title: Russell's viper venom affects regulation of small GTPases and causes nuclear damage.
abstract: Russell's viper with its five sub-species is found throughout the Indian subcontinent. Its venom is primarily hemotoxic. However, its envenomation causes damage to several physiological systems. The present work was aimed to study the dose and time dependent cytotoxic effects of Russell's viper venom (RVV) on human A549 cells grown in vitro. Time dependent changes have been observed in cellular morphology following exposure to RVV. Presence of stress granules, rounding-off of the cells, and formation of punctate structure and loss of cell-cell contact characterized the cellular effects. Fluorescence microscopic studies revealed that apoptotic cell population increased on exposure to RVV. Further to understand the mechanism of these effects, status of small GTPase (smGTPases) expression were studied by Western blot and RT-PCR; as smGTPases play pivotal roles in deciding the cellular morphology, polarity, cell movement and overall signaling cascade. It was shown for the first time that expression patterns of Rac, Rho and CDC42 genes are altered on exposure to RVV. Similarly, significant difference in the expression pattern of HSP70 and p53 at the mRNA levels were noted. Our results confirmed that RVV induces apoptosis in A549 cells; this was further confirmed by AO/EtBr staining as well as caspase-3 assay. All experiments were compared using RVV unexposed cells. We propose for the first time that RVV induces morphological changes in human A549 cells through modulation of smGTPase expression and affects the cellular-nuclear architecture which in turn interferes in proliferation and migration of these cells along with apoptosis.
authors.affiliation: Department of Biological Sciences, BITS Pilani, K K Birla Goa Campus, Zuarinagar, Goa 403726, India.
authors.forename: Jigni
authors.initials: J
authors.lastname: Pathan
authors.affiliation: Department of Biological Sciences, BITS Pilani, K K Birla Goa Campus, Zuarinagar, Goa 403726, India.
authors.forename: Ansie
authors.initials: A
authors.lastname: Martin
authors.affiliation: Department of Biological Sciences, BITS Pilani, Pilani Campus, Rajasthan 333031, India.
authors.forename: Rajdeep
authors.initials: R
authors.lastname: Chowdhury
authors.affiliation: Department of Biological Sciences, BITS Pilani, K K Birla Goa Campus, Zuarinagar, Goa 403726, India. Electronic address: dibakarchakrabarty@goa.bits-pilani.ac.in.
authors.forename: Dibakar
authors.initials: D
authors.lastname: Chakrabarty
authors.affiliation: Department of Biological Sciences, BITS Pilani, K K Birla Goa Campus, Zuarinagar, Goa 403726, India. Electronic address: asarkar@goa.bits-pilani.ac.in.
authors.forename: Angshuman
authors.initials: A
authors.lastname: Sarkar
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017840:Daboia; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014757:Viper Venoms / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D014757:Viper Venoms; D051028:bcl-2-Associated X Protein; D020559:Monomeric GTP-Binding Proteins
keywords: Apoptosis; Cell damage (nuclear damage); Cytoskeleton; Cytotoxicity; Russell's viper venom; Snake venom; smGTPase