scholarly journals Peroxiredoxin 6 regulates the phosphoinositide 3-kinase/AKT pathway to maintain human sperm viability

Author(s):  
Maria C Fernandez ◽  
Alex Yu ◽  
Adel R Moawad ◽  
Cristian O’Flaherty

Abstract Peroxiredoxins (PRDXs) are antioxidant enzymes proven to control the levels of reactive oxygen species (ROS) and to avoid oxidative damage in the spermatozoon. Previously, we have shown that low amounts of PRDXs are associated with male infertility and that PRDX6 is the primary antioxidant defence in human spermatozoa, maintaining survival and DNA integrity (Gong et al., 2012, Fernandez and O’Flaherty, 2018). Oxidative stress can trigger different pathway cascades in the spermatozoa, including truncated apoptosis. It has been reported that the phosphorylation status of phosphoinositide 3-kinase (PI3K) and its target AKT (protein kinase B) prevent the spermatozoon from entering the truncated apoptotic cascade. Here, we aim to study the regulation of the PI3K/AKT pathway by PRDX6 and assess its role in maintaining sperm viability. Human semen samples were obtained over 1 year from 20 healthy non-smoking volunteers aged 22–30 years old. Sperm viability, lipid peroxidation and apoptosis-like changes were determined by flow cytometry while phosphorylation of PI3K and AKT substrates were assessed by immunoblotting using anti-phospho-PI3K and anti-phospho-AKT substrates antibodies. We found that the addition of arachidonic acid and lysophosphatidic acid, products of PRDX6 calcium independent phospholipase A2 (Ca2+-iPLA2), prevented loss of sperm viability and maintained the phosphorylation of PI3K. Antioxidant compounds such as D-penicillamine partially prevented the oxidative damage on spermatozoa that led to a reduction of their viability. Thus, other pathways can also participate in sperm survival and be regulated by PRDXs. In conclusion, PRDX6 contributes to the regulation of ROS production and the PI3K/AKT pathway for the maintenance of sperm survival.

2017 ◽  
Vol 29 (6) ◽  
pp. 1169 ◽  
Author(s):  
Nicola A. Pascarelli ◽  
Antonella Fioravanti ◽  
Elena Moretti ◽  
Giacomo M. Guidelli ◽  
Lucia Mazzi ◽  
...  

Tumour necrosis factor (TNF)-α is primarily involved in the regulation of cell proliferation and apoptosis; in addition it possesses pro-inflammatory properties. Anti-TNF-α strategies involve either administration of anti-TNF-α antibody or soluble TNF receptor to mop up circulating TNF-α. Etanercept, a recombinant human TNF-α receptor, was found to be effective in the treatment of rheumatoid arthritis. The impact of TNF-α inhibitors on human fertility is of notable interest. This in vitro study investigated the effect of different concentrations of TNF-α and etanercept used alone or in combination on sperm viability, motility, mitochondrial function, percentage of apoptosis and chromatin integrity in swim-up selected human spermatozoa. A negative effect of TNF-α (300 and 500 ng mL–1) and etanercept (from 800 µg mL–1 to 2000 µg mL–1) individually on sperm viability, motility, mitochondrial function, percentage of apoptotic spermatozoa and sperm DNA integrity was demonstrated. However, at concentrations of 100 and 200 µg mL–1, etanercept can block, in a significant way, the toxic effects of TNF-α (500 ng mL–1) on studied sperm characteristics. Our results confirm that TNF-α has a detrimental effect on sperm function and suggest, for the first time, that etanercept may counteract the in vitro toxic action of TNF-α. This data appears to be quite promising, although further studies, both in vivo and in vitro, are needed to understand the exact mechanism of action of TNF-α and TNF-α antagonists on sperm function.


Cryobiology ◽  
2012 ◽  
Vol 65 (3) ◽  
pp. 326-331 ◽  
Author(s):  
Nassira Zribi ◽  
Nozha Feki Chakroun ◽  
Fatma Ben Abdallah ◽  
Henda Elleuch ◽  
Afifa Sellami ◽  
...  

2009 ◽  
Vol 422 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Ana Ibáñez ◽  
Paula Río ◽  
José Antonio Casado ◽  
Juan Antonio Bueren ◽  
José Luis Fernández-Luna ◽  
...  

FA (Fanconi anaemia) is a hereditary disease characterized by congenital malformations, progressive bone marrow failure and an extraordinary elevated predisposition to develop cancer. In the present manuscript we describe an anomalous high level of the proinflammatory cytokine IL-1β (interleukin-1β) present in the serum of FA patients. The elevated levels of IL-1β were completely reverted by transduction of a wild-type copy of the FancA cDNA into FA-A (FA group A) lymphocytes. Although the transcription factor NF-κB (nuclear factor-κB) is a well established regulator of IL-1β expression, our experiments did not show any proof of elevated NF-κB activity in FA-A cells. However, we found that the overexpression of IL-1β in FA-A cells is related to a constitutively activated PI3K (phosphoinositide 3-kinase)-Akt pathway in these cells. We provide evidence that the effect of Akt on IL-1β activation is mediated by the inhibition of GSK3β (glycogen synthase kinase 3β). Finally, our data indicate that the levels of IL-1β produced by FA-A lymphoblasts are enough to promote an activation of the cell cycle in primary glioblastoma progenitor cells. Together, these results demonstrate that the constitutive activation of the PI3K-Akt pathway in FA cells upregulates the expression of IL-1β through an NF-κB-independent mechanism and that this overproduction activates the proliferation of tumour cells.


2020 ◽  
Vol 98 (6) ◽  
pp. 653-660 ◽  
Author(s):  
Xiaoxing Xie ◽  
Gaoyun Xiong ◽  
Wenjun Chen ◽  
Hongdan Fu ◽  
Mingqian Li ◽  
...  

FOXD3 has been found previously to positively regulate miR-26b, a tumor inhibitor of nasopharyngeal carcinoma (NPC). However, FOXD3’s precise function and associated mechanism of action in NPC have not yet been investigated. In this study, the expression of FOXD3 mRNA and protein was evaluated using RT-qPCR, western blotting, and immunohistochemistry. Protein levels involved in the phosphoinositide 3-kinase – protein kinase B (PI3K–Akt) pathway were assessed by western blot, and cell proliferation was determined by MTT and colony forming assays. Additionally, cell apoptosis was assessed by flow cytometric assay. Finally, the migration and invasion capabilities of the NPC cells were determined using wound healing and Transwell assays. We found that FOXD3 levels were relatively low in NPC tissue and cells, while an increase caused the inhibition of the PI3K–Akt pathway. Functional experiments found that overexpression of FOXD3 suppressed cell proliferation, migration, and invasion and enhanced cell apoptosis in NPC C6661 cells. IGF-1, an activator of the PI3K–Akt pathway, reversed the inhibitory effect of FOXD3. Furthermore, we found upregulation of the PI3K–Akt pathway and upregulation of the inhibitory effects of FOXD3 on C6661 cellular activities. In conclusion, FOXD3 negatively affected the PI3K–Akt pathway to restrain the processes involved in C6661 cell pathology. These findings further exposed the function and downstream axis of FOXD3 in NPC and displayed a promising new target for NPC therapy.


2017 ◽  
Vol 42 (5) ◽  
pp. 1897-1906 ◽  
Author(s):  
Kai Dong ◽  
Pengjie Hao ◽  
Sheng Xu ◽  
Shutai Liu ◽  
Wenjuan Zhou ◽  
...  

Background/Aims: Patients with diabetes mellitus have a higher risk of dental implant failure. One major cause is high-glucose induced oxidative stress. Alpha-lipoic acid (ALA), a naturally occurring compound and dietary supplement, has been established as a potent antioxidant that is a strong scavenger of free radicals. However, few studies have yet investigated the effect of ALA on osteogenic differentiation of osteoblasts cultured with high glucose medium. The aim of this study is to investigate the effects of ALA on the osteoblastic differentiation in MC3T3-E1 cells under high glucose condition. Methods: MC3T3-E1 cells were divided into 4 groups including normal glucose (5.5 mM) group (control), high glucose (25.5 mM) group, high glucose + 0.1 mM ALA group, and high glucose + 0.2 mM ALA group. The proliferation, osteogenic differentiation and mineralization of cells were evaluated by MTT assay, alkaline phosphatase (ALP) activity assay, alizarin red staining and real time-polymerase chain reaction. High-glucose induced oxidative damage was also assessed by the production of reactive oxygen species (ROS) and superoxide dismutase (SOD). Western blots were performed to examine the role of PI3K/Akt pathway. Results: The proliferation, osteogenic differentiation and mineralization of MC3T3-E1 cells were significantly decreased by the ROS induced by high-glucose. All observed oxidative damage and osteogenic dysfunction induced were inhibited by ALA. Moreover, the PI3K/Akt pathway was activated by ALA. Conclusions: We demonstrate that ALA may attenuate high-glucose mediated MC3T3-E1 cells dysfunction through antioxidant effect and modulation of PI3K/Akt pathway.


2021 ◽  
Author(s):  
Mo Chen ◽  
Suyong Choi ◽  
Tianmu Wen ◽  
Changliang Chen ◽  
Narendra Thapa ◽  
...  

The tumor suppressor p53 and the phosphoinositide 3-kinase (PI3K)-Akt pathway have fundamental roles in regulating cell growth, apoptosis and are frequently mutated in cancer. Here, we show that genotoxic stress induces nuclear Akt activation by a p53-dependent mechanism that is independent from the canonical membrane-localized PI3K-Akt pathway. Upon genotoxic stress a nuclear p53-PI3,4,5P3 complex is generated in regions devoid of membranes by a nuclear PI3K, and this complex recruits all the kinases required to activate Akt and phosphorylate FOXOs, inhibiting DNA damage-induced apoptosis. Wild-type p53 activates nuclear Akt in an on/off fashion upon stress, whereas mutant p53 stimulates high basal Akt activity, indicating a fundamental difference. The nuclear p53-phosphoinositide signalosome is distinct from the canonical membrane-localized pathway and insensitive to PI3K inhibitors currently in the clinic, underscoring its therapeutic relevance.


2020 ◽  
Author(s):  
Kristina Ames ◽  
Imit Kaur ◽  
Yang Shi ◽  
Meng Tong ◽  
Taneisha Sinclair ◽  
...  

AbstractHematopoietic stem cells (HSCs) maintain the blood system through a delicate equilibrium between self-renewal and differentiation. Most hematopoietic growth factors and cytokines signal through phosphoinositide 3-kinase (PI3K) via three Class IA catalytic PI3K isoforms (P110α, β, and δ), encoded by Pik3ca, Pik3cb, and Pik3cd, respectively. The PI3K/AKT pathway is commonly activated in acute myeloid leukemia (AML), and PI3K is a common therapeutic target in cancer. However, it is not known whether PI3K is required for HSC differentiation or self-renewal. We previously demonstrated that individual PI3K isoforms are dispensable in HSCs1,2. To determine the redundant roles of PI3K isoforms in HSCs, we generated a triple knockout (TKO) mouse model with deletion of all three Class IA PI3K isoforms in the hematopoietic system. Surprisingly, we observed significant expansion of TKO HSCs after transplantation, with decreased differentiation capacity and impaired multilineage repopulation. Additionally, the bone marrow of TKO mice exhibited myelodysplastic features with chromosomal abnormalities. Interestingly, we found that macroautophagy (thereafter autophagy) is impaired in TKO HSCs, and that pharmacologic induction of autophagy improves their differentiation. Therefore, we have uncovered important roles for PI3K in autophagy regulation in HSCs to maintain the balance between self-renewal and differentiation.


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