Expanding the toolset of fluorescent covalent staining of biological samples by labeling carboxylate and phosphate groups.

Recently, fluorescent covalent staining methods have been developed for visualization of anatomical structures in cells and tissues. Coupled with expansion microscopy, these stains revealed various ultrastructural details. However, the covalently stainable chemical groups have been limited to amines, carbohydrates, and thiols. Here, we developed procedures for covalently labeling tissues for carboxylate and phosphate groups, utilizing carbodiimide crosslinker chemistry. In porcine kidney tissues, the carboxylate and phosphate stain provides 1.8-4.8-fold higher signal intensity than those from the three existing stains. In cancer cells, such stain allows 2-8-fold more accurate identification of nucleoli than the amine stain. In expansion microscopy samples, such stain reveals a variety of sub-cellular structures in tissues when combined with the amine stain. Such stain also allows imaging of lipid-based structures in cultured cells. With these advantages, this new covalent staining method further expands the toolset for fluorescent visualization of histology.

The association between platelet-lymphocyte ratio and the risk of all-cause mortality in chronic kidney disease: a systematic review and meta-analysis.

BACKGROUND: Chronic kidney disease (CKD) patients have high levels of inflammatory mediators. These inflammatory mediators contribute to the increased risk of cardiovascular events and all-cause mortality. Platelet-lymphocyte ratio (PLR) has recently been recognized as a novel inflammatory marker and has been shown to be associated with the prognosis in CKD patients. However, the quality of these studies varies and their results are controversial. The purpose of this meta-analysis was to investigate the relationship between PLR and all-cause mortality in CKD patients. METHODS: A systematic literature search of PubMed, EMBASE, CENTRAL and ISI Web of Science was conducted. The databases were searched from their inception dates up to the latest issue (31 October 2021). Two reviewers independently searched the databases and screened studies. Data were extracted using a standardized collection form. Meta-analysis was performed to compare PLR values between CKD and non-CKD patients, and to investigate the association between PLR and all-cause mortality in CKD patients. This meta-analysis is reported in adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). RESULTS: A total of 11 studies involving 4244 participants were selected. The pooled data indicated that PLR values were significantly higher in CKD patients than non-CKD controls (weighted mean difference = 21.6, 95% CI 17.39-25.81, p < 0.01), and PLR is associated with an increased risk of all-cause mortality in CKD patients (hazard ratio = 2.49, 95% CI 1.78-3.49, p < 0.01). CONCLUSIONS: Patients with CKD have higher PLR values compared to non-CKD patients. Meanwhile, PLR values were highly associated with all-cause mortality in CKD patients. PLR is a valid predictor as a clinically accessible indicator for patients with CKD.

The association between the locations of arteriovenous fistulas and patency rates: A systematic review and meta-analysis.

BACKGROUND: The arteriovenous fistulas (AVF) continue to be the most prevalent type of vascular access for hemodialysis (HD). However, the appropriate locations of AVF are controversial. We conducted the meta-analysis to investigate the differences in patency between upper-arm and forearm AVF. METHODS: PubMed, EMBASE, CENTRAL, and ISI Web of Science were searched to identify studies with differences in AVF patency at different locations. Reviewers searched the database, screened studies according to inclusion criteria, and conducted Meta-analysis. RESULTS: A total of 12 studies involving 3437 patients were selected. Pooled data showed that primary patency (PP) of AVF were higher in upper-arm than forearm at 1 and 2 years (odds ratio [OR] = 1.54, p = 0.0005; OR = 2.45, p = 0.001), but the differences in cumulative patency (CP) were not statistically significant at 1 and 2 years (OR = 2.10, p = 0.08; OR = 2.16, p = 0.1). The differences in PP and CP between upper-arm and forearm AVF in patients older than 65 years were not statistically significant at 1 (OR = 1.61, p = 0.05; OR = 2.05, p = 0.17) and 2 years (OR = 3.40, p = 0.13; OR = 1.38, p = 0.16). In Asian patients, the differences in PP and CP between upper-arm and forearm AVF were not statistically significant at 1 (OR = 1.17, p = 0.41; OR = 1.02, p = 0.94) and 2 years (OR = 2.95, p = 0.08; OR = 1.23, p = 0.41). CONCLUSIONS: In this study, the CP of upper-arm and forearm AVF was similar in overall population. There was no difference in PP and CP of AVF between upper-arm and forearm in Asian population or the elderly. The forearm AVF could be consider to be the first choice. for Asian patients or the elderly.

Maturation and survival of arteriovenous fistula: The challenge starts from the preoperative assessment stage.

BACKGROUND: It is necessary to assess the association between the preoperative indicators and the maturation and survival of arteriovenous fistula (AVF). METHODS: We retrospectively identified 236 patients with a new AVF created between 2016 and 2018 in our Dialysis Center. RESULTS: Multivariate Logistic regression showed that preoperative arterial diameter (odds ratio [OR] = 1.452, 95% confidence interval [CI] [1.233, 1.710], p < 0.001), preoperative venous diameter (OR = 1.296, 95% CI [1.166, 1.477], p < 0.001), left ventricular ejection fraction (LVEF) (OR = 1.187, 95% CI [1.103, 1.277], p < 0.001), and diabetes mellitus (OR = 0.245, 95% CI [0.107, 0.560], p = 0.01) were independent influential factors for AVF maturation. Two years after the AVF surgery follow-up, multivariate Cox proportional-hazards model showed that the preoperative arterial diameter (OR = 0.510, 95% CI [0.320, 0.813], p = 0.005), preoperative venous diameter (OR = 0.940, 95% CI [0.897, 0.985], p = 0.010) and diabetes mellitus (OR = 1.785, 95% CI [1.117, 2.855], p = 0.016) was prognostic factors of AVF survival. The Kaplan-Meier method showed that the primary survival of AVF in patients with different preoperative arterial diameter was statistically significant (log-rank χ2 = 15.415, p < 0.001), while the secondary survival was not statistically significant (log-rank χ2 = 0.131, p = 0.717). CONCLUSION: In our cohort, the preoperative arterial and venous diameter and diabetes mellitus were independent influential factors for AVF maturation and prognostic factors of AVF survival. However, the preoperative LVEF only associated with the maturation of AVF. Meanwhile, smaller arterial diameter (≤2.15 mm) was associated with AVF maturation failure, but did not impact secondary survival of AVF.

Circulating irisin level in chronic kidney disease patients: a systematic review and meta-analysis.

BACKGROUND: Irisin is not only a myokine but also an adipokine that is critical in many diseases including in the development of such diseases as obesity, diabetes mellitus, metabolic syndrome, coronary artery disease, and chronic inflammation. However, the association between irisin and chronic kidney disease (CKD) is unclear. This systematic review aimed to assess circulating irisin levels in patients with CKD and compare them with those in non-CKD patients. METHODS: PubMed, EMBASE, CENTRAL, ISI Web of Science, and CNKI were searched to identify observational studies of circulating irisin levels in patients with CKD. Two reviewers independently searched the databases and screened studies according to the inclusion criteria. Data were extracted using a standardized collection form. Meta-analysis was performed to compare the differences in circulating irisin levels between CKD and non-CKD patients. RESULTS: A total of 9 studies (6 cross-sectional and 3 case controls) involving 859 CKD patients and 393 non-CKD individuals were selected. The pooled data indicated that circulating irisin concentrations were significantly lower in CKD nondialysis patients (WMD = - 84.79, 95% CI - 170.23, 0.50; p < 0.05), peritoneal dialysis patients (WMD = - 235.81, 95% CI - 421.99, - 49.62; p = 0.01), and hemodialysis patients (WMD = - 217.46, 95% CI - 381.35, - 53.57; p = 0.009) than in healthy controls. CONCLUSIONS: This study confirmed that irisin levels were decreased in patients with CKD. Moreover, circulating irisin levels were lower in dialysis patients than in nondialysis patients.

Ouabain-induced apoptosis and inhibition of viability of tubulointerstitial cells by regulating NKA/pSrc/pERK/pAkt/pS6k/caspase 3 may contribute to lupus nephritis development.

This study aimed to investigate the underlying molecular mechanism of ouabain-induced apoptosis and inhibited viability of tubulointerstitial cells in lupus nephritis (LN). Serum ouabain expression in 21 LN patients and 20 healthy controls (HCs) was detected by ELISA. Na-K-ATPase α1 (NKA) expression in kidney tissue from 21 LN patients and 6 controls who underwent nephrectomy was determined by immunohistochemistry assay. HK-2 cells were treated by ouabain with concentration 0 nM (control), 0.1 nM, 1 nM, 10 nM, 100 nM and 1000 nM for 72 h; MTT assay was performed at 24 h, 48 h and 72 h to detect cells viability, AV/PI assay was conducted at 24 h to detect the cell apoptosis. NKA expression was detected by immunofluorescence assay and western blot (WB) while pSrc, pERK, pAkt, pS6K and caspase 3 expression was detected by WB after 100 nM ouabain treatment. Serum ouabain was elevated in LN patients compared to HCs, while kidney NKA was reduced in LN patients compared with controls. HK-2 cell viability by MTT assay was decreased while cell apoptosis by AV/PI was increased at each time point after ouabain 0.1 nM, 1 nM, 10 nM, 100 nM and 1000 nM treatment compared to control group. Both immunofluorescence and WB disclosed that NKA expression was decreased at 12 h and 24 h compared to 0 h after 100 nM ouabain treatment. Moreover, pSrc, pERK, pAkt, pS6K and caspase 3 expressions were elevated after 100 nM ouabain treatment. In conclusion, ouabain may contribute to LN etiology by inhibiting human proximal tubular cell viability and promoting cells apoptosis through regulating NKA, pSrc, pERK, pAkt, pS6K and caspase 3.