(C) Densitometric anaysis of the blots showing the ratios of Beclin-1 and LC3-II to β-actin in Figure 10A. * and ** denote p < 0.05 and p < 0.01 respectively in Figure 10B and 10C (vs. control); # and ## denote p < 0.05 and p < 0.01 respectively in Figure 10B and 10C (vs. LPS). (D) Graph represents percentage of remaining E.coli at different time points in each group treated as described above. Data are mean values ± SD (n ≥3). * and ** denote p < 0.05 and p < 0.01 respectively (LPS vs. control); # and ## denote p < 0.05 and

p < 0.01 respectively (LPS + TLR4 siRNA vs. GSK126 research buy LPS). Discussion Although aberrant autophagy is observed in many bacterial infectious diseases, the role of autophagy in PD-related peritonitis remains unknown. Our study has investigated the role of autophagy in PMCs against intrahttps://www.selleckchem.com/products/cb-839.html cellular E.coli. We demonstrated that LPS could induce autophagy in HMrSV5 cells. LPS enhanced the intracellular bactericidal activity of HMrSV5 cells and promoted the co-localization of E.coli (K12-strain) with autophagosomes. Moreover, treatment with microtubule-disrupting agents such as 3-MA or Wm or Beclin-1 siRNA, markedly attenuated the Selleck PF-562271 intracellular bactericidal activity of HMrSV5 cells and the co-localization of E. coli with autophagosomes induced by LPS treatment. Furthermore, knockdown of TLR4 vanished LPS-induced autophagy and bactericidal activity. These data collectively suggest

that autophagy activated by LPS via TLR4 represents an innate defense mechanism for inhibiting intracellular E. TCL coli replication. Autophagy is a process traditionally known to contribute to cellular cleaning

via the removal of intracellular components in lysosomes [26]. Recently, our colleagues reported that LPS stimulation led to autophagy in cultured peritoneal mesothelial cells [27]. In keeping with their reports, our data revealed that LPS induced accumulation of LC3-II in a time- and dose-dependent manner in HMrSV5 cells, as indicated by an increased aggregation of GFP-LC3 puncta and a higher number of autophagosome-like MDC-labeled vacuoles. Furthermore, HMrSV5 cells pretreated with 3-MA, Wm or Beclin-1 siRNA displayed defective autophagy induction in response to LPS. These results indicate that LPS is a general stimulant of autophagic activity in PMCs. In addition, our study showed the viability of LPS-treated cells had no significant difference compared to the control group. It has been demonstrated that exposure of PMCs to LPS resulted first in autophagy and later, apoptosis [27]. Apoptosis was only observed under higher concentrations of LPS (5 to 10 μg/ml) exposure for 48 hours in HMrSV5 cells [27]. We could not detect apoptosis in HMrSV5 cells following the incubation with lower doses of LPS (0-5 μg/ml) for shorter time periods (0-24 h) in present study, which was consistent with the previous report [27].