"All-In-One" Genetic Tool Assessing Endometrial Receptivity for Personalized Screening of Female Sex Steroid Hormones

Endometrium is the uterine lining that undergoes hundreds of cycles of proliferation, differentiation, and desquamation throughout a woman's reproductive life. Recently, much attention is paid to the appropriate endometrial functioning, as decreased endometrial receptivity is stated to be one of the concerns heavily influencing successes of embryo implantation rates and the efficacy of in vitro fertilization (IVF) treatment. In order to acquire and maintain the desired endometrial receptivity during IVF cycles, luteal phase support by various progestagens or other hormonal combinations is generally recommended. However, today, the selection of the specific hormonal therapy during IVF seems to be empirical, mainly due to a lack of appropriate tools for personalized approach. Here, we designed the genetic tool for patient-specific optimization of hormonal supplementation schemes required for the maintenance of endometrial receptivity during luteal phase. We optimized and characterized in vitro endometrial stromal cell (ESC) decidualization model as the adequate physiological reflection of endometrial sensitivity to steroid hormones. Based on the whole transcriptome RNA sequencing and the corresponding bioinformatics, we proposed that activation of the decidual prolactin (PRL) promoter containing ancient transposons MER20 and MER39 may reflect functioning of the core decidual regulatory network. Furthermore, we cloned the sequence of decidual PRL promoter containing MER20 and part of MER39 into the expression vector to estimate the effectiveness of ESC decidual response and verified sensitivity of the designed system. We additionally confirmed specificity of the generated tool using human diploid fibroblasts and adipose-derived human mesenchymal stem cells. Finally, we demonstrated the possibility to apply our tool for personalized hormone screening by comparing the effects of natural progesterone and three synthetic analogs (medroxyprogesterone 17-acetate, 17α-hydroxyprogesterone caproate, dydrogesterone) on decidualization of six ESC lines obtained from patients planning to undergo the IVF procedure. To sum up, we developed the "all-in-one" genetic tool based on the MER20/MER39 expression cassette that provides the ability to predict the most appropriate hormonal cocktail for endometrial receptivity maintenance specifically and safely for the patient, and thus to define the personal treatment strategy prior to the IVF procedure.

The link between endometrial stromal cell senescence and decidualization in female fertility: the art of balance

Cell senescence seems to be an ambivalent biological phenomenon in many aspects. At the cellular level it is considered as an irreversible cell-cycle arrest commonly caused by the DNA damage. Senescent cells harbor a lot of impairments in various intracellular systems. Presence of senescent cells within tissues should ultimately lead to their malfunctioning. However, the interlink between cellular senescence and tissue/organismal functioning is far from always being unidirectional. The entangled and complex relationship between senescence and tissue-specific decidual differentiation of endometrial stromal cells (ESCs) is the excellent example reflecting dualism of cellular senescence. ESCs decidualization conditions endometrium responsiveness to embryonic signals and plays a critical role in embryo biosensoring, selection and implantation. Based on the analysis of the existing literary data, here we will try (1) to puzzle out how cellular senescence simultaneously may be an integral part of normal decidualization and may be involved in the progression of repeated implantation failures and recurrent pregnancy losses; (2) to suppose the sequence of cellular events reflecting the role of ESCs' senescence during normal and impaired decidualization. Together, the deep scan of the interlink between ESCs' senescence and decidualization will allow to suggest the preferable application scheme for senolytics targeting senescent cells as a possible approach to restore impaired endometrial receptivity and thus to increase the effectiveness of in vitro fertilization cycles.

Molecular basis of senescence transmitting in the population of human endometrial stromal cells

Hormone-regulated proliferation and differentiation of endometrial stromal cells (ESCs) determine overall endometrial plasticity and receptivity to embryos. Previously we revealed that ESCs may undergo premature senescence, accompanied by proliferation loss and various intracellular alterations. Here we focused on whether and how senescence may be transmitted within the ESCs population. We revealed that senescent ESCs may induce paracrine senescence in young counterparts via cell contacts, secreted factors and extracellular vesicles. According to secretome-wide profiling we identified plasminogen activator inhibitor -1 (PAI-1) to be the most prominent protein secreted by senescent ESCs (data are available via ProteomeXchange with identifier PXD015742). By applying CRISPR/Cas9 techniques we disclosed that PAI-1 secreted by senescent ESCs may serve as the master-regulator of paracrine senescence progression within the ESCs population. Unraveled molecular basis of senescence transduction in the ESCs population may be further considered in terms of altered endometrial plasticity and sensitivity to invading embryo, thus contributing to the female infertility curing.

Optimization of lentiviral transduction parameters and its application for CRISPR-based secretome modification of human endometrial mesenchymal stem cells

Mesenchymal stem cells (MSCs) hold a great promise for successful development of regenerative medicine. Among the plenty of uncovered MSCs sources, desquamated endometrium collected from the menstrual blood probably remains the most accessible. Though numerous studies have been published on human endometrium-derived mesenchymal stem cells (hMESCs) properties in the past years, there are only a few data regarding their genetic modulation. Moreover, there is a lack of information about the fate of the transduced hMESCs. The present study aimed to optimize hMESCs transduction parameters and apply Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 technology for genome and secretome modification. The fate of hMESCs transduced either in presence of polybrene (Pb) or protamine sulfate (Ps) was assessed by alterations in CD expression profile, growth rate, cell size, migration capability, osteogenic, adipogenic, and decidual differential potentials. Here, we postulated that the use of Ps for hMESCs genetic manipulations is preferable, as it has no impact on the stem-cell properties, whereas Pb application is undesirable, as it induces cellular senescence. Plasminogen activator inhibitor-1 was selected for further targeted hMESCs genome and secretome modification using CRISPR/Cas9 systems. The obtained data provide optimized transduction scheme for hMESCs and verification of its effectiveness by successful hMESCs genome editing via CRISPR/Cas9 technology.

P38 MAPK inhibition prevents polybrene-induced senescence of human mesenchymal stem cells during viral transduction

The unique capacity of mesenchymal stem cells (MSCs) to migrate to the sites of damage, following intravenous transplantation, along with their proliferation and differentiation abilities make them promising candidates for MSC-based gene therapy. This therapeutic approach requires high efficacy delivery of stable transgenes to ensure their adequate expression in MSCs. One of the methods to deliver transgenes is via the viral transduction of MSCs. However, due to low transduction efficiency of MSCs, various polications are used to promote the association of viral particles with membranes of target cells. Among these polications polybrene is the most widely used one. Unfortunately, viral infection in presence of polybrene was shown to negatively affect proliferation rate of stem cells. The molecular mechanism underlying this effect is not yet uncovered. Therefore, the present study aimed to elucidate the mechanism of this phenomenon as well as to develop an effective approach to overcome the negative impact of polybrene on the properties of human endometrium-derived mesenchymal stem cells (hMESCs) during lentiviral infection. We found that the negative effect on proliferation observed during the viral infection in presence of polybrene is mediated by the polycation itself. Furthermore, we revealed that the treatment with polybrene alone led to the p38 MAPK-dependent premature senescence of hMESCs. These findings allowed us to develop an effective strategy to attenuate the negative polybrene impact on the hMESCs properties during lentiviral infection by inhibiting the activity of p38 MAPK. Importantly, the proposed approach did not attenuate the transduction efficiency of hMESCs, yet prevented polybrene-induced senescence and thereby restored the proliferation of the infected cells. These results provide the plausible means to reduce side effects of polybrene during the viral infection of primary cells, particularly MSCs.

Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan

Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post-Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review, we describe in detail the successes, challenges, and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan.