The paper with the title “Hemoglobin: A Gas-Transport Molecule That Is Hormonally Regulated in the Ovarian Follicle in Mice and Humans” has been researched and written by researchers from University of Adelaide, Australia. Some of the important points related to this paper have been presented under the questions.
Introduction and Background:
Hypothesis of the paper
Researchers hypothesized and explored the temporal variations of hemoglobin expression and the genes controlling heme biosynthesis. They have also hypothesized that the possible function of hemoglobin is oxygen transport during in vitro maturation under low oxygen incubation conditions and tested it.
Why authors worked on this experiment?
Initially researchers found Hbb and Hba-a1 mRNA as well as protein at elevated levels within peri-ovulatory cumulus cells of the mouse. These were not found in cumulus after maturation. This causes them to work on the spatial and temporal regulation of hemoglobin in follicular cells at the time of the peri-ovulatory stage.
New methods to work on the problem
Researchers have used already established techniques or methods in this research.
Methods used in the study
Methods in the paper include the taking of tissue samples. Different reagents, antibodies, and hormones were used in the media. Ferro-hemoglobin or ferri-hemoglobin was put in to maturation media. Embryo was allowed to develop and its maturation took place. Ovaries of the female mice were checked. Ovary sections were studied with the help of immunohistochemistry and Real Time PCR techniques.
Use of enabling technologies
In vitro maturation of Granulosa Cell and Cumulus-Oocyte Complex, in vitro fertilization, Immunohistochemistry, and Real Time PCR techniques have been used in this research.
Weaknesses of the method
It was unable to explore the function of hemoglobin in different tissues.
Some other approaches
Hemoglobin electrophoresis can be combined along with other techniques and methods in this research for the better measurement and identification of different types of hemoglobin.
Genetics approach or not
This is a genetics approach in that Gene primers for Real Time RT-PCR were designed from published mRNA sequences from the NCBI Pubmed Database using Primer Express software.
Biochemical or molecular approach or not
It is also a biochemical or molecular approach in that various types of reagents, antibodies, and hormones were used for the study media and research.
Results and Discussion
Primary outcomes of the paper
Hemoglobin transcript and protein are present within both mouse and human cumulus and granulosa cells, and show potent endocrine control.
Hypothesis proved or not
Researchers have reported the potential role of hemoglobin in providing little hypoxic environment by attaching very strongly with any available oxygen.
Novel information from the work
Researchers have shown for the first time that ovarian hormonal regulation of hemoglobin and heme production happens, particularly by the ovulatory signal cascade. They are also the first one to examine the supplementation of HB during in vitro maturation, based on the observations that IVM-derived oocytes lacked cytoplasmic HB, unlike their in vivo counterparts. Researchers have also shown that prior to the ovulatory surge, small level of Hypoxia Inducible Factor (HIF) activity is observed in antral follicles. However, HIF is significantly increased after the LH surge, and is considered to have an important role in signaling luteinization.
Control experiments in the research
Control medium was used for IVM of hemoglobin and compare it with hemoglobin localization in the cumulus oocyte complexes derived in vivo.
Assumptions still unclear or remain at work
The identification of hemoglobin within granulosa and cumulus cells needs further work as it raises many questions about its function in these cells. Moreover, the function of HB within HB-producing tissues in the brain, kidney, lungs, female reproductive system, and cancer cells is still unclear.
Testing of those assumptions
Main purpose of hemoglobin is to get and take oxygen. It can attach with oxygen. We can work on the amount of oxygen that binds to hemoglobin in these tissues. This can be referred to as partial pressure of oxygen (pO2) in the hemoglobin solution.
Other explanations from the study
Research has shown that there are an increasing number of reports about the regulatory role of hemoglobin in different tissues. This shows that the role of hemoglobin in different tissues especially in the reproductive organs could become an emerging research concept in the coming times.