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1.
Nature ; 596(7870): 43-53, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34349292

RESUMO

The genomes of virtually all organisms contain repetitive sequences that are generated by the activity of transposable elements (transposons). Transposons are mobile genetic elements that can move from one genomic location to another; in this process, they amplify and increase their presence in genomes, sometimes to very high copy numbers. In this Review we discuss new evidence and ideas that the activity of retrotransposons, a major subgroup of transposons overall, influences and even promotes the process of ageing and age-related diseases in complex metazoan organisms, including humans. Retrotransposons have been coevolving with their host genomes since the dawn of life. This relationship has been largely competitive, and transposons have earned epithets such as 'junk DNA' and 'molecular parasites'. Much of our knowledge of the evolution of retrotransposons reflects their activity in the germline and is evident from genome sequence data. Recent research has provided a wealth of information on the activity of retrotransposons in somatic tissues during an individual lifespan, the molecular mechanisms that underlie this activity, and the manner in which these processes intersect with our own physiology, health and well-being.


Assuntos
Envelhecimento/genética , Envelhecimento/patologia , Doença/genética , Retroelementos/genética , Animais , Dano ao DNA , Inativação Gênica , Genoma Humano/genética , Genômica , Humanos , Imunidade Inata
2.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445538

RESUMO

Decellularized tissues are biocompatible materials that engraft well, but the age of their source has not been explored for clinical translation. Advanced glycation end products (AGEs) are chemical cross-links that accrue on skeletal muscle collagen in old age, stiffening the matrix and increasing inflammation. Whether decellularized biomaterials derived from aged muscle would suffer from increased AGE collagen cross-links is unknown. We characterized gastrocnemii of 1-, 2-, and 20-month-old C57BL/6J mice before and after decellularization to determine age-dependent changes to collagen stiffness and AGE cross-linking. Total and soluble collagen was measured to assess if age-dependent increases in collagen and cross-linking persisted in decellularized muscle matrix (DMM). Stiffness of aged DMM was determined using atomic force microscopy. AGE levels and the effect of an AGE cross-link breaker, ALT-711, were tested in DMM samples. Our results show that age-dependent increases in collagen amount, cross-linking, and general stiffness were observed in DMM. Notably, we measured increased AGE-specific cross-links within old muscle, and observed that old DMM retained AGE cross-links using ALT-711 to reduce AGE levels. In conclusion, deleterious age-dependent modifications to collagen are present in DMM from old muscle, implying that age matters when sourcing skeletal muscle extracellular matrix as a biomaterial.


Assuntos
Envelhecimento/metabolismo , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Músculo Esquelético/metabolismo , Envelhecimento/patologia , Animais , Matriz Extracelular/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/patologia
3.
Anim Sci J ; 92(1): e13608, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34405491

RESUMO

This study aims to investigate the morphology and distribution of mitochondria, spindles, and chromosomes in oocytes of aged mice and examine the effects of SRT1720 on oocyte maturation. C57BL/6J mice were divided into young (4-8 weeks) and aged groups (48-52 weeks). In vitro maturation media contained (0.05, 0.1, and 1.0 µM) SRT1720 and 0.1-µM dimethyl sulfoxide (DMSO control). The rate of chromosome misalignment and spindle misorientation in oocytes of aged mice were significantly higher than that of young mice (P < 0.01). Fluorescence intensity of mitochondria from oocytes of aged mice was significantly lower than that of young mice (P < 0.01). SRT1720 at 0.1 µM significantly improved oocyte maturation, fertilization, and blastocyst formation in aged mice compared with young mice (P < 0.01). Additionally, immunofluorescence intensity of mitochondria, normal spindle morphology, and chromosome alignment were notably enhanced with SRT1720 when compared with the DSMO control group for metaphase II (MII)-stage oocytes matured in vitro (P < 0.01); 0.1-µM SRT1720 enhanced the expression level of SRIT1 in oocytes from aged mice. In summary, the aged mice oocytes showed increased nuclear and cytoplasmic defects, whereas SRT1720 enhanced oocyte maturation and quality. We concluded that 0.1-µM SRT1720 was an appropriate concentration for in vitro maturation media.


Assuntos
Envelhecimento/efeitos dos fármacos , Envelhecimento/patologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Técnicas de Maturação in Vitro de Oócitos , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Animais , Blastocisto , Cromossomos/metabolismo , Relação Dose-Resposta a Droga , Feminino , Fertilização/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Oócitos/citologia , Oócitos/ultraestrutura , Fuso Acromático/metabolismo , Fuso Acromático/patologia
4.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360708

RESUMO

BACKGROUND: exposure to environmental contaminants has been linked to an increased risk of neurological diseases and poor outcomes. Chemical name of Atrazine (ATR) is 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine, and it is the most commonly used broad-spectrum herbicide in agricultural crops. Several studies have demonstrated that ATR has the potential to be harmful to the brain's neuronal circuits. Until today nobody has explored the effect of ATR inhalation on young and aged mice. METHODS: young and aged mice were subject to 25 mg of ATR in a vehicle made with saline and 10% of Dimethyl sulfoxide (DMSO) every day for 28 days. At the end of experiment different behavioral test were made and brain was collected. RESULTS: exposure to ATR induced the same response in terms of behavioral alterations and motor and memory impairment in mice but in aged group was more marked. Additionally, in both young and aged mice ATR inhalations induced oxidative stress with impairment in physiological antioxidant response, lipid peroxidation, nuclear factor kappa-light-chain-enhancer of activated B cells (nf-κb) pathways activation with consequences of pro-inflammatory cytokines release and apoptosis. However, the older group was shown to be more sensitive to ATR inhalation. CONCLUSIONS: our results showed that aged mice were more susceptible compared to young mice to air pollutants exposure, put in place a minor physiologically response was seen when exposed to it.


Assuntos
Envelhecimento/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Atrazina/efeitos adversos , Encéfalo/metabolismo , Administração por Inalação , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Atrazina/farmacologia , Encéfalo/patologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Masculino , Camundongos
5.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360722

RESUMO

Biological aging research is expected to reveal modifiable molecular mechanisms that can be harnessed to slow or possibly reverse unhealthy trajectories. However, there is first an urgent need to define consensus molecular markers of healthy and unhealthy aging. Established aging hallmarks are all linked to metabolism, and a 'rewired' metabolic circuitry has been shown to accelerate or delay biological aging. To identify metabolic signatures distinguishing healthy from unhealthy aging trajectories, we performed nontargeted metabolomics on skeletal muscles from 2-month-old and 21-month-old mice, and after dietary and lifestyle interventions known to impact biological aging. We hypothesized that common metabolic signatures would highlight specific pathways and processes promoting healthy aging, while revealing the molecular underpinnings of unhealthy aging. Here, we report 50 metabolites that commonly distinguished aging trajectories in all cohorts, including 18 commonly reduced under unhealthy aging and 32 increased. We stratified these metabolites according to known relationships with various aging hallmarks and found the greatest associations with oxidative stress and nutrient sensing. Collectively, our data suggest interventions aimed at maintaining skeletal muscle arginine and lysine may be useful therapeutic strategies to minimize biological aging and maintain skeletal muscle health, function, and regenerative capacity in old age.


Assuntos
Envelhecimento/metabolismo , Arginina/metabolismo , Lisina/metabolismo , Músculo Esquelético/metabolismo , Estresse Oxidativo , Transdução de Sinais , Envelhecimento/patologia , Animais , Masculino , Camundongos , Músculo Esquelético/patologia
6.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360563

RESUMO

For many years, the dogma has been that insulin resistance precedes the development of hyperinsulinemia. However, recent data suggest a reverse order and place hyperinsulinemia mechanistically upstream of insulin resistance. Genetic background, consumption of the "modern" Western diet and over-nutrition may increase insulin secretion, decrease insulin pulses and/or reduce hepatic insulin clearance, thereby causing hyperinsulinemia. Hyperinsulinemia disturbs the balance of the insulin-GH-IGF axis and shifts the insulin : GH ratio towards insulin and away from GH. This insulin-GH shift promotes energy storage and lipid synthesis and hinders lipid breakdown, resulting in obesity due to higher fat accumulation and lower energy expenditure. Hyperinsulinemia is an important etiological factor in the development of metabolic syndrome, type 2 diabetes, cardiovascular disease, cancer and premature mortality. It has been further hypothesized that nutritionally driven insulin exposure controls the rate of mammalian aging. Interventions that normalize/reduce plasma insulin concentrations might play a key role in the prevention and treatment of age-related decline, obesity, type 2 diabetes, cardiovascular disease and cancer. Caloric restriction, increasing hepatic insulin clearance and maximizing insulin sensitivity are at present the three main strategies available for managing hyperinsulinemia. This may slow down age-related physiological decline and prevent age-related diseases. Drugs that reduce insulin (hyper) secretion, normalize pulsatile insulin secretion and/or increase hepatic insulin clearance may also have the potential to prevent or delay the progression of hyperinsulinemia-mediated diseases. Future research should focus on new strategies to minimize hyperinsulinemia at an early stage, aiming at successfully preventing and treating hyperinsulinemia-mediated diseases.


Assuntos
Envelhecimento/patologia , Doenças Cardiovasculares/patologia , Diabetes Mellitus Tipo 2/patologia , Hiperinsulinismo/complicações , Resistência à Insulina , Neoplasias/patologia , Obesidade/patologia , Doenças Cardiovasculares/etiologia , Diabetes Mellitus Tipo 2/etiologia , Humanos , Neoplasias/etiologia
7.
Int J Mol Sci ; 22(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34360590

RESUMO

Poor sleep quality and disrupted circadian behavior are a normal part of aging and include excessive daytime sleepiness, increased sleep fragmentation, and decreased total sleep time and sleep quality. Although the neuronal decline underlying the cellular mechanism of poor sleep has been extensively investigated, brain function is not fully dependent on neurons. A recent antemortem autographic study and postmortem RNA sequencing and immunohistochemical studies on aged human brain have investigated the relationship between sleep fragmentation and activation of the innate immune cells of the brain, microglia. In the process of aging, there are marked reductions in the number of brain microglial cells, and the depletion of microglial cells disrupts circadian rhythmicity of brain tissue. We also showed, in a previous study, that pharmacological suppression of microglial function induced sleep abnormalities. However, the mechanism underlying the contribution of microglial cells to sleep homeostasis is only beginning to be understood. This review revisits the impact of aging on the microglial population and activation, as well as microglial contribution to sleep maintenance and response to sleep loss. Most importantly, this review will answer questions such as whether there is any link between senescent microglia and age-related poor quality sleep and how this exacerbates neurodegenerative disease.


Assuntos
Envelhecimento/patologia , Microglia/patologia , Doenças Neurodegenerativas/complicações , Distúrbios do Início e da Manutenção do Sono/patologia , Animais , Humanos , Distúrbios do Início e da Manutenção do Sono/etiologia
8.
Int J Mol Sci ; 22(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34360831

RESUMO

The neuromuscular junction (NMJ) is a specialized synapse that bridges the motor neuron and the skeletal muscle fiber and is crucial for conversion of electrical impulses originating in the motor neuron to action potentials in the muscle fiber. The consideration of contributing factors to skeletal muscle injury, muscular dystrophy and sarcopenia cannot be restricted only to processes intrinsic to the muscle, as data show that these conditions incur denervation-like findings, such as fragmented NMJ morphology and corresponding functional changes in neuromuscular transmission. Primary defects in the NMJ also influence functional loss in motor neuron disease, congenital myasthenic syndromes and myasthenia gravis, resulting in skeletal muscle weakness and heightened fatigue. Such findings underscore the role that the NMJ plays in neuromuscular performance. Regardless of cause or effect, functional denervation is now an accepted consequence of sarcopenia and muscle disease. In this short review, we provide an overview of the pathologic etiology, symptoms, and therapeutic strategies related to the NMJ. In particular, we examine the role of the NMJ as a disease modifier and a potential therapeutic target in neuromuscular injury and disease.


Assuntos
Envelhecimento/patologia , Músculo Esquelético/patologia , Doenças Neuromusculares/patologia , Junção Neuromuscular/patologia , Animais , Humanos
9.
Int J Mol Sci ; 22(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204098

RESUMO

Ocular graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic stem cell transplantation. Ocular GVHD affects recipients' visual function and quality of life. Recent advanced research in this area has gradually attracted attention from a wide range of physicians and ophthalmologists. This review highlights the mechanism of immune processes and the molecular mechanism, including several inflammation cascades, pathogenic fibrosis, and stress-induced senescence related to ocular GVHD, in basic spectrum topics in this area. How the disease develops and what kinds of cells participate in ocular GVHD are discussed. Although the classical immune process is a main pathological pathway in this disease, senescence-associated changes in immune cells and stem cells may also drive this disease. The DNA damage response, p16/p21, and the expression of markers associated with the senescence-associated secretory phenotype (SASP) are seen in ocular tissue in GVHD. Macrophages, T cells, and mesenchymal cells from donors or recipients that increasingly infiltrate the ocular surface serve as the source of increased secretion of IL-6, which is a major SASP driver. Agents capable of reversing the changes, including senolytic reagents or those that can suppress the SASP seen in GVHD, provide new potential targets for the treatment of GVHD. Creating innovative therapies for ocular GVHD is necessary to treat this intractable ocular disease.


Assuntos
Envelhecimento/patologia , Síndromes do Olho Seco/etiologia , Doença Enxerto-Hospedeiro/complicações , Inflamação/complicações , Estresse Fisiológico , Animais , Doença Crônica , Fibrose , Doença Enxerto-Hospedeiro/imunologia , Humanos , Inflamação/imunologia
10.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208040

RESUMO

(1) Background: The pro-resolving lipid mediator Resolvin D1 (RvD1) has already shown protective effects in animal models of diabetic retinopathy. This study aimed to investigate the retinal levels of RvD1 in aged (24 months) and younger (3 months) Balb/c mice, along with the activation of macro- and microglia, apoptosis, and neuroinflammation. (2) Methods: Retinas from male and female mice were used for immunohistochemistry, immunofluorescence, transmission electron microscopy, Western blotting, and enzyme-linked immunosorbent assays. (3) Results: Endogenous retinal levels of RvD1 were reduced in aged mice. While RvD1 levels were similar in younger males and females, they were markedly decreased in aged males but less reduced in aged females. Both aged males and females showed a significant increase in retinal microglia activation compared to younger mice, with a more marked reactivity in aged males than in aged females. The same trend was shown by astrocyte activation, neuroinflammation, apoptosis, and nitrosative stress, in line with the microglia and Müller cell hypertrophy evidenced in aged retinas by electron microscopy. (4) Conclusions: Aged mice had sex-related differences in neuroinflammation and apoptosis and low retinal levels of endogenous RvD1.


Assuntos
Envelhecimento/patologia , Ácidos Docosa-Hexaenoicos/farmacologia , Inflamação/patologia , Retina/patologia , Caracteres Sexuais , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Caspase 3/metabolismo , Células Ependimogliais/efeitos dos fármacos , Células Ependimogliais/metabolismo , Células Ependimogliais/patologia , Células Ependimogliais/ultraestrutura , Feminino , Masculino , Camundongos Endogâmicos BALB C , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Microglia/ultraestrutura , NF-kappa B/metabolismo , Retina/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo
11.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34298993

RESUMO

Age-related macular degeneration (AMD) is a complex multifactorial neurodegenerative disease that constitutes the most common cause of irreversible blindness in the elderly in the developed countries. Incomplete knowledge about its pathogenesis prevents the search for effective methods of prevention and treatment of AMD, primarily of its "dry" type which is by far the most common (90% of all AMD cases). In the recent years, AMD has become "younger": late stages of the disease are now detected in relatively young people. It is known that AMD pathogenesis-according to the age-related structural and functional changes in the retina-is linked with inflammation, hypoxia, oxidative stress, mitochondrial dysfunction, and an impairment of neurotrophic support, but the mechanisms that trigger the conversion of normal age-related changes to the pathological process as well as the reason for early AMD development remain unclear. In the adult mammalian retina, de novo neurogenesis is very limited. Therefore, the structural and functional features that arise during its maturation and formation can exert long-term effects on further ontogenesis of this tissue. The aim of this review was to discuss possible contributions of the changes/disturbances in retinal neurogenesis to the early development of AMD.


Assuntos
Envelhecimento/patologia , Degeneração Macular/etiologia , Degeneração Macular/metabolismo , Doenças Neurodegenerativas/metabolismo , Neurogênese , Retina/crescimento & desenvolvimento , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Degeneração Macular/genética , Degeneração Macular/patologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Neurogênese/efeitos dos fármacos , Neurogênese/genética , Retina/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Aging (Albany NY) ; 13(13): 17568-17591, 2021 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-34226295

RESUMO

The homeostasis of the ocular lens is maintained by a microcirculation system propagated through gap junction channels. It is well established that the intercellular communications of the lens become deteriorative during aging. However, the molecular basis for this change in human lenses has not been well defined. Here, we present evidence to show that over 90% of Cx46 and Cx50 are lost in the fiber cells of normal human lenses aged 50 and above. From transparent to cataractous lenses, while Cx43 was upregulated, both Cx46 and Cx50 were significantly down-regulated in the lens epithelia. During aging of mouse lenses, Cx43 remained unchanged, but both Cx46 and Cx50 were significantly downregulated. Under oxidative stress treatment, mouse lenses develop in vitro cataractogenesis. Associated with this process, Cx43 was significantly upregulated, in contrast, Cx46 and Cx50 were sharply downregulated. Together, our results for the first time reveal that downregulation in Cx46 and Cx50 levels appears to be the major reason for the diminished coupling conductance, and the aging-dependent loss of Cx46 and Cx50 promotes senile cataractogenesis.


Assuntos
Envelhecimento/fisiologia , Catarata/genética , Catarata/patologia , Conexinas/biossíntese , Conexinas/genética , Cristalino/patologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Epitélio Corneano/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade
13.
Life Sci ; 283: 119855, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34314734

RESUMO

AIMS: Aging is an obvious risk factor for detrusor underactivity. We investigated the effects of aging on bladder function in spontaneously hypertensive rats. MAIN METHODS: Male spontaneously hypertensive rats and Wistar Kyoto rats (used as normotensive controls) at the ages of 18, 36, 54, or 72 weeks were used. Bladder weight, blood pressure, bladder blood flow, and urodynamic and renal parameters were measured. Additionally, detrusor thickness and renal histology were evaluated. KEY FINDINGS: In spontaneously hypertensive rats, significant increases were observed in bladder weight/body weight ratio, blood pressure, detrusor thickness, intercontraction interval, urine output, serum creatinine, and renal glomerular and tubular scores, and decreases in bladder blood flow and urine osmolality at 72 weeks as compared to those at 18 weeks. In spontaneously hypertensive rats, significant increases were observed in single voided volume, post voiding residual urine volume, and bladder capacity, with decrease in voiding efficiency were observed at 54 or 72 weeks than at 18 weeks. However, there were no significant differences in blood pressure, urodynamic and renal parameters, detrusor thickness and renal histology among Wistar Kyoto rats of different ages. SIGNIFICANCE: In spontaneously hypertensive rats, aging induces significant increases in blood pressure, single voided volume, post voiding residual urine volume, intercontraction intervals and urine output, and decreases in voiding efficiency and bladder blood flow indicative of detrusor underactivity. Aging-related severe hypertension could induce voiding dysfunction such as detrusor underactivity via severe bladder ischemia and polyuria. Aged spontaneously hypertensive rats may be useful animal models for detrusor underactivity.


Assuntos
Envelhecimento/metabolismo , Hipertensão , Bexiga Inativa , Bexiga Urinária , Envelhecimento/patologia , Animais , Hipertensão/complicações , Hipertensão/metabolismo , Hipertensão/patologia , Hipertensão/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Índice de Gravidade de Doença , Bexiga Urinária/metabolismo , Bexiga Urinária/patologia , Bexiga Urinária/fisiopatologia , Bexiga Inativa/etiologia , Bexiga Inativa/metabolismo , Bexiga Inativa/patologia , Bexiga Inativa/fisiopatologia
14.
Int J Mol Sci ; 22(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299168

RESUMO

The recent advances in deciphering the human genome allow us to understand and evaluate the mechanisms of human genome age-associated transformations, which are largely unclear. Genome sequencing techniques assure comprehensive mapping of human genetics; however, understanding of gene functional interactions, specifically of time/age-dependent modifications, remain challenging. The age of the genome is defined by the sum of individual (inherited) and acquired genomic traits, based on internal and external factors that impact ontogenesis from the moment of egg fertilization and embryonic development. The biological part of genomic age opens a new perspective for intervention. The discovery of single cell-based mechanisms for genetic change indicates the possibility of influencing aging and associated disease burden, as well as metabolism. Cell populations with transformed genetic background were shown to serve as the origin of common diseases during extended life expectancy (superaging). Consequently, age-related cell transformation leads to cancer and cell degeneration (senescence). This article aims to describe current advances in the genomic mechanisms of senescence and its role in the spatiotemporal spread of epithelial clones and cell evolution.


Assuntos
Envelhecimento/patologia , Senescência Celular , Células Epiteliais/patologia , Genoma Humano , Neoplasias/patologia , Humanos , Neoplasias/etiologia , Fenótipo
15.
Aging (Albany NY) ; 13(13): 16938-16956, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34292877

RESUMO

Macrophage accumulation and nitrosative stress are known mechanisms underlying age-related cardiovascular pathology and functional decline. The cardiac muscle microenvironment is known to change with age, yet the direct effects of these changes have yet to be studied in-depth. The present study sought to better elucidate the role that biochemical and biomechanical alterations in cardiac tissue have in the altered phenotype and functionality of cardiac resident macrophages observed with increasing age. To accomplish this, naïve bone marrow derived macrophages from young mice were seeded onto either functionalized poly-dimethyl-siloxane hydrogels ranging in stiffness from 2kPA to 64kPA or onto tissue culture plastic, both of which were coated with either young or aged solubilized mouse cardiac extracellular matrix (cECM). Both biomechanical and biochemical alterations were found to have a significant effect on macrophage polarization and function. Increased substrate stiffness was found to promote macrophage morphologies associated with pro-inflammatory macrophage activation, increased expression of pro-inflammatory inducible nitric oxide synthase protein with increased nitric oxide secretion, and attenuated arginase activity and protein expression. Additionally, exposure to aged cECM promoted attenuated responsivity to both canonical pro-inflammatory and anti-inflammatory cytokine signaling cues when compared to young cECM treated cells. These results suggest that both biomechanical and biochemical changes in the cardiovascular system play a role in promoting the age-related shift towards pro-inflammatory macrophage populations associated with cardiovascular disease development.


Assuntos
Microambiente Celular/fisiologia , Coração/fisiologia , Macrófagos/fisiologia , Macrófagos/ultraestrutura , Envelhecimento/patologia , Envelhecimento/fisiologia , Animais , Arginase/metabolismo , Fenômenos Biomecânicos , Células da Medula Óssea , Citocinas/metabolismo , DNA/biossíntese , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/patologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/biossíntese , Fenótipo , Transdução de Sinais , Técnicas de Cultura de Tecidos
16.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200434

RESUMO

The auditory system is a fascinating sensory organ that overall, converts sound signals to electrical signals of the nervous system. Initially, sound energy is converted to mechanical energy via amplification processes in the middle ear, followed by transduction of mechanical movements of the oval window into electrochemical signals in the cochlear hair cells, and finally, neural signals travel to the central auditory system, via the auditory division of the 8th cranial nerve. The majority of people above 60 years have some form of age-related hearing loss, also known as presbycusis. However, the biological mechanisms of presbycusis are complex and not yet fully delineated. In the present article, we highlight ion channels and transport proteins, which are integral for the proper functioning of the auditory system, facilitating the diffusion of various ions across auditory structures for signal transduction and processing. Like most other physiological systems, hearing abilities decline with age, hence, it is imperative to fully understand inner ear aging changes, so ion channel functions should be further investigated in the aging cochlea. In this review article, we discuss key various ion channels in the auditory system and how their functions change with age. Understanding the roles of ion channels in auditory processing could enhance the development of potential biotherapies for age-related hearing loss.


Assuntos
Envelhecimento/patologia , Proteínas de Transporte/metabolismo , Canais Iônicos/metabolismo , Presbiacusia/patologia , Envelhecimento/metabolismo , Animais , Humanos , Presbiacusia/metabolismo
17.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201282

RESUMO

Aging is associated with a general decline of cognitive functions, and it is widely accepted that this decline results from changes in the expression of proteins involved in regulation of synaptic plasticity. However, several lines of evidence have accumulated that suggest that the impaired function of the aged brain may be related to significant alterations in the energy metabolism. In the current study, we employed the label-free "Total protein approach" (TPA) method to focus on the similarities and differences in energy metabolism proteomes of young (1-month-old) and aged (22-month-old) murine brains. We quantified over 7000 proteins in each of the following three analyzed brain structures: the hippocampus, the cerebral cortex and the cerebellum. To the best of our knowledge, this is the most extensive quantitative proteomic description of energy metabolism pathways during the physiological aging of mice. The analysis demonstrates that aging does not significantly affect the abundance of total proteins in the studied brain structures, however, the levels of proteins constituting energy metabolism pathways differ significantly between young and aged mice.


Assuntos
Envelhecimento/metabolismo , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Metabolismo Energético , Hipocampo/metabolismo , Proteoma/metabolismo , Envelhecimento/patologia , Animais , Cerebelo/patologia , Córtex Cerebral/patologia , Feminino , Hipocampo/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteoma/análise
18.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201319

RESUMO

Proper skeletal muscle function is controlled by intracellular Ca2+ concentration and by efficient production of energy (ATP), which, in turn, depend on: (a) the release and re-uptake of Ca2+ from sarcoplasmic-reticulum (SR) during excitation-contraction (EC) coupling, which controls the contraction and relaxation of sarcomeres; (b) the uptake of Ca2+ into the mitochondrial matrix, which stimulates aerobic ATP production; and finally (c) the entry of Ca2+ from the extracellular space via store-operated Ca2+ entry (SOCE), a mechanism that is important to limit/delay muscle fatigue. Abnormalities in Ca2+ handling underlie many physio-pathological conditions, including dysfunction in ageing. The specific focus of this review is to discuss the importance of the proper architecture of organelles and membrane systems involved in the mechanisms introduced above for the correct skeletal muscle function. We reviewed the existing literature about EC coupling, mitochondrial Ca2+ uptake, SOCE and about the structural membranes and organelles deputed to those functions and finally, we summarized the data collected in different, but complementary, projects studying changes caused by denervation and ageing to the structure and positioning of those organelles: a. denervation of muscle fibers-an event that contributes, to some degree, to muscle loss in ageing (known as sarcopenia)-causes misplacement and damage: (i) of membrane structures involved in EC coupling (calcium release units, CRUs) and (ii) of the mitochondrial network; b. sedentary ageing causes partial disarray/damage of CRUs and of calcium entry units (CEUs, structures involved in SOCE) and loss/misplacement of mitochondria; c. functional electrical stimulation (FES) and regular exercise promote the rescue/maintenance of the proper architecture of CRUs, CEUs, and of mitochondria in both denervation and ageing. All these structural changes were accompanied by related functional changes, i.e., loss/decay in function caused by denervation and ageing, and improved function following FES or exercise. These data suggest that the integrity and proper disposition of intracellular organelles deputed to Ca2+ handling and aerobic generation of ATP is challenged by inactivity (or reduced activity); modifications in the architecture of these intracellular membrane systems may contribute to muscle dysfunction in ageing and sarcopenia.


Assuntos
Trifosfato de Adenosina/metabolismo , Envelhecimento/patologia , Cálcio/metabolismo , Músculo Esquelético/patologia , Doenças Musculares/patologia , Organelas/patologia , Envelhecimento/metabolismo , Animais , Humanos , Músculo Esquelético/metabolismo , Doenças Musculares/metabolismo , Organelas/metabolismo
19.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201700

RESUMO

DNA repair ensures genomic stability to achieve healthy ageing, including cognitive maintenance. Mutations on genes encoding key DNA repair proteins can lead to diseases with accelerated ageing phenotypes. Some of these diseases are xeroderma pigmentosum group A (XPA, caused by mutation of XPA), Cockayne syndrome group A and group B (CSA, CSB, and are caused by mutations of CSA and CSB, respectively), ataxia-telangiectasia (A-T, caused by mutation of ATM), and Werner syndrome (WS, with most cases caused by mutations in WRN). Except for WS, a common trait of the aforementioned progerias is neurodegeneration. Evidence from studies using animal models and patient tissues suggests that the associated DNA repair deficiencies lead to depletion of cellular nicotinamide adenine dinucleotide (NAD+), resulting in impaired mitophagy, accumulation of damaged mitochondria, metabolic derailment, energy deprivation, and finally leading to neuronal dysfunction and loss. Intriguingly, these features are also observed in Alzheimer's disease (AD), the most common type of dementia affecting more than 50 million individuals worldwide. Further studies on the mechanisms of the DNA repair deficient premature ageing diseases will help to unveil the mystery of ageing and may provide novel therapeutic strategies for AD.


Assuntos
Envelhecimento/patologia , Doença de Alzheimer/complicações , Dano ao DNA , Instabilidade Genômica , Doenças Neurodegenerativas/patologia , Animais , Reparo do DNA , Humanos , Mutação , Doenças Neurodegenerativas/etiologia
20.
J Leukoc Biol ; 110(3): 497-510, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34085308

RESUMO

Diabetes is emerging as a severe global health problem that threatens health and increases socioeconomic burden. Periodontal impairment is one of its well-recognized complications. The destruction of the periodontal defense barrier makes it easier for periodontal pathogens to invade in, triggering a greater inflammatory response, and causing secondary impairment. Macrophages are the major immune cells in periodontium, forming the frontier line of local innate immune barrier. Here, we explored the periodontal impairments and functional changes of macrophages under the diabetic and aging conditions. Besides, we further explored the molecular mechanism of how hyperglycemia and aging contribute to this pathogenesis. To test this, we used young and aged mice to build diabetic mice, and metformin treatment was applied to a group of them. We demonstrated that under hyperglycemia conditions, macrophage functions, such as inflammatory cytokines secretion, phagocytosis, chemotaxis, and immune response, were disturbed. Simultaneously, this condition elevated the local senescent cell burden and induced secretion of senescence-associated secretory phenotype. Meanwhile, we found that expressions of Gasdermin D (GSDMD) and caspase-1 were up-regulated in diabetic conditions, suggesting that the local senescent burden and systemic proinflammatory state during diabetes were accompanied by the initiation of pyroptosis. Furthermore, we found that the changes in aged condition were similar to those in diabetes, suggesting a hyperglycemia-induced pre-aging state. In addition, we show that metformin treatment alleviated and remarkably reversed these functional abnormalities. Our data demonstrated that diabetes initiated macrophage pyroptosis, which further triggered macrophage function impairments and gingival destructions. This pathogenesis could be reversed by metformin.


Assuntos
Citoplasma/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Diabetes Mellitus Experimental/patologia , Macrófagos/patologia , Piroptose , Envelhecimento/patologia , Animais , Apresentação do Antígeno/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Citocinas/metabolismo , Glucose/toxicidade , Hiperglicemia/complicações , Mediadores da Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Periodonto/patologia , Fagocitose/efeitos dos fármacos , Piroptose/efeitos dos fármacos , Células RAW 264.7
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