Apoptotic germ cells regulate Sertoli cell lipid storage and fatty acid oxidation

Reproduction ◽  
2018 ◽  
Author(s):  
Mariana Regueira ◽  
Agostina Gorga ◽  
Gustavo Marcelo Rindone ◽  
Eliana Herminia Pellizzari ◽  
Selva Cigorraga ◽  
...  

The presence of lipid droplets (LD) and the utilization of fatty acids (FA) as a source of energy are Sertoli cell (SC) putative characteristics. It is well known that SC can phagocyte and degrade apoptotic germ cells (AGC) resulting in increasing lipid content and ATP levels. A relationship between the regulation of lipid storage and of lipid oxidation in SC might be envisaged. The aim of this study was to analyze whether AGC and FA are able to simultaneously regulate molecular mechanisms involved in lipid storage and FA oxidation in SC. The experimental model utilized in this study consisted in SC cultures obtained from 20-day-old rats that were co-cultured with AGC or treated with palmitic acid (PA, 500μM) for 24 and 48 hours. AGC and PA increase LD, triacylglycerol (TAG) content, and mRNA levels of Plin1, Plin2, Plin3 (proteins involved in TAG storage). Simultaneously, AGC and PA rise the extent of FA oxidation and mRNA levels of Cpt1, Lcad (proteins involved in FA degradation). PPARs are transcription factors which participate in lipid metabolism regulation. Results show that AGC and PA treatment increase PPAR transcriptional activity in SC. Additionally, the presence of a PPARg antagonist decreases the up-regulation of LD content and Plin1 expression. Similarly, the presence of a PPARb/d antagonist reduces the increase in FA oxidation and Cpt1 mRNA levels. Altogether these results suggest that AGC and FA, which probably generates PPARs ligands, regulate lipid storage and fatty acid utilization, contributing to the energy homeostasis in the seminiferous tubules.

Reproduction ◽  
2016 ◽  
Vol 152 (2) ◽  
pp. R31-R40 ◽  
Author(s):  
Hong Wang ◽  
Liping Wen ◽  
Qingqing Yuan ◽  
Min Sun ◽  
Minghui Niu ◽  
...  

Within the seminiferous tubules there are two major cell types, namely male germ cells and Sertoli cells. Recent studies have demonstrated that male germ cells and Sertoli cells can have significant applications in treating male infertility and other diseases. However, primary male germ cells are hard to proliferatein vitroand the number of spermatogonial stem cells is scarce. Therefore, methods that promote the expansion of these cell populations are essential for their use from the bench to the bed side. Notably, a number of cell lines for rodent spermatogonia, spermatocytes and Sertoli cells have been developed, and significantly we have successfully established a human spermatogonial stem cell line with an unlimited proliferation potential and no tumor formation. This newly developed cell line could provide an abundant source of cells for uncovering molecular mechanisms underlying human spermatogenesis and for their utilization in the field of reproductive and regenerative medicine. In this review, we discuss the methods for establishing spermatogonial, spermatocyte and Sertoli cell lines using various kinds of approaches, including spontaneity, transgenic animals with oncogenes, simian virus 40 (SV40) large T antigen, the gene coding for a temperature-sensitive mutant ofp53, telomerase reverse gene (Tert), and the specific promoter-based selection strategy. We further highlight the essential applications of these cell lines in basic research and translation medicine.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1379
Author(s):  
Xiaorui Fan ◽  
Yihui Liu ◽  
Meishan Yue ◽  
Weidong Yue ◽  
Gaoya Ren ◽  
...  

Spontaneous unilateral cryptorchid boars have one testis in the abdomen or inguinal canal, causing its temperature to be at or near the body temperature, which impairs spermatogenesis, although the histomorphometry and molecular mechanisms underlying this process remain unclear. The aim of the present study was to determine the histomorphometry, proliferation, apoptosis, and autophagy alterations in spermatogonia and Sertoli cells in unilateral cryptorchid, scrotal (contrascrotal), and preweaning piglet (preweaning) testes. Histomorphometrical analysis of cryptorchid testes showed that the seminiferous tubules contained only Sertoli cells and a few spermatogonia, but did not contain post-meiotic germ cells. The number of spermatogonia markedly decreased, and the number of Sertoli cells did not change remarkably in cryptorchid testes. TUNEL assay results showed that apoptosis signals were predominantly observed in spermatogonia. In cryptorchid and contrascrotal testes, proliferating cell nuclear antigen (PCNA) and LC3 were located in spermatogonia. The number of PCNA-positive, TUNEL-positive, and LC3-positive germ cells was low, and the protein and mRNA levels of PCNA and LC3 were significantly decreased in cryptorchid testes. Taken together, the number of Sertoli cells did not change remarkably, whereas the number of germ cells decreased in the cryptorchid testes, compared with that in the contrascrotal testes. Insufficient proliferation, excessive apoptosis, and autophagy were involved in the regulation of the decrease in spermatogonia in cryptorchid boar testes.


2009 ◽  
Vol 44 (2) ◽  
pp. 87-97 ◽  
Author(s):  
Chung Thong Lim ◽  
Blerina Kola ◽  
Márta Korbonits

AMP-activated protein kinase (AMPK) is a key molecular player in energy homeostasis at both cellular and whole-body levels. AMPK has been shown to mediate the metabolic effects of hormones such as leptin, ghrelin, adiponectin, glucocorticoids and insulin as well as cannabinoids. Generally, activated AMPK stimulates catabolic pathways (glycolysis, fatty acid oxidation and mitochondrial biogenesis) and inhibits anabolic pathways (gluconeogenesis, glycogen, fatty acid and protein synthesis), and has a direct appetite-regulating effect in the hypothalamus. Drugs that activate AMPK, namely metformin and thiazolidinediones, are often used to treat metabolic disorders. Thus, AMPK is now recognised as a potential target for the treatment of obesity and associated co-morbidities.


Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1759-1766 ◽  
Author(s):  
K. Yomogida ◽  
H. Ohtani ◽  
H. Harigae ◽  
E. Ito ◽  
Y. Nishimune ◽  
...  

GATA-1 is an essential factor for the transcriptional activation of erythroid-specific genes, and is also abundantly expressed in a discrete subset of cells bordering the seminiferous epithelium in tubules of the murine testis. In examining normal and germ-line defective mutant mice, we show here that GATA-1 is expressed only in the Sertoli cell lineage in mouse testis. GATA-1 expression in Sertoli cells is induced concomitantly with the first wave of spermatogenesis, and GATA-1-positive cells are uniformly distributed among all tubules during prepubertal testis development. However, the number of GATA-1-positive cells declines thereafter and were found only in the peripheral zone of seminiferous tubules in stages VII, VIII and IX of spermatogenesis in the adult mouse testis. In contrast, virtually every Sertoli cell in mutant W/Wv, jsd/jsd or cryptorchid mice (all of which lack significant numbers of germ cells) expresses GATA-1, thus showing that the expression of this transcription factor is negatively controlled by the maturing germ cells. These observations suggest that transcription factor GATA-1 is a developmental stage- and spermatogenic cycle-specific regulator of gene expression in Sertoli cells.


Development ◽  
1996 ◽  
Vol 122 (6) ◽  
pp. 1703-1709 ◽  
Author(s):  
T. Furuchi ◽  
K. Masuko ◽  
Y. Nishimune ◽  
M. Obinata ◽  
Y. Matsui

During normal spermatogenesis, more than half of the germ cells undergo apoptosis, but the physiological significance and molecular mechanisms of this programmed cell death are largely unknown. Because Bcl-2 functions as a death repressor, we have investigated the effect of misexpressing Bcl-2 in spermatogonia in transgenic mice using the human bcl-2 cDNA under the control of the human polypeptide chain elongation factor 1alpha (EF-1alpha) promoter. In the 2-week-old transgenic testes, exogenous Bcl-2 was expressed in spermatogonia and massive accumulation of spermatogonia was observed in seminiferous tubules by 4 weeks. At this time, only a few spermatocytes were apparent, and the accumulated cells degenerated, leading to vacuolization in some seminiferous tubules by 7 weeks. In older transgenic mice, abnormal accumulation of spermatogonia and degeneration of these germ cells was still observed, but some seminiferous tubules in which the level of Bcl-2 expression was reduced recovered normal spermatogenesis. These observations indicate that spermatogonial apoptosis is part of the normal program of mammalian spermatogenesis and is regulated by a pathway affected by Bcl-2.


2000 ◽  
Vol 279 (4) ◽  
pp. H1490-H1501 ◽  
Author(s):  
Gary W. Goodwin ◽  
Heinrich Taegtmeyer ◽  

We postulate that metabolic conditions that develop systemically during exercise (high blood lactate and high nonesterified fatty acids) are favorable for energy homeostasis of the heart during contractile stimulation. We used working rat hearts perfused at physiological workload and levels of the major energy substrates and compared the metabolic and contractile responses to an acute low-to-high work transition under resting versus exercising systemic metabolic conditions (low vs. high lactate and nonesterified fatty acids in the perfusate). Glycogen preservation, resulting from better maintenance of high-energy phosphates, was a consequence of improved energy homeostasis with high fat and lactate. We explained the result by tighter coupling between workload and total β-oxidation. Total fatty acid oxidation with high fat and lactate reflected increased availability of exogenous and endogenous fats for respiration, as evidenced by increased long-chain fatty acyl-CoA esters (LCFA-CoAs) and by an increased contribution of triglycerides to total β-oxidation. Triglyceride turnover (synthesis and degradation) also appeared to increase. Elevated LCFA-CoAs caused high total β-oxidation despite increased malonyl-CoA. The resulting bottleneck at mitochondrial uptake of LCFA-CoAs stimulated triglyceride synthesis. Our results suggest the following. First, both malonyl-CoA and LCFA-CoAs determine total fatty acid oxidation in heart. Second, concomitant stimulation of peripheral glycolysis and lipolysis should improve cardiac energy homeostasis during exercise. We speculate that high lactate contributes to the salutary effect by bypassing the glycolytic block imposed by fatty acids, acting as an anaplerotic substrate necessary for high tricarbocylic acid cycle flux from fatty acid-derived acetyl-CoA.


1996 ◽  
Vol 315 (2) ◽  
pp. 555-562 ◽  
Author(s):  
Fatima DJOUADI ◽  
Jean BASTIN ◽  
Daniel P. KELLY ◽  
Claudie MERLET-BENICHOU

Mitochondrial fatty acid β-oxidation plays a major role in providing the ATP required for reabsorptive processes in the adult rat kidney. However, the molecular mechanisms and signals involved in induction of the enzymes of fatty acid oxidation during development in this and other organs are unknown. We therefore studied the changes in the steady-state levels of mRNA encoding medium-chain acyl-CoA dehydrogenase (MCAD), which catalyses the initial step in mitochondrial fatty acid β-oxidation, in the rat kidney cortex and medulla between postnatal days 10 and 30. Furthermore, we investigated whether the expression of MCAD and of mitochondrial malate dehydrogenase (mMDH), a key enzyme in the tricarboxylic acid cycle, might be co-ordinately regulated by circulating glucocorticoids in the immature kidney during development. In the cortex, the levels of MCAD mRNA rose 4-fold between day 10 and day 21, and then decreased from day 21 to day 30. In the medulla a postnatal increase in the concentration of MCAD mRNA (8-fold) was observed during the same period. Adrenalectomy prevented the 16–21-day developmental increases in MCAD and mMDH mRNA levels in the cortex and medulla; these could be restored by dexamethasone treatment. A single injection of dexamethasone into 10-day-old rats led to a rise in MCAD and mMDH mRNA levels in the renal cortex due to stimulation of gene transcription, as shown by nuclear run-on assays. Therefore MCAD and mMDH gene expression is tightly regulated at the transcriptional level by developmental changes in circulating glucocorticoid levels. These hormones might thus represent a good candidate as a co-ordinating factor in the expression of nuclear genes encoding mitochondrial enzymes in the kidney during postnatal development.


Author(s):  
Katie L Bidne ◽  
Alana L Rister ◽  
Andrea R McCain ◽  
Brianna D Hitt ◽  
Eric D Dodds ◽  
...  

Abstract Dyslipidemia is a characteristic of maternal obesity and previous studies have demonstrated abnormalities in fatty acid oxidation and storage in term placentas. However, there is little information about the effect of pre-pregnancy obesity on placental lipid metabolism during early pregnancy. The objective of this study was to determine the relationship between lipid profiles and markers of metabolism in placentas from obese and lean dams at midgestation. Mice were fed a western diet (WD) or normal diet (ND) and lysophosphatidylcholines (LPCs) and/or phosphatidylcholines (PCs) were measured in dam circulation and placenta sections using liquid chromatography–tandem mass spectrometry and mass spectrometry imaging, respectively. In WD dam, circulating LPCs containing 16:1, 18:1, 20:0, and 20:3 fatty acids were increased and 18:2 and 20:4 were decreased. In WD placenta from both sexes, LPC 18:1 and PC 36:1 and 38:3 were increased. Furthermore, there were moderate to strong correlations between LPC 18:1, PC 36:1, and PC 38:3. Treatment-, spatial-, and sex-dependent differences in LPC 20:1 and 20:3 were also detected. To identify genes that may regulate diet-dependent differences in placenta lipid profiles, the expression of genes associated with lipid metabolism and nutrient transport was measured in whole placenta and isolated labyrinth using droplet digital PCR and Nanostring nCounter assays. Several apolipoproteins were increased in WD placentas. However, no differences in nutrient transport or fatty acid metabolism were detected. Together, these data indicate that lipid storage is increased in midgestation WD placentas, which may lead to lipotoxicity, altered lipid metabolism and transport to the fetus later in gestation.


2016 ◽  
Vol 311 (1) ◽  
pp. H64-H75 ◽  
Author(s):  
Junqin Chen ◽  
Martin E. Young ◽  
John C. Chatham ◽  
David K. Crossman ◽  
Louis J. Dell'Italia ◽  
...  

Myocardial fatty acid β-oxidation is critical for the maintenance of energy homeostasis and contractile function in the heart, but its regulation is still not fully understood. While thioredoxin-interacting protein (TXNIP) has recently been implicated in cardiac metabolism and mitochondrial function, its effects on β-oxidation have remained unexplored. Using a new cardiomyocyte-specific TXNIP knockout mouse and working heart perfusion studies, as well as loss- and gain-of-function experiments in rat H9C2 and human AC16 cardiomyocytes, we discovered that TXNIP deficiency promotes myocardial β-oxidation via signaling through a specific microRNA, miR-33a. TXNIP deficiency leads to increased binding of nuclear factor Y (NFYA) to the sterol regulatory element binding protein 2 (SREBP2) promoter, resulting in transcriptional inhibition of SREBP2 and its intronic miR-33a. This allows for increased translation of the miR-33a target genes and β-oxidation-promoting enzymes, carnitine octanoyl transferase (CROT), carnitine palmitoyl transferase 1 (CPT1), hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase-β (HADHB), and AMPKα and is associated with an increase in phospho-AMPKα and phosphorylation/inactivation of acetyl-CoA-carboxylase. Thus, we have identified a novel TXNIP-NFYA-SREBP2/miR-33a-AMPKα/CROT/CPT1/HADHB pathway that is conserved in mouse, rat, and human cardiomyocytes and regulates myocardial β-oxidation.


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