Reproduction
Chishimba Nathan Mowa, MVM, PhD,
Assistant Professor
BVM, University of Zambia
MVM, Glasgow University
Ph.D, Hokkaido University
Postdoctoral, Northeastern Ohio Universities College of Medicine
Our research interest broadly involves the role of sex steroid hormones (particularly estrogen) and their interaction with vascular factors in male and female reproductive events. Our first area of interest involves the study of the labor process, specifically the process of cervical remodeling or "ripening". Our goal is to elucidate changes and mechanisms associated with, and regulating local cervical microvascular events during pregnancy and their impact on cervical remodeling. Our gene of interest is VEGF and its receptors, KDR and Flt-1.
Our second area of interest involves the role of estrogen in penile development. In 2001, we accidentally found evidence of estrogen receptors (ER), and, later, synthesis, in an unlikely male reproductive organ, the penis. The expression of ER and aromatase, are strongly expressed during the perinatal stage, suggesting a role for estrogen during penile development. We are interested in understanding: 1) the relationship/interaction between estrogen and the "traditional" penile sex hormone, androgen, 2) mechanisms underlying estrogen action during penile development by characterizing the profile of estrogen-regulated genes in various penile cell subpopulations during development, 3) the effects of foods rich in dietary estrogens on penile development.
Figure 1: Characterization, using RT PCR, of VEGF in the cervix (C). Two VEGF-A splice variants, VEGF-120 and 164, were identified in the cervix in late (day 20) pregnancy with VEGF 164 being the predominant variant. The lung (L) and penis (P) of adult male rats, which predominantly express VEGF-188 and –164, respectively, were used as positive control tissues. The cDNA bands on the gel were identified, based on their molecular weight, after which they were isolated, sequenced and blasted, in order to further confirm their identity. Bp= base pair. GAPDH gene was used as a normalizer. Mowa et al J. Histochem Cytochem 2004.
Figure 2: Bright - (Left) and dark (right) - field transverse sections of ER mRNA in rat neonatal penis, as revealed by in situ hybridization. U, uretha; ps, penis spongisus; pc, penis corpus. Jesmin et al 2002 ENDOCRIN
Selected peer-reviewed publications:
Mowa CN, Jesmin S, Miyauchi T. The penis: a new target and source of estrogen in male reproduction. Histol Histopathol (Invited review, in press).
Mowa CN , Jesmin S , Sakuma I , Usip S , Togashi H , Yoshioka M , Hattori Y , Papka R . Characterization of vascular endothelial growth factor (VEGF) in the uterine cervix over pregnancy: effects of denervation and implications for cervical ripening.
J Histochem Cytochem. 2004 Dec; 52 (12):1665-74.
Jesmin S , Mowa CN , Sakuma I , Matsuda N , Togashi H , Yoshioka M , Hattori Y , Kitabatake A . Aromatase is abundantly expressed by neonatal rat penis but downregulated in adulthood. J Mol Endocrinol. 2004 Oct; 33 (2): 343-59.
Jesmin S, Mowa CN, Matsuda N, Salah-Eldin AE, Togashi H, Sakuma I, Hattori Y, Kitabatake A. Evidence for a potential role of estrogen in the penis: detection of estrogen receptor-alpha and -beta messenger ribonucleic acid and protein. Endocrinology 2002 Dec; 143(12): 4764-74.
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