among these viral genes, US31 with previously unknown function was highly expressed in the PBMCs of SLE patients compared to healthy controls. Analysis of function indicated that US31 expression could induce inflammation in monocyte and macrophage and stimulate macrophage differentiation toward an M1 macrophage phenotype. Screening via protein chips in combination with bioinformatic analysis and consequent detection of mono-macrophages function indicates that the direct interaction between US31 and NF-κB2 contributed the NF-kB2 activation. Consequent analysis indicated US31 directly interacted with NF-κB2, contribute to the polyubiquitination of the phosphorylated p100 and consequent activation of NF-κB2. Taken together, our data uncovered a previously unknown role of the HCMV protein US31 in inducing NF-κB-mediated mono-macrophage inflammation in the pathogenesis and development of SLE. Our findings provide a foundation for the continued investigation of novel therapeutic targets for SLE patients.

Assaying kinase activity of the TPL-2/NF-κB1 p105/ABIN-2 complex using an optimal peptide substrate.

The MKK1/2 kinase tumour progression locus 2 (TPL-2) is critical for the production of tumour necrosis factor alpha (TNFα) in innate immune responses and a potential anti-inflammatory drug target. Several earlier pharmaceutical company screens with the isolated TPL-2 kinase domain have identified small-molecule inhibitors that specifically block TPL-2 signalling in cells, but none of these have progressed to clinical development. We have previously shown that TPL-2 catalytic activity regulates TNF production by macrophages while associated with NF-κB1 p105 and ABIN-2, independently of MKK1/2 phosphorylation via an unknown downstream substrate. In the present study, we used a positional scanning peptide library to determine the optimal substrate specificity of a complex of TPL-2, NF-κB1 p105 and ABIN-2. Using an optimal peptide substrate based on this screen and a high-throughput mass spectrometry assay to monitor kinase activity, we found that the TPL-2 complex has significantly altered sensitivities versus existing ATP-competitive TPL-2 inhibitors than the isolated TPL-2 kinase domain. These results imply that screens with the more physiologically relevant TPL-2/NF-κB1 p105/ABIN-2 complex have the potential to deliver novel TPL-2 chemical series; both ATP-competitive and allosteric inhibitors could emerge with significantly improved prospects for development as anti-inflammatory drugs.