J Urol. 2007 Jan;177(1):97-101;
discussion 101.
Links
Dietary fatty acids correlate with prostate
cancer biopsy grade and volume in Jamaican men.
Ritch CR, Wan
RL, Stephens
LB, Taxy JB, Huo D, Gong
EM, Zagaja GP, Brendler CB.
Pritzker School of Medicine, University of Chicago,
Chicago, Illinois, USA.
PURPOSE: Jamaica
has the highest incidence of prostate cancer in the world. Dietary fat is
associated with prostate cancer. The Omega6 polyunsaturated fatty acids
have been shown to stimulate prostate carcinogenesis and the Jamaican diet
is rich in linoleic acid. We hypothesized
positive correlations between Omega6 polyunsaturated fatty acid, prostate
specific antigen and prostate biopsy pathology. MATERIALS AND METHODS: A
total of 148 men were enrolled in Kingston,
Jamaica. Serum
prostate specific antigen and erythrocyte membrane polyunsaturated fatty
acids were analyzed. Men with prostate specific antigen 2.6 ng/ml or greater underwent biopsy. Histopathological
and statistical analyses were performed on available data. RESULTS: Of the
54 men who underwent biopsy 24 had prostate cancer, 17 had a Gleason score
of 7 or greater and 11 had a tumor volume of 50% or greater. There were
significant positive correlations between linoleic
acid and Gleason score (p = 0.009), and the linoleic
acid-to-docosahexaenoic acid (Omega3) ratio and
tumor volume (p = 0.03). There was a significant negative correlation
between the arachidonic acid (Omega6)-to-docosapentanoic acid (Omega3) ratio and Gleason score
(p = 0.04). Statistical correlations between prostate specific antigen and
polyunsaturated fatty acids were inconsistent. CONCLUSIONS: The positive
correlations between linoleic acid and Gleason
score, and the linoleic acid-to-docosahexaenoic acid ratio and tumor volume support
studies showing that Omega6 polyunsaturated fatty acids stimulate and
Omega3 polyunsaturated fatty acids inhibit prostate cancer growth. The
negative correlation between the arachidonic
acid-to-docosapentanoic acid ratio and Gleason
score supports studies that demonstrate increased metabolism of arachidonic acid in prostate cancer to form
carcinogenic metabolites, namely prostaglandin E2. Our findings support the
association between dietary fatty acids and prostate cancer, and they
warrant further dietary and tissue studies in high risk populations.
PMID: 17162011 [PubMed
- indexed for MEDLINE]
J Perinat Med. 2007;35
Suppl 1:S12-8.
Links
Consumption of omega3-fatty acids during perinatal life: role in immuno-modulation
and allergy prevention.
Blümer N, Renz H.
Department
of Clinical Chemistry and Molecular Diagnostics, Philipps University of Marburg, Germany.
Epidemiological data suggest
that dietary factors may have a role in recent increases of the prevalence
of allergic diseases. One food-related component might be the reduced
consumption of omega3-polyunsaturated fatty acids observed especially in
the Western societies; yet, clinical trials supplementing omega3-fatty
acids to adults with established allergies and bronchial asthma have
generally been disappointing. However, it is known that the immature immune
system is highly susceptible to immuno-modulatory
environmental conditions particularly in the pre- and postnatal period.
This review discusses the immuno-modulatory
effects of omega3-fatty acids supplementation in the perinatal
life phase on the immune system of the child. Evidence exists that perinatal omega3-fatty acid exposure affects T-cells
and antigen presenting cells of the neonates likely due to altered eicosanoid metabolism. Although animal experiments
strongly suggest a role of maternal omega3-fatty acid intake on allergic immune
responses in the offspring, the beneficial effect of omega3-fatty acid
supplementation has been studied in a small number of clinical trials. In
these studies perinatal supplementation had some
positive effects on distinct clinical phenotypes of the atopic
syndrome. However, more studies are needed to fully explore the opportunity
of perinatal immuno-modulation.
PMID: 17302535 [PubMed
- indexed for MEDLINE]
Omega-3 supplementation in mild to moderate
Alzheimer's disease: effects on neuropsychiatric
symptoms.
Freund-Levi
Y, Basun H, Cederholm T, Faxén-Irving G, Garlind A, Grut M, Vedin I, Palmblad J, Wahlund LO, Eriksdotter-Jönhagen M.
Department
of NVS, Section of Clinical Geriatrics, Karolinska
Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden.
BACKGROUND: Epidemiological and
animal studies have suggested that dietary fish or fish oil rich in omega-3
fatty acids (omega3), docosahexaenoic acid (DHA)
and eicosapentaenoic acid (EPA), may have effects
in psychiatric and behavioral symptoms in Alzheimer's disease (AD). An
association with APOEomega4 carriers and neuropsychiatric
symptoms in AD has also been suggested. OBJECTIVE: To determine effects of
dietary omega3 supplementation to AD patients with mild to moderate disease
on psychiatric and behavioral symptoms, daily functions and a possible
relation to APOEgenotype. METHODS: Randomized,
double-blind, placebo-controlled clinical trial where 204 AD patients (74
+/- 9 years) with acetylcholine esterase inhibitor treatment and a MMSE
>15 points were randomized to daily intake of 1.7 g DHA and 0.6 g EPA
(omega3 group) or placebo for 6 months. Then, all received the omega3
supplementation for 6 more months. Neuropsychiatric
symptoms were measured with Neuropsychiatric
Inventory (NPI) and Montgomery Asberg Depression
Scale (MADRS). Caregivers burden and activities of daily living (Disability
Assessment for Dementia, DAD) were also assessed. RESULTS: One hundred and
seventy-four patients fulfilled the trial. 72% were APOEomega4 carriers. No
significant overall treatment effects on neuropsychiatric
symptoms, on activities of daily living or on caregiver's burden were
found. However, significant positive treatment effects on the scores in the
NPI agitation domain in APOEomega4 carriers (p = 0.006) and in MADRS scores
in non-APOEomega4 carriers (p = 0.005) were found. CONCLUSIONS:
Supplementation with omega3 in patients with mild to moderate AD did not
result in marked effects on neuropsychiatric
symptoms except for possible positive effects on depressive symptoms
(assessed by MADRS) in non-APOEomega4 carriers and agitation symptoms
(assessed by NPI) in APOEomega4 carriers. ClinicalTrials.gov identifier:
NCT00211159 Copyright (c) 2007 John Wiley & Sons, Ltd.
PMID: 17582225 [PubMed
- as supplied by publisher]
Tumor necrosis
factor-alpha-308A/G polymorphism is associated with age at onset of
Alzheimer's disease.
Lio
D, Annoni
G, Licastro
F, Crivello
A, Forte GI, Scola
L, Colonna-Romano G,
Candore
G, Arosio
B, Galimberti
L, Vergani
C, Caruso C.
Gruppo di Studio sull'Immunosenescenza, Dipartimento
di Biopatologia e Metodologie, Biomediche, Universita di Palermo, Corso Tukory 211, 90134
Palermo, Italy.
Pro-inflammatory cytokines and acute-phase proteins play an important role
in Alzheimer's disease (AD) neurodegeneration,
and common polymorphisms of genes controlling their production have been
shown to be associated with AD. Tumor necrosis factor (TNF)-alpha is an
inflammatory cytokine involved in the local immune response occurring in
the central nervous system of AD patients. Genetic variation could
contribute to the risk of developing AD or influence the age at the onset
of the disease. We genotyped 222 patients (152 women, 70
men; age range 60-87) and 240 non-demented age-matched healthy controls for
TNF-alpha -308 G/A single nucleotide polymorphism (SNP). No
significant differences were observed in genotyped frequencies between
patients and controls, whereas carriers of -308A showed a significantly
lower mean age at onset than non-carriers of this allele. This difference
was more evident taking into account ApolipoproteinE
(ApoE) status since the lowest age at onset was
observed in patients carrying the -308ATNF+/APOE4+ genotypes. In
conclusion, our data support previous suggestions that, at least in
Caucasians, the TNF gene is a disease modifier gene in patients in which AD
is rising, bringing to light the importance of genetic variation at the pro-inflammatory
components in the progression of AD.
Self-assembly of HEK
cell-secreted ApoE particles resembles ApoE enrichment of lipoproteins as a ligand for the LDL receptor-related protein.
LaDu
MJ, Stine WB Jr, Narita M, Getz GS, Reardon CA,
Bu G.
Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
Recent studies have shown that the lipidation and
assembly state of apolipoprotein E (apoE) determine receptor recognition and amyloid-beta peptide (Abeta)
binding. We previously demonstrated that apoE
secreted by HEK cells stably expressing apoE3 or apoE4 (HEK-apoE) binds Abeta and
inhibits Abeta-induced neurotoxicity
by an isoform-specific process that requires apoE receptors. Here we characterized the structure of
HEK-apoE assemblies and determined their receptor
binding specificity. By chromatography, HEK-apoE
elutes in high molecular mass fractions and is the size of plasma HDL,
consistent with a multiprotein assembly. No lipid
was associated with these apoE assemblies.
Several methods for analyzing receptor binding indicate that HEK-apoE is a ligand for
low-density lipoprotein (LDL) receptor-related protein (LRP) but not the
LDL receptor. This suggests that self-assembly of apoE
may induce a functional conformation necessary for binding to LRP. Our
results indicate that, in addition to lipid content, the assembly state of apoE influences Abeta binding
and receptor recognition.
PMID: 16401069 [PubMed - in process]
mTOR/RICTOR is the Ser473 kinase
for Akt/PKB in 3T3-L1 adipocytes.
Hresko
RC, Mueckler
M.
Department of Cell Biology and Physiology, Washington University, School of
Medicine, St. Louis, MO 63110-1093.
The insulin-signaling pathway leading to the activation of Akt/PKB has been well-characterized except for a single
step, the phosphorylation of Akt
at Ser473. Double-stranded DNA-dependent protein kinase (DNA-PK). ataxia
telangiectasia mutated (ATM) gene product, Integrin-linked kinase (ILK),
Protein Kinase Ca (PKCa), and mammalian target of
Rapamycin (mTOR) when complexed to rapamycin
insensitive companion of mTOR (RICTOR) have all
been identified as playing a critical role in Akt-Ser473 phosphorylation. However, the apparently disparate
results reported in these studies are difficult to evaluate, given that
different stimuli and cell types were examined and that all of the
candidate proteins have never been systematically studied in a single
system. Additionally, none of these studies were performed in a classical
insulin-responsive cell-type or tissue such as muscle or fat. We therefore
examined each of these candidates in 3T3-L1 adipocytes.
In vitro kinase assays, using different subcellular fractions of 3T3-L1 adipocytes,
revealed that phosphatidylinositol 3,4,5-trisphosphate (PIP3)-stimulated Ser473 phosphorylation correlated well with the amount of
DNA-PK, mTOR, and RICTOR but did not correlate
with levels of ATM, ILK, and PKCa. PKCa was completely absent from compartments with
Ser473 phosphorylation activity. Although
purified DNA-PK could phosphorylate a peptide
derived from Akt that contains amino acid Ser473,
it could not phosphorylate full-length Akt2.
Vesicles immunoprecipitated from low-density microsomes (LDM) using antibodies directed against mTOR or RICTOR had PIP3-stimulated Ser473 activity that
was sensitive to wortmannin but not staurosporine. In contrast, immunopurified
LDM vesicles containing ILK could not phosphorylate
Akt on Ser473 in vitro. Small
interference RNA (siRNA)-knockdown of RICTOR, but
not DNA-PK, ATM, or ILK, suppressed insulin-activated Ser473 phosphorylation and to a lesser extent Thr308 phosphorylation in 3T3-L1 adipocytes.
Based on our cell-free kinase and siRNA results, we conclude mTOR
complexed to RICTOR is the Ser473 kinase in 3T3-L1 adipocytes.
Lycopene induces apoptosis in immortalized fibroblasts
exposed to tobacco smoke condensate through arresting cell cycle and
down-regulating cyclin D1, pAKT
and pBad.
Palozza
P, Sheriff A,
Serini
S, Boninsegna
A, Maggiano
N, Ranelletti
FO, Calviello
G, Cittadini
A.
Institute of General Pathology, Catholic University, Rome.
There is a lot of interest in the health benefits of dietary carotenoids and on the relationship of these compounds
with smoke. In particular, it is unknown if the enhanced cancer risk
observed in smokers following beta-carotene supplementation can be also
found using other carotenoids. Here, we studied
the effects of the tomato carotenoid lycopene on molecular pathways involved in cell cycle
progression, apoptosis and survival in immortalized RAT-1 fibroblasts
exposed to cigarette smoke condensate (TAR). Lycopene
(0.5-2.0 muM) inhibited cell growth in a dose-and
time-dependent manner, by arresting cell cycle progression and by promoting
apoptosis in cells exposed to TAR. The arrest of cell cycle was independent
of p53 and of 8-OH-dG DNA damage and related to a decreased expression of cyclin D1. Moreover, the carotenoid
up-regulated apoptosis and down-regulated the phosphorylation
of AKT and Bad in cells exposed to TAR. Such an effect was associated to an
inhibition of TAR-induced expression of Cox-2 and hsp90, which is known to
maintain AKT activity. This study suggests that lycopene,
differently from beta-carotene, can exert protective effects against
cigarette smoke condensate.
PMID: 16215689 [PubMed - as supplied
conclude
mTOR complexed to
RICTOR is the Ser473 kinase in 3T3-L1 adipocytes.
PMID: 16221682 [PubMed - as supplied by
publisher]
Ovarian follicle development is dependent
on growth factors that stimulate cell proliferation and act as survival factors
to prevent apoptosis of follicle cells. We examined the mechanism of the
protective effect of IGF-I against Fas ligand (FasL)-induced
apoptosis of granulosa cells and its relationship
to cell proliferation. IGF-I activated both the phosphoinositide
3'-OH kinase (PI3K) and the mitogen-activated
protein kinase (MAPK) pathways. Experiments using
specific inhibitors of these pathways showed that protection by IGF-I was
mediated by the PI3K pathway and not the MAPK pathway. Recombinant
adenoviruses were used to test whether the downstream target of PI3K
activation, Akt kinase,
was required for protection against apoptosis. Expression of dominant
negative Akt (dnAkt)
prevented protection by IGF-I while expression of constitutively active Akt (myrAkt) mimicked the
effect of IGF-I. Treatment with IGF-I, or expression of myrAkt,
increased progression from G0/G1 to S phase of the cell cycle while
expression of dnAkt inhibited G0/G1 to S phase
progression and prevented the stimulatory effect of IGF-I. We tested whether
cell cycle progression was required for protection from apoptosis using the
cyclin dependent kinase-2 inhibitor roscovitine, which blocks cells at the G1/S transition.
Roscovitine prevented the protective effect of
IGF-I and myrAkt expression against apoptosis.
Therefore, activation of Akt is not sufficient to
protect granulosa cells from apoptosis in the
absence of cell cycle progression. In summary, IGF-I protects granulosa cells from apoptosis by activation of the
PI3K/Akt pathway. This protective effect can only occur when progression
from G1 to S phase of the cell cycle regulated by the PI3K/Akt pathway is
unperturbed