Effect of laminarin on the expression of GRP78 and GRP94 in rat after unilateral ureteral obstruction

Laminarin Alleviates the Ischemia/Reperfusion Injury in PC12 Cells via Regulation of PTEN/PI3K/AKT Pathway

Objective. To investigate the protective effect of laminarin on PC12 cells damaged by oxygen glucose deprivation/reoxygenation (OGD/R) and its molecular mechanism. Methods. PC12 cells in the logarithmic phase were randomly divided into the control group, OGD/R group, and OGD/R+laminarin (0.5, 2.5, and 5 μg/ml) group. CCK-8 activity assay kit was used to detect cell viability. ELISA kit was performed to examine the levels of proinflammatory factors (TNF-α, IL-1β, and IL-6) and oxidative stress markers (ROS, LDH, and MPO). In addition, flow cytometry was employed to determine cell cycle and apoptosis. The expression of cell proliferation-related proteins (PCNA and Ki67), apoptosis-related proteins (Bcl-2, Bax, and Caspase-3), and PTEN/PI3K/AKT pathway-related proteins was evaluated by Western blot. Results. Compared with the control group, the cell viability was decreased significantly in the OGD/R group. CCK-8 results showed that laminarin could attenuate the damage of PC12 cell viability induced by OGD/R in a concentration-dependent manner. Meanwhile, the highest concentration of 5 μg/ml laminarin could significantly promote the viability of PC12 cells and the expression of PCNA and Ki67 than the OGD/R group. Additionally, ELISA assays showed that laminarin significantly inhibited the expression of proinflammatory factors (TNF-α, IL-1β, and IL-6) and the levels of oxidative stress markers (ROS, LDH, and MPO). Flow cytometry results demonstrated that laminarin promoted the cell cycle. And laminin upregulated the expression of apoptotic protein Bcl-2, while downregulated the expression of apoptotic proteins Bax and Caspase-3. Finally, laminarin significantly suppressed the expression of PTEN and facilitated the expression of PI3K and p-AKT compared to the OGD/R group. Conclusion. Laminarin could alleviate the OGD/R-induced PC12 cell neuronal injury via promoting cell activity and cycle and inhibiting inflammation, oxidative stress, and apoptosis. The mechanism may be related to the downregulation of PTEN protein and the activation of the PI3K/AKT pathway.

Regulation of eIF2α expression and renal interstitial fibrosis by resveratrol in rat renal tissue after unilateral ureteral obstruction

PURPOSE

This study was performed to assess the effect of resveratrol on the expression of eukaryotic initiation factor 2α (eIF2α) and activating transcription factor 4 (ATF4) in renal tissues of rats with unilateral ureteral obstruction (UUO).

METHODS

Using UUO animal model, after 14 days of surgery, pathological changes were detected by HE staining, renal tubular damage index, renal interstitial collagen deposition area were evaluated by Masson staining, in situ cell apoptosis in renal tissue was analyzed by TUNEL assay, and protein expression of eIF2α and ATF4 in renal tissue was analyzed using western blot detection.

RESULTS

After comparison of the treatment groups with model group, we observed that the degree of renal tubular damage, relative area of renal interstitial collagen and eIF2α, ATF4 protein expression were also significantly reduced (p<0.05, p  <0.01) in the high-dose resveratrol group.

CONCLUSION

Resveratrol can reduce the level of eIF2α protein expression, which further reduces the ATF4 levels.

Proteomic profile of an acute partial bladder outlet obstruction

INTRODUCTION

Partial bladder outlet obstruction (pBOO) is a ubiquitous problem in urology. From posterior urethral valves to prostatic hypertrophy, pBOO results in significant morbidity and mortality. However, the pathophysiology is not completely understood. Proteomics uses mass spectrometry to accurately quantify change in tissue protein concentration. Therefore, we have applied proteomic analysis to a rodent model to assess for protein changes after a surgically induced pBOO. We hypothesize that proteomic analysis after an acute obstruction will determine the most prevalent initial protein response and, potentially, novel molecular pathways.

METHODS

Sprague Dawley rats underwent a surgically induced pBOO (n = 3 per group) for 3, 7, or 14 days. Bladders were assessed for weight and urodynamic parameters. Proteomics used liquid-chromatography based mass spectrometry. Polymerase chain reaction (PCR) was performed on tissue samples to confirm increased mRNA transcription.

RESULTS

Bladder weight and capacity increased over the experimental period, but no changes were seen in bladder pressure. Statistically significant increases in protein quantities were seen in 3 proteins related to endoplasmic reticulum stress: GRP-78 (3.66-fold), RhoA (1.90-fold), and RhoA-GDP (1.95-fold), and 2 cytoskeleton molecules: actin (1.7-fold) and tubulin a/b (3.01-fold). Decorin and lumican, members of the small leucine rich proteoglycan (SLRP) family, were also elevated (0.35- and 0.34-fold, respectively). Real-time PCR data confirmed protein elevation.

CONCLUSION

Our experiment confirms that molecular changes occur very soon after the initiation of pBOO, and implicates several molecular pathways. We believe these insights may provide insight into novel prevention and treatment strategies targeted at the pathophysiology of pBOO.

Effect of stachydrine on endoplasmic reticulum stress-induced apoptosis in rat kidney after unilateral ureteral obstruction

Our study aimed at determining the effect of stachydrine on the PERK, CHOP, and caspase-3 in rat kidney with RIF. Rats were randomly divided into control group, model group, enalapril group, high stachydrine group, medium stachydrine group, and low stachydrine group. RIF models of five groups were developed by unilateral ureteral obstruction except the control group. The rats were sacrificed 12 days after surgery and blood samples were collected. Serum creatinine (Scr) and blood urea nitrogen (BUN) levels were detected. Renal tubular damage index was determined by HE staining. The area percentage of RIF was determined by the Masson method. Expressions of PERK, CHOP, and caspase-3 in kidney were determined by immunohistochemistry. Tubulointerstitial injury index, RIF, serum Scr, BUN level, and expressions of PERK, CHOP, and caspase-3 were different between the model and treatment groups (P < 0.05; P < 0.01). The expressions of PERK, CHOP, and caspase-3 in nephridial tissue were reduced (P < 0.05), tubulointerstitial injury and RIF were reduced (P < 0.05), and Scr and BUN were lower (P < 0.05) in the high stachydrine group than those in the enalapril group. The expressions of PERK, CHOP, and caspase-3 were reduced in the endoplasmic reticulum stress-related apoptosis pathway after stachydrine treatment. Consequently, apoptosis was prevented, and RIF was inhibited.