Complex Relationships between HIV-1 Integrase and Its Cellular Partners.

RNA viruses, in pursuit of genome miniaturization, tend to employ cellular proteins to facilitate their replication. HIV-1, one of the most well-studied retroviruses, is not an exception. There is numerous evidence that the exploitation of cellular machinery relies on nucleic acid-protein and protein-protein interactions. Apart from Vpr, Vif, and Nef proteins that are known to regulate cellular functioning via interaction with cell components, another viral protein, integrase, appears to be crucial for proper virus-cell dialog at different stages of the viral life cycle. The goal of this review is to summarize and systematize existing data on known cellular partners of HIV-1 integrase and their role in the HIV-1 life cycle.

The dienogest-related cystitis in women with endometriosis: a prospective, controlled, comparative study.

The aim of the study was to examine the severity of clinical symptoms of acute cystitis and the level bacteriuria in female patients who underwent to laparoscopic surgery followed by a postoperative administration of dienogest 2 mg and combined oral contraceptives pills (COCP). One hundred and forty five women who had a laparoscopic surgery prospectively were enrolled. Criteria inclusions were the age from 30 to 45 years old; body mass index (BMI) absence of previous hormonal therapy at least 6 month and recent performed a laparoscopy surgery for endometriosis. The women (n = 35) who had uterine myoma, abnormal coagulation profile; concomitant neoplastic diseases; chronic pelvic inflammatory disease and chronic recurrent cystitis were excluded from study. The female patients were assigned into both groups treatment: group I (n = 54) and group II (control, n = 56) who received dienogest 2 mg once daily and COCP, respectively. During follow-up three female patients of group I were withdrawn due to prolonged genital bleedings. The final analysis included 105 women. The patients of both groups had a low level of bacteriuria <103 CFU/ml without clinical symptoms of acute cystitis before treatment. The level of bacteriuria in-group I significantly increased from 102 to 106 CFU/ml whereas in-group II did not exceed 102 CFU/ml during 4 weeks of hormonal treatment. The differences of values of acute cystitis symptom score (ACSS) for differential, typical, quality of life domains were statistically significant after 4, 8 and 12 weeks of therapy in-group I compared with group II. During 3 months of hormonal treatment with dienogest 2 mg in group I, the acute cystitis developed in 10 (18.5%), in 19 (38%) and in 34 (68%) women at 4, 8 and 12 weeks of follow-up, respectively. All cases of acute cystitis in-group I were successfully treated with fosfomycin trometamol 3 g single dose or nitrofurantoin 50 mg four times a day during 5 days. We concluded that the dienogest might increase the level bacteriuria and severity of clinical symptoms of acute cystitis during a postoperative prophylaxis of endometriosis.Impact statementWhat is already known on this subject? Dienogest is a 19-nortestosterone derivative progestogen that is highly selective for progesterone receptors with high efficacy for reducing endometriosis-related pelvic pain syndrome. The administration of dienogest is a standard treatment option after laparoscopic excision of endometrial heterotopic tissue with prophylactic purpose. However, there are some adverse events, which are a cause for discontinuation.What do the results of this study add? Despite the low incidence of urinary tract infection (1-5.4%) reported in different studies this study has shown that there was a significant increase of level bacteriuria and severity of clinical symptoms of cystitis in the dienogest group.What are the implications of these findings for clinical practice and/or further research? The implications of these findings are that the administration of dienogest may lead to enhancing of clinical symptoms of cystitis and increasing bacteriuria in some women after operative treatment of endometriosis.

The cellular SFPQ protein as a positive factor in the HIV-1 integration.

The cellular SFPQ protein is involved in several stages of the HIV-1 life cycle, but the detailed mechanism of its involvement is not yet fully understood. Here, the role of SFPQ in the early stages of HIV-1 replication has been studied. It is found that changes in the intracellular level of SFPQ affect the integration of viral DNA, but not reverse transcription, and SFPQ is a positive factor of integration. A study of the SFPQ interaction with HIV-1 integrase (IN) has revealed two diRGGX1-4 motifs in the N-terminal region of SFPQ, which are involved in IN binding. Substitution of a single amino acid residue in any of these regions led to a decrease in binding efficiency, while mutations in both motifs almost completely disrupted the SFPQ interaction with IN. The effect of the SFPQ mutants with impaired ability to bind IN on viral replication has been analyzed. Unlike the wild-type protein, the SFPQ mutants did not affect viral integration. This confirms that SFPQ influences the integration stage through direct interaction with IN. Our results indicate that the SFPQ/IN complex can be considered as a potential therapeutic target for the development of new inhibitors of HIV replication.

IGFBP6 regulates extracellular vesicles formation via cholesterol abundance in MDA-MB-231 cells.

Breast cancer recurrence is associated with the growth of disseminated cancer cells that separate from the primary tumor before surgical treatment and hormonal therapy and form a metastatic niche in distant organs. We previously demonstrated that IGFBP6 expression is associated with the risk of early relapse of luminal breast cancer. Knockdown of IGFBP6 in MDA-MB-231 breast cancer cells increased their invasiveness, proliferation, and metastatic potential. In addition, the knockdown of IGFBP6 leads to impaired lipid metabolism. In this study, we demonstrated that the knockdown of the IGFBP6 gene, a highly selective inhibitor of IGF-II, led to a significant decline in the number of secreted extracellular vesicles (EVs) and altered cholesterol metabolism in MDA-MB-231 cells. Knockdown of IGFBP6 led to a decrease in the essential proteins responsible for the biogenesis of cholesterol LDLR and LSS, which reduced the amount by more than 13 times. In addition, the knockdown of IGFBP6 led to a possible change in the profile of adhesion molecules on the surface of EVs. The expression of L1CAM, IGSF3, EpCAM, CD24, and CD44 decreased, and the expression of EGFR increased. We can conclude that the negative prognostic value of low expression of this gene could be associated with increased activity of IGF2 in tumor-associated fibroblasts due to low secretion of IGFBP6 by tumor cells. In addition, changing the profile of adhesion molecules on the surface of tumor EVs may contribute to the more efficient formation of metastatic niches.