Monocytes and macrophages are the innate immune cells that are the first-line responders to invad... more Monocytes and macrophages are the innate immune cells that are the first-line responders to invading pathogens or foreign objects[...]
Communicated by M.Dorde the mechanism maintaining the metaphase arrest in mouse oocytes involves ... more Communicated by M.Dorde the mechanism maintaining the metaphase arrest in mouse oocytes involves an equilibrium between cyclin synthesis and degradation, probably controlled by CSF, and which is also dependent upon the three-dimensional organization of the spindle.
Tom 70 2021 Numer 3 (332) Strony 437-444 PIERWSZE OBSERWACJE DOTYCZĄCE COVID-19 COVID-19 jest cho... more Tom 70 2021 Numer 3 (332) Strony 437-444 PIERWSZE OBSERWACJE DOTYCZĄCE COVID-19 COVID-19 jest chorobą wywołaną przez zupełnie nowy, odzwierzęcy zarazek-koronawirus SARS-CoV-2 (Lai i współaut. 2020). Pojawienie się COVID-19 było precedensem w nauce, gdyż pozwoliło na prześledzenie tempa pojawiania się informacji naukowych
Below we present the main discoveries of Prof. Andrzej K. Tarkowski and his contributions for the... more Below we present the main discoveries of Prof. Andrzej K. Tarkowski and his contributions for the development of the Polish school of experimental embryology of mammals. The jubilee of 80 years of Prof. Tarkowski and the recognition of his work by the Foundation for Polish Science through the annual scientific award called the Polish Nobel Prize were special opportunities to write this article.
International audienceIn sexually reproducing multicellular organisms, germ cell fate is specifie... more International audienceIn sexually reproducing multicellular organisms, germ cell fate is specified in early embryogenesis, and the resulting germ cells differ structurally, mechanistically and functionally from the somatic cells. In the majority of animals, germ cells contain a subset of distinct organelles and molecules, which attributes and polar and/or asymmetrical distributions are fundamental for the proper function of the gamete, for fertilization and for the subsequent development and patterning of the embryo. Some of these organelles are shared among many different species, while some are unique and have been specifically acquired or adjusted to fit species-specific developmental requirements. In this review, we describe the current state of knowledge on the structures, dynamics and the role of germ cell-specific organelles, molecules, pathways and polarities, and we provide an overview on the most recent insights into their intraspecific uniqueness and interspecific similarities
Typically, all cells of a given organism have the same set of chromosomes. However, there are exc... more Typically, all cells of a given organism have the same set of chromosomes. However, there are exceptions to this rule, and in many organisms, the somatic cells and germ cells, various types of somatic cells or organs, or females and males, have different genomes. One of the sources of such differences is chromosome/DNA elimination/chromatin diminution that is a naturally programmed phenomenon. We describe chromosome/DNA elimination in various organisms and present the current hypotheses on its origin, mechanisms, significance, and consequences.
The International Journal of Developmental Biology, 2021
The timing of the M-phase is precisely controlled by a CDC6-dependent mechanism inhibiting the mi... more The timing of the M-phase is precisely controlled by a CDC6-dependent mechanism inhibiting the mitotic histone H1 kinase. Here, we describe the differential regulation of the dynamics of this mitotic kinase activity by exogenous cyclin A or cyclin B in the Xenopus laevis cycling extracts. We show that the experimental increase in cyclin A modifies only the level of histone H1 kinase activity, while the cyclin B increase modifies two parameters: histone H1 kinase activity and the timing of its full activation, which is accelerated. On the other hand, the cyclin A depletion significantly delays full activation of histone H1 kinase. However, when CDC6 is added to such an extract, it inhibits cyclin B-associated histone H1 kinase, but does not modify the mitotic timing in the absence of cyclin A. Further, we show via p9 co-precipitation with Cyclin-Dependent Kinases (CDKs), that both CDC6 and the bona fide CDK1 inhibitor Xic1 associate with the mitotic CDKs. Finally, we show that the Xic1 temporarily separates from the mitotic CDKs complexes during the peak of histone H1 kinase activity. These data show the differential coordination of the M-phase progression by cyclin A- and cyclin B-dependent CDKs, confirm the critical role of the CDC6-dependent histone H1 kinase inhibition in this process, and show that CDC6 acts differentially through the cyclin B- and cyclin A-associated CDKs. This CDC6- and cyclins-dependent mechanism likely depends on the precisely regulated association of Xic1 with the mitotic CDKs complexes. We postulate that: i. the dissociation of Xic1 from the CDKs complexes allows the maximal activation of CDK1 during the M-phase, ii. the switch between cyclin A- and cyclin B-CDK inhibition upon M-phase initiation may be responsible for the diauxic growth of mitotic histone H1 kinase activity.
International Archives of Allergy and Immunology, 2020
The difference between the female and male immune response to COVID-19 infection, and infections ... more The difference between the female and male immune response to COVID-19 infection, and infections in general, is multifactorial. The well-known determiners of the immune response, such as X and Y chromosomes, sex hormones, and microbiota, are functionally interconnected and influence each other in shaping the organism's immunity. We focus our commentary on the interplay between the genetic sex and mitochondria and how this may affect a sex-dependent immune response in COVID-19 infection. Realizing the existence of these interactions may help in designing novel methods or fine-tuning the existing and routine therapies to fight COVID-19 and other infections.
Vitamin D is a hormone regulating the immune system and playing a pivotal role in responses to mi... more Vitamin D is a hormone regulating the immune system and playing a pivotal role in responses to microbial infections. It regulates inflammatory processes by influencing the transcription of immune-response genes in macrophages, T cells, and dendritic cells. The proven role of vitamin D in many infectious diseases of the respiratory tract indicated that vitamin D should also play a role in SARS-CoV-2 infection. Vitamin D inhibits cytokine storm by switching the pro-inflammatory Th1 and Th17 to the anti-inflammatory Th2 and Treg response. Vitamin D is therefore expected to play a role in preventing, relieving symptoms, or treating SARS-CoV-2 infection symptoms, including severe pneumonia. There are several possible mechanisms by which vitamin D may reduce the risk of COVID-19 infection, such as induction of the transcription of cathelicidin and defensin. Also a nongenomic antiviral action of vitamin D and lumisterol, the molecule closely related to vitamin D, was reported. Despite this enormous progress, currently, there is still insufficient scientific evidence to support the claim that vitamin D supplementation may help treat COVID-19 infection. The pandemic restrictions were also shown to impact vitamin D uptake by limiting exposure to sunlight.
Unlike other organ anlagens, the primordial gonad is sexually bipotential in all animals. In mous... more Unlike other organ anlagens, the primordial gonad is sexually bipotential in all animals. In mouse, the bipotential gonad differentiates into testis or ovary depending on the genetic sex (XY or XX) of the fetus. During gonad development cells segregate, depending on genetic sex, into distinct compartments: testis cords and interstitium form in XY gonad, and germ cell cysts and stroma in XX gonad. However, our knowledge of mechanisms governing gonadal sex differentiation remains very vague. Because it is known that adhesion molecules (CAMs) play a key role in organogenesis, we suspected that diversified expression of CAMs should also play a crucial role in gonad development. Using microarray analysis we identified 129 CAMs and factors regulating cell adhesion during sexual differentiation of mouse gonad. To identify genes expressed differentially in three cell lines in XY and XX gonads: i) supporting (Sertoli or follicular cells), ii) interstitial or stromal cells, and iii) germ cells, we used transgenic mice expressing EGFP reporter gene and FACS cell sorting. Although a large number of CAMs expressed ubiquitously, expression of certain genes was cell line-and genetic sex-specific. The sets of CAMs differentially expressed in supporting versus interstitial/stromal cells may be responsible for segregation of these two cell lines during gonadal development. There was also a significant difference in CAMs expression pattern between XY supporting (Sertoli) and XX supporting (follicular) cells but not between XY and XX germ cells. This indicates that differential CAMs expression pattern in the somatic cells but not in the germ line arbitrates structural organization of gonadal anlagen into testis or ovary.
Vitamin D is a fat-soluble steroid hormone. Its main role is to regulate calcium and phosphate le... more Vitamin D is a fat-soluble steroid hormone. Its main role is to regulate calcium and phosphate levels, which are strictly associated with ossification and bone homeostasis. However, due to the presence of a nuclear vitamin D receptor (VDR) in the majority of cells of the human body, vitamin D also displays multiple effects beyond the bones. Calcitriol (1,25(OH) 2 D) not only affects cell growth and differentiation, but also stimulates the immune system by, for example, modulating the production of IL-4 and IL-5 anti-inflammatory cytokines. High numbers of VDRs have been found on macrophages, dendritic cells and lymphocytes, among other cells, which can be considered a very strong argument for the participation of vitamin D in autoimmune and anti-inflammatory processes. In recent months we have been witnessing the development of the COVID-19 pandemic. One of the most dangerous consequences of SARS-CoV-2 infection is acute respiratory distress syndrome caused by the activation of lung macrophages and the so-called cytokine storm. A recent study on COVID-19 patients suggests that vitamin D activates the innate immune response and suppresses the acquired immune response; the resultant decreased cytokine expression can reduce the severity of inflammation associated with COVID-19. Among older children and adults, vitamin D deficiency is widespread and observed worldwide, including in the Polish population. Based on numerous studies, normal serum vitamin D levels were established. Vitamin D concentration below 20 ng/mL is considered deficient and a level between 20 and 30 ng/mL is regarded as suboptimal. An optimal vitamin D concentration is 30-50 ng/mL.
Maternal Embryonic Leucine zipper Kinase (MELK) was recently shown to be involved in cell divisio... more Maternal Embryonic Leucine zipper Kinase (MELK) was recently shown to be involved in cell division of Xenopus embryo epithelial cells. The cytokinetic furrow of these cells ingresses asymmetrically and is developmentally regulated. Two subpopulations of xMELK, the mMELK (for ''mitotic'' xMELK) and iMELK (''interphase'' xMELK), which differ in their spatial and temporal regulation, are detected in Xenopus embryo. How cells regulate these two xMELK populations is unknown. In this study we show that, in epithelial cells, xMELK is present at a higher concentration at the apical junctional complex, in contrast to mesenchyme-like cells, which have uniform distribution of cortical MELK. Interestingly, mMELK and iMELK also differ by their requirements towards cell-cell contacts to establish their proper cortical localization both in epithelial and mesenchyme-like cells. Receptor for Activated protein Kinase C (RACK1), which we identified as an xMELK partner, co-localizes with xMELK at the tight junction. Moreover, a truncated RACK1 construct interferes with iMELK localization at cell-cell contacts. Collectively, our results suggest that iMELK and RACK1 are present in the same complex and that RACK1 is involved in the specific recruitment of iMELK at the apical junctional complex in epithelial cells of Xenopus embryos.
DOAJ (DOAJ: Directory of Open Access Journals), Oct 1, 2011
MAP kinases of ERK family play important roles in oocyte maturation, fertilization, and early emb... more MAP kinases of ERK family play important roles in oocyte maturation, fertilization, and early embryo development. The role of the signaling pathway involving ERK5 MAP kinase during meiotic and mitotic M-phase of the cell cycle is not well known. Here we studied localization of phosphorylated, thus, activated form of ERK5 in mouse maturing oocytes and mitotically dividing early embryos. We show that phosphorylation/dephosphorylation, i.e. activation/inactivation of ERK5 correlates with Mphase progression. Phosphorylated form of ERK5 accumulates in divisi le of bo otic and mitotic cells, and precisely co-local zes w h sp ndle microtubules at metaphase. This localization changes drastically in anapha hen ospho-ERK5 com letely disappears from microtubules and transits to the cytoplasmic granular, vesicle-like structures. In telophase oocytes it becomes incorporated into the midbody. Localization of phospho-ERK5 suggests that it may play important role both in meiotic and mitotic division.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
International Journal of Molecular Sciences, Apr 30, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Monocytes and macrophages are the innate immune cells that are the first-line responders to invad... more Monocytes and macrophages are the innate immune cells that are the first-line responders to invading pathogens or foreign objects[...]
Communicated by M.Dorde the mechanism maintaining the metaphase arrest in mouse oocytes involves ... more Communicated by M.Dorde the mechanism maintaining the metaphase arrest in mouse oocytes involves an equilibrium between cyclin synthesis and degradation, probably controlled by CSF, and which is also dependent upon the three-dimensional organization of the spindle.
Tom 70 2021 Numer 3 (332) Strony 437-444 PIERWSZE OBSERWACJE DOTYCZĄCE COVID-19 COVID-19 jest cho... more Tom 70 2021 Numer 3 (332) Strony 437-444 PIERWSZE OBSERWACJE DOTYCZĄCE COVID-19 COVID-19 jest chorobą wywołaną przez zupełnie nowy, odzwierzęcy zarazek-koronawirus SARS-CoV-2 (Lai i współaut. 2020). Pojawienie się COVID-19 było precedensem w nauce, gdyż pozwoliło na prześledzenie tempa pojawiania się informacji naukowych
Below we present the main discoveries of Prof. Andrzej K. Tarkowski and his contributions for the... more Below we present the main discoveries of Prof. Andrzej K. Tarkowski and his contributions for the development of the Polish school of experimental embryology of mammals. The jubilee of 80 years of Prof. Tarkowski and the recognition of his work by the Foundation for Polish Science through the annual scientific award called the Polish Nobel Prize were special opportunities to write this article.
International audienceIn sexually reproducing multicellular organisms, germ cell fate is specifie... more International audienceIn sexually reproducing multicellular organisms, germ cell fate is specified in early embryogenesis, and the resulting germ cells differ structurally, mechanistically and functionally from the somatic cells. In the majority of animals, germ cells contain a subset of distinct organelles and molecules, which attributes and polar and/or asymmetrical distributions are fundamental for the proper function of the gamete, for fertilization and for the subsequent development and patterning of the embryo. Some of these organelles are shared among many different species, while some are unique and have been specifically acquired or adjusted to fit species-specific developmental requirements. In this review, we describe the current state of knowledge on the structures, dynamics and the role of germ cell-specific organelles, molecules, pathways and polarities, and we provide an overview on the most recent insights into their intraspecific uniqueness and interspecific similarities
Typically, all cells of a given organism have the same set of chromosomes. However, there are exc... more Typically, all cells of a given organism have the same set of chromosomes. However, there are exceptions to this rule, and in many organisms, the somatic cells and germ cells, various types of somatic cells or organs, or females and males, have different genomes. One of the sources of such differences is chromosome/DNA elimination/chromatin diminution that is a naturally programmed phenomenon. We describe chromosome/DNA elimination in various organisms and present the current hypotheses on its origin, mechanisms, significance, and consequences.
The International Journal of Developmental Biology, 2021
The timing of the M-phase is precisely controlled by a CDC6-dependent mechanism inhibiting the mi... more The timing of the M-phase is precisely controlled by a CDC6-dependent mechanism inhibiting the mitotic histone H1 kinase. Here, we describe the differential regulation of the dynamics of this mitotic kinase activity by exogenous cyclin A or cyclin B in the Xenopus laevis cycling extracts. We show that the experimental increase in cyclin A modifies only the level of histone H1 kinase activity, while the cyclin B increase modifies two parameters: histone H1 kinase activity and the timing of its full activation, which is accelerated. On the other hand, the cyclin A depletion significantly delays full activation of histone H1 kinase. However, when CDC6 is added to such an extract, it inhibits cyclin B-associated histone H1 kinase, but does not modify the mitotic timing in the absence of cyclin A. Further, we show via p9 co-precipitation with Cyclin-Dependent Kinases (CDKs), that both CDC6 and the bona fide CDK1 inhibitor Xic1 associate with the mitotic CDKs. Finally, we show that the Xic1 temporarily separates from the mitotic CDKs complexes during the peak of histone H1 kinase activity. These data show the differential coordination of the M-phase progression by cyclin A- and cyclin B-dependent CDKs, confirm the critical role of the CDC6-dependent histone H1 kinase inhibition in this process, and show that CDC6 acts differentially through the cyclin B- and cyclin A-associated CDKs. This CDC6- and cyclins-dependent mechanism likely depends on the precisely regulated association of Xic1 with the mitotic CDKs complexes. We postulate that: i. the dissociation of Xic1 from the CDKs complexes allows the maximal activation of CDK1 during the M-phase, ii. the switch between cyclin A- and cyclin B-CDK inhibition upon M-phase initiation may be responsible for the diauxic growth of mitotic histone H1 kinase activity.
International Archives of Allergy and Immunology, 2020
The difference between the female and male immune response to COVID-19 infection, and infections ... more The difference between the female and male immune response to COVID-19 infection, and infections in general, is multifactorial. The well-known determiners of the immune response, such as X and Y chromosomes, sex hormones, and microbiota, are functionally interconnected and influence each other in shaping the organism's immunity. We focus our commentary on the interplay between the genetic sex and mitochondria and how this may affect a sex-dependent immune response in COVID-19 infection. Realizing the existence of these interactions may help in designing novel methods or fine-tuning the existing and routine therapies to fight COVID-19 and other infections.
Vitamin D is a hormone regulating the immune system and playing a pivotal role in responses to mi... more Vitamin D is a hormone regulating the immune system and playing a pivotal role in responses to microbial infections. It regulates inflammatory processes by influencing the transcription of immune-response genes in macrophages, T cells, and dendritic cells. The proven role of vitamin D in many infectious diseases of the respiratory tract indicated that vitamin D should also play a role in SARS-CoV-2 infection. Vitamin D inhibits cytokine storm by switching the pro-inflammatory Th1 and Th17 to the anti-inflammatory Th2 and Treg response. Vitamin D is therefore expected to play a role in preventing, relieving symptoms, or treating SARS-CoV-2 infection symptoms, including severe pneumonia. There are several possible mechanisms by which vitamin D may reduce the risk of COVID-19 infection, such as induction of the transcription of cathelicidin and defensin. Also a nongenomic antiviral action of vitamin D and lumisterol, the molecule closely related to vitamin D, was reported. Despite this enormous progress, currently, there is still insufficient scientific evidence to support the claim that vitamin D supplementation may help treat COVID-19 infection. The pandemic restrictions were also shown to impact vitamin D uptake by limiting exposure to sunlight.
Unlike other organ anlagens, the primordial gonad is sexually bipotential in all animals. In mous... more Unlike other organ anlagens, the primordial gonad is sexually bipotential in all animals. In mouse, the bipotential gonad differentiates into testis or ovary depending on the genetic sex (XY or XX) of the fetus. During gonad development cells segregate, depending on genetic sex, into distinct compartments: testis cords and interstitium form in XY gonad, and germ cell cysts and stroma in XX gonad. However, our knowledge of mechanisms governing gonadal sex differentiation remains very vague. Because it is known that adhesion molecules (CAMs) play a key role in organogenesis, we suspected that diversified expression of CAMs should also play a crucial role in gonad development. Using microarray analysis we identified 129 CAMs and factors regulating cell adhesion during sexual differentiation of mouse gonad. To identify genes expressed differentially in three cell lines in XY and XX gonads: i) supporting (Sertoli or follicular cells), ii) interstitial or stromal cells, and iii) germ cells, we used transgenic mice expressing EGFP reporter gene and FACS cell sorting. Although a large number of CAMs expressed ubiquitously, expression of certain genes was cell line-and genetic sex-specific. The sets of CAMs differentially expressed in supporting versus interstitial/stromal cells may be responsible for segregation of these two cell lines during gonadal development. There was also a significant difference in CAMs expression pattern between XY supporting (Sertoli) and XX supporting (follicular) cells but not between XY and XX germ cells. This indicates that differential CAMs expression pattern in the somatic cells but not in the germ line arbitrates structural organization of gonadal anlagen into testis or ovary.
Vitamin D is a fat-soluble steroid hormone. Its main role is to regulate calcium and phosphate le... more Vitamin D is a fat-soluble steroid hormone. Its main role is to regulate calcium and phosphate levels, which are strictly associated with ossification and bone homeostasis. However, due to the presence of a nuclear vitamin D receptor (VDR) in the majority of cells of the human body, vitamin D also displays multiple effects beyond the bones. Calcitriol (1,25(OH) 2 D) not only affects cell growth and differentiation, but also stimulates the immune system by, for example, modulating the production of IL-4 and IL-5 anti-inflammatory cytokines. High numbers of VDRs have been found on macrophages, dendritic cells and lymphocytes, among other cells, which can be considered a very strong argument for the participation of vitamin D in autoimmune and anti-inflammatory processes. In recent months we have been witnessing the development of the COVID-19 pandemic. One of the most dangerous consequences of SARS-CoV-2 infection is acute respiratory distress syndrome caused by the activation of lung macrophages and the so-called cytokine storm. A recent study on COVID-19 patients suggests that vitamin D activates the innate immune response and suppresses the acquired immune response; the resultant decreased cytokine expression can reduce the severity of inflammation associated with COVID-19. Among older children and adults, vitamin D deficiency is widespread and observed worldwide, including in the Polish population. Based on numerous studies, normal serum vitamin D levels were established. Vitamin D concentration below 20 ng/mL is considered deficient and a level between 20 and 30 ng/mL is regarded as suboptimal. An optimal vitamin D concentration is 30-50 ng/mL.
Maternal Embryonic Leucine zipper Kinase (MELK) was recently shown to be involved in cell divisio... more Maternal Embryonic Leucine zipper Kinase (MELK) was recently shown to be involved in cell division of Xenopus embryo epithelial cells. The cytokinetic furrow of these cells ingresses asymmetrically and is developmentally regulated. Two subpopulations of xMELK, the mMELK (for ''mitotic'' xMELK) and iMELK (''interphase'' xMELK), which differ in their spatial and temporal regulation, are detected in Xenopus embryo. How cells regulate these two xMELK populations is unknown. In this study we show that, in epithelial cells, xMELK is present at a higher concentration at the apical junctional complex, in contrast to mesenchyme-like cells, which have uniform distribution of cortical MELK. Interestingly, mMELK and iMELK also differ by their requirements towards cell-cell contacts to establish their proper cortical localization both in epithelial and mesenchyme-like cells. Receptor for Activated protein Kinase C (RACK1), which we identified as an xMELK partner, co-localizes with xMELK at the tight junction. Moreover, a truncated RACK1 construct interferes with iMELK localization at cell-cell contacts. Collectively, our results suggest that iMELK and RACK1 are present in the same complex and that RACK1 is involved in the specific recruitment of iMELK at the apical junctional complex in epithelial cells of Xenopus embryos.
DOAJ (DOAJ: Directory of Open Access Journals), Oct 1, 2011
MAP kinases of ERK family play important roles in oocyte maturation, fertilization, and early emb... more MAP kinases of ERK family play important roles in oocyte maturation, fertilization, and early embryo development. The role of the signaling pathway involving ERK5 MAP kinase during meiotic and mitotic M-phase of the cell cycle is not well known. Here we studied localization of phosphorylated, thus, activated form of ERK5 in mouse maturing oocytes and mitotically dividing early embryos. We show that phosphorylation/dephosphorylation, i.e. activation/inactivation of ERK5 correlates with Mphase progression. Phosphorylated form of ERK5 accumulates in divisi le of bo otic and mitotic cells, and precisely co-local zes w h sp ndle microtubules at metaphase. This localization changes drastically in anapha hen ospho-ERK5 com letely disappears from microtubules and transits to the cytoplasmic granular, vesicle-like structures. In telophase oocytes it becomes incorporated into the midbody. Localization of phospho-ERK5 suggests that it may play important role both in meiotic and mitotic division.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
International Journal of Molecular Sciences, Apr 30, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
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