Issue 3, 2008

By the abstracts:

"CD7− T Cells are Late Memory Cells Generated from CD7+ T Cells" by Gunter Rappl, David Schrama, Andreas Hombach, Eva Katharina Meuer, Annette Schmidt, Jürgen C. Becker, and Hinrich Abken. Details of immune system about which I understand practically nothing. For the record, they say CD7- cells are T cells in late memory cell development, have a high activation threshold, low effector capacities and high sensitivity to activation-induced cell death.

"Carotenoids as Protection Against Disability in Older Persons" by Fulvio Lauretani, Richard D. Semba, Stefania Bandinelli, Margaret Dayhoff-Brannigan, Fabrizio Lauretani, Anna Maria Corsi, Jack M. Guralnik, and Luigi Ferrucci. Measured plasma carotenoids in 928 >65 year olds, as supposed proxy of fruit and vegetable intake. Higher carotenoid correlated with higher walking speed at original measurement, higher speed at remeasurement 6 years later and lower likelihood of becoming unable to walk (all the odd ratios around 0.5).

"Altered Expression of Mismatch Repair Proteins Associated with Acquisition of Microsatellite Instability in a Clonal Model of Human T Lymphocyte Aging" by Simona Neri, Graham Pawelec, Andrea Facchini, Cinzia Ferrari, and Erminia Mariani. T-cell clones in vitro that develop microsatellite instability have disregulated expression of mismatch repair proteins. Those that don't don't.

"Homeostatic Cytokines and Expansion of Regulatory T Cells Accompany Thymic Impairment in Children with Down Syndrome" by Erika Roat, Nicole Prada, Enrico Lugli, Milena Nasi, Roberta Ferraresi, Leonarda Troiano, Chiara Giovenzana, Marcello Pinti, Ornella Biagioni, Mauro Mariotti, Angelo Di Iorio, Ugo Consolo, Fiorella Balli, and Andrea Cossarizza. Kids with Down syndrome have very different immunological profiles from control kids.

"Brain Magnetic Resonance Imaging Structural Changes in a Pedigree of Asymptomatic Progranulin Mutation Carriers" by B. Borroni, A. Alberici, E. Premi, S. Archetti, V. Garibotto, C. Agosti, R. Gasparotti, M. Di Luca, D. Perani, and A. Padovani. Measurements of differences and non-differences in brain areas between controls, asymptomatic carriers of progranulin mutations with family history of frontotemporal lobar degeneration and people with family history of FTLD but no progranulin mutation.

"Caloric Restriction Retards the Age-Related Decline in Mitochondrial Function of Brown Adipose Tissue" by Adamo Valle, Rocío Guevara, Francisco José García-Palmer, Pilar Roca, and Jordi Oliver. The english in this one isn't very clear: they compared 2-year old 40% CR rats with 2-year old and 6-month old controls: lower brown adipose tissue (BAT) "size with respect to fat content and adipocyte number" (ratio?). Higher mtDNA content in CR > old control > young control. CR BAT slowed decline of total and mt protein, COX activity and uncoupling capacity. They think CR prevents decline in mt function, probably due to lower decline in mt biogenesis.

"Caloric Restriction But Not Exercise-Induced Reductions in Fat Mass Decrease Plasma Triiodothyronine Concentrations: A Randomized Controlled Trial" by Edward P. Weiss, Dennis T. Villareal, Susan B. Racette, Karen Steger-May, Bhartur N. Premachandra, Samuel Klein, and Luigi Fontana. What the title says. 18 CR, 17 exercise, 9 controls. 50-60 year olds. No change in TSH, T4 and FT4. Decent weight changes in CR and exercise.

"Mitochondrial DNA Mutations May Contribute to Aging Via Cell Death Caused by Peptides that Induce Cytochrome c Release" by Steven J. Dubec, Rajeev Aurora, and H. Peter Zassenhaus. Biochemical evidence saying that mtDNA mutations generate a peptide that causes release of cytochrome c. Simulations from that to age-related mtDNA mutations causing significant levels of cell death. Also, mice with shitty proofreading version of poly gamma in the heart develop cardiomyopathy.

"Effect of Every Other Day Feeding on Mitochondrial Free Radical Production and Oxidative Stress in Mouse Liver" by Pilar Caro, José Gómez, Mónica López-Torres, Inés Sánchez, Alba Naudi, Manuel Portero-Otín, Reinald Pamplona, and Gustavo Barja. EOD feeding of mice lowered free radical leakeage from complex 1 but not complex 3 of liver mt. Also lowered mtDNA oxidative marker, protein oxidation, glycoxidation and lipoxidation, apoptosis inducing factor, PGC1-alpha and UCP2.

"Ketogenic Diets Cause Opposing Changes in Synaptic Morphology in CA1 Hippocampus and Dentate Gyrus of Late-Adult Rats" by Marta Balietti, Belinda Giorgetti, Patrizia Fattoretti, Yessica Grossi, Giuseppina Di Stefano, Tiziana Casoli, Daniela Platano, Moreno Solazzi, Fiorenza Orlando, Giorgio Aicardi, and Carlo Bertoni-Freddari. Brain stuff. Bad effects from fat-producing diets in hippocampal CA1, good in dentate gyrus. In mice.

"Creatine Supplementation Augments Skeletal Muscle Carnosine Content in Senescence-Accelerated Mice (SAMP8)" by Wim Derave, Glenys Jones, Peter Hespel, and Roger C. Harris. Accelerated-aging mice had drops in muscle content of carnosine, anserine, taurine and total creatine. Creatine supplementation raised it compared to controls while young but not when old.

"Regulating the Age-Related Oxidative Damage, Mitochondrial Integrity, and Antioxidative Enzyme Activity in Fischer 344 Rats by Supplementation of the Antioxidant Epigallocatechin-3-Gallate" by Qingying Meng, Chidambaram Natesa Velalar, and Runsheng Ruan. Epigallocatechin-3-Gallate aka EGCG is the main catechin in tea. High EGCG doses had lower DNA-oxidation marker and better mt potential in lymphocytes and lower deletion of ND4 region in mtDNA in the liver. In rats.

"L-Cysteine Influx in Erythrocytes as a Function of Human Age" by Syed Ibrahim Rizvi and Pawan Kumar Maurya. Red-blood cells from old people suspended in L-cysteine solution absorb less L-cysteine than red blood cells from young people.


Some leftovers from SENS3 that probably didn't fit in the previous issue:

"Genetic Susceptibility Sets for Alzheimer's Disease Identified from Diverse Candidate Loci" by Elizabeth H. Corder, Kaj Blennow, and Jonathan A. Prince. Fancy statistical analysis of GWAS plus physiological measures for detecting sets of features that lead to high risk of AD. 938 AD patients and 397 controls. Sounds interesting, need to understand details.

"Senescence Induces a Proangiogenic Switch in Human Peritoneal Mesothelial Cells" by Krzysztof Ksiazek, Achim Jörres, and Janusz Witowski. What the title says. They think this is why cancers metastise to the peritoneum when old.


Commentaries:

"On Methionine Restriction, Suppression of Mitochondrial Dysfunction and Aging" by Alan R. Hipkiss. Gives possible mechanisms by which methionine restriction might be beneficial: lower protein synthesis leading to lower mutant proteins. Ligher work for proteases so they can deal with post-translational problems. Alteration of protein folding (how?), increased lysosomal proteolysis, autophagy of mt and mitogenesis. May decrease SAM => decrease in O6-methylguanine, also might affect gene silencing.

A look at a thesis by Tamuna Chadashvili that looks at neural stem cell generation in rats. Seems to have found another region of generation aside from measuring a whole bunch of correlates with generation.