Elevated Protein Kinase A Activity in Stomach Mesenchyme Disrupts Mesenchymal-epithelial Crosstalk and Induces Preneoplasia.

BACKGROUND & AIMS: Mesenchymal-epithelial crosstalk (MEC) in the stomach is executed by pathways such as bone morphogenetic protein (BMP) and extracellular signal-regulated kinase (ERK). Mis-regulation of MEC disrupts gastric homeostasis and causes tumorigenesis. Protein Kinase A (PKA) crosstalks with BMP and ERK signaling; however, PKA function(s) in stomach development and homeostasis remains undefined. METHODS: We generated a novel Six2-Cre+/-PKAcαRfl/wt (CA-PKA) mouse in which expression of constitutive-active PKAcαR was induced in gastric mesenchyme progenitors. Lineage tracing determined spatiotemporal activity of Six2-Cre in the stomach. For phenotyping CA-PKA mice histological, co-immunofluorescence, immunoblotting, mRNA sequencing, and bioinformatics analyses were performed. RESULTS: Lineage tracing showed that Six2-Cre activity in the stomach is restricted to the mesenchymal compartment. CA-PKA mice showed disruption of gastric homeostasis characterized by aberrant mucosal development and epithelial hyperproliferation; ultimately developing multiple features of gastric corpus preneoplasia including decreased parietal cells, mucous cell hyperplasia, spasmolytic peptide expressing metaplasia with intestinal characteristics, and dysplastic and invasive cystic glands. Furthermore, mutant corpus showed marked chronic inflammation characterized by infiltration of lymphocytes and myeloid-derived suppressor cells along with the upregulation of innate and adaptive immune system components. Striking upregulation of inflammatory mediators and STAT3 activation was observed. Mechanistically, we determined there is an activation of ERK1/2 and downregulation of BMP/SMAD signaling characterized by marked upregulation of BMP inhibitor gremlin 1. CONCLUSIONS: We report a novel role of PKA signaling in gastric MEC execution and show that PKA activation in the gastric mesenchyme drives preneoplasia by creating a proinflammatory and proproliferative microenvironment associated with the downregulation of BMP/SMAD signaling and activation of ERK1/2.

Knowledge and Awareness about Cervical Cancer and Human Papillomavirus among Women Living in Macon County, Alabama.

In Alabama, despite the high screening rates for cervical cancer in Blacks, they still have higher mortality rates compared to Whites. Our objective was to increase knowledge and awareness of cervical cancer with the intention to encourage more women to have Pap tests, Human Papillomavirus (HPV) tests and HPV vaccinations after a short-term educational-based intervention. Pre and post questionnaires were administered to collect data before and after a primary educational intervention in Macon County was taught by a team of experts in the subject area. Descriptive statistics were done using SAS software to generate frequency and chi-square tests. Out of the 100 participants: 9% had cervical cancer; 86% were Blacks; about 65% were over the age of 35 and earned less than $50,000/year; 62% lived in the Tuskegee community; 34% were students, staff or faculty of Tuskegee University; about 25% were either married or living with their partner; leaving about 75% of the women as single, divorced or widowed; and more than 80% were students between their first year of college and graduate school with only 40% working for pay. The short-term educational intervention increased participants' knowledge of: who knew what cervical cancer was; ever heard of HPV; and ever had an HPV-test by margins of 9%, 23% and 4% respectively. Participants who had ever heard of Pap test had the same knowledge of 97% before and after the intervention. There was a significant knowledge level increased: in understanding that cervical cancer was caused by 38% HPV infection; 39% of all HPV infections lead to cervical cancer; and cervical cancer has decreased in recent years by 50%. Significant differences were observed only among participants who had ever heard of Pap test before and after the educational intervention with p-values of 0.004 and 0.03 respectively, compared to participants who knew what cervical cancer was and who had ever heard of HPV test. Although some participants lacked knowledge in certain areas, this study showed an apparent increase in their knowledge and awareness following the educational intervention.

Molecular characterization of nephron progenitors and their early epithelial derivative structures in the nephrogenic zone of the canine fetal kidney.

Nephron progenitors (NPs) and nephrogenesis have been extensively studied in mice and humans and have provided insights into the mechanisms of renal development, disease and possibility of NP-based therapies. However, molecular features of NPs and their derivatives in the canine fetal kidney (CFK) remain unknown. This study was focused to characterize the expression of potential markers of canine NPs and their derivatives by immuno-fluorescence and western blot analysis. Transcription factors (TFs) SIX1 and SIX2, well-characterized human NP markers, were expressed in NPs surrounding the ureteric bud in the CFK. Canine NPs also expressed ITGA8 and NCAM1, surface markers previously used to isolate NPs from the mouse and human fetal kidneys. TF, PAX2 was detected in the ureteric bud, NPs and their derivative structures such as renal vesicle and S-shaped body. This study highlights the similarities in dog, mouse and human renal development and characterizes markers to identify canine NPs and their derivatives. These results will facilitate the isolation of canine NPs and their functional characterization to develop NP-based therapies for canine renal diseases.

Cell clustering and delay/arrest in T-cell division implicate a novel mechanism of immune modulation by E. coli heat-labile enterotoxin B-subunits.

The B-subunits of heat-labile enterotoxins LT-I (LT-IB) and LT-IIa (LT-IIaB) are strong adjuvants that bind to cell-surface receptors, including gangliosides G(M1) and GD1b, respectively. LT-IIaB also binds TLR-2. We demonstrate for the first time that co-incubation with the B-subunits induces significant clustering of B cells after only 4h, and B and T cells in 24h. Clustering was dependent on intact B-subunits, but not on the TLR-2 binding activity of LT-IIaB, indicating it was ganglioside-mediated. Treatment of B cells with LT-IB, a mixture of LT-IB+LT-IIaB, but not LT-IIaB alone, caused a delay in T cell division following ovalbumin endocytosis. B cell receptor-mediated uptake in presence of each treatment caused an arrest, but with increased production of IL-2. Further, treatments differentially increased the proportion of macrophages expressing MHC class-II. These results highlight the outcomes of interplay between signals involving different receptors and implicate a novel mechanism of adjuvanticity.