Protease-Activated Receptor-2 and Phospholipid Metabolism Analysis in Hyperuricemia-Induced Renal Injury.

Interstitial inflammation is an important mechanism of pathological damage in renal injury caused by hyperuricemia. Protease-activated receptor-2 (PAR2) is a class of targets that act upstream of the PI3K/AKT/NF-κB pathway and is involved in various inflammatory diseases. We induced a hyperuricemia model in rats by adenine and ethambutol gavage in an in vivo experiment. We demonstrated that PAR2 and PI3K/AKT/NF-κB pathway expression were significantly upregulated in renal tissues, with massive inflammatory cell infiltration in the renal interstitium and renal tissue injury. Treating hyperuricemic rats with AZ3451, a selective metabotropic antagonist of PAR2, we demonstrated that PAR2 antagonism inhibited the PI3K/AKT/NF-κB pathway and attenuated tubular dilation and tubulointerstitial inflammatory cell infiltration. The phospholipid metabolism profiles provided a perfect separation between the normal and hyperuricemic rats. In addition, we also found that AZ3451 can affect phospholipid metabolism. Our work suggests that PAR2 may mediate hyperuricemia-mediated renal injury by activating the PI3K/AKT/NF-κB pathway. The PAR2 antagonist AZ3451 may be a promising therapeutic strategy for hyperuricemia-induced inflammatory responses.

Trends in Corneal Transplantation and Characteristics of Donors in the Chongqing Eye Bank, China: A Retrospective Study, 1999-2018.

Aim: This study aimed to analyze corneal transplantation trends and voluntary donor characteristics at the Chongqing Eye Bank in China. Methods: We retrospectively reviewed and analyzed data from January 1, 1999, to December 31, 2018, covering 5,397 preregistered voluntary donors, 1,955 actual donors, 3,910 donated tissues, and 2,374 corneal transplantations. Results: The 5,397 preregistered donors included 13 ethnic groups, with an overall mean age of 39.6 years (SD 21.5) and 3,010 were women (55.8%). The most prevalent education level was college and above (2,546, 47.2%), and the most common ethnic group was Han (5,335, 98.85%). Of the 1,955 actual donors, the male-to-female ratio was 3.3, and the mean age was 57.1 (SD 23.0 years). Based on population size in 2018, Jiangbei county was the most active in donation willingness, with ~60 × 10-6 per capita, and the Yuzhong county was the most active in cornea donations, with ~451 × 0-6 per capita. Of the 3,910 donated corneas, 2,540 (65.0%) were clinically used. Of those not used, 978 (71.4%) were rejected for poor corneal quality. The 2,374 (93.5%) corneal transplantation procedures were done at the Department of Ophthalmology of the First Affiliated Hospital of Chongqing Medical University and the rest (n = 166, 6.5%) were performed in other centers. Of those 2,374 corneal transplantations, there were 1,671 penetrating keratoplasty (70.39%), 700 anterior lamellar keratoplasty (29.49%), and three corneal endothelial transplantations in our center (0.13%). The number of annual corneal transplantations increased by nearly 10 times, from 35 cases in 1999 to 327 cases in 2018. Among them, cases of penetrating keratoplasty and anterior lamellar keratoplasty increased from 27, and eight cases in 1999 to 230 and 94 cases in 2018, respectively. Infectious keratitis (37.0%) was the leading indication for keratoplasty, followed by corneal scar (19.8%). Over the study period, corneal scars dropped from the first (41.1% in 1999-2003) to the second indication (20.5% in 2014-2018), while infectious keratitis advanced to take the lead, ranging from 12.2% in 1999-2003 to 26.3% in 2014-2018. Conclusion: Our study reports corneal donation and transplantation trends in Chongqing over 20 years, showing that infectious keratitis is a leading indication for keratoplasty and that penetrating keratoplasty and anterior lamellar keratoplasty show upward trends. The analysis further suggests that a potential preregistered cornea donor is a female Han, with a higher education level.

Correlation between histone H3K4 trimethylation and DNA methylation and evaluation of the metabolomic features in acute rejection after kidney transplantation.

OBJECTIVE: To investigate the difference between trimethylation of monocyte histone H3K4 and DNA methylation in acute rejection (AR) after renal transplantation in rats and reveal the epigenetic mechanism of the AR rats based on metabolomics. METHOD: Peripheral blood mononuclear cells (PBMCs) were isolated, and CD4 +CD25 + Treg cells were sorted by flow cytometry. The Foxp3 mRNA and protein levels of CD4 +CD25 + Treg cells were detected by real-time RT-PCR and Western blotting, respectively. High-throughput screening was applied to evaluate the H3K4 methylation of monocytes using chromatin immunoprecipitation with DNA microarray (ChIP-chip) and verified by ChIP with real-time PCR (ChIP-qPCR). Methylated DNA immunoprecipitation sequencing was combined with real-time PCR (MeDIP-qPCR) to detect the DNA methylation level of positive genes (ABCC4, Mef2d, Tbx1 and Eif6). Real-time quantitative PCR (qRT-PCR) and Western blotting were used to detect the mRNA and protein levels of positive genes. The difference in lipid metabolism in the blood of (non) acute rejection rats was analysed by HPLC/MS. RESULTS: AR rats showed an apparent increase in BUN and Cr levels, as well as IL-2, IL-10 and IFN-γ. Compared with non-AR rats, the expression of CD4 +CD25 + Treg cells and Foxp3 mRNA and protein were significantly lower in AR rats. AR rats also showed an increase in H3K4 trimethylation of CD4 +CD25 + Treg and decrease in DNA methylation. There were significant differences in the DNA methylation level of four positive genes between AR and non-AR rats (P<0.05), in addition to differences in the expression levels of mRNA and protein. Pathological examination of the transplanted kidney indicated that AR rats had more severe pathological injury of the kidney than the non-AR rats. There were significant increase in the contents of several phosphatidylcholines, lysophosphatidylcholine, free fatty acids and carnitine in AR rats which detected by HPLC/MS. CONCLUSION: H3K4 trimethylation increased in PBMCs in AR rats, while DNA methylation decreased, indicating the presence of epigenetic differences between AR and non-AR rats. Metabolomic studies indicated a significant increase in AR rats in the contents of several metabolites, such as phosphatidylcholines, lysophosphatidylcholine, free fatty acids and carnitine, suggesting an increasein phospholipase activity and leading to an energy metabolism imbalance with intensification of ß-oxidation. DNA methylation may be associated with an increase in phosphatidylcholines, lysophosphatidylcholine and free fatty acids in AR rats, which may further affect energy metabolism by enhancing the tricarboxylic acid cycle in AR rats.

Association between Nod-like receptor protein 3 inflammasome and gouty nephropathy.

Crystalized deposits of monosodium urate activate the Nod-like receptor protein 3 (NLRP3) inflammasome, resulting in kidney damage. The present study investigated whether the NLRP3 inflammasome is associated with the progression of hyperuricaemia and gouty nephropathy. Adult male patients were recruited at the Affiliated Baoan Hospital of Shenzhen and divided into three groups of 15 patients each: The control group, the hyperuricaemia group and the gouty nephropathy group. General characteristics and organ function indicators were also measured for each patient. NLRP3, apoptosis-associated speck like protein (ASC) and caspase-1 mRNA and protein expressions in peripheral blood mononuclear cells were detected. The expression of certain downstream inflammatory factors, including interleukin (IL)-1ß and IL-18 were also assessed in plasma. The results demonstrated that the concentration of uric acid and creatinine were increased in the hyperuricaemia and gouty nephropathy groups compared with the control group. NLRP3, ASC and caspase-1 mRNA and protein expression, and IL-1ß and IL-18 expression were increased in the hyperuricaemia and gouty nephropathy groups compared with the control group. In addition, ASC and caspase-1 mRNA and protein expression, and IL-1ß expression were higher in the gouty nephropathy group compared with the hyperuricaemia group. In conclusion, the present results supported the hypothesis that the NLRP3 inflammasome signalling pathway is associated with gouty nephropathy leading to initiation of the inflammatory response and causing renal damage.

Outcomes of therapeutic keratoplasty for severe infectious keratitis in Chongqing, a 16-year experience.

PURPOSE: This study aimed to evaluate the outcomes of therapeutic keratoplasty for severe infectious keratitis in Chongqing (Southwest China). PATIENTS AND METHODS: The records of 561 eyes that underwent therapeutic keratoplasty for refractory microbial keratitis from 2001 to 2016 were analyzed in this retrospective study. Data included demographic information, microbiological investigations, associated factors, graft size, preoperative status, postoperative complications, and final anatomical outcomes. RESULTS: Trauma was the most common cause (267, 47.6%) for corneal ulcers leading to therapeutic keratoplasty. The etiological diagnosis included bacterial keratitis (80 eyes, 14.3%), fungal keratitis (317 eyes, 56.5%), acanthamoeba keratitis (3 eyes, 0.5%), and mixed bacteria/fungal infection (15 eyes, 2.7%). Anatomical success was achieved for 492 eyes (87.7%), with bacterial keratitis having a better outcome than fungal and mixed infections. Diabetes and preoperative time ≥30 days were significantly associated with anatomical failure in the multivariate logistic regression (P=0.028 and P=0.022, respectively). Patients with hypopyon, corneal perforation, surgical delay, and/or large graft size had a higher incidence of postoperative complications (reinfection, cataract, glaucoma, hyphema, or graft rejection) (P<0.05). CONCLUSION: Therapeutic keratoplasty was an effective procedure in managing refractory infectious keratitis. Prompt and appropriate surgery would result in fewer complications and better outcomes.

NLRP3 inflammasome and lipid metabolism analysis based on UPLC-Q-TOF-MS in gouty nephropathy.

To determine the differences in plasma metabolism between healthy patients and patients with hyperuricaemia and gouty nephropathy, the present study identified differentially expressed metabolites associated with gouty nephropathy. Furthermore, the NLRP3 inflammasome signalling pathway in gouty nephropathy was explored, and the mechanism of hyperuricaemia­induced renal damage. Adult male patients examined between July 2016 and June 2017 were selected as the patient cohort for the present study from the Affiliated Bao'an Hospital of Shenzhen, Southern Medical University (Shenzhen, China). These patients were divided into three groups of 30 patients each: Control, hyperuricaemia and gouty nephropathy groups. The expression levels of NLRP3, ASC and caspase­1 mRNA and protein were detected in peripheral blood mononuclear cells, and the plasma levels of IL­1ß and IL­18. Ultra­performance liquid chromatography coupled with quadrupole time­of­flight mass spectrometry was used to determine differential levels of metabolites between patients from different groups, in order to identify potential biomarkers. The expression of the NLRP3 inflammasome in peripheral blood mononuclear cells, and the levels of IL­1ß and IL­18 in the plasma were increased in the gouty nephropathy group compared with the control and hyperuricaemia groups. In addition, 46 metabolites were identified as potential plasma metabolic biomarkers that were able to distinguish gouty nephropathy from hyperuricaemia. The majority of these metabolites were involved in lipid metabolism, in particular the activity of phospholipase Α2 and ß­oxidation. These data indicated that lipid metabolism and the NLRP3 inflammasome serve a pivotal role in gouty nephropathy. In addition, the results suggested that lipids may mediate the progression of gouty nephropathy through the activity of phospholipase A2, ß­oxidation and activation of the NLRP3 inflammasome.

Monocytes, endoplasmic reticulum stress and metabolomics in dogs with multiple organ dysfunction syndrome treated by continuous venovenous hemodiafiltration.

OBJECTIVES: We tried to investigate the mechanism of continuous venovenous hemodiafiltration (CVVHDF) treatment in monocytes function, endoplasmic reticulum (ER) stress signaling pathways, metabolomics and histopathological changes of MODS dogs, and aimed to enhance the understanding of pathogenesis and provide novel avenues to potential therapies. METHODS: 12 male Beagle dogs were used to develop the stable models of MODS by using hemorrhagic shock plus resuscitation and endotoxemia, and assigned randomly to CVVHDF group (n=6) and MODS group (n=6). The dogs in CVVHDF group were given the typical CVVHDF treatment for 24h after the completion of endotoxin intravenous infusion, while those in MODS group were offered the i.v heparin instead only. Serum sample were collected at five time points, i.e. before anesthesia, 0h, 6h, 12h and 24h after the endotoxin injection (T1~T5, respectively), and meanwhile, the changes of mRNA, protein and human umbilical vein endothelial cells (HUVECs) apoptosis rates in JNK, CHOP and Caspase-12 were observed before and after interfered by RNA interference technology. RESULTS: The levels of DLA-DR, IL-1ß and IL-4 were higher than those in MODS group after the CVVHDF treatment, and the early and late apoptosis rates showed downward trend compared with MODS group. In vitro and prior to RNA interference (RNAi), the levels of mRNA and protein expression and HUVECs apoptosis rates of JNK, CHOP and Caspase-12 in CVVHDF group were significantly lower compared to T1 and MODS group respectively. However, the levels of mRNA and protein expression and HUVECs apoptosis rates were significantly lower than those before interfered by RNAi in both two groups. The serum levels of LPCs, ornithine, proline, methionine, etc. were down-regulated while carnitines, FFAs, PC, etc. were increased significantly in MODS (T4), and the serum levels of methionine, proline, arginine and lysine were increased while carnitine, LPCs, PCs, SMs and orthophosporic acid were decreased after 12 hours CVVHDF treatment (T4). CONCLUSION: CVVHDF treatment could reduce the apoptosis of the cells by enhancing the antigen presentation, improving the anti-inflammatory and proinflammatory imbalance and even correcting the metabolic disorder of amino acids and phospholipids.

Interleukin-17 induces angiogenesis in human choroidal endothelial cells in vitro.

PURPOSE: The proinflammatory cytokine interleukin-17 (IL-17) has recently been shown to promote angiogenesis. In addition, a receptor for IL-17, IL-17 receptor C (IL-17RC), is enriched in patients with wet, age-related macular degeneration (AMD), a disease characterized by the formation of choroidal neovascularization. However, the role of IL-17 in choroidal endothelial cells (CECs) angiogenesis has not been defined. This study was conducted to determine the effect of IL-17 on proliferation, migration, and tube formation of human CECs. METHODS: Expression patterns of IL-17 receptor A (IL-17RA) and IL-17RC on isolated human CECs were analyzed by flow cytometry and immunofluorescent staining. Proangiogenic effects of IL-17 on CECs was determined by proliferation assays with a water-soluble tetrazolium cell proliferation reagent kit, wound healing migration assays, and tube formation assays using basement membrane matrix. Cytoskeletal changes were observed by F-actin immunofluorescent staining. Activated Rac1 and RhoA levels were analyzed by pull-down assays. RESULTS: Interleukin-17RA and IL-17RC were present on human CECs. Interleukin-17 enhanced migration and tube formation but did not affect proliferation. Moreover, IL-17 induced rearrangement of the actin cytoskeleton and upregulated activated Rac1 and RhoA in CECs. The PI3K inhibitor wortmannin suppressed CEC migration, cytoskeleton rearrangement, and upregulation of activated Rac1 and RhoA induced by IL-17. CONCLUSIONS: Interleukin-17 elicits a proangiogenesis effect on human CECs in vitro by promoting migration and tube formation. The promoted migration effect was dependent on PI3K-Rac1 and RhoA-mediated actin cytoskeleton remodeling.