scholarly journals The Signaling Pathways Involved in Ovarian Follicle Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Liyuan Li ◽  
Xiaojin Shi ◽  
Yun Shi ◽  
Zhao Wang

The follicle is the functional unit of the ovary, which is composed of three types of cells: oocytes, granulosa cells, and theca cells. Ovarian follicle development and the subsequent ovulation process are coordinated by highly complex interplay between endocrine, paracrine, and autocrine signals, which coordinate steroidogenesis and gametogenesis. Follicle development is regulated mainly by three organs, the hypothalamus, anterior pituitary, and gonad, which make up the hypothalamic-pituitary-gonadal axis. Steroid hormones and their receptors play pivotal roles in follicle development and participate in a series of classical signaling pathways. In this review, we summarize and compare the role of classical signaling pathways, such as the WNT, insulin, Notch, and Hedgehog pathways, in ovarian follicle development and the underlying regulatory mechanism. We have also found that these four signaling pathways all interact with FOXO3, a transcription factor that is widely known to be under control of the PI3K/AKT signaling pathway and has been implicated as a major signaling pathway in the regulation of dormancy and initial follicular activation in the ovary. Although some of these interactions with FOXO3 have not been verified in ovarian follicle cells, there is a high possibility that FOXO3 plays a core role in follicular development and is regulated by classical signaling pathways. In this review, we present these signaling pathways from a comprehensive perspective to obtain a better understanding of the follicular development process.

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xue Sun ◽  
Xiaoxia Chen ◽  
Jinghua Zhao ◽  
Chang Ma ◽  
Chunchi Yan ◽  
...  

Abstract Background Ovarian follicle development plays an important role in determination of poultry egg production. The follicles at the various developmental stages possess their own distinct molecular genetic characteristics and have different biological roles in chicken ovary development and function. In the each stage, several genes of follicle-specific expression and biological pathways are involved in the vary-sized follicular development and physiological events. Identification of the pivotal genes and signaling pathways that control the follicular development is helpful for understanding their exact regulatory functions and molecular mechanisms underlying egg-laying traits of laying hens. Results The comparative mRNA transcriptomic analysis of ovarian follicles at three key developmental stages including slow growing white follicles (GWF), small yellow follicles (SYF) of recruitment into the hierarchy, and differentiated large yellow follicles (LYF), was accomplished in the layers with lower and higher egg production. Totally, 137, 447, and 229 of up-regulated differentially expressed genes (DEGs), and 99, 97, and 157 of down-regulated DEGs in the GWF, SYF and LYF follicles, including VIPR1, VIPR2, ADRB2, and HSD17B1 were identified, respectively. Moreover, NDUFAB1 and GABRA1 genes, two most promising candidates potentially associated with egg-laying performance were screened out from the 13 co-expressed DEGs in the GWF, SYF and LYF samples. We further investigated the biological effects of NDUFAB1 and GABRA1 on ovarian follicular development and found that NDUFAB1 promotes follicle development by stimulating granulosa cell (GC) proliferation and decreasing cell apoptosis, increases the expression of CCND1 and BCL-2 but attenuates the expression of caspase-3, and facilitates steroidogenesis by enhancing the expression of STAR and CYP11A1. In contrast, GABRA1 inhibits GC proliferation and stimulates cell apoptosis, decreases the expression of CCND1, BCL-2, STAR, and CYP11A1 but elevates the expression of caspase-3. Furthermore, the three crucial signaling pathways such as PPAR signaling pathway, cAMP signaling pathway and neuroactive ligand-receptor interaction were significantly enriched, which may play essential roles in ovarian follicle growth, differentiation, follicle selection, and maturation. Conclusions The current study provided new molecular data for insight into the regulatory mechanism underlying ovarian follicle development associated with egg production in chicken.


Author(s):  
Md. Junaid ◽  
Yeasmin Akter ◽  
Syeda Samira Afrose ◽  
Mousumi Tania ◽  
Md. Asaduzzaman Khan

Background: AKT/PKB is an important enzyme with numerous biological functions, and its overexpression is related to the carcinogenesis. AKT stimulates different signaling pathways that are downstream of activated tyrosine kinases and phosphatidylinositol 3-kinase, hence functions as an important target for anti-cancer drugs. Objective: In this review article, we have interpreted the role of AKT signaling pathways in cancer and natural inhibitory effect of Thymoquinone (TQ) in AKT and its possible mechanism. Method: We have collected the updated information and data on AKT, their role in cancer and inhibitory effect of TQ in AKT signaling pathway from google scholar, PubMed, Web of Science, Elsevier, Scopus and many more. Results: There are many drugs already developed, which can target AKT, but very few among them have passed clinical trials. TQ is a natural compound, mainly found in black cumin, which has been found to have potential anti-cancer activities. TQ targets numerous signaling pathways, including AKT, in different cancers. In fact, many studies revealed that AKT is one of the major targets of TQ. The preclinical success of TQ suggests its clinical studies on cancer. Conclusion: This review article summarizes the role of AKT in carcinogenesis, its potent inhibitors in clinical trials, and how TQ acts as an inhibitor of AKT and TQ’s future as a cancer therapeutic drug.


2008 ◽  
Vol 78 (Suppl_1) ◽  
pp. 289-290
Author(s):  
Ghanim Almahbobi ◽  
Chantelle Ruoss ◽  
Amanda Tadros ◽  
Tim O'Shea ◽  
Jim McFarlane

Reproduction ◽  
2014 ◽  
Vol 148 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Amanda Feeney ◽  
Eric Nilsson ◽  
Michael K Skinner

An ovarian follicle is composed of an oocyte and surrounding theca and granulosa cells. Oocytes are stored in an arrested state within primordial follicles until they are signaled to re-initiate development by undergoing primordial-to-primary follicle transition. Previous gene bionetwork analyses of primordial follicle development identified a number of critical cytokine signaling pathways and genes potentially involved in the process. In the current study, candidate regulatory genes and pathways from the gene network analyses were tested for their effects on the formation of primordial follicles (follicle assembly) and on primordial follicle transition using whole ovary organ culture experiments. Observations indicate that the tyrphostin inhibitor (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased follicle assembly significantly, supporting a role for the MAPK signaling pathway in follicle assembly. The cytokine interleukin 16 (IL16) promotes primordial-to-primary follicle transition as compared with the controls, where as Delta-like ligand 4 (DLL4) and WNT-3A treatments have no effect. Immunohistochemical experiments demonstrated the localization of both the cytokine IL16 and its receptor CD4 in the granulosa cells surrounding each oocyte within the ovarian follicle. The tyrphostin LDN193189 (LDN) is an inhibitor of the bone morphogenic protein receptor 1 within the TGFB signaling pathway and was found to promote the primordial-to-primary follicle transition. Observations support the importance of cytokines (i.e., IL16) and cytokine signaling pathways in the regulation of early follicle development. Insights into regulatory factors affecting early primordial follicle development are provided that may associate with ovarian disease and translate to improved therapy in the future.


2006 ◽  
Vol 18 (2) ◽  
pp. 220
Author(s):  
R. McCorkell ◽  
M. Woodbury ◽  
G. Adams

Wapiti are seasonally polyestrous. The transition into and out of the breeding season is marked by resumption of ovulation in autumn and cessation of ovulation in winter. Onset of ovulatory cyclicity is distinct and associated with aggressive breeding behavior of stags in rut. Cessation of ovulation at the end of the breeding season is not distinguished by behavioral patterns. The objective of the present study was to characterize follicular and luteal dynamics in wapiti during the transitional periods into and out of the breeding seasons. Transition from anestrus to estrus was monitored in 15 hinds, aged 2 to 14 years, over two successive seasons (11 in year 1, with 5 hinds from year 1 used again in year 2 along with 4 new hinds; n = 20 observations). Transition from estrus to anestrus was monitored in 11 hinds over 1 season (n = 11 observations). Hinds were maintained on a farm near Saskatoon, Saskatchewan (52°07′N, 106°38′W). The ovaries were examined daily during September through October by transrectral ultrasonography using a B-mode ultrasound machine and a 7.5 MHz linear array transducer for transition to estrus, and December through April for transition to anestrus. The first ovulation was recorded on September 15 and all hinds had ovulated for the first time by October 7. In 17 of 20 observations, the duration of the first interovulatory interval (IOI) was 9.3 ± 0.4 days (mean ± SEM). With one exception, these IOIs were characterized by one wave of follicular development. The remaining three IOIs ranged from 16 to 23 days and consisted of two or three waves of follicle development. The second ovulation occurred by October 15 in hinds with a short IOI and by October 17 in all remaining hinds. The mean dates of first and last ovulation were September 25 and February 7, respectively, an interval of 135 days. The median date of the last ovulation was February 15 and the range was from December 3 to March 22. Duration of the last IOI of the season (21.2 ± 0.6 days) was similar to the notional 21-day cycle for wapiti, but longer (P < 0.05) than the duration of the first IOI (10.9 ± 1.0 days). Maximum diameters of the first 2 ovulatory follicles were similar (11.3 ± 0.4 vs. 11.3 ± 0.2 mm), but were larger (P < 0.05) than the last 2 ovulatory follicles of the breeding season (10.3 ± 0.3 vs. 10.1 ± 0.4 mm). Maximum diameter of the corpus luteum (CL) tended (P = 0.06) to be smaller for the short IOI than for longer IOI of the first and last cycles. Diameter of the last CL of the season was not different from that of the previous CL (12.8 ± 0.6 vs. 12.5 ± 0.6 mm); however, it was detected for a longer period (22.3 ± 1.2 vs. 19.3 ± 0.7 days; P < 0.05). Estrous cycles during transition into the breeding season have been described as being irregular and those out of the breeding season as increasingly long. In the present study, the transition periods were characterized by regular events. Transition to regular estrous cycles was preceded by one short (9 days) IOI. The last IOI of the breeding season was the same as that reported during the rut. Transition to anestrus occurred most commonly in February and was marked by a failure of the dominant follicle to ovulate after luteal regression.


2007 ◽  
Vol 77 (Suppl_1) ◽  
pp. 171-171
Author(s):  
Ankur Nagaraja ◽  
Stephanie Pangas ◽  
Martin Matzuk

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