The rat tapeworm Hymenolepis diminuta has been shown to cause alterations in gastrointestinal tissues. Since hymenolepiasis induces a number of reactions in the host, it is reasonable to assume that it may also be involved in the mechanisms of apoptosis in the intestines. Individual research tasks included an examination of the effect of H. diminuta infection on; (i) the cellular localization of the expression of pro-apoptotic protein Bax and anti-apoptotic protein Bcl-2, as well as caspase-3 and caspase-9, and (ii) the effects of the infection on the expression of Bcl-2, Bax, Cas-3 and Cas-9, at the mRNA and protein levels. Molecular tests (including mRNA (qRT PCR) and the protein (Western blot) expression of Bax, Bcl-2, and caspases-3, -9) and immunohistochemical tests were performed during the experiment. They showed that H. diminuta infection activates the intrinsic apoptosis pathway in the small and large intestine of the host. H. diminuta infection triggered the apoptosis via the activation of the caspase cascade, including Cas-3 and Cas-9. Hymenolepiasis enhanced apoptosis in the small and large intestine of the host by increasing the expression of the pro-apoptotic gene and protein Bax and by decreasing the expression of the anti-apoptotic gene and protein Bcl-2.
Keywords: apoptosis; hymenolepiasis; parasite–host system; rat.