Hrvoje Jakovac - Academia.edu (original) (raw)

Papers by Hrvoje Jakovac

Research paper thumbnail of Autopsies during COVID-19 pandemic - Caution is never too much: Postmortem detection of SARS-CoV-2 in the severely burned and carbonized bodies

Research paper thumbnail of Upregulation of osteopontin during the presymptomatic stage of chronic relapsing experimental autoimmune encephalomyelitis in rats

Research paper thumbnail of Endoplasmic reticulum-resident heat shock protein gp96, natural killer T cells and regulatory T cells as regulators of self-tissue damages induced by various types of injuries

American Journal of Reproductive Immunology, Jun 15, 2007

Research paper thumbnail of Prevalence of metabolic syndrome among patients with major depressive disorder--differences between newly diagnosed first episode and recurrent disease

PubMed, Dec 1, 2013

The objective of the present study was to assess differences in prevalence of the metabolic syndr... more The objective of the present study was to assess differences in prevalence of the metabolic syndrome among depressed patients in regard to the duration of the illness (first episode versus recurrent episodes). A total of 190 patients suffering from major depressive disorder were included in the study, diagnosed according to International classification of disorders, 10th revision. The same criteria were used to divide participants into two groups: first episode major depressive disorder and major depressive disorder with recurrent episodes. The metabolic syndrome was defined according to the criteria of the American National Cholesterol Education Program-Treatment Panel III. Results showed that metabolic syndrome is significantly more prevalent in patients with recurrent major depressive disorder (45.2%) compared to patients with first episode of major depressive disorder (27.3%), mainly due to differences in plasma glucose, triglycerides and HDL-cholesterol levels. These findings indicate the importance of the duration of depression and the number of recurring episodes as factors involved in etiopathogenesis of the associated metabolic syndrome.

Research paper thumbnail of Neuroimmune characterization of optineurin insufficiency mouse model during ageing

Scientific Reports, Jul 22, 2023

Optineurin is a multifunctional polyubiquitin-binding protein implicated in inflammatory signalli... more Optineurin is a multifunctional polyubiquitin-binding protein implicated in inflammatory signalling. Optineurin mutations are associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), neurodegenerative diseases characterised by neuronal loss, neuroinflammation, and peripheral immune disbalance. However, the pathogenic role of optineurin mutations is unclear. We previously observed no phenotype in the unmanipulated young optineurin insufficiency mice (Optn 470T), designed to mimic ALS/FTD-linked truncations deficient in polyubiquitin binding. The purpose of this study was to investigate whether ageing would trigger neurodegeneration. We performed a neurological, neuropathological, and immunological characterization of ageing wild-type (WT) and Optn 470T mice. No motor or cognitive differences were detected between the genotypes. Neuropathological analyses demonstrated signs of ageing including lipofuscin accumulation and microglial activation in WT mice. However, this was not worsened in Optn 470T mice, and they did not exhibit TAR DNA-binding protein 43 (TDP-43) aggregation or neuronal loss. Spleen immunophenotyping uncovered T cell immunosenescence at two years but without notable differences between the WT and Optn 470T mice. Conventional dendritic cells (cDC) and macrophages exhibited increased expression of activation markers in two-year-old Optn 470T males but not females, although the numbers of innate immune cells were similar between genotypes. Altogether, a combination of optineurin insufficiency and ageing did not induce ALS/FTD-like immune imbalance and neuropathology in mice. Abbreviations ALS Amyotrophic lateral sclerosis cDC Conventional dendritic cells FTD Frontotemporal dementia GFAP Glial fibrillary acidic protein IFN Interferon MFI Mean fluorescence intensity NK cells Natural killer cells OPTN Optineurin SOD1 Superoxide dismutase 1 TBK1 TANK-binding kinase 1 TDP-43 TAR DNA-binding protein 43 TNF Tumour necrosis factor

Research paper thumbnail of Protective and immunoregulatory roles of metallothioneins expressed on fetoplacental unit and in maternal liver during pregnancy

Research paper thumbnail of Stress-induced changes in heat shock protein gp-96 and metallothioneins in the liver, spleen and thymus

Research paper thumbnail of Endoplasmic reticulum-resident heat shock protein gp96 as an innate sensor of damage induced by tissue remodelling, stress and bacterial peptidoglycan

Research paper thumbnail of Metallothionein and tissue metal kinetics after partial hepatectomy in liver, thymus and spleen

Research paper thumbnail of Upregulation of heat shock protein gp-96 in the liver, spleen and thymus induced by stress in mice

Research paper thumbnail of Metallothioneins and heat shock proteins in marine mussels as biomarkers of environmental pollution

Exposure of cells to wide variety of stressors, such as heat, heavy metals, organic poison, injur... more Exposure of cells to wide variety of stressors, such as heat, heavy metals, organic poison, injuries, hypoxia etc alters the tertiary structure of proteins and leads in cells to general stress response, which consists in transient enhancement of the expression of cytoprotective proteins- heat shock proteins (HSP) and metallothioneins (MT), which act as molecular chaperons or as regulators of heavy-metal homeostasis, respectively. Since both families, as evolutionary conserved proteins are distributed also in animals, in this study the expression of HPS 70 and MTs I/II have been evaluated in tissues of marine mussel Mytilus galloprovincialis collected along the coast of the Kvarnerian bay in the zones, which are differently exposed to environmental pollution (industrial, urban, peri-urban and turistic area), as well as in mussels exposed to heat or to CdCl2 and HgCl2 in vitro. The level of HSP 70 and MTs expression was detected in mussel gills and in the digestive gland, using Western blot analysis and immunohistochemistry. The data have shown that mussels collected from industrial and urban zones have elevated concentrations of Pb in soft tissues, as well as significantly higher HSP 70 and MTs immunoreactivity in digestive glands. Moreover, mussels collected at zones with different pollution, differently reacted on stressors (heat shock and toxic metals) used in vitro. Conclusion: The data suggests that HPS and MTs may be useful biomarkers of environmental pollutions.

Research paper thumbnail of My life as an Editor - Daniel Rukavina

European Science Editing, 2017

Research paper thumbnail of Expression pattern of the endoplasmic reticulum stress protein gp96 during chronic relapsing experimental autoimmune encephalomyelitis in rats

ABSTRACT Gp96 is the endoplasmic reticulum (ER)-resident molecular chaperone, which is involved i... more ABSTRACT Gp96 is the endoplasmic reticulum (ER)-resident molecular chaperone, which is involved in the correction of unfolded proteins, in the activation of proteasome-dependent ER-associated degradation of the misfolded proteins, and in activation of the protein translation that modulates polypeptide traffic into the ER. Furthermore, owing to its peptide chaperone capacity and ability to interact with professional antigen-presenting cells, as well as with growth factors, integrins and Toll-like receptors, it is also endowed with crucial immunological functions acting as a "danger signal" to the innate and adaptive immunity. Considering these properties, in the present study the tissue expression of gp96 was examined during the monophasic and chronic relapsing form of experimental autoimmune encephalomyelitis (CR-EAE), induced in genetically susceptible DA rats by subcutaneous injection of myelin basic protein (MBP) or bovine brain homogenate in complete Freund's adjuvant (CFA). Immunohistochemical analyses were done in periods of attacks and remissions of EAE, and the results were compared with findings in intact rats and those treated only with CFA. The data revealed that the constitutive gp96 expression, found in several neurons and glial cells in the brain and spinal cord of intact animals, significantly diminished during the attacks of CR-EAE. On the contrary, the remission of disease was followed by high upregulation of gp96, mainly in the oligodendrocytes within the white matter, in the neurons of the hippocampal area, as well as in the motoneurons of lumbar spinal cord, suggesting that gp96 might be involved in proteostasis and immune-related pathways linked with the reparative processes in the CNS.

Research paper thumbnail of Metallothioneins I+II expression and tissue metals kinetics during chronic relapsing experimental autoimmune encephalomyelitis in rats

Research paper thumbnail of Endoplasmic reticulum resident heat shock protein Gp96 as morphogenetic and immunoregulatory factor in syngeneic pregnancy

Research paper thumbnail of Endoplasmic reticulum resident heat shock protein-gp96 as morphogenetic and immunoregulatory factor in syngeneic pregnancy

PubMed, Oct 1, 2013

The severe remodeling of endometrial stroma during blastocyst adhesion and trophoblast invasion i... more The severe remodeling of endometrial stroma during blastocyst adhesion and trophoblast invasion initiates at maternal-fetal interface the reaction of evolutionary old heat shock response, in which heat shock proteins, as molecular chaperons, monitor the configurations of newly synthesized proteins and prevent the formation of functionless aggregates of misfolded proteins, targeting them to degradation by a the ubiquitin-proteasome system. In addition, the endoplasmic reticulum (ER)-resident HSPs, such as gp96/GRP94 may, after binding to CD91 and TLRs, elicit antigen-specific and antigen-unspecific immune responses, owing to its peptide-chaperoning capacity and ability to activate APCs. Considering these properties, we examined tissue expression of gp96 at the maternal-fetal interface and in the maternal liver and spleen on the 16th day of undisturbed syngeneic pregnancy and after the treatment with peptidoglycan monomer linked with zinc (PGM-Zn). The data showed that in undisturbed pregnancy the gp96, CD91 and TLR2 were markedly expressed on extravillous and villous trophoblast. PGM-Zn enhanced these findings, as well as the number of uterine natural killer cells and local NFκB immunoreactivity. Gp96 expression arose also in the maternal spleen and liver, where an accumulation of NKT cells or γδT lymphocytes was seen. The data point to roles of gp96 in maintenance of proteostasis and local and systemic immune balance in pregnancy complicated by infection.

Research paper thumbnail of The impact of exercise on adult neurogenesis and clinical course of experimental autoimmune encephalomyelitis

Research paper thumbnail of Metallothionein I/II distribution in maternal and fetal tissues during syngeneic pregnancy

Metallothioneins (MTs), the intracellular, ubiquitous, low molecular cysteine rich proteins are s... more Metallothioneins (MTs), the intracellular, ubiquitous, low molecular cysteine rich proteins are stress-proteins, which participate in cell reactions on different kinds of injuries, as well as in host defense responses, affecting the functions of several immune cells, TLR signaling, expression of MHC proteins and co-stimulatory molecules on dendritic cells and the production and release of pro-inflammatory cytokines. Furthermore, MTs participate in cell growth, repair and differentiation, since as metal-donors or metal-acceptors they alter the functional state of metal-dependent proteins, such as zinc finger domain-containing transcription factors, DNA synthesis enzymes and signal transduction molecules. Moreover, they may prevent apoptosis by scavenging reactive oxygen species or by interaction with other intracellular messengers, such as caspase 3, ATP and GTP nucleotides and NFkB. Owing to the possibility that MTs contribute to the structural integrity of the placenta and participate in local immunoregulation and in fetal organogenesis and development, in this study, using the immunohistochemistry, we analyzed the tissue distribution of MTs I/II on 16th day of syngeneic pregnancy in maternal (placenta, liver, thymus and spleen), as well as in neonatal tissues (skin, liver, kidney, colon, brain). The data have shown that syngeneic pregnancy induces high cytoplasmic expression of MTs I/II in maternal liver, as well as in fetoplacental unit, affecting syncytiotrophoblast, cytotrophoblast, stromal and macrophages-like cells within the core of the chorionic vili and some decidual cells. Additionally, a high cytoplasmic and nuclear MT I/II immunoreactivity was noticed in fetal liver and in epithelial tissues, such as skin, intestine, pancreas and gallbladder, as well as in fetal kidney, and developing hair folicules, pointing to the role of MTs in organogenesis and protection of fetus during pregnancy. Supported by grant 0621341-1337 from Croatian Ministry of Science.

Research paper thumbnail of Fast metallothionein and tissue metal response to partial hepatectomy in regenerating liver, thymus and spleen

Introduction: Liver regeneration that follows after partial hepatectomy (pHx) is well-defined pro... more Introduction: Liver regeneration that follows after partial hepatectomy (pHx) is well-defined process, which involves the concerted action of extra and intracellular factors resulting in induction of cell replication and its inhibition at time when the entire liver mass is restored. Concomitantly, the breakdown of previously maintained tolerance and the exposure of self antigens lead to the activation of pre-immune and immune repertoire, which participate in surveillance against aberrant cells and re-establishment of previous morphostasis. Since, in these events, important biological function might have metallothioneins and tissue minerals which are affecting the structural integrity and enzyme activities, transduction signals, and replication factors during cell proliferation and apoptosis, as well as, the development and maintenance of immune functions, in this study we analyzed early metallothionein I+II (MT) expression and tissue kinetics of zinc, iron, magnesium and calcium in the liver, thymus and spleen after pHx. Material & Method: Analysis were done on 1st, 2nd, 6th, 12th, 24th and 48th hour after 1/3 pHx in C57Bl mice, using immunohistological staining and inductivity coupled plasma spectrometry for determination of MTs and tissue metals kinetics, respectively. Results: Hepatectomy was followed by fast upregulation of MT expression in the remnant liver, but also in the spleen and the thymus. In the liver it started in sinusoids (1h after pHx) and became impressive in hepatocytes (between the 6th and 72nd hour), where cytoplasmic and nuclear staining was seen (between the 6th and 72nd hour). In the spleen a marked overexpression of MT was found in parafollicular areas 24h after pHx, while in the thymus MT staining moderately increased in the subcortical and medullar zones (after 24h). Simultaneously, in the regenerating liver, immediately after the operation, accumulated Zn++, Fe++, Mg++ and Ca++, while their concentrations significantly decreased in the thymus (Zn++) and in the spleen (Zn++, Fe++, Ca++ and Mg++). Conclusions: The data point to early activation of highly interconnected network of growth-factors and cytokine-regulated pathways by pHx, in which metallothioneins in the regenerating liver, thymus and spleen could participate in a DNA synthesis-related processes, and transduction signals through abstraction or donation of metals such as Zn++, Fe++, Mg++ and Ca++. ((Supported by grants from Croatian Ministry of Science, projects No 0062018 and 0062002).

Research paper thumbnail of Regulatory T and NKT cells in syngeneic pregnancy

NKT cells and regulatory T cells (Treg) were claimed to be important players in the tolerance tow... more NKT cells and regulatory T cells (Treg) were claimed to be important players in the tolerance towards the fetus bearing alloantigens, having the pivotal role in triggering and inhibition of immune responses against self-antigens, as well as in regulation of innate immune response. They, however, might be related also with fetal invasion mechanisms at the maternal-fetal interface, with bacterial exposure, as well as with the systemic hormonal changes, induced by pregnancy, showing that they reflect more global changes of the maternal immune system. In an attempt to enlarge our previous findings showing that during syngeneic pregnancy in the liver accumulate cytotoxic self-reactive NKT cells, which usually cooperate with Treg cells, in this study we estimated the presence of CD4+CD25+Foxp3+ T cells in the liver, spleen and thymus of nonpregnant and pregnant C57/BL6 females matted with C57 BL/6 males. Furthermore, to examine the potential effects of bacterial toxins a group of pregnant mice was treated with peptidoglycan-monomer linked with zinc (PGM-Zn). Phenotypic analysis and cytotoxicity against syngeneic thymocytes and YAC-1 targets was made on the 16th day after detection of vaginal plugs. The data have shown that during syngeneic pregnancy in the maternal liver increases the proportion of CD4+CD25+Foxp3+, as well as CD3intermediate, NK1.1+ and IL-2Rb+ cells (NKT cells). Similar changes were induced by PGM-Zn, which additionally increased the Treg accumulation, particularly in the liver. The data point to interplay between the NKT and Treg cells, pointing to the liver as a place important for the activation of protective and tolerance-promoting mechanisms during the pregnancy.

Research paper thumbnail of Autopsies during COVID-19 pandemic - Caution is never too much: Postmortem detection of SARS-CoV-2 in the severely burned and carbonized bodies

Research paper thumbnail of Upregulation of osteopontin during the presymptomatic stage of chronic relapsing experimental autoimmune encephalomyelitis in rats

Research paper thumbnail of Endoplasmic reticulum-resident heat shock protein gp96, natural killer T cells and regulatory T cells as regulators of self-tissue damages induced by various types of injuries

American Journal of Reproductive Immunology, Jun 15, 2007

Research paper thumbnail of Prevalence of metabolic syndrome among patients with major depressive disorder--differences between newly diagnosed first episode and recurrent disease

PubMed, Dec 1, 2013

The objective of the present study was to assess differences in prevalence of the metabolic syndr... more The objective of the present study was to assess differences in prevalence of the metabolic syndrome among depressed patients in regard to the duration of the illness (first episode versus recurrent episodes). A total of 190 patients suffering from major depressive disorder were included in the study, diagnosed according to International classification of disorders, 10th revision. The same criteria were used to divide participants into two groups: first episode major depressive disorder and major depressive disorder with recurrent episodes. The metabolic syndrome was defined according to the criteria of the American National Cholesterol Education Program-Treatment Panel III. Results showed that metabolic syndrome is significantly more prevalent in patients with recurrent major depressive disorder (45.2%) compared to patients with first episode of major depressive disorder (27.3%), mainly due to differences in plasma glucose, triglycerides and HDL-cholesterol levels. These findings indicate the importance of the duration of depression and the number of recurring episodes as factors involved in etiopathogenesis of the associated metabolic syndrome.

Research paper thumbnail of Neuroimmune characterization of optineurin insufficiency mouse model during ageing

Scientific Reports, Jul 22, 2023

Optineurin is a multifunctional polyubiquitin-binding protein implicated in inflammatory signalli... more Optineurin is a multifunctional polyubiquitin-binding protein implicated in inflammatory signalling. Optineurin mutations are associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), neurodegenerative diseases characterised by neuronal loss, neuroinflammation, and peripheral immune disbalance. However, the pathogenic role of optineurin mutations is unclear. We previously observed no phenotype in the unmanipulated young optineurin insufficiency mice (Optn 470T), designed to mimic ALS/FTD-linked truncations deficient in polyubiquitin binding. The purpose of this study was to investigate whether ageing would trigger neurodegeneration. We performed a neurological, neuropathological, and immunological characterization of ageing wild-type (WT) and Optn 470T mice. No motor or cognitive differences were detected between the genotypes. Neuropathological analyses demonstrated signs of ageing including lipofuscin accumulation and microglial activation in WT mice. However, this was not worsened in Optn 470T mice, and they did not exhibit TAR DNA-binding protein 43 (TDP-43) aggregation or neuronal loss. Spleen immunophenotyping uncovered T cell immunosenescence at two years but without notable differences between the WT and Optn 470T mice. Conventional dendritic cells (cDC) and macrophages exhibited increased expression of activation markers in two-year-old Optn 470T males but not females, although the numbers of innate immune cells were similar between genotypes. Altogether, a combination of optineurin insufficiency and ageing did not induce ALS/FTD-like immune imbalance and neuropathology in mice. Abbreviations ALS Amyotrophic lateral sclerosis cDC Conventional dendritic cells FTD Frontotemporal dementia GFAP Glial fibrillary acidic protein IFN Interferon MFI Mean fluorescence intensity NK cells Natural killer cells OPTN Optineurin SOD1 Superoxide dismutase 1 TBK1 TANK-binding kinase 1 TDP-43 TAR DNA-binding protein 43 TNF Tumour necrosis factor

Research paper thumbnail of Protective and immunoregulatory roles of metallothioneins expressed on fetoplacental unit and in maternal liver during pregnancy

Research paper thumbnail of Stress-induced changes in heat shock protein gp-96 and metallothioneins in the liver, spleen and thymus

Research paper thumbnail of Endoplasmic reticulum-resident heat shock protein gp96 as an innate sensor of damage induced by tissue remodelling, stress and bacterial peptidoglycan

Research paper thumbnail of Metallothionein and tissue metal kinetics after partial hepatectomy in liver, thymus and spleen

Research paper thumbnail of Upregulation of heat shock protein gp-96 in the liver, spleen and thymus induced by stress in mice

Research paper thumbnail of Metallothioneins and heat shock proteins in marine mussels as biomarkers of environmental pollution

Exposure of cells to wide variety of stressors, such as heat, heavy metals, organic poison, injur... more Exposure of cells to wide variety of stressors, such as heat, heavy metals, organic poison, injuries, hypoxia etc alters the tertiary structure of proteins and leads in cells to general stress response, which consists in transient enhancement of the expression of cytoprotective proteins- heat shock proteins (HSP) and metallothioneins (MT), which act as molecular chaperons or as regulators of heavy-metal homeostasis, respectively. Since both families, as evolutionary conserved proteins are distributed also in animals, in this study the expression of HPS 70 and MTs I/II have been evaluated in tissues of marine mussel Mytilus galloprovincialis collected along the coast of the Kvarnerian bay in the zones, which are differently exposed to environmental pollution (industrial, urban, peri-urban and turistic area), as well as in mussels exposed to heat or to CdCl2 and HgCl2 in vitro. The level of HSP 70 and MTs expression was detected in mussel gills and in the digestive gland, using Western blot analysis and immunohistochemistry. The data have shown that mussels collected from industrial and urban zones have elevated concentrations of Pb in soft tissues, as well as significantly higher HSP 70 and MTs immunoreactivity in digestive glands. Moreover, mussels collected at zones with different pollution, differently reacted on stressors (heat shock and toxic metals) used in vitro. Conclusion: The data suggests that HPS and MTs may be useful biomarkers of environmental pollutions.

Research paper thumbnail of My life as an Editor - Daniel Rukavina

European Science Editing, 2017

Research paper thumbnail of Expression pattern of the endoplasmic reticulum stress protein gp96 during chronic relapsing experimental autoimmune encephalomyelitis in rats

ABSTRACT Gp96 is the endoplasmic reticulum (ER)-resident molecular chaperone, which is involved i... more ABSTRACT Gp96 is the endoplasmic reticulum (ER)-resident molecular chaperone, which is involved in the correction of unfolded proteins, in the activation of proteasome-dependent ER-associated degradation of the misfolded proteins, and in activation of the protein translation that modulates polypeptide traffic into the ER. Furthermore, owing to its peptide chaperone capacity and ability to interact with professional antigen-presenting cells, as well as with growth factors, integrins and Toll-like receptors, it is also endowed with crucial immunological functions acting as a "danger signal" to the innate and adaptive immunity. Considering these properties, in the present study the tissue expression of gp96 was examined during the monophasic and chronic relapsing form of experimental autoimmune encephalomyelitis (CR-EAE), induced in genetically susceptible DA rats by subcutaneous injection of myelin basic protein (MBP) or bovine brain homogenate in complete Freund's adjuvant (CFA). Immunohistochemical analyses were done in periods of attacks and remissions of EAE, and the results were compared with findings in intact rats and those treated only with CFA. The data revealed that the constitutive gp96 expression, found in several neurons and glial cells in the brain and spinal cord of intact animals, significantly diminished during the attacks of CR-EAE. On the contrary, the remission of disease was followed by high upregulation of gp96, mainly in the oligodendrocytes within the white matter, in the neurons of the hippocampal area, as well as in the motoneurons of lumbar spinal cord, suggesting that gp96 might be involved in proteostasis and immune-related pathways linked with the reparative processes in the CNS.

Research paper thumbnail of Metallothioneins I+II expression and tissue metals kinetics during chronic relapsing experimental autoimmune encephalomyelitis in rats

Research paper thumbnail of Endoplasmic reticulum resident heat shock protein Gp96 as morphogenetic and immunoregulatory factor in syngeneic pregnancy

Research paper thumbnail of Endoplasmic reticulum resident heat shock protein-gp96 as morphogenetic and immunoregulatory factor in syngeneic pregnancy

PubMed, Oct 1, 2013

The severe remodeling of endometrial stroma during blastocyst adhesion and trophoblast invasion i... more The severe remodeling of endometrial stroma during blastocyst adhesion and trophoblast invasion initiates at maternal-fetal interface the reaction of evolutionary old heat shock response, in which heat shock proteins, as molecular chaperons, monitor the configurations of newly synthesized proteins and prevent the formation of functionless aggregates of misfolded proteins, targeting them to degradation by a the ubiquitin-proteasome system. In addition, the endoplasmic reticulum (ER)-resident HSPs, such as gp96/GRP94 may, after binding to CD91 and TLRs, elicit antigen-specific and antigen-unspecific immune responses, owing to its peptide-chaperoning capacity and ability to activate APCs. Considering these properties, we examined tissue expression of gp96 at the maternal-fetal interface and in the maternal liver and spleen on the 16th day of undisturbed syngeneic pregnancy and after the treatment with peptidoglycan monomer linked with zinc (PGM-Zn). The data showed that in undisturbed pregnancy the gp96, CD91 and TLR2 were markedly expressed on extravillous and villous trophoblast. PGM-Zn enhanced these findings, as well as the number of uterine natural killer cells and local NFκB immunoreactivity. Gp96 expression arose also in the maternal spleen and liver, where an accumulation of NKT cells or γδT lymphocytes was seen. The data point to roles of gp96 in maintenance of proteostasis and local and systemic immune balance in pregnancy complicated by infection.

Research paper thumbnail of The impact of exercise on adult neurogenesis and clinical course of experimental autoimmune encephalomyelitis

Research paper thumbnail of Metallothionein I/II distribution in maternal and fetal tissues during syngeneic pregnancy

Metallothioneins (MTs), the intracellular, ubiquitous, low molecular cysteine rich proteins are s... more Metallothioneins (MTs), the intracellular, ubiquitous, low molecular cysteine rich proteins are stress-proteins, which participate in cell reactions on different kinds of injuries, as well as in host defense responses, affecting the functions of several immune cells, TLR signaling, expression of MHC proteins and co-stimulatory molecules on dendritic cells and the production and release of pro-inflammatory cytokines. Furthermore, MTs participate in cell growth, repair and differentiation, since as metal-donors or metal-acceptors they alter the functional state of metal-dependent proteins, such as zinc finger domain-containing transcription factors, DNA synthesis enzymes and signal transduction molecules. Moreover, they may prevent apoptosis by scavenging reactive oxygen species or by interaction with other intracellular messengers, such as caspase 3, ATP and GTP nucleotides and NFkB. Owing to the possibility that MTs contribute to the structural integrity of the placenta and participate in local immunoregulation and in fetal organogenesis and development, in this study, using the immunohistochemistry, we analyzed the tissue distribution of MTs I/II on 16th day of syngeneic pregnancy in maternal (placenta, liver, thymus and spleen), as well as in neonatal tissues (skin, liver, kidney, colon, brain). The data have shown that syngeneic pregnancy induces high cytoplasmic expression of MTs I/II in maternal liver, as well as in fetoplacental unit, affecting syncytiotrophoblast, cytotrophoblast, stromal and macrophages-like cells within the core of the chorionic vili and some decidual cells. Additionally, a high cytoplasmic and nuclear MT I/II immunoreactivity was noticed in fetal liver and in epithelial tissues, such as skin, intestine, pancreas and gallbladder, as well as in fetal kidney, and developing hair folicules, pointing to the role of MTs in organogenesis and protection of fetus during pregnancy. Supported by grant 0621341-1337 from Croatian Ministry of Science.

Research paper thumbnail of Fast metallothionein and tissue metal response to partial hepatectomy in regenerating liver, thymus and spleen

Introduction: Liver regeneration that follows after partial hepatectomy (pHx) is well-defined pro... more Introduction: Liver regeneration that follows after partial hepatectomy (pHx) is well-defined process, which involves the concerted action of extra and intracellular factors resulting in induction of cell replication and its inhibition at time when the entire liver mass is restored. Concomitantly, the breakdown of previously maintained tolerance and the exposure of self antigens lead to the activation of pre-immune and immune repertoire, which participate in surveillance against aberrant cells and re-establishment of previous morphostasis. Since, in these events, important biological function might have metallothioneins and tissue minerals which are affecting the structural integrity and enzyme activities, transduction signals, and replication factors during cell proliferation and apoptosis, as well as, the development and maintenance of immune functions, in this study we analyzed early metallothionein I+II (MT) expression and tissue kinetics of zinc, iron, magnesium and calcium in the liver, thymus and spleen after pHx. Material & Method: Analysis were done on 1st, 2nd, 6th, 12th, 24th and 48th hour after 1/3 pHx in C57Bl mice, using immunohistological staining and inductivity coupled plasma spectrometry for determination of MTs and tissue metals kinetics, respectively. Results: Hepatectomy was followed by fast upregulation of MT expression in the remnant liver, but also in the spleen and the thymus. In the liver it started in sinusoids (1h after pHx) and became impressive in hepatocytes (between the 6th and 72nd hour), where cytoplasmic and nuclear staining was seen (between the 6th and 72nd hour). In the spleen a marked overexpression of MT was found in parafollicular areas 24h after pHx, while in the thymus MT staining moderately increased in the subcortical and medullar zones (after 24h). Simultaneously, in the regenerating liver, immediately after the operation, accumulated Zn++, Fe++, Mg++ and Ca++, while their concentrations significantly decreased in the thymus (Zn++) and in the spleen (Zn++, Fe++, Ca++ and Mg++). Conclusions: The data point to early activation of highly interconnected network of growth-factors and cytokine-regulated pathways by pHx, in which metallothioneins in the regenerating liver, thymus and spleen could participate in a DNA synthesis-related processes, and transduction signals through abstraction or donation of metals such as Zn++, Fe++, Mg++ and Ca++. ((Supported by grants from Croatian Ministry of Science, projects No 0062018 and 0062002).

Research paper thumbnail of Regulatory T and NKT cells in syngeneic pregnancy

NKT cells and regulatory T cells (Treg) were claimed to be important players in the tolerance tow... more NKT cells and regulatory T cells (Treg) were claimed to be important players in the tolerance towards the fetus bearing alloantigens, having the pivotal role in triggering and inhibition of immune responses against self-antigens, as well as in regulation of innate immune response. They, however, might be related also with fetal invasion mechanisms at the maternal-fetal interface, with bacterial exposure, as well as with the systemic hormonal changes, induced by pregnancy, showing that they reflect more global changes of the maternal immune system. In an attempt to enlarge our previous findings showing that during syngeneic pregnancy in the liver accumulate cytotoxic self-reactive NKT cells, which usually cooperate with Treg cells, in this study we estimated the presence of CD4+CD25+Foxp3+ T cells in the liver, spleen and thymus of nonpregnant and pregnant C57/BL6 females matted with C57 BL/6 males. Furthermore, to examine the potential effects of bacterial toxins a group of pregnant mice was treated with peptidoglycan-monomer linked with zinc (PGM-Zn). Phenotypic analysis and cytotoxicity against syngeneic thymocytes and YAC-1 targets was made on the 16th day after detection of vaginal plugs. The data have shown that during syngeneic pregnancy in the maternal liver increases the proportion of CD4+CD25+Foxp3+, as well as CD3intermediate, NK1.1+ and IL-2Rb+ cells (NKT cells). Similar changes were induced by PGM-Zn, which additionally increased the Treg accumulation, particularly in the liver. The data point to interplay between the NKT and Treg cells, pointing to the liver as a place important for the activation of protective and tolerance-promoting mechanisms during the pregnancy.