scholarly journals PI3K/PTEN/Akt and TSC/mTOR signaling pathways, ovarian dysfunction, and infertility: an update

2014 ◽  
Vol 53 (3) ◽  
pp. R103-R118 ◽  
Author(s):  
Annu Makker ◽  
Madhu Mati Goel ◽  
Abbas Ali Mahdi

Abnormalities in ovarian function, including defective oogenesis and folliculogenesis, represent a key female reproductive deficiency. Accumulating evidence in the literature has shown that the PI3K/PTEN/Akt and TSC/mTOR signaling pathways are critical regulators of ovarian function including quiescence, activation, and survival of primordial follicles, granulosa cell proliferation and differentiation, and meiotic maturation of oocytes. Dysregulation of these signaling pathways may contribute to infertility caused by impaired follicular development, intrafollicular oocyte development, and ovulation. This article reviews the current state of knowledge of the functional role of the PI3K/PTEN/Akt and TSC/mTOR pathways during mammalian oogenesis and folliculogenesis and their association with female infertility.

Reproduction ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 537-543 ◽  
Author(s):  
Takashi Shimizu ◽  
Yasunori Miyahayashi ◽  
Masaki Yokoo ◽  
Yumi Hoshino ◽  
Hiroshi Sasada ◽  
...  

Growth differentiation factor-9 (GDF-9) is a growth factor secreted by oocytes in growing ovarian follicles. To investigate the ovarian function of GDF-9 in pigs, we first cloned porcine GDF-9 complementary DNA (cDNA), and then injected its gene fragments into the ovary in gilts. Porcine GDF-9 has open reading frame (ORF) homologies of 81.4%, 84.6%, 84.2%, 72.7% and 72.6% with its human, bovine, ovine, rat and mouse counterparts respectively. Regarding the deduced amino-acid sequence of the mature protein, the corresponding homologies reach 92.1%, 97.8%, 97.0%, 89.6% and 88.1% respectively. To investigate the role of GDF-9 in early folliculogenesis, the ovaries of 2-month-old prepubertal gilts were injected with GDF-9 gene fragments. The injection of porcine GDF-9 gene fragments resulted in an increase in the number of primary, secondary and tertiary follicles, concomitant with a decrease in the number of primordial follicles. These results indicated that exogenous GDF-9 can promote early folliculogenesis in the porcine ovary, and that a technique for direct ovarian injection of GFD-9 gene fragments may contribute to a novel therapy for prevention and treatment of infertility associated with ovarian dysfunction.


2020 ◽  
Vol 10 (11) ◽  
pp. 4071-4081
Author(s):  
Yan Zhou ◽  
Jie Liu ◽  
Qiuxia Lei ◽  
Haixia Han ◽  
Wei Liu ◽  
...  

As a class of transcription regulators, numerous miRNAs have been verified to participate in regulating ovary follicular development in chickens (Gallus gallus). Previously we showed that gga-miR-135a-5p has significant differential expression between high and low-yield chicken ovaries, and the abundance of gga-miR-135a-5p is significantly higher in follicular theca cells than in granulosa cells. However, the exact role of gga-miR-135a-5p in chicken follicular theca cells is unclear. In this study, primary chicken follicular theca cells were isolated and then transfected with gga-miR-135a-5p inhibitor. Transcriptome sequencing was performed in chicken follicular theca cells with or without transfection. Differentially expressed genes (DEGs) were analyzed using bioinformatics. A dual-luciferase reporter assay was used to verify the target relationship between gga-miR-135a-5p and predicted targets within the DEGs. Compared with the normal chicken follicle theca cells, 953 up-regulated and 1060 down-regulated genes were detected in cells with gga-miR-135a-5p inhibited. The up-regulated genes were significantly enriched in Gene Ontology terms and pathways involved in cell proliferation and differentiation. In chicken follicular theca cells, Krüppel-like factor 4 (KLF4), ATPase phospholipid transporting 8A1 (ATP8A1), and Complexin-1 (CPLX1) were significantly up-regulated when the expression of gga-miR-135a-5p was inhibited. In addition, KLF4, ATP8A1, and CPLX1 confirmed as targets of gga-miR-135a-5p by using a dual-luciferase assay in vitro. The results suggest that gga-mir-135a-5p may involve in proliferation and differentiation in chicken ovarian follicular theca cells by targeting KLF4, ATP8A1, and CPLX1.


2020 ◽  
Vol 3 (2) ◽  
pp. 216-242 ◽  
Author(s):  
Mayuri Shukla ◽  
Areechun Sotthibundhu ◽  
Piyarat Govitrapong

The revelation of adult brain exhibiting neurogenesis has established that the brain possesses great plasticity and that neurons could be spawned in the neurogenic zones where hippocampal adult neurogenesis attributes to learning and memory processes. With strong implications in brain functional homeostasis, aging and cognition, various aspects of adult neurogenesis reveal exuberant mechanistic associations thereby further aiding in facilitating the therapeutic approaches regarding the development of neurodegenerative processes in Alzheimer’s Disease (AD). Impaired neurogenesis has been significantly evident in AD with compromised hippocampal function and cognitive deficits. Melatonin the pineal indolamine augments neurogenesis and has been linked to AD development as its levels are compromised with disease progression. Here, in this review, we discuss and appraise the mechanisms via which melatonin regulates neurogenesis in pathophysiological conditions which would unravel the molecular basis in such conditions and its role in endogenous brain repair. Also, its components as key regulators of neural stem and progenitor cell proliferation and differentiation in the embryonic and adult brain would aid in accentuating the therapeutic implications of this indoleamine in line of prevention and treatment of AD.   


1988 ◽  
Vol 8 (2) ◽  
pp. 963-973
Author(s):  
J T Holt ◽  
R L Redner ◽  
A W Nienhuis

To study the role of a nuclear proto-oncogene in the regulation of cell growth and differentiation, we inhibited HL-60 c-myc expression with a complementary antisense oligomer. This oligomer was stable in culture and entered cells, forming an intracellular duplex. Incubation of cells with the anti-myc oligomer decreased the steady-state levels of c-myc protein by 50 to 80%, whereas a control oligomer did not significantly affect the c-myc protein concentration. Direct inhibition of c-myc expression with the anti-myc oligomer was associated with a decreased cell growth rate and an induction of myeloid differentiation. Related antisense oligomers with 2- to 12-base-pair mismatches with c-myc mRNA did not influence HL-60 cells. Thus, the effects of the antisense oligomer exhibited sequence specificity, and furthermore, these effects could be reversed by hybridization competition with another complementary oligomer. Antisense inhibition of a nuclear proto-oncogene apparently bypasses cell surface events in affecting cell proliferation and differentiation.


Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4774
Author(s):  
Giulia Anichini ◽  
Laura Carrassa ◽  
Barbara Stecca ◽  
Fabio Marra ◽  
Chiara Raggi

Cholangiocarcinoma (CCA) is a poorly treatable type of cancer and, along with hepatocellular carcinoma (HCC), is the predominant type of primitive liver cancer in adults. The lack of understanding of CCA biology has slowed down the identification of novel targets and the development of effective treatments. While tumors share some general characteristics, detailed knowledge of specific features is essential for the development of effectively tailored therapeutic approaches. The Hedgehog (HH) signaling cascade regulates stemness biology, embryonal development, tissue homeostasis, and cell proliferation and differentiation. Its aberrant activation has been associated with a variety of solid and hematological human malignancies. Several HH-inhibiting compounds have been indeed developed as potential anticancer agents in different types of tumors, with Smoothened and GLI inhibitors showing the most promising results. Beside its well-established function in other tumors, findings regarding the HH signaling in CCA are still controversial. Here we will give an overview of the most important clinical and molecular features of cholangiocarcinoma, and we will discuss the available evidence of the crosstalk between the HH signaling pathway and the cholangiocarcinoma cell biology.


2021 ◽  
pp. 1-13
Author(s):  
Yuying Wang ◽  
Rui He ◽  
Anqi Yang ◽  
Rui Guo ◽  
Jie Liu ◽  
...  

BACKGROUND: The effectiveness and availability of conservative therapies for osteonecrosis of the femoral head (ONFH) are limited. Transplantation of bone marrow mesenchymal stem cells (BMSCs) combined with Bio-Oss, which is a good bone scaffold biomaterial for cell proliferation and differentiation, is a new potential therapy. Of note, the expression of miRNAs was significantly modified in cells cultured with Bio-Oss, and MiR-214 was correlated positively with osteonecrosis. Furthermore, miR-214 was upregulated in cells exposed to Bio-Oss. OBJECTIVE: To investigate whether targeting miR-214 further improves the transplantation effect. METHODS: We treated BMSCs with agomiR-214 (a miR-214 agonist), antagomiR-214 (a miR-214 inhibitor), or vehicle, followed by their transplantation into ONFH model rats. RESULTS: Histological and histomorphometric data showed that bone formation was significantly increased in the experimental groups (Bio-Oss and BMSCs treated with antagomiR-214) compared with other groups. CONCLUSIONS: miR-214 participates in the inhibition of osteoblastic bone formation, and the inhibition of miR-214 to bone formation during transplantation therapy with Bio-Oss combined with BMSCs for ONFH.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A Volodarsky-Perel ◽  
M Zajicek ◽  
D Shai ◽  
H Raanani ◽  
N Gruber ◽  
...  

Abstract Study question What is the predictive value of ovarian reserve evaluation in patients with non-iatrogenic primary ovarian insufficiency (NIPOI) for follicle detection in ovarian tissue harvested for cryopreservation? Summary answer Ovarian tissue cryopreservation (OTCP) should be considered if patients present at least one of the following parameters: detectable AMH, FSH≤20mIU/ml, detection of ≥ 1 antral follicle. What is known already In pre-pubertal girls suffering from NIPOI, which majorly has a genetic etiology, fertility preservation using OTCP is commonly practiced. When OTCP was performed in an unselected group of children and adolescents with NIPOI, only 26% of them had follicles in ovarian tissue while 74% did not benefit from the surgery. The role of preoperative evaluation of anti-müllerian hormone (AMH) serum level, follicular stimulating hormone (FSH) serum level, and trans-abdominal ultrasound for the antral follicle count to predict the detection of primordial follicles in the harvested ovarian tissue is unclear. Study design, size, duration We conducted a retrospective analysis of all patients ≤ 18 years old who were referred for fertility preservation counseling due to NIPOI at a single tertiary hospital between 2010 and 2020. If initial evaluation suggested a diminished ovarian reserve and at least one positive parameter indicating a follicular activity (AMH > 0.16ng/ml, FSH ≤ 20mIU/ml, detection of ≥ 1 antral follicle by transabdominal sonography), OTCP was offered. Patients with 46XY gonadal dysgenesis were excluded. Participants/materials, setting, methods OTCP was performed laparoscopically in all cases. A fresh sample of cortical tissue was fixed in buffered formaldehyde for histological analysis. The rest of the ovarian tissue was cut into small cuboidal slices 1–2 mm in thickness and cryopreserved. After the serial sections, the histological slides were evaluated for the presence of follicles by a certified pathologist. Follicles were counted and categorized as primordial, primary, and secondary. Main results and the role of chance During the study period, 39 patients with suspected NIPOI were referred to the fertility preservation center. Thirty-seven patients included in the study were diagnosed with Turner’s syndrome (n = 28), Galactosemia (n = 3), Blepharophimosis-Ptosis-Epicanthus Inversus syndrome (n = 1), and idiopathic NIPOI (n = 6). Of 28 patients with Turner’s syndrome, 6 had 45X monosomy, 15 had mosaicism and 7 had structural anomalies in X-chromosome. One patient with gonadal dysgenesis and one with the presence of Y-chromosome in 20% of somatic cells were excluded from the study. OTCP was conducted in 14 patients with at least one positive parameter suggesting ovarian function. No complications of the surgical procedure or the anesthesia were observed. Primordial follicles were found in all patients with two or three positive parameters (100%) and in three of six cases with one positive parameter (50%). In total, of the 14 patients who underwent OTCP with at least one positive parameter, 11 (79%) had primordial follicles at biopsy (mean 23.9, range 2–47). This study demonstrates a positive predictive value of 79% for the detection of primordial follicles in patients who had at least one positive parameter of ovarian reserve evaluation. If two or three parameters were positive, the positive predictive value increased to 100%. Limitations, reasons for caution This study did not examine the negative predictive value of our protocol as OTCP was not recommended in the absence of positive parameters. The future fertility potential of cryopreserved tissue in the population with NIPOI is unclear and should be discovered in further studies. Wider implications of the findings: We suggest the evaluation of ovarian reserve by antral follicles count, AMH, and FSH serum levels prior to OTCP in patients with NIPOI. By recommendation of OTCP only if ≥ 1 parameter suggesting the ovarian function is positive, unnecessary procedures can be avoided. Trial registration number Not applicable


2019 ◽  
Vol 317 (1) ◽  
pp. C3-C19 ◽  
Author(s):  
Qingyi Ma ◽  
Lubo Zhang ◽  
William J. Pearce

MicroRNAs (miRNAs) are a class of highly conserved non-coding RNAs with 21–25 nucleotides in length and play an important role in regulating gene expression at the posttranscriptional level via base-paring with complementary sequences of the 3′-untranslated region of the target gene mRNA, leading to either transcript degradation or translation inhibition. Brain-enriched miRNAs act as versatile regulators of brain development and function, including neural lineage and subtype determination, neurogenesis, synapse formation and plasticity, neural stem cell proliferation and differentiation, and responses to insults. Herein, we summarize the current knowledge regarding the role of miRNAs in brain development and cerebrovascular pathophysiology. We review recent progress of the miRNA-based mechanisms in neuronal and cerebrovascular development as well as their role in hypoxic-ischemic brain injury. These findings hold great promise, not just for deeper understanding of basic brain biology but also for building new therapeutic strategies for prevention and treatment of pathologies such as cerebral ischemia.


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