A Faculty-Led, Community-Building Program That Enhances Student-Faculty Connections within Biology.

Connections between students and faculty on campus may influence students' sense of belonging, and a greater sense of belonging has a positive effect on student success. We developed a low-cost, faculty-led program of community-building events and implemented the program in the biology department at a small liberal-arts institution with the goal of improving students' sense of community. Student responses to surveys indicated that the majority of students felt connected to faculty and students in the department; however, Black or African American students initially felt a lower level of connection to faculty than did white students. After implementing our series of community-building events, students surveyed reported high levels of satisfaction with the events. Furthermore, there was a trend toward a higher percentage of Black or African American students than white students reporting that they were more likely to reach out to faculty after participating in the community-building events. Thus, our low-cost program improved connections between students and faculty in the biology department. Collectively, our results suggest that academic departments can implement community-building programs to improve students' sense of belonging.

Protein C inhibitor (plasminogen activator inhibitor-3) expression in the CWR22 prostate cancer xenograft.

The serine protease inhibitor (serpin) protein C inhibitor (PCI) has been found in the prostate and possibly is a marker to distinguish normal prostate, benign prostatic hyperplasia, and prostate cancer. In this study, we assessed PCI expression in normal, hyperplastic, and malignant prostatic tissues, prostate cancer cell lines, and the CWR22 prostate cancer xenograft model that allowed us to study PCI expression and its regulation in response to androgens. By Northern blot, immunohistochemistry, and in situ hybridization, we found that PCI was expressed in both benign and malignant prostate tissues. Protein C inhibitor was expressed in both androgen-independent (PC-3) and androgen-dependent (LNCaP) prostate cancer cell lines. Furthermore, PCI was detected in all CWR22 tumor samples (androgen dependent, 6 days post-castration, 12 days post-castration followed by 72 h of testosterone treatment, and recurrent CWR22 tumor), although expression of the mature forms of both prostate-specific antigen (PSA) and its homolog, kallikrein 2 (hK2), was clearly androgen-dependent. These results suggest that PCI expression is not regulated by androgens and that PCI is unlikely to be a tumor suppressor gene, but also that PCI may be involved in regulating key serine proteases involved in metastatic prostate disease.

Basic residues in the 37-loop of activated protein C modulate inhibition by protein C inhibitor but not by alpha(1)-antitrypsin.

The role of lysines 37-39 (chymotrypsin numbering) in the 37-loop of the serine protease activated protein C (APC) was studied by expressing acidic and neutral recombinant APC (rAPC) mutants. Activity of the APC mutants was assessed using human plasma and plasma-purified and recombinant derivatives of protein C inhibitor (PCI; also known as plasminogen activator inhibitor-3) and alpha(1)-antitrypsin, with and without heparin. The catalytic properties of the mutants to small peptidyl substrates were essentially the same as wild-type rAPC (wt-rAPC), yet their plasma anticoagulant activities were diminished. Analysis of the rAPC-protease inhibitor complexes formed after addition of wt-rAPC and mutants to plasma revealed no change in the inhibition pattern by alpha(1)-antitrypsin but a reduction in mutant complex formation by PCI in the presence of heparin. Using purified serpins, we found that inhibition rates of the mutants were the same as wt-rAPC with alpha(1)-antitrypsin; however, PCI (plasma-derived and recombinant forms) inhibition rates of the acidic mutants were slightly faster than that of wt-rAPC without heparin. By contrast, PCI-heparin inhibition rates of the mutants were not substantially accelerated compared to wt-rAPC. The mutants had reduced heparin-binding properties compared to wt-rAPC. Molecular modeling of the PCI-APC complex with heparin suggests that heparin may function not only to bridge PCI to APC, but also to alleviate putative non-optimal intermolecular interactions. Our results suggest that the basic residues of the 37-loop of APC are involved in macromolecular substrate interactions and in heparin binding, and they influence inhibition by PCI (with or without heparin) but not by alpha(1)-antitrypsin, two important blood plasma serpins.