Neuroprotection of Botch in experimental intracerebral hemorrhage in rats

Abstract

Notch1 maturation participates in apoptosis and inflammation following intracerebral hemorrhage (ICH). It has been reported that Botch bound to and blocked Notch1 maturation. Here we estimated the role of Botch in ICH-induced secondary brain injury and underlying mechanisms. Experimental ICH model was induced by autologous arterial blood injection in Sprague-Dawley rats, and cultured primary rat cortical neurons were exposed to oxyhemoglobin to mimic ICH in vitro. Specific small interfering RNAs and expression plasmids encoding wild type Botch and Botch with Glu115Ala mutation were exploited. The protein levels of Botch and Notch1 transmembrane intracellular domain (Notch1-TMIC) were increased within brain tissue around hematoma. Botch overexpression led to an increase in unprocessed Notch1 full-length form accompanied by a significant decrease in Notch1-TMIC, while Botch knockdown resulted in an approximately 1.5-fold increase in Notch1-TMIC. There were increased cell apoptosis, necrosis and neurobehavioral deficits after ICH, which was inhibited by Botch overexpression and enhanced by Botch knockdown. Double immunofluorescence showed a colocalization of Botch and Notch1 in the trans-Golgi. Overexpression of wild type Botch, but not Botch E115A mutant, led to an increase in the interaction between Botch and Notch1, reduced the formation and the nuclear localization of Notch1 intracellular domain, and attenuated cell apoptosis and inflammation. In conclusion, Botch exerts neuroprotection against neuronal damage via antagonizing the maturation of Notch1 in Glu115-denpendent manner. However, neuroprotection mediated by endogenous Botch is not enough to reverse ICH-induced secondary brain injury.

Mesenchymal stem cells alleviate the early brain injury of subarachnoid hemorrhage partly by suppression of Notch1-dependent neuroinflammation: involvement of Botch

“…Previous study demonstrated that overexpression of Botch in vivo alleviated neuronal apoptosis and inflammation in intracerebral hemorrhage [48]. We hypothesized that BMSCs transplantation inhibited Notch1 signaling by increasing Botch expression in brain tissue; we first detected Botch protein and mRNA levels in BMSCs, with results indicating that Botch strongly expressed in cultured BMSCs.…”

“…As an endogenous blocker of Notch1 receptor, Botch inhibits the S1 furin-like cleavage of Notch1, thus promoting maintenance of full-length Notch1 [46]. Recent studies reported that Botch promoted neurogenesis through antagonizing the maturation of Notch1 during neocortical development and intracerebral hemorrhage [47, 48]. However, whether Botch participates in the suppressive effects of BMSCs on Notch1 expression remains unexplored.…”

Protective effects of the ROCK inhibitor fasudil against cognitive dysfunction following status epilepticus in male rats

“…The p‐RhoA (RRID: can’t be found), MAG (RRID: AB_2042411), OMgp (RRID: AB_1587278), synaptophysin (SYP; RRID: AB_2286949) antibodies were detected at 28, 53, 20, and 35 kDa, respectively (Carlson, Henchir, & Dixon, ; Pritchard, Mir, & Dev, ; Soliman et al, ; Vose et al, ). The neuronal nuclei (NeuN; RRID: AB_2532109) recognized two bands corresponding to 48 and 50 kDa (Mei et al, ; Zhou et al, ). β‐actin (RRID: can’t be found) was detected as a 43 kDa immunoreactive band (North, Galazkiewicz, Byers, Glenney, & Small, ).…”