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Aim To test whether actin stabilization by jasplakinolide induces inhibition of cell viability and apoptosis in epithelial cell rests of Malassez ( ERM). Methodology ERM derived from porcine were spread in a 96-well dish (5 × 104/well) using Dulbecco's modified Eagle's medium. The actin-specific stabilization reagent, jasplakinolide, was incorporated into the culture medium and incubated for 24 h. To evaluate cell viability, the WST-1 assay was carried out and absorption (450 nm) was measured. To detect apoptotic cells, monoclonal antibody to single-strand DNA (ss DNA) was used and absorption (405 nm) was measured. Actin stabilization and apoptosis induced by jasplakinolide were morphologically investigated by staining with Alexa Fluor 568 phalloidin and observed under a fluorescent microscope. As a negative control, DMSO was used instead of jasplakinolide. Differences between the jasplakinolide-treated group and the control group were analysed statistically using the Student's t-test. Results Cell viability decreased in a concentration-dependent manner, and cell viability in the jasplakinolide-treated ERM was lower than that in nontreated ERM ( n = 16, P < 0.01). Apoptotic cells in the jasplakinolide-treated ERM were more frequently detected compared to that in nontreated ERM ( n = 16, P < 0.01). Morphologically, shrinkage, irregular forms and fragmentation of nuclei suggesting apoptotic bodies were observed in jasplakinolide-treated ERM, whilst actin filaments were extended in non-treated ERM. Conclusion Actin stabilization by jasplakinolide inhibited cell viability and induced apoptosis in epithelial cell rests of Malassez. [ABSTRACT FROM AUTHOR]

Objectives – To clarify the clinical variability, including central nervous system (CNS) involvement, in X-linked Charcot–Marie–Tooth disease (CMTX) patients. Materials and methods – We clinically, pathologically and genetically studied six CMTX patients with distinct symptoms and four different GJB1 mutations. Results – One patient with Val63Ile had deafness, low intelligence, saccadic eye movement, upper extremity distal dominant muscle weakness and normal sensation. Another patient with Glu186Lys had severe sensorineural deafness at the age of 6 years, but did not develop muscle weakness until the age of 20 years. Two patients with Arg22Gln had typical CMT1A-like clinical features, no CNS symptoms and obvious onion bulb formations. Two siblings with deletion of the entire GJB1 gene had mild to moderate lower extremity muscle weakness and sensory disturbance without CNS involvement. Conclusion – These findings suggest that some gain of function mutations of GJB1 may be related to CNS symptoms because the patients with GJB1 deletion only had peripheral neuropathy, although other unknown associated factors may contribute to their clinical phenotypes. [ABSTRACT FROM AUTHOR]

Abstract To clarify the pathomechanism in three patients with X-linked Charcot-Marie-Tooth disease (CMTX) and unique clinical features, we studied three connexin (Cx) 32 (GJB1) mutants with respect to cellular localization in cultured cells. Wild-type Cx32 and three Cx32 mutants (Va163I1e and Glu186Lys, obtained from CMTX patients with hearing impairment; and Arg22G1n, obtained from a CMTX patient with a fair number of onion-bulb formations) were transfected to rat pheochromocytoma cells (PC12). We investigated the expression of Cx32 protein in each clone by immunoblotting and immunohistochemical staining. While Cx32 protein with the Arg22G1n mutation was detectable immunohistochemically only in the cytoplasm, Cx32 protein with the Va163I1e or Glu186Lys mutation was detected in both the plasma membrane and the cytoplasm. Cx32 protein with the wild-type sequence was detected mostly in the plasma membrane, with plaques indicating the existence of active gap junction formation. These three Cx32 mutations associated with CMTX patients with unique clinical and pathological findings caused altered trafficking of the Cx32 protein. These altered expressions indicated loss of active gap junction formation with different expression abnormalities in these CMTX patients. [ABSTRACT FROM AUTHOR]