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1.
C R Biol ; 344(2): 165-175, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34213854

RESUMO

The sizes of living organisms range over twenty orders of magnitude. Within the same species, the size of individuals also varies according to the environmental conditions to which they are subjected. From the studies conducted on organisms as diverse as the drosophila, the salamander or the mouse, laws and conserved mechanisms emerge that shed light on the fundamental aspects of growth, but also on more medical issues such as tissue regeneration, metabolic homeostasis and cancer.


Assuntos
Drosophila , Animais , Homeostase , Camundongos
2.
Int J Mol Sci ; 22(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198511

RESUMO

The insulin receptor (IR) is critically involved in maintaining glucose homeostasis. It undergoes proteolytic cleavage by proprotein convertases, which is an essential step for its activation. The importance of the insulin receptor in liver is well established, but its role in pancreatic ß cells is still controversial. In this study, we investigated the cleavage of the IR by the proprotein convertase FURIN in ß cells and hepatocytes, and the contribution of the IR in pancreatic ß cells and liver to glucose homeostasis. ß-cell-specific Furin knockout (ßFurKO) mice were glucose intolerant, but liver-specific Furin knockout (LFurKO) mice were normoglycemic. Processing of the IR was blocked in ßFurKO cells, but unaffected in LFurKO mice. Most strikingly, glucose homeostasis in ß-cell-specific IR knockout (ßIRKO) mice was normal in younger mice (up to 20 weeks), and only mildly affected in older mice (24 weeks). In conclusion, FURIN cleaves the IR non-redundantly in ß cells, but redundantly in liver. Furthermore, we demonstrated that the IR in ß cells plays a limited role in glucose homeostasis.


Assuntos
Furina/deficiência , Glucose/metabolismo , Células Secretoras de Insulina/metabolismo , Fígado/metabolismo , Receptor de Insulina/metabolismo , Animais , Furina/metabolismo , Intolerância à Glucose/metabolismo , Intolerância à Glucose/patologia , Homeostase , Camundongos Knockout , Proteólise , Receptor de Insulina/deficiência , Transdução de Sinais
3.
Int J Mol Sci ; 22(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198897

RESUMO

The introduction of metallic nanoparticles (mNPs) into the diet is a matter of concern for human health. In particular, their effect on the gastrointestinal tract may potentially lead to the increased passage of gluten peptides and the activation of the immune response. In consequence, dietary mNPs could play a role in the increasing worldwide celiac disease (CeD) incidence. We evaluated the potential synergistic effects that peptic-tryptic-digested gliadin (PT) and the most-used food mNPs may induce on the intestinal mucosa. PT interaction with mNPs and their consequent aggregation was detected by transmission electron microscopy (TEM) analyses and UV-Vis spectra. In vitro experiments on Caco-2 cells proved the synergistic cytotoxic effect of PT and mNPs, as well as alterations in the monolayer integrity and tight junction proteins. Exposure of duodenal biopsies to gliadin plus mNPs triggered cytokine production, but only in CeD biopsies. These results suggest that mNPs used in the food sector may alter intestinal homeostasis, thus representing an additional environmental risk factor for the development of CeD.


Assuntos
Doença Celíaca/dietoterapia , Dieta , Glutens/metabolismo , Nanopartículas/uso terapêutico , Biópsia , Células CACO-2 , Doença Celíaca/imunologia , Doença Celíaca/metabolismo , Doença Celíaca/patologia , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Homeostase/imunologia , Humanos , Imunidade/efeitos dos fármacos , Imunidade/imunologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Nanopartículas/metabolismo , Triticum/efeitos adversos
4.
Int J Mol Sci ; 22(12)2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34199317

RESUMO

Empagliflozin, an established treatment for type 2 diabetes (T2DM), has shown beneficial effects on liver steatosis and fibrosis in animals and in humans with T2DM, non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH). However, little is known about the effects of empagliflozin on liver function in advanced NASH with liver fibrosis and without diabetes. This study aimed to assess the effects of empagliflozin on hepatic and metabolic outcomes in a diet-induced obese (DIO) and insulin-resistant but non-diabetic biopsy-confirmed mouse model of advanced NASH. Male C57BL/6JRj mice with a biopsy-confirmed steatosis and fibrosis on AMLN diet (high fat, fructose and cholesterol) for 36-weeks were randomized to receive for 12 weeks: (a) Empagliflozin (10 mg/kg/d p.o.), or (b) vehicle. Metabolic outcomes, liver pathology, markers of Kupffer and stellate cell activation and lipidomics were assessed at the treatment completion. Empagliflozin did not affect the body weight, body composition or insulin sensitivity (assessed by intraperitoneal insulin tolerance test), but significantly improved glucose homeostasis as assessed by oral glucose tolerance test in DIO-NASH mice. Empagliflozin improved modestly the NAFLD activity score compared with the vehicle, mainly by improving inflammation and without affecting steatosis, the fibrosis stage and markers of Kupffer and stellate cell activation. Empagliflozin reduced the hepatic concentrations of pro-inflammatory lactosylceramides and increased the concentrations of anti-inflammatory polyunsaturated triglycerides. Empagliflozin exerts beneficial metabolic and hepatic (mainly anti-inflammatory) effects in non-diabetic DIO-NASH mice and thus may be effective against NASH even in non-diabetic conditions.


Assuntos
Compostos Benzidrílicos/uso terapêutico , Glucosídeos/uso terapêutico , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Animais , Antígenos CD/metabolismo , Compostos Benzidrílicos/farmacologia , Biópsia , Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Modelos Animais de Doenças , Glucose/metabolismo , Glucosídeos/farmacologia , Homeostase/efeitos dos fármacos , Resistência à Insulina , Lactosilceramidas/metabolismo , Lipidômica , Fígado/efeitos dos fármacos , Fígado/patologia , Camundongos Endogâmicos C57BL , Camundongos Obesos , Hepatopatia Gordurosa não Alcoólica/patologia , Triglicerídeos/metabolismo
5.
Sci Transl Med ; 13(600)2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193609

RESUMO

The paired box 6 (PAX6) transcription factor is crucial for normal pancreatic islet development and function. Heterozygous mutations of PAX6 are associated with impaired insulin secretion and early-onset diabetes mellitus in humans. However, the molecular mechanism of PAX6 in controlling insulin secretion in human beta cells and its pathophysiological role in type 2 diabetes (T2D) remain ambiguous. We investigated the molecular pathway of PAX6 in the regulation of insulin secretion and the potential therapeutic value of PAX6 in T2D by using human pancreatic beta cell line EndoC-ßH1, the db/db mouse model, and primary human pancreatic islets. Through loss- and gain-of-function approaches, we uncovered a mechanism by which PAX6 modulates glucose-stimulated insulin secretion (GSIS) through a cAMP response element-binding protein (CREB)/Munc18-1/2 pathway. Moreover, under diabetic conditions, beta cells and pancreatic islets displayed dampened PAX6/CREB/Munc18-1/2 pathway activity and impaired GSIS, which were reversed by PAX6 replenishment. Adeno-associated virus-mediated PAX6 overexpression in db/db mouse pancreatic beta cells led to a sustained amelioration of glycemic perturbation in vivo but did not affect insulin resistance. Our study highlights the pathophysiological role of PAX6 in T2D-associated beta cell dysfunction in humans and suggests the potential of PAX6 gene transfer in preserving and restoring beta cell function.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Ilhotas Pancreáticas , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Homeostase , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo
6.
Int J Mol Sci ; 22(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199458

RESUMO

As we age, our bodies accrue damage in the form of DNA mutations. These mutations lead to the generation of sub-optimal proteins, resulting in inadequate cellular homeostasis and senescence. The build-up of senescent cells negatively affects the local cellular micro-environment and drives ageing associated disease, including neurodegeneration. Therefore, limiting the accumulation of DNA damage is essential for healthy neuronal populations. The naked mole rats (NMR) are from eastern Africa and can live for over three decades in chronically hypoxic environments. Despite their long lifespan, NMRs show little to no biological decline, neurodegeneration, or senescence. Here, we discuss molecular pathways and adaptations that NMRs employ to maintain genome integrity and combat the physiological and pathological decline in organismal function.


Assuntos
Adaptação Fisiológica/genética , Senescência Celular/genética , Dano ao DNA/genética , Estresse Oxidativo/genética , Envelhecimento/genética , Animais , DNA/genética , Homeostase , Ratos-Toupeira/genética , Estresse Oxidativo/fisiologia
7.
Int J Mol Sci ; 22(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199590

RESUMO

In living cells Reactive Oxygen Species (ROS) participate in intra- and inter-cellular signaling and all cells contain specific systems that guard redox homeostasis. These systems contain both enzymes which may produce ROS such as NADPH-dependent and other oxidases or nitric oxide synthases, and ROS-neutralizing enzymes such as catalase, peroxiredoxins, thioredoxins, thioredoxin reductases, glutathione reductases, and many others. Most of the genes coding for these enzymes contain sequences targeted by micro RNAs (miRNAs), which are components of RNA-induced silencing complexes and play important roles in inhibiting translation of their targeted messenger RNAs (mRNAs). In this review we describe miRNAs that directly target and can influence enzymes responsible for scavenging of ROS and their possible role in cellular redox homeostasis. Regulation of antioxidant enzymes aims to adjust cells to survive in unstable oxidative environments; however, sometimes seemingly paradoxical phenomena appear where oxidative stress induces an increase in the levels of miRNAs which target genes which are supposed to neutralize ROS and therefore would be expected to decrease antioxidant levels. Here we show examples of such cellular behaviors and discuss the possible roles of miRNAs in redox regulatory circuits and further cell responses to stress.


Assuntos
Antioxidantes/metabolismo , Homeostase/genética , MicroRNAs/genética , Estresse Oxidativo/genética , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Humanos , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Oxirredução , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo
8.
Acta Biomed ; 92(3): e2021232, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34212898

RESUMO

BACKGROUND: The natural history of the glycometabolic state in transfusion-dependent ß-thalassemia (TDT) patients is characterized by a deterioration of glucose tolerance over time. AIMS: This review depicts our current knowledges on the complex and multifacet pathophysiologic mechanisms implicated in the development of alteration of glucose homeostasis in patients with TDT. SEARCH STRATEGY: A systematic search was done on December 2020 including Web of Science (ISI), Scopus,  PubMed, Embase, and Scholar for papers published in the last 20 years. Moreover, we checked the reference lists of the relevant articles and previously performed reviews for additional pertinent studies. The personal experience on the care of patients with thalassemias is also reported. CONCLUSION: A regular packed red blood cells (PRBCs) transfusion program, optimization of chelation therapy, and prevention and treatment of liver infections are critical to achieve adequate glucometabolic control in TDT patients. Many exciting opportunities remain for further research and therapeutic development.


Assuntos
Talassemia , Talassemia beta , Transfusão de Sangue , Glucose , Homeostase , Humanos , Talassemia beta/terapia
9.
Chimia (Aarau) ; 75(6): 495-499, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34233811

RESUMO

Among the many molecular entities suitable for therapeutic use, peptides have emerged as a particularly attractive option for academic drug discovery and development. Their modular structure and extendibility, the availability of powerful and affordable screening platforms, and the relative ease-of-synthesis render therapeutic peptides highly approachable for teaching and research alike. With a strong focus on the therapeutic modulation of host defence pathways, including the complement and renin-angiotensin systems, the Molecular Pharmacy group at the University of Basel strongly relies on peptides to introduce students to practical aspects of modern drug design, to discover novel therapeutics for immune and inflammatory diseases, and to expand on options for the preclinical development of a promising drug class. Current projects reach from student-driven iterative design of peptidic angiotensin-converting enzyme inhibitors and the use of phage display technology to discover novel immune modulators to the development of protective peptide coatings for biomaterials and transplants and the structure-activity-relationship-guided optimization of therapeutic peptide drug candidates in late-stage clinical trials. Even at the current stage, peptides allow for a perfect circle between pharmaceutical research and education, and the recent spark of clinical applications for peptide-based drugs may only increase the value and relevance of this versatile drug class.


Assuntos
Desenho de Fármacos , Peptídeos , Descoberta de Drogas , Homeostase , Humanos
10.
Front Cell Infect Microbiol ; 11: 668859, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34262881

RESUMO

Splenectomy or congenital asplenia in humans increases susceptibility to infections. We have previously reported that congenital asplenia in zebrafish reduces resistance to Aeromonas hydrophila infection. However, the molecular mechanism of systemic immune response in congenitally asplenic individuals is largely unexplored. In this study, we found that pro-inflammatory cytokines were more highly induced in congenitally asplenic zebrafish than wild-type after pathogenic A. hydrophila infection and lipopolysaccharide exposure. In addition, a higher aggregation of apoptotic cells was observed in congenitally asplenic zebrafish than that in wild-type. Next, we examined the transcriptome profiles of whole kidneys from wild-type and congenitally asplenic zebrafish to investigate the effects of congenital asplenia on innate and adaptive immune responses induced by the inactivated A. hydrophila. Congenital asplenia inactivated the splenic anti-inflammatory reflex, disrupted immune homeostasis, and induced excessive inflammation as evidenced by the highly induced stress response-related biological processes, inflammatory and apoptosis-associated pathways, and pro-inflammatory cytokines/chemokines in congenitally asplenic zebrafish compared with wild-type after vaccination. In addition, complement component genes (c3a.1, c3a.6, c4, c6, and c9) and several important immune-related genes (tabp.1, tap1, hamp, prg4b, nfil3, defbl1, psmb9a, tfr1a, and sae1) were downregulated in congenitally asplenic zebrafish. Furthermore, congenital asplenia impaired adaptive immunity as demonstrated by downregulation of biological processes and signaling pathways involved in adaptive immune response after vaccination in congenitally asplenic zebrafish. The expression of MHCII/IgM was also significantly reduced in the congenitally asplenic zebrafish when compared with wild-type. Together, our study provides an in-depth understanding of spleen function in controlling immune homeostasis and may offer insight into the pathological response in splenectomized or congenitally asplenic patients after infections.


Assuntos
Esplenectomia , Peixe-Zebra , Animais , Homeostase , Humanos , Inflamação , Baço
11.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204327

RESUMO

Despite its abundance in the environment, iron is poorly bioavailable and subject to strict conservation and internal recycling by most organisms. In vertebrates, the stability of iron concentration in plasma and extracellular fluid, and the total body iron content are maintained by the interaction of the iron-regulatory peptide hormone hepcidin with its receptor and cellular iron exporter ferroportin (SLC40a1). Ferroportin exports iron from duodenal enterocytes that absorb dietary iron, from iron-recycling macrophages in the spleen and the liver, and from iron-storing hepatocytes. Hepcidin blocks iron export through ferroportin, causing hypoferremia. During iron deficiency or after hemorrhage, hepcidin decreases to allow iron delivery to plasma through ferroportin, thus promoting compensatory erythropoiesis. As a host defense mediator, hepcidin increases in response to infection and inflammation, blocking iron delivery through ferroportin to blood plasma, thus limiting iron availability to invading microbes. Genetic diseases that decrease hepcidin synthesis or disrupt hepcidin binding to ferroportin cause the iron overload disorder hereditary hemochromatosis. The opposite phenotype, iron restriction or iron deficiency, can result from genetic or inflammatory overproduction of hepcidin.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Hepcidinas/metabolismo , Homeostase , Ferro/metabolismo , Animais , Comunicação Autócrina , Transporte Biológico , Proteínas de Transporte de Cátions/química , Suscetibilidade a Doenças , Hepcidinas/química , Humanos , Ligantes , Redes e Vias Metabólicas , Comunicação Parácrina , Ligação Proteica , Transdução de Sinais , Distribuição Tecidual
12.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204587

RESUMO

Structural disturbances of the subchondral bone are a hallmark of osteoarthritis (OA), including sclerotic changes, cystic lesions, and osteophyte formation. Osteocytes act as mechanosensory units for the micro-cracks in response to mechanical loading. Once stimulated, osteocytes initiate the reparative process by recruiting bone-resorbing cells and bone-forming cells to maintain bone homeostasis. Osteocyte-expressed sclerostin is known as a negative regulator of bone formation through Wnt signaling and the RANKL pathway. In this review, we will summarize current understandings of osteocytes at the crossroad of allometry and mechanobiology to exploit the relationship between osteocyte morphology and function in the context of joint aging and osteoarthritis. We also aimed to summarize the osteocyte dysfunction and its link with structural and functional disturbances of the osteoarthritic subchondral bone at the molecular level. Compared with normal bones, the osteoarthritic subchondral bone is characterized by a higher bone volume fraction, a larger trabecular bone number in the load-bearing region, and an increase in thickness of pre-existing trabeculae. This may relate to the aberrant expressions of sclerostin, periostin, dentin matrix protein 1, matrix extracellular phosphoglycoprotein, insulin-like growth factor 1, and transforming growth factor-beta, among others. The number of osteocyte lacunae embedded in OA bone is also significantly higher, yet the volume of individual lacuna is relatively smaller, which could suggest abnormal metabolism in association with allometry. The remarkably lower percentage of sclerostin-positive osteocytes, together with clustering of Runx-2 positive pre-osteoblasts, may suggest altered regulation of osteoblast differentiation and osteoblast-osteocyte transformation affected by both signaling molecules and the extracellular matrix. Aberrant osteocyte morphology and function, along with anomalies in molecular signaling mechanisms, might explain in part, if not all, the pre-osteoblast clustering and the uncoupled bone remodeling in OA subchondral bone.


Assuntos
Homeostase , Articulações/fisiologia , Osteoartrite/etiologia , Osteoartrite/metabolismo , Osteócitos/metabolismo , Animais , Biomarcadores , Remodelação Óssea , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Suscetibilidade a Doenças , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Osteoartrite/diagnóstico por imagem , Osteoartrite/patologia , Osteoblastos/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
13.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199719

RESUMO

Heart failure is a complex disease process with underlying aberrations in neurohormonal systems that promote dysregulated cellular signaling and gene transcription. Over the past 10 years, the advent of small-molecule inhibitors that target transcriptional machinery has demonstrated the importance of the bromodomain and extraterminal (BET) family of epigenetic reader proteins in regulating gene transcription in multiple mouse models of cardiomyopathy. BETs bind to acetylated histone tails and transcription factors to integrate disparate stress signaling networks into a defined gene expression program. Under myocardial stress, BRD4, a BET family member, is recruited to superenhancers and promoter regions of inflammatory and profibrotic genes to promote transcription elongation. Whole-transcriptome analysis of BET-dependent gene networks suggests a major role of nuclear-factor kappa b and transforming growth factor-beta in the development of cardiac fibrosis and systolic dysfunction. Recent investigations also suggest a prominent role of BRD4 in maintaining cardiomyocyte mitochondrial respiration under basal conditions. In this review, we summarize the data from preclinical heart failure studies that explore the role of BET-regulated transcriptional mechanisms and delve into landmark studies that define BET bromodomain-independent processes involved in cardiac homeostasis.


Assuntos
Regulação da Expressão Gênica , Insuficiência Cardíaca/genética , Fatores de Transcrição/metabolismo , Animais , Homeostase , Humanos , Modelos Biológicos , Miócitos Cardíacos/metabolismo
14.
Int J Mol Sci ; 22(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204139

RESUMO

The prohibitin (PHB)-binding compound fluorizoline as well as PHB-downregulation activate the integrated stress response (ISR) in HEK293T and U2OS human cell lines. This activation is denoted by phosphorylation of eIF2α and increases in ATF4, ATF3, and CHOP protein levels. The blockage of the activation of the ISR by overexpression of GRP78, as well as an increase in IRE1 activity, indicate the presence of ER stress after fluorizoline treatment. The inhibition of the ER stress response in HEK293T and U2OS led to increased sensitivity to fluorizoline-induced apoptosis, indicating a pro-survival role of this pathway after fluorizoline treatment in these cell lines. Fluorizoline induced an increase in calcium concentration in the cytosol and the mitochondria. Finally, two different calcium chelators reduced fluorizoline-induced apoptosis in U2OS cells. Thus, we have found that fluorizoline causes increased ER stress and activation of the integrated stress response, which in HEK293T and U2OS cells are protective against fluorizoline-induced apoptosis.


Assuntos
Apoptose , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Tiazóis/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Células HEK293 , Homeostase/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras/metabolismo , Transdução de Sinais/efeitos dos fármacos
15.
Int J Mol Sci ; 22(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204152

RESUMO

In nature, plants are exposed to an ever-changing environment with increasing frequencies of multiple abiotic stresses. These abiotic stresses act either in combination or sequentially, thereby driving vegetation dynamics and limiting plant growth and productivity worldwide. Plants' responses against these combined and sequential stresses clearly differ from that triggered by an individual stress. Until now, experimental studies were mainly focused on plant responses to individual stress, but have overlooked the complex stress response generated in plants against combined or sequential abiotic stresses, as well as their interaction with each other. However, recent studies have demonstrated that the combined and sequential abiotic stresses overlap with respect to the central nodes of their interacting signaling pathways, and their impact cannot be modelled by swimming in an individual extreme event. Taken together, deciphering the regulatory networks operative between various abiotic stresses in agronomically important crops will contribute towards designing strategies for the development of plants with tolerance to multiple stress combinations. This review provides a brief overview of the recent developments in the interactive effects of combined and sequentially occurring stresses on crop plants. We believe that this study may improve our understanding of the molecular and physiological mechanisms in untangling the combined stress tolerance in plants, and may also provide a promising venue for agronomists, physiologists, as well as molecular biologists.


Assuntos
Produtos Agrícolas/fisiologia , Estresse Fisiológico/fisiologia , Produtos Agrícolas/crescimento & desenvolvimento , Homeostase , Fotossíntese/fisiologia , Espécies Reativas de Oxigênio/metabolismo
16.
BMC Plant Biol ; 21(1): 320, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217224

RESUMO

N-terminal acetylation (NTA) is a highly abundant protein modification catalyzed by N-terminal acetyltransferases (NATs) in eukaryotes. However, the plant NATs and their biological functions have been poorly explored. Here we reveal that loss of function of CKRC3 and NBC-1, the auxiliary subunit (Naa25) and catalytic subunit (Naa20) of Arabidopsis NatB, respectively, led to defects in skotomorphogenesis and triple responses of ethylene. Proteome profiling and WB test revealed that the 1-amincyclopropane-1-carboxylate oxidase (ACO, catalyzing the last step of ethylene biosynthesis pathway) activity was significantly down-regulated in natb mutants, leading to reduced endogenous ethylene content. The defective phenotypes could be fully rescued by application of exogenous ethylene, but less by its precursor ACC. The present results reveal a previously unknown regulation mechanism at the co-translational protein level for ethylene homeostasis, in which the NatB-mediated NTA of ACOs render them an intracellular stability to maintain ethylene homeostasis for normal growth and responses.


Assuntos
Aminoácido Oxirredutases/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Homeostase , Acetiltransferase N-Terminal B/metabolismo , Acetilação , Sequência de Aminoácidos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Biocatálise , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas , Morfogênese , Mutação/genética , Proteoma/metabolismo , Regulação para Cima/genética
17.
Rinsho Ketsueki ; 62(5): 521-527, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34248130

RESUMO

Cell cycle quiescence is a fundamental property of hematopoietic stem cells (HSCs). Quiescent HSCs form a healthy pool of cells that serve as a reserve for massive HSC expansion under various conditions of stress. We previously reported that thrombopoietin (THPO) maintains quiescent HSCs and stimulates mitochondrial metabolism, megakaryocyte-lineage differentiation, and proliferation of HSCs. The underlying mechanism by which THPO balances its contradictory effect of promoting proliferation or quiescence on HSCs remains unknown. This review explores the role of THPO signaling in HSC differentiation and quiescence regulation. We present our data, which suggests that a THPO-independent HSC subpopulation sustaining a low mitochondrial metabolic profile reverts to quiescence and regains stem cell potential with external stimuli. There is a possibility that THPO-independent HSCs form a non-quiescent reserve HSC pool from which quiescent HSCs originate in the adult bone marrow.


Assuntos
Células-Tronco Hematopoéticas , Trombopoetina , Ciclo Celular , Células-Tronco Hematopoéticas/metabolismo , Homeostase , Mitocôndrias , Receptores de Trombopoetina
18.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208774

RESUMO

Bile acids (BA) play a significant role in the pathophysiology of nonalcoholic steatohepatitis (NASH). The present study evaluates the modulation of bile acid metabolomics by atorvastatin, a cholesterol-lowering agent commonly used to treat cardiovascular complications accompanying NASH. NASH was induced in mice by 24 weeks of consuming a high-saturated fat, high-fructose, and high-cholesterol diet (F), with atorvastatin administered orally (20 mg/kg/day) during the last three weeks. Biochemical and histological analyses confirmed the effectiveness of the F diet in inducing NASH. Untreated NASH animals had significantly reduced biliary secretion of BA and increased fecal excretion of BA via decreased apical sodium-dependent bile salt transporter (Asbt)-mediated reabsorption. Atorvastatin decreased liver steatosis and inflammation in NASH animals consistently with a reduction in crucial lipogenic enzyme stearoyl-coenzyme A (CoA) desaturase-1 and nuclear factor kappa light chain enhancer of activated B-cell pro-inflammatory signaling, respectively. In this group, atorvastatin also uniformly enhanced plasma concentration, biliary secretion and fecal excretion of the secondary BA, deoxycholic acid (DCA). However, in the chow diet-fed animals, atorvastatin decreased plasma concentrations of BA, and reduced BA biliary secretions. These changes stemmed primarily from the increased fecal excretion of BA resulting from the reduced Asbt-mediated BA reabsorption in the ileum and suppression of synthesis in the liver. In conclusion, our results reveal that atorvastatin significantly modulates BA metabolomics by altering their intestinal processing and liver synthesis in control and NASH mice.


Assuntos
Atorvastatina/farmacologia , Ácidos e Sais Biliares/metabolismo , Homeostase , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Animais , Biomarcadores , Dieta Hiperlipídica , Modelos Animais de Doenças , Fígado/metabolismo , Camundongos , Modelos Biológicos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/patologia , Triglicerídeos/biossíntese
19.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204294

RESUMO

Persistent infection with High Risk-Human Papilloma Viruses (HR-HPVs) is a primary cause of cervical cancer worldwide. Vaginal-dysbiosis-associated bacteria were correlated with the persistence of HR-HPVs infection and with increased cancer risk. We obtained strains of the most represented bacterial species in vaginal microbiota and evaluated their effects on the survival of cervical epithelial cells and immune homeostasis. The contribution of each species to supporting the antiviral response was also studied. Epithelial cell viability was affected by culture supernatants of most vaginal-dysbiosis bacteria, whereas Lactobacillus gasseri or Lactobacillus jensenii resulted in the best stimulus to induce interferon-γ (IFN-γ) production by human mononuclear cells from peripheral blood (PBMCs). Although vaginal-dysbiosis-associated bacteria induced the IFN-γ production, they were also optimal stimuli to interleukin-17 (IL-17) production. A positive correlation between IL-17 and IFN-γ secretion was observed in cultures of PBMCs with all vaginal-dysbiosis-associated bacteria suggesting that the adaptive immune response induced by these strains is not dominated by TH1 differentiation with reduced availability of IFN-γ, cytokine most effective in supporting virus clearance. Based on these results, we suggest that a vaginal microbiota dominated by lactobacilli, especially by L. gasseri or L. jensenii, may be able to assist immune cells with clearing HPV infection, bypasses the viral escape and restores immune homeostasis.


Assuntos
Antibiose , Disbiose , Homeostase , Lactobacillus/fisiologia , Membrana Mucosa/imunologia , Membrana Mucosa/microbiologia , Vagina/imunologia , Vagina/microbiologia , Sobrevivência Celular , Citocinas/biossíntese , Células Epiteliais/metabolismo , Ácidos Graxos Voláteis/biossíntese , Feminino , Humanos , Vagina/metabolismo
20.
Nihon Yakurigaku Zasshi ; 156(4): 225-229, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34193701

RESUMO

Microglia originating from yolk sac exert various functions to maintain the homeostasis in the brain, and their functional breakdown appears to be involved in the pathophysiology of various neurological diseases. In this review article, loss of homeostatic microglia and new therapeutic approaches for rare neurological disorders are discussed. ASLP (adult-onset leukoencephalopathy with axonal spheroids and pigmented glia) known as a primary microgliopathy is an adult-onset leukoencephalopathy caused by CSF1R mutation. CSF1 receptor encoded by CSF1R plays an important role in the function of microglia. In brain of ALSP patients, homeostatic microglia are significantly reduced. The biallelic mutations for CSF1R cause childhood-onset severe phenotype and elimination of microglia from the brain parenchyma. Since microglia also almost disappear in CSF1R-deficient mice and rats, CSF1R deficiency and loss of microglia appear to be tightly associated across species. Based on the underlying mechanism of homeostatic microglia loss, novel approaches using cell transplantation of normal microglia-like cells have been attempted. Transplantation of wild-type bone marrow cells into Csf1r-/- mice results in replacement by donor-derived microglial-like cells in the recipient's brain. The concept of "microglial niche" may explain the rationale behind the microglial cell transplantation in disease condition(s). Hematopoietic stem cell transplantation (HSCT) has been attempted in 4 patients with ALSP. Beneficial effects by showing stabilization of the disease course have been observed. Although the effectiveness of HSCT for ALSP patients warrants further investigation, the approach of cell transplantation that replaces ruptured homeostatic microglia with normal microglia-like cells seems to be promising.


Assuntos
Leucoencefalopatias , Microglia , Adulto , Animais , Transplante de Células , Criança , Homeostase , Humanos , Camundongos , Ratos , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos
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