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Comment |
HO-1 reduces heat stress-induced apoptosis in bovine granulosa cells by suppressing oxidative stress. Wang Y et al. (2020) Heat stress negatively affects reproduction in cattle by disrupting the normal function of ovarian granulosa cells (GCs), ultimately leading to oxidative damage and cell death via apoptosis. Heme oxygenase-1(HO-1) is a member of the heat shock protein family, which are associated with cellular antioxidant defenses and anti-apoptotic functions. Recent studies demonstrated that HO-1 is upregulated in heat-stressed cells. In the present study, we investigated the expression of HO-1 in bovine GCs transiently exposed to heat stress and characterized the expression and activity of key oxidative stress enzymes and molecules. We show that heat stress induced oxidative stress and apoptosis, and enhanced Nrf2 and HO-1 expression in primary GC cultures. Knocking down HO-1 expression using siRNA exacerbated both oxidative stress and apoptosis, whereas pre-treating GCs with hemin, which induces HO-1 expression, partially prevented these effects. These findings demonstrate that HO-1 attenuates heat stress-induced apoptosis in bovine GCs by decreasing production of reactive oxygen species and activating the antioxidant response.////////////////// of HO-1 Attenuates LPS-Stimulated Proinflammatory Responses Through Downregulation of p38 Signaling Pathways in Rat Ovary. Li L et al. (2014) Heme oxygenase-1 (HO-1) plays a key role in the regulation of the inflammatory response. However, the specific mechanism underlying the anti-inflammatory role of HO-1 in the reproductive system is unclear. The aim of this study was to evaluate the role of the mechanism of HO-1 in the regulation of the inflammatory response stimulated by lipopolysaccharide (LPS) in rat ovary. LPS-stimulated inflammatory models were established. Rats were pretreated with HO-1 activator (hemin) or inhibitor (ZnPP) before LPS stimulation, and we evaluated the expression of HO-1 by real-time PCR and Western blot. The messenger RNA (mRNA) expression and secretion of IL-1β and IL-6 in rat ovary were analyzed using real-time PCR and ELISA. In addition, we also analyzed the p38 and p-p38 protein expression in the ovary. Our results demonstrate that HO-1 is an anti-inflammatory factor in LPS-stimulated ovary, which regulates the inflammatory response through downregulation of p38 signaling pathways in rat ovary.//////////////////
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Comment |
Inducible Nitric Oxide Synthase and Heme Oxygenase 1 Are Expressed in Human Cumulus Cells and May Be Used as Biomarkers of Oocyte Competence. Loredana B 2014 et al.
The interplay between oocyte and surrounding cumulus cells (CCs) during follicular growth influences oocyte competence to undergo fertilization and sustain embryo development. The expression of many genes and proteins in CCs has been suggested as potential biomarker of oocyte competence in human in vitro fertilization (IVF). In the present study, we analyzed 90 human cumulus-oocyte complexes obtained during IVF procedure: 30 CCs were analyzed using quantitative real-time polymerase chain reaction and 60 CCs using Western blotting analysis to detect gene and protein expression of some enzymes related to oxidative stress, that is, the 3 nitric oxide synthase (NOS) isoforms and heme oxygenase 1 (HO-1). In the group of 60 CCs, we also investigated the expression and phosphorylation of IkBa, a known inhibitor of the nuclear factor ?B (NF-?B) pathway, which controls several redox-sensitive genes. The expression of the messenger RNAs (mRNAs) was related to the oocyte morphological analysis performed by polarized light microscopy and to the occurrence of normal fertilization after intracytoplasmic sperm injection. We observed that the amount of iNOS and HO-1 mRNAs and proteins is significantly higher, and that in the meanwhile the NF-?B pathway is activated, in CCs corresponding to oocytes that were not fertilized in comparison to CCs whose corresponding oocyte showed normal fertilization. Instead, no correlation between the fertilization and the oocytes' morphological data was observed. These results suggest that the increase in iNOS and HO-1 mRNAs expression in CCs is a negative index of oocyte fertilizability and might be an useful tool for oocyte selection.
/////////////////////////Differences in embryo quality are associated with differences in oocyte composition: A proteomic study in inbred mice. Pfeiffer MJ et al. (2015) Current models of early mouse development assign roles to stochastic processes and epigenetic regulation, which are considered to be as influential as the genetic differences that exist between strains of the species Mus musculus. The aim of this study was to test whether mouse oocytes vary from each other in the abundance of gene products that could influence, prime, or even predetermine developmental trajectories and features of derivative embryos. Using the paradigm of inbred mouse strains, we quantified 2010 protein groups (SILAC LC-MS/MS) and 15205 transcripts (RNA deep sequencing) present simultaneously in oocytes of four strains tested (129/Sv, C57Bl/6J, C3H/HeN, DBA/2J). Oocytes differed according to donor strain in the abundance of catalytic and regulatory proteins, as confirmed for a subset (bromodomain adjacent to zinc finger domain, 1B [BAZ1B], heme oxygenase 1 [HMOX1], estrogen related receptor, beta [ESRRB]) via immunofluorescence in situ. Given a Pearson's r correlation coefficient of 0.18-0.20, the abundance of oocytic proteins could not be predicted from that of cognate mRNAs. Our results document that a prerequisite to generate embryo diversity, namely the different abundances of maternal proteins in oocytes, can be studied in the model of inbred mouse strains. Thus, we highlight the importance of proteomic quantifications in modern embryology. All MS data have been deposited in the ProteomeXchange with identifier PXD001059 (http://proteomecentral.proteomexchange.org/dataset/PXD001059).//////////////////
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Mutations |
2 mutations
Species: mouse
Mutation name: None
type: null mutation
fertility: subfertile
Comment: Heme Oxygenase-1 Expression in the Ovary Dictates a Proper Oocyte Ovulation, Fertilization, and Corpora Lutea Maintenance. Zenclussen ML et al. Citation Zenclussen ML, Jensen F, Rebelo S, El-Mousleh T, Casalis PA, Zenclussen AC. Heme oxygenase-1 expression in the ovary dictates a proper oocyte ovulation, fertilization, and corpora lutea maintenance. Am J Reprod Immunol 2011 Problem Animals deficient in Heme oxygenase-1 (HO-1, Hmox1(-/-) mice) have impaired pregnancies, characterized by intrauterine fetal death. HO-1 expression has been shown to be essential for pregnancy by dictating placentation and intrauterine fetal development. Its absence leads to intrauterine fetal growth restriction and fetal loss, which is independent of the immune system. Defect in previous steps, e.g., ovulation, may, however, also count for their poor reproductive outcome. Method of study Here, we investigated ovulation after hormonal hyperstimulation in Hmox1 wild-type and knockout animals. Results and Conclusions We observed that animals lacking HO-1 produced significantly less oocytes after hormonal stimulation than wild type animals and this was mirrored by the number of corpora lutea in the ovary. Furthermore, ovulated oocytes from Hmox1(-/-) animals were poorly fertilized compared with those from wild-type animals. In conclusion, we demonstrate here that HO-1 plays a pivotal role in the process of oocyte ovulation as well as fertilization, bringing to light a new and unsuspected role for HO-1.
Species: human
Mutation name: None
type: naturally occurring
fertility: subfertile
Comment: Association of heme oxygenase-1 with the risk of polycystic ovary syndrome in non-obese women. Gao H 2014 et al.
STUDY QUESTION
Is circulating heme oxygenase-1 (HO-1) associated with the risk of polycystic ovary syndrome (PCOS)?
SUMMARY ANSWER
Lower circulating HO-1 is associated with a higher risk of PCOS in non-obese women, in a dose-related manner.
WHAT IS KNOWN ALREADY
PCOS is one of the most common endocrine disorders in women of reproductive age, with increasing worldwide incidence. HO-1 plays a crucial role in many physiological systems, with potent anti-inflammatory, antioxidant and antimetabolic properties.
STUDY DESIGN, SIZE, DURATION
This hospital-based case-control study included 80 women with PCOS and 80 healthy control women seen at the Reproductive Center of Tongji Hospital (Wuhan, China) from November 2011 to May 2012. Cases and controls were frequency-matched on age and BMI and were enrolled into the study once written informed consent had been obtained.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Serum hormones, glucose, insulin and lipid concentrations were measured using an automated platform. Correlation coefficients and multiple linear regression models were calculated in the combined group (both cases and controls) using serum HO-1 concentration as the independent variable and age and BMI as covariate variables to explore the association between HO-1 and the pathophysiology of PCOS. To examine the independent association of serum HO-1 levels with the likelihood of PCOS, multivariate logistic analysis was used. The strength of the association was tested further by receiver-operating characteristic (ROC) curve models, with or without the addition of HO-1.
MAIN RESULTS AND THE ROLE OF CHANCE
Compared with controls, women with PCOS were found to have significantly increased insulin resistance (IR), oxidative stress (OS) and inflammation levels, creating a vicious circle of effects in the pathophysiology of PCOS. However, serum HO-1 was negatively associated with this vicious circle. Women with the highest tertile of HO-1 (=5.29 ng/ml) had an odds ratio (OR) of PCOS of 0.02 (95% CI 0.0034-0.07) compared with women with the lowest quartile (<3.14 ng/ml) (P < 0.01). This trend remained after adjustment for potential confounders in the multivariable model (all P < 0.01). ROC analysis based on an existing prognostic model yielded significantly discriminative values for PCOS, with or without the addition of HO-1 (areas under the curves were 0.86 (95% CI 0.81-0.92) versus 0.95 (95% CI 0.92-0.98); P for difference = 0.0005).
LIMITATIONS, REASONS FOR CAUTION
It is difficult to establish a time-integrated measure of circulating HO-1 during the progression of PCOS and these findings should be confirmed in large-scale studies involving different ethnic groups. Moreover, the study lacks measurements of glycated hemoglobin (HbA1c) to provide an index of blood glucose concentrations over time.
WIDER IMPLICATIONS OF THE FINDINGS
Circulating HO-1 that provides protection against IR, OS and chronic inflammation is markedly reduced in non-obese women with PCOS. Low serum HO-1 is suggested as an independent risk factor for PCOS; thus, circulating HO-1 levels may be a novel biomarker for PCOS in young, non-obese women.
STUDY FUNDING/COMPETING INTEREST(S)
This work was supported by grants from the National Natural Science Foundation of China (81202210) and the National Science and Technology Support Program of China (2012BAI02B02). None of the authors has any conflict of interest to declare.
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