LACC1 contributes to inflammation and cognitive disorder after stroke via the AMPK/NLRP3 pathway.

The current study aimed to investigate the effects of LACC1 on cognitive disorder due to stroke, as well as its underlying mechanism. LACC1 promoted inflammation and aggravated cognitive impairment in a mouse model of stroke. In an in vitro model of stroke, inhibition of LACC1 reduced inflammation and ROS­induced oxidative stress by activating AMP­activated protein kinase (AMPK) expression and suppressing NLPR3 expression. Furthermore, our studies revealed that inhibition of AMPK activity reduced the effects of si­LACC1 on cognitive disorder in mice after stroke via the AMPK/NLPR3 pathway. AMPK activation also reduced the effects of LACC1 on inflammation and ROS­induced oxidative stress via the NLPR3 pathway in the in vitro model that we evaluated. Our study suggests that LACC1­aggravated inflammation causes cognitive impairment after stroke via the AMPK/NLRP3 pathway, which may provide a new therapeutic target for stroke and other neurological diseases and their associated complications. In sum, we identified an important role and regulatory mechanism for LACC1 in maintaining stroke­induced cognitive disorder via the AMPK/NLRP3 pathway.

Increased Serum E-Selectin Levels Were Associated with Cognitive Decline in Patients with Stroke.

BACKGROUND: Previous studies have reported that patients with stroke have a high incidence of cognitive decline. The aim was to elucidate the association between serum E-selectin levels and cognitive function in stroke patients. MATERIALS AND METHODS: Serum levels of E-selectin were measured in 322 patients with stroke at baseline. Cox proportional hazard analysis was used to evaluate the predictive value of serum E-selectin for predicting cognitive decline (end point) in patients with stroke. RESULTS: Multivariate linear regression analysis revealed that serum E-selectin levels were independently associated with MOCA score after adjusting for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history and laboratory measurements in patients with stroke at baseline (Sß= -0.156; 95% CI, - 0.170- - 0.074; P<0.001). The multivariate Cox proportional hazard analysis revealed that serum E-selectin (HR=2.481, 95% CI 1.533-4.327, P-trend <0.001) was an independent prognostic factor for cognitive decline in these patients with stroke during the follow-up period. CONCLUSION: Our results showed that increased serum E-selectin levels were significantly and independently associated with cognitive decline and had independent predictive value for cognitive decline in patients with stroke. Serum E-selectin might enable early recognition of cognitive decline among stroke patients.

Lupeol Alleviates Cerebral Ischemia-Reperfusion Injury in Correlation with Modulation of PI3K/Akt Pathway.

BACKGROUND/AIM: This study aimed to investigate the effect and mechanism of lupeol on cerebral ischemia-reperfusion injury in rats. METHODS: The effects of lupeol on cerebral infarction, cerebral water content, neurological symptoms and cerebral blood flow in rats were evaluated. Nissl staining was carried out to assess the neuronal damage of ischemic brain after I/R in rats. Apoptosis of ischemic brain neurons after I/R was detected by TUNEL staining. Western blotting was carried out to detect the effects of lupeol on the expression of p-PDK1, p-Akt, pc-Raf, p-BAD, cleaved caspase-3 and p-PTEN. RESULTS: Lupeol significantly increased cerebral blood flow after I/R in rats, reduced brain water content and infarct volume, and decreased neurological function scores. It significantly reduced neuronal damage after I/R in rats, and significantly reduced neuronal cell loss. PI3K inhibitor (LY294002) can eliminate the effect of lupeol on I/R in rats. In addition, lupeol significantly increased the protein expression of p-PDK1, p-Akt, pc-Raf, p-BAD, and down-regulated the expression of cleaved caspase-3. LY294002 reversed the effects of lupeol on the expression of PI3K/Akt signaling pathway-related proteins and cleaved caspase-3 after I/R in rats. CONCLUSION: Lupeol had significant neuroprotective effects on brain I/R injury and neuronal apoptosis, and its mechanism may be related to the activation of PI3K/Akt signaling pathway.

[Protective effects of Genistein on human renal tubular epithelial cells damage of microwave radiation].

OBJECTIVE: To observe the effects of microwave irradiation on human proximal renal tubular epithelial cells (HKC) and protec-tive effects of genistein. METHODS: HKC cells were divided into control group, microwave irradiation group and genistein group(n=6) re-spectively. The genistein group cells were pre-incubated with 30µmol/L genistein in DMEM for 2 hours. After irradiation for 24 hours, the concentrations of lactate dehydrogenase(LDH) and ß-N-acetyl glucosaminidase(NAG) in culture solution were measured to evaluate cell injury. Cells were curetted to measure the levels of malondialdehyde (MDA) and superoxide dismutase (SOD). Cell apoptosis and necrosis were de-tected with Hoechst 33258 stain. RESULTS: Compared with the control group, the NAG activity of the microwave irradiation group was signifi-cantly increased(P < 0.01), and NAG activity of genistein pre-incubated group was significantly decreased(P < 0.01). The levels of LDH in microwave irradiation group were also increased significantly (P < 0.01 vs control group). LDH levels could be decreased obviously (P < 0.01 vs microwave irradiation group) after genistein pre-incubate. Hoechst 33258 fluorescent staining revealed that the nucleus crimpled, cres-cent liked and chromatin condensed, even nucleus disintegrated. Our research showed that microwave irradiation could lead to large amount of cell apoptosis and necrosis, and genistein pre-treatment could reduce the ratio of apoptosis and necrosis than that in microwave irradiation group (P < 0.01). The concentration of MDA in microwave irradiation group was higher than that in control group (P < 0.01). At the same time, the activity of SOD was significantly reduced (P < 0.01). Pre-incubated with genistein could not decrease the MDA levels, but could increase the activities of SOD (P < 0.01 vs microwave irradiation group). CONCLUSIONS: microwave irradiation can induce human proximal renal tubular epithelial cells injury. The protective effects of genistein may partly correlated with decreasing oxidative stress damage and cell apoptosis in HKC cells.

[Regulatory effect of anthraquinone derivatives from rhubarb on aquaporin 4 expression in colon of rats and in LoVo cell line].

OBJECTIVE: To investigate the cathartic effect of total anthraquinone (AQ) from rhubarb on SD rats and its regulatory effect on aquaporin 4 (AQP4) expression in rat colon and in vitro cultured LoVo cell line. METHODS: Twenty-four SD rats were randomly divided into the normal control group treated with distilled water, and the two AQ groups administered with AQ suspension in cathartic and high dose (AQcd and AQhd) respectively via gastrogavage for 5 days. Water content in colonic stool was detected and the expression of AQP4 in rat's proximal colon was measured using Western blot and RT-PCR. LoVo cells cultured in vitro were used in the experimental study. The AQP4 protein and mRNA expressions in the cells were detected by Western blot and semiquantitative RT-PCR after they were cultured for 24 h with RPMI-1640 medium containing rhein/emodin in different concentrations, and those cultured with RPMI-1640 containing 20 mg/L rhein/emodin for different time points. RESULTS: After treatment, the stool water content in the AQcd and AQhd groups was higher than that in the control group and the AQP4 expression in rats treated with AQ decreased in a dose-dependent manner. The study showed that rhein/emodin could significantly down-regulate the protein and mRNA expressions of AQP4 in cultured LoVo cells, with the effectiveness related with dose and acting time. CONCLUSION: At the same time of playing cathartic action, total AQ of rhubarb can effectively down-regulate the expression of AQP4 in rat's proximal colon; rhein/emodin can suppress the AQP4 expression in LoVo cells in vitro. One mechanism of cathartic effect of rhubarb AQ is possibly its down-regulation on AQP4 expression.

[Regulative effects of aquaporin 4 expression by rhein in rhubarb to intestinal epithelial cell line LoVo].

OBJECTIVE: To investigate the effects of rhein on regulating aquaporin4 (AQP4) to LoVo cells cultured with RPMI-1640 medium containing rhein. METHODS: LoVo cells were cultured with RPMI-1640 medium containing different concentration rhein for 24 hours and were cultured with RPMI-1640 containing rhein (20 mg/L) for different time. Four groups were assigned as LoVo cells were cultured respectively with RPMI-1640 medium containing different concentration rhein (40, 20, 10 mg/L and control group), while six groups were assigned as LoVo cells were cultured with RPMI-1640 medium containing rhein (20 mg/L) for different time (3, 6, 12, 24, 48 h and control group). The location of AQP4 protein in LoVo cells was definited by immuocytochemistry dying. Western blotting and semiquantitative RT-PCR were adopted to detect the relative expression of AQP4 protein and mRNA. RESULTS: AQP4 was located mainly in plasma membrane of LoVo cells while partly in cytoplasm. The relative expression of AQP4 protein and mRNA decreased with the increasing of rhein concentration; there was no significant difference of the relative expression of AQP4 in 10 mg/L group compared with that in control group, but it decreased significantly in 40 and 20 mg/L groups. The relative expression of AQP4 in 3 and 6 h groups was lower than that in control group but there was no statistical significance, however that in 12, 24, 48 h groups was lower significantly compared with that in control group. CONCLUSION: Rhein can inhibit the genetic transcription and the translation of AQP4 gene in LoVo cells, which demonstrates that the change of AQP4 expression regulated by rhein may be related to the cathartic effect of rhubarb.

[Effect of total anthraquinone in rheum on aquaporin 2 expression in rat distal colon].

OBJECTIVE: To investigate effect of total anthraquinone in rheum on aquaporin 2 expression in rat distal colon. METHOD: SD rats were randomly divided into control group, low dose group, middle dose group and high dose group. Gavaged to control group, and treated group were administered saline and total anthraquinone in rheum with dosage of 0.14, 2.5, 4.5 g x kg(-1) x d(-1), respectively. All rats were put sacrificed after 5 days and stool in full length colon was gently collected to detect water content stool. Distal colon was removed to detect AQP2 expression with immunohistochemistry, western blot and RT-PCR. RESULT: No diarrhea was found in low dose group and control group, there were not significant difference water content of stool and AQP2 expression between low dose group and control group. However, soft feces and loose stools occurred in diarrheic dose group, loose stools and watery stool appeared in high dose group. Stool water content increased in diarrheic dose group and High dose group, expression of AQP2 decreased evidently in these two groups (P < 0.01). CONCLUSION: Total anthraquinone in rheum can reduce the transcription and translation of AQP2 in rats' distal colon, increase fecal water content, which probably is one of the mechanisms of diarrhea caused by total anthraquinone in rheum.

[Effect of rhubarb on expressions of aquaporin-2 and -4 in rat's kidney].

OBJECTIVE: To investigate the effect of rhubarb on expressions of aquaporin-2 and 4 (AQP2 and AQP4) in rat's kidney. METHODS: Thirty-two SD rats were randomly divided into 4 groups, the normal control group, and the three rhubarb groups medicated via gastrogavage with low, mid and high dose of rhubarb extract (total anthraquinone) respectively. The 6 h and 24 h urine volume were measured, and the protein and mRNA expressions of AQP2 and AQP4 in renal tissue were determined with immunohistochemistry, Western blot and RT-PCR. RESULTS: No significant difference between the control group and the low dose rhubarb treated group was found in urine volume, as well as in AQP2 and AQP4 protein and mRNA expressions. But the urine volume was obviously higher, the protein and mRNA expressions of AQP2 and AQP4 were markedly lower in rats after mid/high dose rhubarb medication respectively when compared with those in the normal controls (all P < 0.01). CONCLUSION: Rhubarb can inhibit the protein and mRNA expressions of AQP2 and AQP4 in rats' kidney, which probably is one of the mechanisms of rhubarb for diuresis.