AMPK agonist alleviate renal tubulointerstitial fibrosis via activating mitophagy in high fat and streptozotocin induced diabetic mice.

Renal tubulointerstitial fibrosis was a crucial pathological feature of diabetic nephropathy (DN), and renal tubular injury might associate with abnormal mitophagy. In this study, we investigated the effects and molecular mechanisms of AMPK agonist metformin on mitophagy and cellular injury in renal tubular cell under diabetic condition. The high fat diet (HFD) and streptozotocin (STZ)-induced type 2 diabetic mice model and HK-2 cells were used in this study. Metformin was administered in the drinking water (200 mg/kg/d) for 24 weeks. Renal tubulointerstitial lesions, oxidative stress and some indicators of mitophagy (e.g., LC3II, Pink1, and Parkin) were examined both in renal tissue and HK-2 cells. Additionally, compound C (an AMPK inhibitor) and Pink1 siRNA were applied to explore the molecular regulation mechanism of metformin on mitophagy. We found that the expression of p-AMPK, Pink1, Parkin, LC3II, and Atg5 in renal tissue of diabetic mice was decreased obviously. Metformin reduced the levels of serum creatinine, urine protein, and attenuated renal oxidative injury and fibrosis in HFD/STZ induced diabetic mice. In addition, Metformin reversed mitophagy dysfunction and the over-expression of NLRP3. In vitro pretreatment of HK-2 cells with AMPK inhibitor compound C or Pink1 siRNA negated the beneficial effects of metformin. Furthermore, we noted that metformin activated p-AMPK and promoted the translocation of Pink1 from the cytoplasm to mitochondria, then promoted the occurrence of mitophagy in HK-2 cells under HG/HFA ambience. Our results suggested for the first time that AMPK agonist metformin ameliorated renal oxidative stress and tubulointerstitial fibrosis in HFD/STZ-induced diabetic mice via activating mitophagy through a p-AMPK-Pink1-Parkin pathway.

Identification of Eltrombopag as a Repurposing Drug Against Staphylococcus epidermidis and its Biofilms.

Staphylococcus epidermidis is a common cause of nosocomial infections, and readily adheres to medical apparatus to form biofilms consisting of highly resistant persister cells. Owing to the refractory infections caused by S. epidermidis biofilms and persisters in immunosuppressed patients, it is crucial to develop new antimicrobials. In the present study, we analyzed the antimicrobial effects of the thrombopoietin receptor agonist eltrombopag (EP) against S. epidermidis planktonic cells, biofilms, and persister cells. EP was significantly toxic to S. epidermidis with the minimal inhibitory concentration of 8 µg/ml, and effectively inhibited the biofilms and persisters in a strain-dependent manner. In addition, EP was only mildly toxic to mammalian cells after 12 to 24 h treatment. It also partially synergized with vancomycin against S. epidermidis, which enhanced its antimicrobial effects and reduced its toxicity to mammalian cells. Taken together, EP is a potential antibiotic for treating refractory infections caused by S. epidermidis.

Mitochondria-Targeted Peptide SS31 Attenuates Renal Tubulointerstitial Injury via Inhibiting Mitochondrial Fission in Diabetic Mice.

OBJECTIVE: Renal tubular injury is an early characteristic of diabetic nephropathy (DN) that is related to mitochondrial dysfunction. In this study, we explore the effects and mechanisms of mitochondria-targeted peptide SS31 on renal tubulointerstitial injury in DN. METHOD: 40 C57BL/6 mice were randomly divided into control group, STZ group, STZ+SS31 group, and STZ+normal saline group. SS31 was intraperitoneally injected to the mice every other day for 24 weeks. Renal lesions and the expression of Drp1, Mfn1, Bcl-2, Bax, Caspase1, IL-1ß, and FN were detected. In in vitro studies, HK-2 cells were incubated with different concentrations of D-glucose (5, 30 mM) or combined with SS31 and Drp1 inhibitor Midivi1. Mitochondrial ROS, membrane potential, and morphology have been detected to evaluate the mitochondrial function. RESULTS: Compared with diabetic mice, the levels of serum creatinine and microalbuminuria were significantly decreased in the SS31 group. Renal tubulointerstitial fibrosis, oxidative stress, and apoptosis were observed in diabetic mice, while the pathological changes were reduced in the SS31-treatment group. SS31 could decrease the expression of Drp1, Bax, Caspase1, IL-1ß, and FN in the renal tissue of diabetic mice, while increasing the expression of Mfn1. Additionally, mitochondria exhibit focal enlargement and crista swelling in renal tubular cells of diabetic mice, while SS31 treatment could partially block these changes. An in vitro study showed that pretreatment with SS31 or Drp1 inhibitor Mdivi1 could restore the level of mitochondrial ROS, the membrane potential levels, and the expressions of Drp1, Bax, Caspase1, IL-1ß, and FN in HK-2 cells under high-glucose conditions. CONCLUSION: SS31 protected renal tubulointerstitial injury in diabetic mice through a decrease in mitochondrial fragmentation via suppressing the expression of Drp1 and increasing the expression of Mfn1.

Neutrophil-lymphocyte ratio in systemic lupus erythematosus disease: a retrospective study.

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. Lupus nephritis (LN) is an important cause of morbidity and even mortality in patients with SLE. Some evidences suggest that neutrophil-lymphocyte ratio (NLR) associated with different inflammatory malignancies, ischemic injury and cardiovascular disease. Few scholars have investigated the relationship between NLR and SLE. This study aims to evaluate the role of NLR in SLE without nephritis and LN patients. METHODS: A total of 228 subjects were participated in this study. 79 diagnosed with SLE in patients group and 149 healthy age-and sex-matched in control group. In patient team, 20 of them were diagnosed with LN. RESULTS: The SLE without nephritis group showed significantly higher NLR than control group (control=2.00±0.76, SLE=4.26±3.38, P<0.001), and the NLR values of the patients with LN were higher than those of the patients without LN (SLE=4.26±3.38, LN=7.21±6.01, P<0.001). Receiver-operating characteristics analysis (ROC) of NLR to predict SLE showed that the area under the curve (AUC) was 0.757. The cutoff value using the ROC curve was 3.13 (sensitivity, 0.574; specificity, 0.926; 95% confidence interval (CI), 0.668-0.845; P<0.001). While ROC analysis of NLR to predict LN showed that the AUC was 0.828). Logistic regression analysis showed that SLE without nephritis and LN were independently related to NLR. CONCLUSION: NLR is independently associated with SLE, and it may be a promising marker that reflects renal involvement in patients with SLE.

HPLC determination and clinical significance of serum prednisone in patients with nephrotic syndrome.

AIM: A rapid protocol is necessary to determine the serum concentrations of prednisone. METHODS: The HP1100 high-performance liquid chromatographic (HPLC) system was employed. The HP Lichrosphere C8 column (250 mm × 4 mm, i.d., 5 µm particle size) was used. The mobile phase was methanol, tetrahydrofuran and water in the ratio 25:25:50. The flow rate was 1.0 ml/min. The sample was monitored by UV absorbance at 240 nm. Acetanilide was used as the internal standard, and methanol was added into the serum for depositing the protein. RESULTS: The chromatography was effective and was not interfered with by the serum components. Good linearity was observed, within the range of 10-500 µg/L for prednisone, and the detection limit was 5 µg/L. The serum concentrations of prednisone between the nephrotic syndrome (NS) group and the control group were significantly different (P < 0.05), while there was no significant difference between the females and males of the NS group (P > 0.05). The serum ncentration of prednisone in the steroid-resistant group was lower than that in the steroid-sensitive group (P < 0.05). CONCLUSIONS: HPLC is a practical and reliable method to determine the serum concentration of prednisone with high accuracy, precision, linearity and repeatability.

Influencing factors for saliva urea and its application in chronic kidney disease.

OBJECTIVES: To analyze possible influencing factors on concentration of saliva urea (SaU) and to validate its application in chronic kidney disease(CKD). DESIGN AND METHODS: Level of SaU in patients and normal subjects was researched. RESULTS: The concentration of SaU did not vary with sampling time and genders, but was related to ages and level of serum urea (U). CONCLUSION: SaU concentration is stable and it is useful in application in CKD.

[Evaluation of dialysis in patients with end-stage renal disease by salivary urea, creatinine and uric acid].

OBJECTIVE: To explore the changes of saliva urea, creatinine (Cr), and uric acid (UA) before and after hemodialysis in patients with end-stage renal disease (ESRD), and to evaluate the clearing effect of Urea, Cr, and UA. METHODS: Saliva and serum (2 mL) were collected from the dialysis patients. The concentrations of Urea, Cr, and UA in both samples were measured by biochemical analyzer. The concentrations of Urea, Cr, and UA in the saliva and the serum, and their correlation were analyzed. Before and after the hemodialysis, the reduction ratio (RR) of Urea, Cr, and UA in the saliva and the serum was calculated. RESULTS: In ESRD dialysis patients, the levels of Urea, Cr, and UA in the saliva and the serum were highly correlated (correlation coefficients were 0.979, 0.973, and 0.948, respectively). The concentrations of Urea, Cr, and UA in the saliva and the serum before the dialysis were lower than those after the dialysis, with significant difference (P<0.05). The RR of Urea, Cr, and UA in the saliva and the serum did not differ statistically (P>0.05). CONCLUSION: The clearing effect of salivar Urea, Cr, and UA is similar to that of the serum. Saliva is expected to replace the serum to evaluate hemodialysis efficacy and monitor the renal disease in ESRD patients.

[Clinical significance of saliva urea, creatinine, and uric acid levels in patients with chronic kidney disease].

OBJECTIVE: To explore the changes and clinical significance of saliva urea, creatinine (Cr), uric acid (UA) in both healthy people and chronic kidney disease (CKD) patients, and to provide a noninvasive, quick, accurate and reliable test to diagnose kindey disease. METHODS: Urea, Cr and UA in the saliva and serum collected from both healthy people and the CKD patients were measured by biochemical analyzer. We calculated the correlation coefficient of Urea, Cr and UA between the saliva and serum, compared the levels of saliva Urea, Cr and UA among CKD patients in different periods, drew the receiver operation characteristic (ROC) curve and analyzed the sensitivity and specificity of saliva Urea, Cr and UA to predict CKD patients in various periods. RESULTS: The concentrations of Urea, Cr and UA in both the saliva and the serum were positively correlated in healthy individuals and CKD patients (r = 0.918, 0.932, 0.840 and 0.984, 0.971, 0.920). The levels of saliva Urea, Cr and UA in the CKD patients were significantly higher than those of healthy people (P<0.05). Saliva Urea, Cr and UA concentrations of middle and late stage CKD patients were obviously higher than those of healthy people and early stage CKD patients (P<0.05). Areas under the curve (AUC) of the ROC of Urea, Cr and UA to diagnose diverse periods of CKD were 0.898, 0.897 and 0.848. The sensitivity was 0.806, 0.776 and 0.704; and the specificity was 0.968, 0.989 and 0.871. CONCLUSION: The levels of Urea, Cr and UA between the saliva and the serum are closely related. The concentration of saliva Urea, Cr and UA can reflect the renal damage, monitor kidney function of the CKD patients, and help diagnose middle to late stage CKD patients. It is a simple, nonivasive and quick method.

[Correlation studies between urinary retinol binding protein and renal tubular damage].

OBJECTIVE: To study correlation between urinary retinol binding protein (RBP) content and renal tubular damage. METHODS: A total of 1 353 healthy people and 186 patients with renal tubular damage diagnosed by renal biopsy were enrolled. The indicators such as endogenous creatinine clearance rate (Ccr), creatinine(Cr), urinary retinol binding protein(RBP), urinary ß(2)-microglobulin(ß(2)-MG), urinary N-acety1-beta-D-glucosaminidase (NAG), urine specific gravity(SG), urine osmolality of the 2 groups were examined and compared. Score of tubulointerstitial impairing and all indicators were analyzed by Spearman rank correlation analysis, and the sensitivity and specificity of indicators were calculated. RESULTS: Renal tubular damage was positively correlated with urinary RBP, ß2-MG, NAG (r=0.863, P<0.001; r=0.777, P<0.001; r=0.374, P=0.002, respectively), while negatively correlated with urine osmolaling, SG (r=-0.519, P<0.001; r=-0.624, P<0.001, respectively). The specificity and sensitivity for renal tubular damage of RBP were 91.03% and 72.06%. CONCLUSION: RBP is an idea marker for renal tubular damage, and is useful to diagnose renal tubular damage and assess the extent of the damage.