per Marlin e Julien, parere
- Thread starter juliensorel
- Start date
interessante, attendo commenti... ;-)
http://www.fernandlabrie.com/files/SamsonM(2010)Biosynthesis%20of%20dihydrotestosterone....pdf
http://www.fernandlabrie.com/files/SamsonM(2010)Biosynthesis%20of%20dihydrotestosterone....pdf
http://jcem.endojournals.org/cgi/reprint/88/9/4043 (validissimi spunti...ma che fine hanno fatto gli ASCJ-9 e 15 della Androscience? maledizione!! [:O][:O])
http://www.corriere.it/salute/cardiologia/10_febbraio_14/anziani-sovrappeso_09d2e3ae-1979-11df-b019-00144f02aabe.shtml
Ricordi ? Ne avavemo parlato in pvt perchè mi avevi inviato uno studio in cui, tra le altre cose, si parlava di BMI e sopravvivenza nell'anziano. Ora non so se alla base ci fosse sempre questo studio o questa equipe (comunque alla fine ci sono arrivati anche i giornali...[
])
Ciao
MA - r l i n
Ricordi ? Ne avavemo parlato in pvt perchè mi avevi inviato uno studio in cui, tra le altre cose, si parlava di BMI e sopravvivenza nell'anziano. Ora non so se alla base ci fosse sempre questo studio o questa equipe (comunque alla fine ci sono arrivati anche i giornali...[
])Ciao
MA - r l i n
Pensa alla rabbia dell'anziano che pratica la restrizione calorica ... cornuto e mazziato! []
Ricerca interessante per il nostro scalpo: http://www.ncbi.nlm.nih.gov/pubmed/20138991
]Ricerca interessante per il nostro scalpo: http://www.ncbi.nlm.nih.gov/pubmed/20138991
Kaspar...e io che sto a faticare nel fine settimana ?...[]:
http://www.calvizie.net/documento.asp?args=6.1.1074
comunque pare che tutto il beneficio venga dal recettore e non dal ligando (che nel caso della vit.D sarebbe pure anti-proliferativo...).
Ciao
MA - r l i n
]:http://www.calvizie.net/documento.asp?args=6.1.1074
comunque pare che tutto il beneficio venga dal recettore e non dal ligando (che nel caso della vit.D sarebbe pure anti-proliferativo...).
Ciao
MA - r l i n
http://inhumanexperiment.blogspot.com/2010/02/dietary-supplement-increases-lifespan.html
Poi uno spunto-domanda(?!). Sappiamo che nei modelli animali l'inibizione della traslaton porta ad un incremento della maximum lifespan (ML). Come sai prima della traduzione operata nei ribosomi dall'mRNA a gli amminoacidi, abbiamo la modificazione dell'attorcigliamento e il taglio della doppia elica del DNA ad opera degli enzimi topoisomerasi e, in seguito, la duplicazione del DNA in RNA ad opera della RNA-polimerasi.
Ora, Dieticamente parlando, esistono ad esempio sostanze che inibiscono aspecificamente la topoisomerasi (ad esempio i flavonoidi). Sarebbe interssante sapere dalle letteratura se ciò implichi anche una ridotta sintesi proteica e benefici sulla ML. Da approfondire insomma.
Poi uno spunto-domanda(?!). Sappiamo che nei modelli animali l'inibizione della traslaton porta ad un incremento della maximum lifespan (ML). Come sai prima della traduzione operata nei ribosomi dall'mRNA a gli amminoacidi, abbiamo la modificazione dell'attorcigliamento e il taglio della doppia elica del DNA ad opera degli enzimi topoisomerasi e, in seguito, la duplicazione del DNA in RNA ad opera della RNA-polimerasi.
Ora, Dieticamente parlando, esistono ad esempio sostanze che inibiscono aspecificamente la topoisomerasi (ad esempio i flavonoidi). Sarebbe interssante sapere dalle letteratura se ciò implichi anche una ridotta sintesi proteica e benefici sulla ML. Da approfondire insomma.
Studio dedicato a quanti prendono il decaffeinato perché la caffeina fa male al cuore.
J Epidemiol Community Health. 2009 Dec 8. [Epub ahead of print]
Coffee, green tea, black tea and oolong tea consumption and risk of
mortality from cardiovascular disease in Japanese men and women.
Mineharu Y, Koizumi A, Wada Y, Iso H, Watanabe Y, Date C, Yamamoto A,
Kikuchi S, Inaba Y, Toyoshima H, Kondo T, Tamakoshi A.
BACKGROUND: The effects of coffee and green, black and oolong teas and
caffeine intake on cardiovascular disease (CVD) mortality have not
been well defined in Asian countries. METHODS: To examine the
relationship between consumption of these beverages and risk of
mortality from CVD, we prospectively followed 76,979 individuals aged
40-79 y free of stroke, coronary heart disease (CHD), and cancer at
entry. Daily consumption of beverages was assessed by questionnaires.
RESULTS: We documented 1362 deaths from strokes and 650 deaths from
CHD after 1,010,787 person-years of follow-up . Compared with non-
drinkers of coffee, the multivariable hazard ratios (HRs) and 95%
confidence interval for those drinking 1-6 cups/wk, 1-2 cups/d and a
per thousandPsi3 cups/d were 0.78 (0.50-1.20), 0.67 (0.47-0.96) and
0.45 (0.17-0.87) for strokes among men (p=0.009 for trend). Compared
with non-drinkers of green tea, the multivariable HRs for those
drinking 1-6 cups/wk, 1-2 cups/d, 3-5 cups/d and a per thousandPsi6
cups/d were 0.34 (0.06-1.75), 0.28 (0.07-1.11), 0.39 (0.18-0.85), and
0.42 (0.17-0.88) for CHD among women (p=0.038 for trend). As for
oolong tea, the multivariable HRs of those drinking 1-6 cups/wk and a
per thousandPsi1 cups/d were 1.00 (0.65-1.55) and 0.39 (0.17-0.88) for
total CVD among men (p=0.049 for trend). Risk reduction for total CVD
across categories of caffeine intake was most prominently observed in
the second highest quintile with a 38% lower risk among men and 22%
among women. CONCLUSIONS: Consumption of coffee, green tea and oolong
tea and total caffeine intake was associated with a reduced risk of
mortality from CVD.
PMID: 19996359 [PubMed - as supplied by publisher]
J Epidemiol Community Health. 2009 Dec 8. [Epub ahead of print]
Coffee, green tea, black tea and oolong tea consumption and risk of
mortality from cardiovascular disease in Japanese men and women.
Mineharu Y, Koizumi A, Wada Y, Iso H, Watanabe Y, Date C, Yamamoto A,
Kikuchi S, Inaba Y, Toyoshima H, Kondo T, Tamakoshi A.
BACKGROUND: The effects of coffee and green, black and oolong teas and
caffeine intake on cardiovascular disease (CVD) mortality have not
been well defined in Asian countries. METHODS: To examine the
relationship between consumption of these beverages and risk of
mortality from CVD, we prospectively followed 76,979 individuals aged
40-79 y free of stroke, coronary heart disease (CHD), and cancer at
entry. Daily consumption of beverages was assessed by questionnaires.
RESULTS: We documented 1362 deaths from strokes and 650 deaths from
CHD after 1,010,787 person-years of follow-up . Compared with non-
drinkers of coffee, the multivariable hazard ratios (HRs) and 95%
confidence interval for those drinking 1-6 cups/wk, 1-2 cups/d and a
per thousandPsi3 cups/d were 0.78 (0.50-1.20), 0.67 (0.47-0.96) and
0.45 (0.17-0.87) for strokes among men (p=0.009 for trend). Compared
with non-drinkers of green tea, the multivariable HRs for those
drinking 1-6 cups/wk, 1-2 cups/d, 3-5 cups/d and a per thousandPsi6
cups/d were 0.34 (0.06-1.75), 0.28 (0.07-1.11), 0.39 (0.18-0.85), and
0.42 (0.17-0.88) for CHD among women (p=0.038 for trend). As for
oolong tea, the multivariable HRs of those drinking 1-6 cups/wk and a
per thousandPsi1 cups/d were 1.00 (0.65-1.55) and 0.39 (0.17-0.88) for
total CVD among men (p=0.049 for trend). Risk reduction for total CVD
across categories of caffeine intake was most prominently observed in
the second highest quintile with a 38% lower risk among men and 22%
among women. CONCLUSIONS: Consumption of coffee, green tea and oolong
tea and total caffeine intake was associated with a reduced risk of
mortality from CVD.
PMID: 19996359 [PubMed - as supplied by publisher]
http://www.scienceagainstaging.com/Books/Booklet_25_ENG_final.pdf
resumé dei trend di ricerca in biogerontologia. Interessante l'impiego di Biotina.
Introduction of biotin into diet positively affects genome stability and slows down aging process
Biotin is a water-soluble vitamin of group B, also known as vitamin H,
vitamin §£7 and coenzyme R. Covalent binding of biotin with histones
is mediated through holocarboxilase synthetase. The group of
Professor Zempleni from University of Nebraska showed that
introduction of high doses of biotin into a diet of adult people results
in an increased level of biotinylated histones in lymphocytes and a
reduced number of retroelement transpositions (3).
Thus, histone biotinylation is a new diet-dependent way of epigenetic
regulation of genome stability and the related aging process.
resumé dei trend di ricerca in biogerontologia. Interessante l'impiego di Biotina.
Introduction of biotin into diet positively affects genome stability and slows down aging process
Biotin is a water-soluble vitamin of group B, also known as vitamin H,
vitamin §£7 and coenzyme R. Covalent binding of biotin with histones
is mediated through holocarboxilase synthetase. The group of
Professor Zempleni from University of Nebraska showed that
introduction of high doses of biotin into a diet of adult people results
in an increased level of biotinylated histones in lymphocytes and a
reduced number of retroelement transpositions (3).
Thus, histone biotinylation is a new diet-dependent way of epigenetic
regulation of genome stability and the related aging process.
Ma allora l'acido butirrico derivante dalla degradazione delle fibre nell'intestino da parte dei batteri, che attiva alcuni geni normalmente silenti proprio agendo sugli istoni, avrebbe in questo senso un effetto di riduzione sul lifespan?
Un'altra questione: ho letto su questo post che la vitamina E favorisce l'azione delle telomerasi e la vitamina C in qualche modo fa aumentare la quota di cellule embrionali, quindi aggiungerle su un topico dovrebbe essere positivo per i nostri scopi. Ma la vitamina E inibisce d'altro canto la sintesi di collagene, quindi avrebbe un effetto parzialmente negativo per la ricrescita.
Vorrei un vostro parere per tutti e due i quesiti.
Un'altra questione: ho letto su questo post che la vitamina E favorisce l'azione delle telomerasi e la vitamina C in qualche modo fa aumentare la quota di cellule embrionali, quindi aggiungerle su un topico dovrebbe essere positivo per i nostri scopi. Ma la vitamina E inibisce d'altro canto la sintesi di collagene, quindi avrebbe un effetto parzialmente negativo per la ricrescita.
Vorrei un vostro parere per tutti e due i quesiti.
Io sapevo che vitamina C con E incrementano la sintesi di collagene, comunque il collagene di un certo tipo, pare che abbia anche un ruolo negativo nella ricrescita dei capelli (se ne era parlato...) anche se a livello di scalpo dovrebbe, insieme all'elastina, contrastare efficacemente la fibrosi tipica delle parti dello scalpo esposte all'aga.
Non capisco però perchè l'acido butirrico, secondo Pollino, dovrebbe avere effetto contrario all'estensione della vita, sopra si parlava giusto della biotina che ha un effetto di biotinilazione sugli istoni dei linfociti (e comunque non dovrebbe silenziare i geni)... Ricordo che per l'acido butirrico si è scomodato di nuovo e più di recente il paradosso francese....
Ciao
MA - r l i n
Non capisco però perchè l'acido butirrico, secondo Pollino, dovrebbe avere effetto contrario all'estensione della vita, sopra si parlava giusto della biotina che ha un effetto di biotinilazione sugli istoni dei linfociti (e comunque non dovrebbe silenziare i geni)... Ricordo che per l'acido butirrico si è scomodato di nuovo e più di recente il paradosso francese....
Ciao
MA - r l i n
>>che attiva alcuni geni normalmente silenti proprio agendo sugli istoni, avrebbe in questo senso un effetto di >>riduzione sul lifespan?
No escluderei categoricamente. E' vero che i corpi ketonici agiscono come sirtuin inhibitor aspecifici (motivo per cui non raccomando fra l'altro una dieta strettamente ketogenica basata sulla riduzione assoluta di carboidrati e utilizzo predominante di burro chiarificato o altro ), ma ricavare ATP dall'ac. butirrico riduce la necessità di glucosio e aumenta di molto la sensibilità all'insulina. Ciò allontana diabete, cancro e quindi è impossibile che agisca negativamente. Io sono arrivato al compromesso che in genere non mi preoccupo di limitare i grassi ma evito i carboidrati con un IG maggiore di 20.
Provvisti del nostro genoma, riusciremmo cmq difficilmente a vivere, con tutte le precauzioni del caso, oltre i 110 anni. Il punto è vivere in salute, abbastanza a lungo e con un reddito adeguato per beneficiare dei vantaggi della singolarità tecnologica, come sostiene R. Kurzweil. Inoltre ciò che conta non è la ML (maximum lifespan) ma la HML (healthy maximum lifespan). ;-)
No escluderei categoricamente. E' vero che i corpi ketonici agiscono come sirtuin inhibitor aspecifici (motivo per cui non raccomando fra l'altro una dieta strettamente ketogenica basata sulla riduzione assoluta di carboidrati e utilizzo predominante di burro chiarificato o altro ), ma ricavare ATP dall'ac. butirrico riduce la necessità di glucosio e aumenta di molto la sensibilità all'insulina. Ciò allontana diabete, cancro e quindi è impossibile che agisca negativamente. Io sono arrivato al compromesso che in genere non mi preoccupo di limitare i grassi ma evito i carboidrati con un IG maggiore di 20.
Provvisti del nostro genoma, riusciremmo cmq difficilmente a vivere, con tutte le precauzioni del caso, oltre i 110 anni. Il punto è vivere in salute, abbastanza a lungo e con un reddito adeguato per beneficiare dei vantaggi della singolarità tecnologica, come sostiene R. Kurzweil. Inoltre ciò che conta non è la ML (maximum lifespan) ma la HML (healthy maximum lifespan). ;-)
http://www3.interscience.wiley.com/journal/123261481/abstract?CRETRY=1&SRETRY=0
Kefir! kefir! kefir!
Kefir! kefir! kefir!
Dopo i miei dubbi passati spariscono completamente i miei riserve sulla niacina. Mi chiedo se non sia il caso di integrarla prima di coricarsi per beneficiare di un picco di autofagia notturna. Per ora resto col b complex 50 nei periodi di digiuno.
Nicotinamide extends the replicative life span of primary human cells
Chang-Su Lim, a, , Malcolm Pottsa and Richard F. Helma
aDepartment of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
Accepted 7 February 2006. Available online 20 March 2006.
Keywords: Nicotinamide; Fibroblasts; Replicative life span; Aging; Deacetylase
Article Outline
Acknowledgements
References
Aging and longevity in humans are regulated by genes as well as environmental factors (i.e., lifestyle). It is believed that antioxidants and vitamins, whether obtained naturally or through nutritional supplements, play a critical role in the aging process by prolonging normal cellular functions and inhibiting deleterious ones. While there is an apparent direct relationship between vitamin intake and human health, the relationship between vitamin intake and cellular aging remains unclear (Thomas, 2004). Here we show that nicotinamide (NAM) (a component of Vitamin B3) extends the replicative life span of primary human cells, in stark contrast to what has been reported for Saccharomyces cerevisiae.
Nicotinamide and nicotinic acid in combination comprise Vitamin B3, otherwise known as niacin. The sirtuin (silent information regulator-2, Sir2) family of protein/histone deacetylases are nicotinamide adenine dinucleotide (NAD+)-dependent enzymes of ancient origin. NAM is a product of sirtuin catalyzed deacetylation, and is also a natural non-competitive inhibitor of Sir2p (yeast), Sir2alpha (mouse) and hSIRT1 (human) activity ([Luo et al., 2001], [Bitterman et al., 2002], [Langley et al., 2002], [Senawong et al., 2003], [Blander and Guarente, 2004] and [Avalos et al., 2005]). Sirtuin protein activity was associated directly with aging and longevity in a number of model organisms, and it was hypothesized that activation of hSIRT1 increases longevity in humans ([Guarente and Kenyon, 2000], [Imai et al., 2000], [Tissenbaum and Guarente, 2001] and [Porcu and Chiarugi, 2005]). NAM was shown to shorten the replicative life span of Saccharomyces cerevisiae by inhibiting Sir2p activity (Bitterman et al., 2002).
The NAM-mediated shortening of life span in yeast prompted us to test whether NAM also negatively regulated the replicative life span of human cells. Based on the known health benefits of vitamins in nutrition, we hypothesized that the role of NAM in life span regulation in humans and yeast may be distinctly different. Support for this hypothesis rests largely on the facts that the metabolic pathways involving the conversion of NAM to the redox cofactor NAD+ differ, and human cells do not accumulate lethal extrachromosomal rDNA circles. To test the hypothesis, we examined the replicative life span of primary human neonatal skin fibroblasts (82-6, a kind gift from Dr. Junko Oshima) in the presence and absence of NAM (0–10 mM; 1 M stock solution in distilled water and then filter-sterilized). It was shown that 82-6 cells senesce after approximately 40 population doublings (Krtolica et al., 2001). Cells (82-6) were maintained in Dulbecco's Modified Eagle Medium (DMEM; 4.5 g/l d-glucose) (Invitrogen, Carlsbad, CA) supplemented with 10% FBS (v/v), 100 units/ml penicillin, and 100 mg/ml streptomycin in an incubator at 37 °C, 5% CO2 and 98% humidity. Approximately 125,000 cells were plated into a 75 mm2-flask and were trypsinized and counted when they reached 70–80% confluency. Population doublings versus time were plotted to determine the replicative life spans. Young to middle-aged 82-6 cells treated with 5–10 mM of NAM had significantly extended replicative life span relative to the control (Fig. 1A). To examine whether NAM differentially affects cell proliferation of 82-6 cells with differing concentration of NAM (0–10 mM), cell proliferation assay was performed (Fig. 1B and C), revealing that 10 mM NAM is the most potent concentration leading to life span extension.
Full-size image (82K)
Fig. 1. NAM extends the replicative life span of primary human diploid somatic fibroblasts (82-6 and IMR-90). (A) Middle-aged primary human skin fibroblasts (82-6) were allowed to proliferate in the presence (0.5, 5, and 10 mM) or absence of NAM. Cell counts were performed at 70–80% confluency. Population doublings vs. time were plotted to determine the replicative life span. Samples were in duplicate and the average values of designated time points were plotted. (B) Cell proliferation assay of 82-6 cells. For cell proliferation measurements, cells were plated in duplicate at a density of 10,000 cells in 30 mm2 glass slide dishes and grown for 13 days and then fixed with 100% methanol for 5 min for imaging. Fixed 82-6 cells were then stained with 0.5% crystal violet dissolved in 50% methanol. Cells were extensively washed with ample distilled water three times and air-dried. Crystal violet was subsequently extracted with 10% acetic acid. Optical density (OD) measurements were performed at 562 nm to indicate the relative number of cells in each designated NAM treatment. Cell proliferation of 82-6 cells without NAM was defined as 1-fold. The relative cell proliferation in each NAM treatment was displayed in comparison with the control in fold, which correspond to each designated cellular images shown in figure. A representative of two independent experiments is shown. Average values between samples in duplicate are shown and the error bar shows a range of errors. (C) Transmitted light confocal images showing cell proliferation of age-matched 82-6 cells in the presence/absence of NAM [0 mM (PD42), 0.5 mM (PD42), 5 mM (PD43), and 10 mM (PD43)]. Scale bars, 100 #956;m. A Zeiss LSM 510 laser scanning microscope was used to capture cellular images (10×). (D) Normal human embryonic fibroblasts (IMR-90) were allowed to proliferate in the presence (5 mM) or absence of NAM. Cells were counted at 70–80% confluency. Population doublings vs. time were plotted to determine the replicative life span. This is a representative of three independent life span assays. (E) Transcriptional activity of p53 is increased in the presence of hSIRT1-H363Y. Transient transfection assays were carried out, which revealed that hSIRT1-H363Y functions as a dominant negative for p53 transcriptional activity due to its failure to inactivate p53 by deacetylation. (1) Saos-2 cells were transfected with p53 reporter (#946;-galactosidase, p53RE) DNA (a generous gift of Dr. Koji Itahana) and internal transfection control (luciferase, CMV-Luc); (2) cells were transfected with p53RE, CMV-Luc and p53; (3) cells were transfected p53RE, CMV-luc, p53 and hSIRT1; (4) cells were transfected with p53RE, CMV-Luc, p53 and hSIRT1-H363Y. Transient transfections were performed by plating Saos-2 cells at a density of 200,000 cells per well in 6 well plates 24 h before transfection using FuGene 6 (Roche Diagnostics, Indianapolis, IN) according to manufacturer's instructions. 72 h after transfection, luciferase assay was done using the luciferase assay kit (Promega, Madison, WI), and luciferase activity was used to normalize transfection efficiency. To measure p53 transcriptional activity, #946;-galactosidase activity was measured using the Galacto-Star™ #946;-galactosidase reporter gene assay system (Applied Biosystems, Foster City, CA). X-axis denotes designated transfections, and Y-axis shows p53 transcriptional activity as fold induction (#946; galactosidase activity) compared to control (1-fold). A representative of four independent transient transfections is shown. Each independent transfection was in duplicate. Average values of duplicate samples are shown and the error bar shows a range of errors. (F) A dominant negative form of hSIRT1 (H363Y) provided no change in
Nicotinamide extends the replicative life span of primary human cells
Chang-Su Lim, a, , Malcolm Pottsa and Richard F. Helma
aDepartment of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
Accepted 7 February 2006. Available online 20 March 2006.
Keywords: Nicotinamide; Fibroblasts; Replicative life span; Aging; Deacetylase
Article Outline
Acknowledgements
References
Aging and longevity in humans are regulated by genes as well as environmental factors (i.e., lifestyle). It is believed that antioxidants and vitamins, whether obtained naturally or through nutritional supplements, play a critical role in the aging process by prolonging normal cellular functions and inhibiting deleterious ones. While there is an apparent direct relationship between vitamin intake and human health, the relationship between vitamin intake and cellular aging remains unclear (Thomas, 2004). Here we show that nicotinamide (NAM) (a component of Vitamin B3) extends the replicative life span of primary human cells, in stark contrast to what has been reported for Saccharomyces cerevisiae.
Nicotinamide and nicotinic acid in combination comprise Vitamin B3, otherwise known as niacin. The sirtuin (silent information regulator-2, Sir2) family of protein/histone deacetylases are nicotinamide adenine dinucleotide (NAD+)-dependent enzymes of ancient origin. NAM is a product of sirtuin catalyzed deacetylation, and is also a natural non-competitive inhibitor of Sir2p (yeast), Sir2alpha (mouse) and hSIRT1 (human) activity ([Luo et al., 2001], [Bitterman et al., 2002], [Langley et al., 2002], [Senawong et al., 2003], [Blander and Guarente, 2004] and [Avalos et al., 2005]). Sirtuin protein activity was associated directly with aging and longevity in a number of model organisms, and it was hypothesized that activation of hSIRT1 increases longevity in humans ([Guarente and Kenyon, 2000], [Imai et al., 2000], [Tissenbaum and Guarente, 2001] and [Porcu and Chiarugi, 2005]). NAM was shown to shorten the replicative life span of Saccharomyces cerevisiae by inhibiting Sir2p activity (Bitterman et al., 2002).
The NAM-mediated shortening of life span in yeast prompted us to test whether NAM also negatively regulated the replicative life span of human cells. Based on the known health benefits of vitamins in nutrition, we hypothesized that the role of NAM in life span regulation in humans and yeast may be distinctly different. Support for this hypothesis rests largely on the facts that the metabolic pathways involving the conversion of NAM to the redox cofactor NAD+ differ, and human cells do not accumulate lethal extrachromosomal rDNA circles. To test the hypothesis, we examined the replicative life span of primary human neonatal skin fibroblasts (82-6, a kind gift from Dr. Junko Oshima) in the presence and absence of NAM (0–10 mM; 1 M stock solution in distilled water and then filter-sterilized). It was shown that 82-6 cells senesce after approximately 40 population doublings (Krtolica et al., 2001). Cells (82-6) were maintained in Dulbecco's Modified Eagle Medium (DMEM; 4.5 g/l d-glucose) (Invitrogen, Carlsbad, CA) supplemented with 10% FBS (v/v), 100 units/ml penicillin, and 100 mg/ml streptomycin in an incubator at 37 °C, 5% CO2 and 98% humidity. Approximately 125,000 cells were plated into a 75 mm2-flask and were trypsinized and counted when they reached 70–80% confluency. Population doublings versus time were plotted to determine the replicative life spans. Young to middle-aged 82-6 cells treated with 5–10 mM of NAM had significantly extended replicative life span relative to the control (Fig. 1A). To examine whether NAM differentially affects cell proliferation of 82-6 cells with differing concentration of NAM (0–10 mM), cell proliferation assay was performed (Fig. 1B and C), revealing that 10 mM NAM is the most potent concentration leading to life span extension.
Full-size image (82K)
Fig. 1. NAM extends the replicative life span of primary human diploid somatic fibroblasts (82-6 and IMR-90). (A) Middle-aged primary human skin fibroblasts (82-6) were allowed to proliferate in the presence (0.5, 5, and 10 mM) or absence of NAM. Cell counts were performed at 70–80% confluency. Population doublings vs. time were plotted to determine the replicative life span. Samples were in duplicate and the average values of designated time points were plotted. (B) Cell proliferation assay of 82-6 cells. For cell proliferation measurements, cells were plated in duplicate at a density of 10,000 cells in 30 mm2 glass slide dishes and grown for 13 days and then fixed with 100% methanol for 5 min for imaging. Fixed 82-6 cells were then stained with 0.5% crystal violet dissolved in 50% methanol. Cells were extensively washed with ample distilled water three times and air-dried. Crystal violet was subsequently extracted with 10% acetic acid. Optical density (OD) measurements were performed at 562 nm to indicate the relative number of cells in each designated NAM treatment. Cell proliferation of 82-6 cells without NAM was defined as 1-fold. The relative cell proliferation in each NAM treatment was displayed in comparison with the control in fold, which correspond to each designated cellular images shown in figure. A representative of two independent experiments is shown. Average values between samples in duplicate are shown and the error bar shows a range of errors. (C) Transmitted light confocal images showing cell proliferation of age-matched 82-6 cells in the presence/absence of NAM [0 mM (PD42), 0.5 mM (PD42), 5 mM (PD43), and 10 mM (PD43)]. Scale bars, 100 #956;m. A Zeiss LSM 510 laser scanning microscope was used to capture cellular images (10×). (D) Normal human embryonic fibroblasts (IMR-90) were allowed to proliferate in the presence (5 mM) or absence of NAM. Cells were counted at 70–80% confluency. Population doublings vs. time were plotted to determine the replicative life span. This is a representative of three independent life span assays. (E) Transcriptional activity of p53 is increased in the presence of hSIRT1-H363Y. Transient transfection assays were carried out, which revealed that hSIRT1-H363Y functions as a dominant negative for p53 transcriptional activity due to its failure to inactivate p53 by deacetylation. (1) Saos-2 cells were transfected with p53 reporter (#946;-galactosidase, p53RE) DNA (a generous gift of Dr. Koji Itahana) and internal transfection control (luciferase, CMV-Luc); (2) cells were transfected with p53RE, CMV-Luc and p53; (3) cells were transfected p53RE, CMV-luc, p53 and hSIRT1; (4) cells were transfected with p53RE, CMV-Luc, p53 and hSIRT1-H363Y. Transient transfections were performed by plating Saos-2 cells at a density of 200,000 cells per well in 6 well plates 24 h before transfection using FuGene 6 (Roche Diagnostics, Indianapolis, IN) according to manufacturer's instructions. 72 h after transfection, luciferase assay was done using the luciferase assay kit (Promega, Madison, WI), and luciferase activity was used to normalize transfection efficiency. To measure p53 transcriptional activity, #946;-galactosidase activity was measured using the Galacto-Star™ #946;-galactosidase reporter gene assay system (Applied Biosystems, Foster City, CA). X-axis denotes designated transfections, and Y-axis shows p53 transcriptional activity as fold induction (#946; galactosidase activity) compared to control (1-fold). A representative of four independent transient transfections is shown. Each independent transfection was in duplicate. Average values of duplicate samples are shown and the error bar shows a range of errors. (F) A dominant negative form of hSIRT1 (H363Y) provided no change in
segnalo il seguente blog
http://aging-academic.blogspot.com/
non perdetevi gli ultimi aggiornamenti su Ouroboros. in particolare
http://ouroboros.wordpress.com/2010/02/23/a-conflict-between-exercise-and-longevity-control/
http://ouroboros.wordpress.com/2010/02/25/orally-available-rapamycin-dont-forget-to-take-your-pill/
http://aging-academic.blogspot.com/
non perdetevi gli ultimi aggiornamenti su Ouroboros. in particolare
http://ouroboros.wordpress.com/2010/02/23/a-conflict-between-exercise-and-longevity-control/
http://ouroboros.wordpress.com/2010/02/25/orally-available-rapamycin-dont-forget-to-take-your-pill/
Come si evidenzia negli articoli che hai postato di ouroboros, ci sono sempre i pro e i contro, per esempio nell'inibizione del percorso mTOR...restando in questa pagina è facile che curcumina e nicotinammide agiscano in senso almeno parzialmente opposto (speriamo solo non si annullino gli effetti, ma quale potrebbe prevalere ?[]).
Per esempio alcuni studi hanno evidenziato che la maggiore massa magra favorirebbe la longevità (in altre parole vivono più a lungo le persone che mantengono da anziane una maggiore massa muscolare), però questa massa si deve creare e mantenere con l'esercizio fisico e quindi inevitabilmente con fattori di crescita come l'IGF-1 che sono attivatori (o meglio attivati) del percorso mTOR, lo stesso che inibito porterebbe a maggiore longevità...
Però c'è poca chiarezza in genere su queste cose perchè altre ricerche dicono che il maggiore Indice di Massa Corporea (IMC o BMI) favorirebbe la sopravvivenza negli anziani....
Credo che ci siano meccanismi compensativi in gioco (li abbiamo visti anche per le staminali della pelle e dei follicoli, con mTOR attivato dopo attivazione WNT, probabilmente per evitare derive cancerogene...) dovuti magari al fatto che si muore di almeno due cose diverse, se non opposte, tipo i tumori con la riproduzione indiscriminata dei tessuti e all'opposto i break down sistemici dovuti alla senescenza dei vari apparati.
Ciao
MA - r l i n
]).Per esempio alcuni studi hanno evidenziato che la maggiore massa magra favorirebbe la longevità (in altre parole vivono più a lungo le persone che mantengono da anziane una maggiore massa muscolare), però questa massa si deve creare e mantenere con l'esercizio fisico e quindi inevitabilmente con fattori di crescita come l'IGF-1 che sono attivatori (o meglio attivati) del percorso mTOR, lo stesso che inibito porterebbe a maggiore longevità...
Però c'è poca chiarezza in genere su queste cose perchè altre ricerche dicono che il maggiore Indice di Massa Corporea (IMC o BMI) favorirebbe la sopravvivenza negli anziani....
Credo che ci siano meccanismi compensativi in gioco (li abbiamo visti anche per le staminali della pelle e dei follicoli, con mTOR attivato dopo attivazione WNT, probabilmente per evitare derive cancerogene...) dovuti magari al fatto che si muore di almeno due cose diverse, se non opposte, tipo i tumori con la riproduzione indiscriminata dei tessuti e all'opposto i break down sistemici dovuti alla senescenza dei vari apparati.
Ciao
MA - r l i n