scholarly journals Ionizing Radiation Mediates a Greater Mutagenic Response in Spermatogenic Cells from Middle-Aged and Old Mice Compared to Young Adult Mice.

2010 ◽  
Vol 83 (Suppl_1) ◽  
pp. 294-294
Author(s):  
Guogang Xu ◽  
Damon Herbert ◽  
Kim Hildreth ◽  
Christi A. Walter
Keyword(s):  
Young Adult ◽  
Ionizing Radiation ◽  
Spermatogenic Cells ◽  
Middle Aged ◽  
Adult Mice ◽  
Mutagenic Response ◽  
Old Mice

scholarly journals Healthy Brain Aging Modifies Microglial Calcium Signaling In Vivo

2019 ◽  
Vol 20 (3) ◽  
pp. 589 ◽  
Author(s):  
Maria Olmedillas del Moral ◽  
Nithi Asavapanumas ◽  
Néstor Uzcátegui ◽  
Olga Garaschuk
Keyword(s):  
Young Adult ◽  
Brain Aging ◽  
Critical Role ◽  
Low Grade ◽  
Middle Aged ◽  
Senescent Phenotype ◽  
Adult Mice ◽  
Age Related ◽  
Old Mice

Brain aging is characterized by a chronic, low-grade inflammatory state, promoting deficits in cognition and the development of age-related neurodegenerative diseases. Malfunction of microglia, the brain-resident immune cells, was suggested to play a critical role in neuroinflammation, but the mechanisms underlying this malfunctional phenotype remain unclear. Specifically, the age-related changes in microglial Ca2+ signaling, known to be linked to its executive functions, are not well understood. Here, using in vivo two-photon imaging, we characterize intracellular Ca2+ signaling and process extension of cortical microglia in young adult (2–4-month-old), middle-aged (9–11-month-old), and old (18–21-month-old) mice. Our data revealed a complex and nonlinear dependency of the properties of intracellular Ca2+ signals on an animal’s age. While the fraction of cells displaying spontaneous Ca2+ transients progressively increased with age, the frequencies and durations of the spontaneous Ca2+ transients followed a bell-shaped relationship, with the most frequent and largest Ca2+ transients seen in middle-aged mice. Moreover, in old mice microglial processes extending toward an ATP source moved faster but in a more disorganized manner, compared to young adult mice. Altogether, these findings identify two distinct phenotypes of aging microglia: a reactive phenotype, abundantly present in middle-aged animals, and a dysfunctional/senescent phenotype ubiquitous in old mice.

scholarly journals Old Mice Have Less Transcriptional Activation But Similar Periosteal Cell Proliferation Compared to Young‐Adult Mice in Response to in vivo Mechanical Loading

2020 ◽  
Vol 35 (9) ◽  
pp. 1751-1764 ◽  
Author(s):  
Christopher J Chermside‐Scabbo ◽  
Taylor L Harris ◽  
Michael D Brodt ◽  
Ingrid Braenne ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Young Adult ◽  
Mechanical Loading ◽  
Transcriptional Activation ◽  
Adult Mice ◽  
Periosteal Cell ◽  
Old Mice

Free radical injury to skeletal muscles of young, adult, and old mice

1990 ◽  
Vol 258 (3) ◽  
pp. C429-C435 ◽  
Author(s):  
E. Zerba ◽  
T. E. Komorowski ◽  
J. A. Faulkner
Keyword(s):  
Free Radical ◽  
Young Adult ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Free Radical Damage ◽  
Control Value ◽  
Delayed Onset ◽  
Adult Mice ◽  
Old Mice

We tested the hypotheses that 1) muscles of old mice are more susceptible to injury than muscles of young and adult mice, and 2) secondary or delayed onset injury results from free radical damage. Extensor digitorum longus muscles were injured in situ by lengthening contractions. Injury was assessed by measurement of maximum isometric tetanic force (Po) expressed as a percentage of the control value and by morphological damage. Mice were treated with a free radical scavenger, polyethylene glycol-superoxide dismutase (PEG-SOD). Three days postinjury, the Po of 44% for muscles of nontreated old mice was significantly lower than the Po of 58 and 61% for those of young and adult mice. In each group, the secondary injury at 3 days was alleviated by treatment with PEG-SOD. For treated muscles of young, adult, and old mice, values for Po were 88, 80, and 70%, respectively. We conclude that muscles of old mice are more susceptible to injury than muscles of young or adult mice and that free radicals contribute to the secondary or delayed onset injury.

scholarly journals Neuroinflammation Induced by Surgery Does Not Impair the Reference Memory of Young Adult Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yanhua Zhao ◽  
Lili Huang ◽  
Huan Xu ◽  
Guangxi Wu ◽  
Mengyi Zhu ◽  
...  
Keyword(s):  
Risk Factor ◽  
Young Adult ◽  
Postoperative Cognitive Dysfunction ◽  
Underlying Mechanism ◽  
Reference Memory ◽  
Behavior Changes ◽  
Spatial Reference ◽  
Adult Mice ◽  
Spatial Reference Memory ◽  
Old Mice

Postoperative cognitive dysfunction (POCD) increases morbidity and mortality after surgery. But the underlying mechanism is not clear yet. While age is now accepted as the top one risk factor for POCD, results from studies investigating postoperative cognitive functions in adults have been controversial, and data about the very young adult individuals are lacking. The present study investigated the spatial reference memory, IL-1β, IL-6, and microglia activation changes in the hippocampus in 2-month-old mice after anesthesia and surgery. We found that hippocampal IL-1βand IL-6 increased at 6 hours after surgery. Microglia were profoundly activated in the hippocampus 6 to 24 hours after surgery. However, no significant behavior changes were found in these mice. These results indicate that although anesthesia and surgery led to neuroinflammation, the latter was insufficient to impair the spatial reference memory of young adult mice.

Abstract 123: Age-Related Diminishment of the Subventricular Zone Cytogenic Response and Its Contributions to Motor Recovery After Cortical Infarcts

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Michael R Williamson ◽  
Stephanie Le ◽  
Ronald L Franzen ◽  
Michael R Drew ◽  
Theresa A Jones
Keyword(s):  
Young Adult ◽  
Subventricular Zone ◽  
Motor Recovery ◽  
Lineage Tracing ◽  
Stem Cell Markers ◽  
Middle Aged ◽  
Reaching Task ◽  
Aged Mice ◽  
Adult Mice ◽  
Age Related

Stroke increases proliferation within the subventricular zone (SVZ) cytogenic niche and causes subsequent migration of newborn cells towards the site of injury. We investigated the functional consequences of age-related blunting of the SVZ cytogenic response to ischemia. We found that there was a marked reduction in proliferation and neural stem cell markers within the SVZ of middle aged (aged 12-16 months) versus young adult (aged 3-5 months) mice in the intact brain and after photothrombotic infarcts in motor cortex. Using an inducible, heritable lineage tracing system (Nestin-CreER T2 :: Ai14 mice) to quantify SVZ-derived neural precursor cells (NPCs) that migrated towards the infarct, we found that there was a considerable age-related reduction in the number of NPCs in peri-infarct cortex. These findings indicate a marked diminishment of SVZ NPC proliferation and migration after focal ischemia by middle age. Next, we assessed the contributions of the SVZ cytogenic response to recovery of skilled motor function. We used glial fibrillary acidic protein-thymidine kinase mice to conditionally ablate NPCs with ganciclovir administration. In young adult mice, NPC ablation significantly impaired recovery of motor performance on the single seed reaching task after motor cortical infarcts. By contrast, NPC ablation did not affect motor recovery in middle aged mice. Importantly, the magnitude of recovery was less in middle aged mice—regardless of NPC ablation—than in control young adult mice. Middle aged mice recovered similarly to young adult mice lacking NPCs. These results indicate that SVZ cytogenesis contributes to functional improvements after cortical infarcts and that the diminishment of the cytogenic response with age may be implicated in age-related worsening of outcome after stroke. Restoration of SVZ cytogenesis in aged animals might improve behavioral recovery.

scholarly journals Distinct physical condition and social behavior phenotypes of CD157 and CD38 knockout mice during aging

2020 ◽  
Author(s):  
Maria Gerasimenko ◽  
Olga Lopatina ◽  
Anna A. Shabalova ◽  
Stanislav M. Cherepanov ◽  
Alla B. Salmina ◽  
...  
Keyword(s):  
Body Weight ◽  
Young Adult ◽  
Social Behavior ◽  
Body Weight Gain ◽  
Male Mice ◽  
Aging Effects ◽  
Middle Aged ◽  
Nad Metabolism ◽  
Cd38 Expression ◽  
Adult Mice

Abstract The ability of CD38 and CD157 to consume nicotinamide adenine dinucleotide (NAD) has received much attention because aging-induced elevation of CD38 expression plays a role in the senescence-related decline in NAD levels. Therefore, it is of interest to examine and compare the effects of age-associated changes on the general health and brain function impairment of Cd157 and Cd38 knockout (CD157 KO and CD38 KO) mice. Body weight and behaviors were measured in 8-week-old (young adult) or 12-month-old (middle-aged) male mice of both KO strains. The locomotor activity, anxiety-like behavior, and social behavior of mice were measured in open field, and three-chamber tests. Middle-aged CD157 KO male mice gained more body weight than young adult mice, while little or no body weight gain was observed in middle-aged CD38 KO mice. Middle-aged CD157 KO mice displayed increased anxiety-like behavior and decreased sociability and interaction compared with young adult KO mice. Middle-aged CD38 KO mice showed less anxiety and hyperactivity than CD157 KO mice, similar to young adult CD38 KO mice. The results reveal marked age-dependent changes in male CD157 KO mice but not in male CD38 KO mice. We discuss the distinct differences in aging effects from the perspective of inhibition of NAD metabolism in CD157 and CD38 KO mice, which may contribute to differential behavioral changes during aging.

scholarly journals Gene Conversion of Major Histocompatibility Complex Genes in the Mouse Spermatogenesis is a Premeiotic Event

1997 ◽  
Vol 8 (12) ◽  
pp. 2511-2517 ◽  
Author(s):  
Kari Högstrand ◽  
Jan Böhme
Keyword(s):  
Major Histocompatibility Complex ◽  
Gene Conversion ◽  
Molecular Genetic ◽  
Spermatogenic Cells ◽  
Major Histocompatibility ◽  
Adult Mice ◽  
Histocompatibility Complex ◽  
Specific Fragment ◽  
Pachytene Spermatocytes ◽  
Old Mice

The molecular genetic mechanism of gene conversion in higher eukaryotes remains unknown. We find it of considerable interest to determine when during spermatogenesis gene conversion occurs. We have therefore purified pachytene spermatocytes and haploid spermatocytes from adult mice and analyzed these fractions for the presence of gene conversion products resulting from the transfer between the major histocompatibility complex class II genes Ebd and Abk in a polymerase chain reaction assay. We have further isolated spermatogenic cells from prepubescent mice and analyzed them for the presence of the same gene conversion products. We can detect gene conversion products in testis cells as early as in 8-d-old mice where the only existing spermatogenic cells are spermatogonia. The frequency of gene conversion products remains the same as the cells reach meiosis in 18-d-old mice, and is unchanged after meiosis is completed in haploid spermatocytes. Gene conversion of this specific fragment therefore appears to be a premeiotic event and, consequently, relies on genetic mechanisms other than normal meiotic recombination.

scholarly journals Aging-Induced Dysbiosis of Gut Microbiota as a Risk Factor for Increased Listeria monocytogenes Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Mohammad S. Alam ◽  
Jayanthi Gangiredla ◽  
Nur A. Hasan ◽  
Tammy Barnaba ◽  
Carmen Tartera
Keyword(s):  
Listeria Monocytogenes ◽  
Young Adult ◽  
Gut Microbiota ◽  
Dna Sequences ◽  
Post Infection ◽  
Bacterial Species ◽  
Case Fatality ◽  
Adult Mice ◽  
Α Diversity ◽  
Old Mice

Invasive foodborne Listeria monocytogenes infection causes gastroenteritis, septicemia, meningitis, and chorioamnionitis, and is associated with high case-fatality rates in the elderly. It is unclear how aging alters gut microbiota, increases risk of listeriosis, and causes dysbiosis post-infection. We used a geriatric murine model of listeriosis as human surrogate of listeriosis for aging individuals to study the effect of aging and L. monocytogenes infection. Aging and listeriosis-induced perturbation of gut microbiota and disease severity were compared between young-adult and old mice. Young-adult and old mice were dosed intragastrically with L. monocytogenes. Fecal pellets were collected pre- and post-infection for microbiome analysis. Infected old mice had higher Listeria colonization in liver, spleen, and feces. Metagenomics analyses of fecal DNA-sequences showed increase in α-diversity as mice aged, and infection reduced its diversity. The relative abundance of major bacterial phylum like, Bacteroidetes and Firmicutes remained stable over aging or infection, while the Verrucomicrobia phylum was significantly reduced only in infected old mice. Old mice showed a marked reduction in Clostridaiceae and Lactobacillaceae bacteria even before infection when compared to uninfected young-adult mice. L. monocytogenes infection increased the abundance of Porphyromonadaceae and Prevotellaceae in young-adult mice, while members of the Ruminococcaceae and Lachnospiraceae family were significantly increased in old mice. The abundance of the genera Blautia and Alistipes were significantly reduced post-infection in young-adult and in old mice as compared to their uninfected counterparts. Butyrate producing, immune-modulating bacterial species, like Pseudoflavonifractor and Faecalibacterium were significantly increased only in old infected mice, correlating with increased intestinal inflammatory mRNA up-regulation from old mice tissue. Histologic analyses of gastric tissues showed extensive lesions in the Listeria-infected old mice, more so in the non-glandular region and fundus than in the pylorus. Commensal species like Lactobacillus, Clostridiales, and Akkermansia were only abundant in infected young-adult mice but their abundance diminished in the infected old mice. Listeriosis in old mice enhances the abundance of butyrate-producing inflammatory members of the Ruminococcaceae/Lachnospiraceae bacteria while reducing/eliminating beneficial commensals in the gut. Results of this study indicate that, aging may affect the composition of gut microbiota and increase the risk of invasive L. monocytogenes infection.

scholarly journals The Relationship of Age, Strain and Species to the Reducing Activity of Leukocytes

Blood ◽  
1959 ◽  
Vol 14 (9) ◽  
pp. 1033-1039 ◽  
Author(s):  
ALBINA ANN YAKAITIS
Keyword(s):  
Young Adults ◽  
Young Adult ◽  
Healthy Adult ◽  
Young Rats ◽  
Adult Mice ◽  
Reducing Activity ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship ◽  
Old Mice

Abstract A method is presented for studying the reducing activity of leukocytes of mice and rats using 2-(p-iodophenyl)-3-)p-nitrophenyl)-5-phenyltetrazolium chloride (INT). Between 48.0 per cent and 83.8 per cent of the leukocytes of young adult mice and between 47.8 per cent and 68.0 per cent of the leukocytes of young rats showed formazan formation. Infant mice of C3Hf and BALBf strains had appreciably fewer leukocytes with the ability to reduce tetrazolium than did young adults of their respective strains. Healthy adult mice belonging to the leukemia susceptible AKR strain showed a relatively high degree of leukocytic reduction. Old mice of the C3Hfstrain showed less formazan formation than young adult animals. This decrease was more marked for the male members of the species.

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