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Frontiers in Nutrition 2022Wheat germ, a byproduct of wheat industrial processing, contains 30% protein and is a comprehensive source of plant-based protein. But a large amount of wheat germs are... (Review)
Review
Wheat germ, a byproduct of wheat industrial processing, contains 30% protein and is a comprehensive source of plant-based protein. But a large amount of wheat germs are disposed of as waste every year. Wheat germ protein can be hydrolyzed into polypeptides with antioxidant, antihypertensive, anti-tumor, bacteriostatic and other activities. At present, researches on the hydrolysis of wheat germ protein and the preparation of bioactive peptides from wheat germ protein have attracted increasing attentions. However, the traditional protein hydrolysis method, protease hydrolysis, can no longer meet the market's needs for efficient production. Various auxiliary means, such as ultrasound, microwave and membrane separation, were applied to boost the yield and biological activity of wheat germ peptides by enzymatic hydrolysis. Under ultrasound and microwave, the protein structure may expand to increase the binding sites between enzyme and substrate and promote hydrolysis efficiency. Membrane separation is applied to separate products from enzymatic hydrolysate to reduce the inhibitory effect of the product on the hydrolysis reaction. The paper reviewed the hydrolysis methods of wheat germ protein and summarized the biological activity of wheat germ peptides to provide references for further study of wheat germ peptides.
PubMed: 35923206
DOI: 10.3389/fnut.2022.943950 -
BMJ Clinical Evidence Jan 2016More than half of painless solid swellings of the body of the testis are malignant, with a peak incidence in men aged 30 to 34 years. Most testicular cancers are germ... (Review)
Review
INTRODUCTION
More than half of painless solid swellings of the body of the testis are malignant, with a peak incidence in men aged 30 to 34 years. Most testicular cancers are germ cell tumours and half of these are seminomas, which tend to affect older men and have a good prognosis.
METHODS AND OUTCOMES
We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of treatments following orchidectomy in men diagnosed with stage 1 germ cell tumours (confined to testis)? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview).
RESULTS
At this update, 76 records were screened for inclusion. Appraisal of titles and abstracts led to the exclusion of 47 studies and the further review of 29 full publications. Of the 29 full articles evaluated, two systematic reviews and one RCT, were added at this update. Data from long-term follow-up of an already reported study were also added. We performed a GRADE evaluation for seven PICO combinations.
CONCLUSIONS
In this systematic overview, we categorised the efficacy for seven interventions based on information about the effectiveness and safety of adjuvant chemotherapy (including different drugs and the number of cycles), adjuvant radiotherapy (including different regimens), adjuvant surgery, and surveillance/observation.
Topics: Chemotherapy, Adjuvant; Humans; Male; Neoplasms, Germ Cell and Embryonal; Radiotherapy, Adjuvant; Testicular Neoplasms
PubMed: 26741128
DOI: No ID Found -
Frontiers in Cell and Developmental... 2021Germ cell acts as a link between transfer of genetic information and process of species evolution. Defects or malformations of germ cells can lead to infertility or... (Review)
Review
Germ cell acts as a link between transfer of genetic information and process of species evolution. Defects or malformations of germ cells can lead to infertility or tumors. Germ cell regeneration is one of the effective ways to treat the infertility. Therefore, it is of great scientific and clinical interests to dissect the cellular and molecular mechanisms underlying germ cell regeneration. Progress have already been achieved in germ cell regeneration using model organisms for decades. However, key open issues regarding the underpinning mechanisms still remain poorly understood. Zebrafish is well known for its powerful regenerative capacity to regenerate various tissues and organs. Recently, advances in genomics, genetics, microscopy, and single cell technologies have made zebrafish an attractive model to study germ cell development and regeneration. Here we review recent technologies for the study of germ cell regeneration in zebrafish, highlight the potential of germline stem cells (GSCs) in the contribution to reproductive system regeneration, and discuss the . Wnt signaling and germ cell-specific factors involved in the regulation of germ cell regeneration.
PubMed: 34368134
DOI: 10.3389/fcell.2021.685001 -
Stem Cell Research Oct 2017Germ cells have been considered "the ultimate stem cell" because they alone, during normal development of sexually reproducing organisms, are able to give rise to all... (Review)
Review
Germ cells have been considered "the ultimate stem cell" because they alone, during normal development of sexually reproducing organisms, are able to give rise to all organismal cell types. Morphological descriptions of a specialized cytoplasm termed 'germ plasm' and associated electron dense ribonucleoprotein (RNP) structures called 'germ granules' within germ cells date back as early as the 1800s. Both germ plasm and germ granules are implicated in germ line specification across metazoans. However, at a molecular level, little is currently understood about the molecular mechanisms that assemble these entities in germ cells. The discovery that in some animals, the gene products of a small number of lineage-specific genes initiate the assembly (also termed nucleation) of germ granules and/or germ plasm is the first step towards facilitating a better understanding of these complex biological processes. Here, we draw on research spanning over 100years that supports the hypothesis that these nucleator genes may have evolved convergently, allowing them to perform analogous roles across animal lineages.
Topics: Animals; Biological Evolution; Genes, Developmental; Germ Cells; Models, Biological; Phylogeny
PubMed: 28801028
DOI: 10.1016/j.scr.2017.07.018 -
Genesis (New York, N.Y. : 2000) May 2014This review summarizes and integrates our current understanding of how sea stars make gametes. Although little is known of the mechanism of germ line formation in these... (Review)
Review
This review summarizes and integrates our current understanding of how sea stars make gametes. Although little is known of the mechanism of germ line formation in these animals, recent results point to specific cells and to cohorts of molecules in the embryos and larvae that may lay the ground work for future research efforts. A coelomic outpocketing forms in the posterior of the gut in larvae, referred to as the posterior enterocoel (PE), that when removed, significantly reduces the number of germ cell later in larval growth. This same PE structure also selectively accumulates several germ-line associated factors-vasa, nanos, piwi-and excludes factors involved in somatic cell fate. Since its formation is relatively late in development, these germ cells may form by inductive mechanisms. When integrated into the morphological observations of germ cells and gonad development in larvae, juveniles, and adults, the field of germ line determination appears to have a good model system to study inductive germ line determination to complement the recent work on the molecular mechanisms in mice. We hope this review will also guide investigators interested in germ line determination and regulation of the germ line into how these animals can help in this research field. The review is not intended to be comprehensive-sea star reproduction has been studied for over 100 years and many reviews are comprehensive in their coverage of, for example, seasonal growth of the gonads in response to light, nutrient, and temperature. Rather the intent of this review is to help the reader focus on new experimental results attached to the historical underpinnings of how the germ cell functions in sea stars with particular emphasis to clarify the important areas of priority for future research.
Topics: Animals; Cell Differentiation; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Germ Cells; Gonads; Regeneration; Starfish
PubMed: 24648114
DOI: 10.1002/dvg.22772 -
Sexual Development : Genetics,... 2022The germ cell lineage involves dynamic epigenetic changes during its formation and differentiation that are completely different from those of the somatic cell lineage.... (Review)
Review
BACKGROUND
The germ cell lineage involves dynamic epigenetic changes during its formation and differentiation that are completely different from those of the somatic cell lineage. Metabolites and metabolic pathways have been reported as key factors related to the regulation of epigenetics as cofactors and substrates. However, our knowledge about the metabolic characteristics of germ cells, especially during the fetal stage, and their transition during differentiation is quite limited due to the rarity of the cells. Nevertheless, recent developments in omics technologies have made it possible to extract comprehensive metabolomic features of germ cells.
SUMMARY
In this review, we present the latest researches on the metabolic properties of germ cells in 4 stages: primordial germ cell specification, fetal germ cell differentiation, spermatogenesis, and oogenesis. At every stage, extensive published data has been accumulated on energy metabolism, and it is possible to describe its changes during germ cell differentiation in detail. As pluripotent stem cells differentiate into germ cells, energy metabolism shifts from glycolysis to oxidative phosphorylation; however, in spermatogenesis, glycolytic pathways are also temporarily dominant in spermatogonial stem cells. Although the significance of metabolic pathways other than energy metabolism in germ cell differentiation is largely unknown, the relation of the pentose phosphate pathway and Ser-Gly-one-carbon metabolism with germ cell properties has been suggested at various stages. We further discuss the relationship between these characteristic metabolic pathways and epigenetic regulation during germ cell specification and differentiation. Finally, the relevance of dietary and supplemental interventions on germ cell function and epigenomic regulation is also discussed.
KEY MESSAGES
Comprehensive elucidation of metabolic features and metabolism-epigenome crosstalk in germ cells is important to reveal how the characteristic metabolic pathways are involved in the germ cell regulation. The accumulation of such insights would lead to suggestions for optimal diets and supplements to maintain reproductive health through modulating metabolic and epigenetic status of germ cells.
PubMed: 35086109
DOI: 10.1159/000520662 -
IUBMB Life Jul 2012Germ granules are an evolutionarily conserved feature of germ cell cytoplasm and are critical for gametogenesis and embryonic development. Germ granules are highly... (Review)
Review
Germ granules are an evolutionarily conserved feature of germ cell cytoplasm and are critical for gametogenesis and embryonic development. Germ granules are highly enriched for RNA and RNA-binding proteins and are key centers for post-transcriptional gene regulation in germ cells. Over the last 20 years, the molecular events in germ granule function and formation in several organisms have begun to be revealed. This review seeks to give an overview of some conserved features of germ granules and highlights a conserved strategy for regulating translation of maternal mRNAs.
Topics: Animals; Caenorhabditis elegans; Drosophila; Gametogenesis; Germ Cells; Humans; Models, Biological; Phenotype; Protein Biosynthesis; Protein Processing, Post-Translational; RNA; RNA, Messenger; RNA-Binding Proteins; Xenopus laevis
PubMed: 22639345
DOI: 10.1002/iub.1039 -
Stem Cells International 2021Germ cells are capable of maintaining species continuity through passing genetic and epigenetic information across generations. Female germ cells mainly develop during... (Review)
Review
Germ cells are capable of maintaining species continuity through passing genetic and epigenetic information across generations. Female germ cells mainly develop during the embryonic stage and pass through subsequent developmental stages including primordial germ cells, oogonia, and oocyte. However, due to the limitation of using early human embryos as research model, research models are needed to reveal the early developmental process and related mechanisms of female germ cells. After birth, the number of follicles gradually decreases with age. Various conditions which damage ovarian functions would cause premature ovarian failure. Alternative treatments to solve these problems need to be investigated. Germ cell differentiation from pluripotent stem cells can simulate early embryonic development of female germ cells and clarify unresolved issues during the development process. In addition, pluripotent stem cells could potentially provide promising applications for female fertility preservation after proper differentiation. Mouse female germ cells have been successfully reconstructed and delivered to live offspring. However, the derivation of functional human female germ cells has not been fully achieved due to technical limitations and ethical issues. To provide an updated and comprehensive information, this review centers on the major studies on the differentiation of mouse and human female germ cells from pluripotent stem cells and provides references to further studies of developmental mechanisms and potential therapeutic applications of female germ cells.
PubMed: 33510796
DOI: 10.1155/2021/8849230 -
International Journal of Molecular... Feb 2021In the present era, infertility is one of the major issues which restricts many couples to have their own children. Infertility is the inability to achieve a clinical... (Review)
Review
In the present era, infertility is one of the major issues which restricts many couples to have their own children. Infertility is the inability to achieve a clinical pregnancy after regular unprotected sexual intercourse for the period of one year or more. Various factors including defective male or female germ cell development, unhealthy and improper lifestyles, diseases like cancer and associated chemo-or-radiation therapies, congenital disorders, etc., may be responsible for infertility. Therefore, it is highly important to understand the basic concepts of germ cell development including primordial germ cell (PGC) formation, specification, migration, entry to genital ridges and their molecular mechanisms, activated pathways, paracrine and autocrine signaling, along with possible alteration which can hamper germ cell development and can cause adversities like cancer progression and infertility. Knowing all these aspects in a proper way can be very much helpful in improving our understanding about gametogenesis and finding possible ways to cure related disorders. Here in this review, various aspects of gametogenesis especially female gametes and relevant factors causing functional impairment have been thoroughly discussed.
Topics: Animals; Carcinogenesis; Epigenesis, Genetic; Female; Germ Cells; Humans; Neoplasms, Germ Cell and Embryonal; Oocytes
PubMed: 33671303
DOI: 10.3390/ijms22041979 -
Andrology Jul 2019Germ cells have a unique and critical role as the conduit for hereditary information and therefore employ multiple strategies to protect genomic integrity and avoid... (Review)
Review
BACKGROUND
Germ cells have a unique and critical role as the conduit for hereditary information and therefore employ multiple strategies to protect genomic integrity and avoid mutations. Unlike somatic cells, which often respond to DNA damage by arresting the cell cycle and conducting DNA repair, germ cells as well as long-lived pluripotent stem cells typically avoid the use of error-prone repair mechanisms and favor apoptosis, reducing the risk of genetic alterations. Testicular germ cell tumors, the most common cancers of young men, arise from pre-natal germ cells.
OBJECTIVES
To summarize the current understanding of DNA damage response mechanisms in pre-meiotic germ cells and to discuss how they impact both the origins of testicular germ cell tumors and their remarkable responsiveness to genotoxic chemotherapy.
MATERIALS AND METHODS
We conducted a review of literature gathered from PubMed regarding the DNA damage response properties of testicular germ cell tumors and the germ cells from which they arise, as well as the influence of these mechanisms on therapeutic responses by testicular germ cell tumors.
RESULTS AND DISCUSSION
This review provides a comprehensive evaluation of how the developmental origins of male germ cells and their inherent germ cell-like DNA damage response directly impact the development and therapeutic sensitivity of testicular germ cell tumors.
CONCLUSIONS
The DNA damage response of germ cells directly impacts the development and therapeutic sensitivity of testicular germ cell tumors. Recent advances in the study of primordial germ cells, post-natal mitotically dividing germ cells, and pluripotent stem cells will allow for new investigations into the initiation, progression, and treatment of testicular germ cell tumors.
Topics: Animals; DNA Damage; Drug Resistance, Neoplasm; Embryonic Germ Cells; Humans; Neoplasms, Germ Cell and Embryonal; Testicular Neoplasms
PubMed: 31119900
DOI: 10.1111/andr.12651