ERK1/2 regulates heat stress-induced lactate production via enhancing the expression of HSP70 in immature boar Sertoli cells

Abstract

Lactate produced by Sertoli cells plays an important role in spermatogenesis, and heat stress induces lactate production in immature boar Sertoli cells. Extracellular signaling regulated kinase 1 and 2 (ERK1/2) participates in heat stress response. However, the effect of ERK1/2 on heat stress-induced lactate production is unclear. In the present study, Sertoli cells were isolated from immature boar testis and cultured at 32 °C. Heat stress was induced in a 43 °C incubator for 30 min. Proteins and RNAs were detected by western blotting and RT-PCR, respectively. Lactate production and lactate dehydrogenase (LDH) activity were detected using commercial kits. Heat stress promoted ERK1/2 phosphorylation, showing a reducing trend with increasing recovery time. In addition, heat stress increased heat shock protein 70 (HSP70), glucose transporter 3 (GLUT3), and lactate dehydrogenase A (LDHA) expressions, enhanced LDH activity and lactate production at 2-h post-heat stress. Pretreatment with U0126 (1 × 10 mol/L), a highly selective inhibitor of ERK1/2 phosphorylation, reduced HSP70, GLUT3, and LDHA expressions and decreased LDH activity and lactate production. Meanwhile, ERK2 siRNA1 reduced the mRNA level of ERK2 and weakened ERK1/2 phosphorylation. Additionally, ERK2 siRNA1 reduced HSP70, GLUT3, and LHDA expressions decreased LDH activity and lactate production. Furthermore, HSP70 siRNA3 downregulated GLUT3 and LDHA expressions and decreased LDH activity and lactate production. These results show that activated ERK1/2 increases heat stress-induced lactate production by enhancing HSP70 expression to promote the expressions of molecules related to lactate production (GLUT3 and LDHA). Our study reveals a new insight in reducing the negative effect of heat stress in boars.

Targeting Cancer Metabolism Breaks Radioresistance by Impairing the Stress Response

“…However, despite its potential importance, insight into the relationship between the pro-tumorigenic lactate metabolism and the antiapoptotic stress response is limited. In immature boar Sertoli cells, a heat-induced upregulation of Hsp70, glucose transporter 3 (Glut-3) and lactate production has been shown to improve spermatogenesis and male fertility via LDHA [14], and high cytosolic Hsp70 levels in HeLa human cervical cancer cells shift the energy metabolism towards anaerobic glycolysis [15]. The mechanistic link between the heat shock response, lactate metabolism and sensitivity of tumor cells to radiation has not yet been elucidated.…”

Responses and coping methods of different testicular cell types to heat stress: overview and perspectives

“…When heat stress starts, ERK1/2 induce different cascade reactions to regulate the level of cellular survival or apoptosis molecule, which protects part of male germ cells and somatic cells from being destroyed in testis. Study shows that 30-min heat stress can induce the enhance of pERK1/2 in immature boar Sertoli cells, which increase the level of HSP70 and then promote the production of lactate, the main substrate of ATP in developing germ cells, by accelerating glucose metabolism [ 69 ]. ERK can also make pachytene spermatocytes free from short-term heat stress-induced apoptosis by up-regulate metastasis-associated 1 against p53 [ 70 ].…”

Melatonin alleviates the heat stress‐induced impairment of Sertoli cells by reprogramming glucose metabolism

“…SCs were isolated and cultured according to our previous publications. [13][14][15]35 After shearing, digestion, filtration, and centrifugation of testicular tissue, primary SCs were obtained for subsequent experiments. Detailed information on tissue processing and cellular treatment is given in the Supporting Information: Methods.…”

“…[6][7][8][9] Many studies have found that metabolic disorders of SCs could interfere with spermiogenesis. [10][11][12] The effect of heat stress on glycolysis of SCs has been observed, [13][14][15] but the details of these changes remain elusive.…”