-
International Journal of Molecular... Feb 2022Maturing male germ cells undergo a unique developmental process in spermiogenesis that replaces nucleosomal histones with protamines, the process of which is critical...
Maturing male germ cells undergo a unique developmental process in spermiogenesis that replaces nucleosomal histones with protamines, the process of which is critical for testicular development and male fertility. The progress of this exchange is regulated by complex mechanisms that are not well understood. Now, with mouse genetic models, we show that barrier-to-autointegration factor-like protein (BAF-L) plays an important role in spermiogenesis and spermatozoal function. BAF-L is a male germ cell marker, whose expression is highly associated with the maturation of male germ cells. The genetic deletion of BAF-L in mice impairs the progress of spermiogenesis and thus male fertility. This effect on male fertility is a consequence of the disturbed homeostasis of histones and protamines in maturing male germ cells, in which the interactions between BAF-L and histones/protamines are implicated. Finally, we show that reduced testicular expression of BAF-L represents a risk factor of human male infertility.
Topics: Animals; Biomarkers; Gene Expression Regulation, Developmental; Germ Cells; Histones; Humans; Infertility, Male; Intracellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nuclear Proteins; Protamines; Spermatids; Spermatogenesis; Testis
PubMed: 35216101
DOI: 10.3390/ijms23041985 -
Frontiers in Cell and Developmental... 2022Protamine is an arginine-rich peptide that replaces histones in the DNA-protein complex during spermatogenesis. Protamine is clinically used in cardiopulmonary bypass...
Protamine is an arginine-rich peptide that replaces histones in the DNA-protein complex during spermatogenesis. Protamine is clinically used in cardiopulmonary bypass surgery to neutralize the effects of heparin that is required during the treatment. Here we demonstrate that protamine and its 14-22 amino acid long fragments overcome the neurite outgrowth inhibition by chondroitin sulfate proteoglycans (CSPGs) that are generally regarded as major inhibitors of regenerative neurite growth after injuries of the adult central nervous system (CNS). Since the full-length protamine was found to have toxic effects on neuronal cells we used the neurite outgrowth assay to select a protamine fragment that retains the activity to overcome the neurite outgrowth inhibition on CSPG substrate and ended up in the 14 amino acid fragment, low-molecular weight protamine (LMWP). In contrast to the full-length protamine, LMWP displays very low or no toxicity in our assays and . We therefore started studies on LMWP as a possible drug lead in treatment of CNS injuries, such as the spinal cord injury (SCI). LMWP mimicks HB-GAM (heparin-binding growth-associated molecule; pleiotrophin) in that it overcomes the CSPG inhibition on neurite outgrowth in primary CNS neurons and inhibits binding of protein tyrosine phosphatase (PTP) sigma, an inhibitory receptor in neurite outgrowth, to its CSPG ligand. Furthermore, the chondroitin sulfate (CS) chains of the cell matrix even enhance the LMWP-induced neurite outgrowth on CSPG substrate. studies using the hemisection and hemicontusion SCI models in mice at the cervical level C5 revealed that LMWP enhances recovery when administered through intracerebroventricular or systemic route. We suggest that LMWP is a promising drug lead to develop therapies for CNS injuries.
PubMed: 35547817
DOI: 10.3389/fcell.2022.865275 -
Clinical Pharmacology : Advances and... 2023Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use... (Review)
Review
Messenger ribonucleic acid (mRNA) was found as the intermediary that transfers genetic information from DNA to ribosomes for protein synthesis in 1961. The emergency use authorization of the two covid-19 mRNA vaccines, BNT162b2 and mRNA-1273, is a significant achievement in the history of vaccine development. Because they are generated in a cell-free environment using the in vitro transcription (IVT) process, mRNA vaccines are risk-free. Moreover, chemical modifications to the mRNA molecule, such as cap structures and changed nucleosides, have proved critical in overcoming immunogenicity concerns, achieving sustained stability, and achieving effective, accurate protein production in vivo. Several vaccine delivery strategies (including protamine, lipid nanoparticles (LNPs), polymers, nanoemulsions, and cell-based administration) were also optimized to load and transport RNA into the cytosol. LNPs, which are composed of a cationic or a pH-dependent ionizable lipid layer, a polyethylene glycol (PEG) component, phospholipids, and cholesterol, are the most advanced systems for delivering mRNA vaccines. Moreover, modifications of the four components that make up the LNPs showed to increase vaccine effectiveness and reduce side effects. Furthermore, the introduction of biodegradable lipids improved LNP biocompatibility. Furthermore, mRNA-based therapies are expected to be effective treatments for a variety of refractory conditions, including infectious diseases, metabolic genetic diseases, cancer, cardiovascular and cerebrovascular diseases. Therefore, the present review aims to provide the scientific community with up-to-date information on mRNA vaccines and their delivery systems.
PubMed: 37554660
DOI: 10.2147/CPAA.S418314 -
Development (Cambridge, England) May 2023Unique chromatin remodeling factors orchestrate dramatic changes in nuclear morphology during differentiation of the mature sperm head. A crucial step in this process is...
Unique chromatin remodeling factors orchestrate dramatic changes in nuclear morphology during differentiation of the mature sperm head. A crucial step in this process is histone-to-protamine exchange, which must be executed correctly to avoid sperm DNA damage, embryonic lethality and male sterility. Here, we define an essential role for the histone methyltransferase DOT1L in the histone-to-protamine transition. We show that DOT1L is abundantly expressed in mouse meiotic and postmeiotic germ cells, and that methylation of histone H3 lysine 79 (H3K79), the modification catalyzed by DOT1L, is enriched in developing spermatids in the initial stages of histone replacement. Elongating spermatids lacking DOT1L fail to fully replace histones and exhibit aberrant protamine recruitment, resulting in deformed sperm heads and male sterility. Loss of DOT1L results in transcriptional dysregulation coinciding with the onset of histone replacement and affecting genes required for histone-to-protamine exchange. DOT1L also deposits H3K79me2 and promotes accumulation of elongating RNA Polymerase II at the testis-specific bromodomain gene Brdt. Together, our results indicate that DOT1L is an important mediator of transcription during spermatid differentiation and an indispensable regulator of male fertility.
Topics: Animals; Male; Mice; Cell Differentiation; Chromatin Assembly and Disassembly; Histone-Lysine N-Methyltransferase; Histones; Protamines; Semen; Spermatids
PubMed: 37082969
DOI: 10.1242/dev.201497 -
Frontiers in Cell and Developmental... 2023Protamines (PRM1 and PRM2) are small, arginine-rich, nuclear proteins that replace histones in the final stages of spermiogenesis, ensuring chromatin compaction and...
Protamines (PRM1 and PRM2) are small, arginine-rich, nuclear proteins that replace histones in the final stages of spermiogenesis, ensuring chromatin compaction and nuclear remodeling. Defects in protamination lead to increased DNA fragmentation and reduced male fertility. Since efficient sperm production requires the translocation of protamines from the cytoplasm to the nucleus, we investigated whether SPAG17, a protein crucial for intracellular protein trafficking during spermiogenesis, participates in protamine transport. Initially, we assessed the protein-protein interaction between SPAG17 and protamines using proximity ligation assays, revealing a significant interaction originating in the cytoplasm and persisting within the nucleus. Subsequently, immunoprecipitation and mass spectrometry (IP/MS) assays validated this initial observation. Sperm and spermatids from knockout mice exhibited abnormal protamination, as revealed by chromomycin A3 staining, suggesting defects in protamine content. However, no differences were observed in the expression of and mRNA or in protein levels between testes of wild-type and knockout mice. Conversely, immunofluorescence studies conducted on isolated mouse spermatids unveiled reduced nuclear/cytoplasm ratios of protamines in knockout spermatids compared to wild-type controls, implying transport defects of protamines into the spermatid nucleus. In alignment with these findings, experiments involving somatic cells, including mouse embryonic fibroblasts, exhibited compromised nuclear translocation of PRM1 and PRM2 in the absence of SPAG17. Collectively, our results present compelling evidence that SPAG17 facilitates the transport of protamines from the cytoplasm to the nucleus.
PubMed: 37766963
DOI: 10.3389/fcell.2023.1125096 -
Supportive Care in Cancer : Official... Oct 2022Cancer patients have an increased risk of bleeding compared to non-cancer patients with anticoagulant therapy. A bleeding risk assessment before initiation of...
Cancer patients have an increased risk of bleeding compared to non-cancer patients with anticoagulant therapy. A bleeding risk assessment before initiation of anticoagulation is recommended. Currently low molecular weight heparin (LMWH) and direct oral anticoagulants (DOACs) are the mainstays of treatment for cancer-associated venous thromboembolism (VTE). Since DOACs are administered orally, they offer some convenience and ease of administration; however, LMWH may be preferred in certain cancers. Given the prevalence of anticoagulant therapies in cancer patients, clinical providers must be able to recognize potentially critical bleeding sites and modalities to reverse major hemorrhage. Reversal agents or antidotes to bleeding may be required when bleeding is persistent or life-threatening. These include vitamin K, fresh frozen plasma (FFP), protamine, prothrombin complex concentrate (PCC) or andexanet alfa, and idarucizumab. Inferior vena cava (IVC) filter insertion can be also considered in those with major bleeding. Evidence for timing and need for re-initiation of anticoagulant therapy after a major bleeding remains sparse, but a multi-disciplinary approach and shared decision-making can be implemented in the interim.
Topics: Administration, Oral; Anticoagulants; Antidotes; Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Neoplasms; Protamines; Vitamin K
PubMed: 35579752
DOI: 10.1007/s00520-022-07136-w -
Biophysical Journal Jun 2021DNA looping plays an important role in cells in both regulating and protecting the genome. Often, studies of looping focus on looping by prokaryotic transcription...
DNA looping plays an important role in cells in both regulating and protecting the genome. Often, studies of looping focus on looping by prokaryotic transcription factors like lac repressor or by structural maintenance of chromosomes proteins such as condensin. Here, however, we are interested in a different looping method whereby condensing agents (charge ≥+3) such as protamine proteins neutralize the DNA, causing it to form loops and toroids. We considered two previously proposed mechanisms for DNA looping by protamine. In the first mechanism, protamine stabilizes spontaneous DNA fluctuations, forming randomly distributed loops along the DNA. In the second mechanism, protamine binds and bends the DNA to form a loop, creating a distribution of loops that is biased by protamine binding. To differentiate between these mechanisms, we imaged both spontaneous and protamine-induced loops on short-length (≤1 μm) DNA fragments using atomic force microscopy. We then compared the spatial distribution of the loops to several model distributions. A random looping model, which describes the mechanism of spontaneous DNA folding, fit the distribution of spontaneous loops, but it did not fit the distribution of protamine-induced loops. Specifically, it failed to predict a peak in the spatial distribution of loops at an intermediate location along the DNA. An electrostatic multibinding model, which was created to mimic the bind-and-bend mechanism of protamine, was a better fit of the distribution of protamine-induced loops. In this model, multiple protamines bind to the DNA electrostatically within a particular region along the DNA to coordinate the formation of a loop. We speculate that these findings will impact our understanding of protamine's in vivo role for looping DNA into toroids and the mechanism of DNA condensation by condensing agents more broadly.
Topics: Chromosomes; DNA; Lac Repressors; Nucleic Acid Conformation; Protamines
PubMed: 34023297
DOI: 10.1016/j.bpj.2021.04.022 -
BioRxiv : the Preprint Server For... May 2024There is a well-established link between abnormal sperm chromatin states and poor motility, however, how these two processes are interdependent is unknown. Here, we...
There is a well-established link between abnormal sperm chromatin states and poor motility, however, how these two processes are interdependent is unknown. Here, we identified a possible mechanistic insight by showing that Protamine 2, a nuclear DNA packaging protein in sperm, directly interacts with cytoskeletal protein Septin 12, which is associated with sperm motility. Septin 12 has several isoforms, and we show, that in the sperm, the short one (Mw 36 kDa) is mislocalized, while two long isoforms (Mw 40 and 41 kDa) are unexpectedly lost in sperm chromatin-bound protein fractions. Septin 12 co-immunoprecipitated with Protamine 2 in the testicular cell lysate of WT mice and with Lamin B1/B2/B3 in co-transfected HEK cells despite we did not observe changes in Lamin B2/B3 protein or SUN4 expression in testes. Furthermore, the sperm have on average a smaller sperm nucleus and aberrant acrosome biogenesis. In humans, patients with low sperm motility (asthenozoospermia) have imbalanced histone- protamine 1/2 ratio and modified levels of cytoskeletal proteins. We detected retained Septin 12 isoforms (Mw 40 and 41 kDa) in the sperm membrane, chromatin-bound and tubulin/mitochondria protein fractions, which was not true for healthy normozoospermic men. In conclusion, our findings expand the current knowledge regarding the connection between Protamine 2 and Septin 12 expression and localization, resulting in low sperm motility and morphological abnormalities.
PubMed: 38854089
DOI: 10.1101/2024.05.28.596175 -
Nutrients Jul 2021Dietary protamine can ameliorate hyperlipidemia; however, the protamine-derived active peptide and its hypolipidemic mechanism of action are unclear. Here, we report the...
Dietary protamine can ameliorate hyperlipidemia; however, the protamine-derived active peptide and its hypolipidemic mechanism of action are unclear. Here, we report the discovery of a novel anti-obesity and hypocholesterolemic peptide, RPR (Arg-Pro-Arg), derived from protamine in mice fed a high-fat diet for 50 days. Serum cholesterol levels were significantly lower in the protamine and RPR groups than in the control group. White adipose tissue weight was significantly decreased in the protamine and RPR groups. The fecal excretion of cholesterol and bile acid was significantly higher in the protamine and RPR groups than in the control group. We also observed a significant decrease in the expression of hepatic SCD1, SREBP1, and adipocyte FAS mRNA, and significantly increased expression of hepatic PPARα and adipocyte PPARγ1 mRNA in the protamine group. These findings demonstrate that the anti-obesity effects of protamine are linked to the upregulation of adipocyte PPARγ1 and hepatic PPARα and the downregulation of hepatic SCD1 via SREBP1 and adipocyte FAS. RPR derived from protamine has a crucial role in the anti-obesity action of protamine by evaluating the effective dose of adipose tissue weight loss.
Topics: Adipose Tissue, White; Adiposity; Animals; Anti-Obesity Agents; Anticholesteremic Agents; Biomarkers; Cholesterol; Diet, High-Fat; Disease Models, Animal; Fatty Acid Synthase, Type I; Liver; Male; Mice, Inbred C57BL; Obesity; Oligopeptides; PPAR alpha; PPAR gamma; Protamines; Stearoyl-CoA Desaturase; Sterol Regulatory Element Binding Protein 1; Weight Loss; Mice
PubMed: 34444660
DOI: 10.3390/nu13082501 -
European Journal of Case Reports in... 2020Heparin is commonly used in clinical practice for the prevention and treatment of various thrombotic conditions. Its use can be associated with bleeding which can range...
UNLABELLED
Heparin is commonly used in clinical practice for the prevention and treatment of various thrombotic conditions. Its use can be associated with bleeding which can range from minor to life threatening. Non-traumatic causes of breast haematoma are very rare. We report a case of spontaneous bleeding into the breast in a female patient who was anticoagulated with heparin.
LEARNING POINTS
Anticoagulant use can be associated with the adverse effect of bleeding at various sites.Physicians should be cautious of such bleeding which can occur at unsuspected sites.Our patient developed spontaneous breast haematoma after unfractionated heparin anticoagulation, and was successfully managed with cessation of anticoagulation, protamine, desmopressin and blood transfusion.
PubMed: 32908833
DOI: 10.12890/2020_001735