BACKGROUND The global obesity epidemic has paralleled a decrease in semen quality. Yet, the association between obesity and sperm parameters remains controversial. The purpose of this report was to update the evidence on the association between BMI and sperm count through a systematic review with meta-analysis. METHODS A systematic review of available literature (with no language restriction) was performed to investigate the impact of BMI on sperm count. Relevant studies published until June 2012 were identified from a Pubmed and EMBASE search. We also included unpublished data (n = 717 men) obtained from the Infertility Center of Bondy, France. Abstracts of relevant articles were examined and studies that could be included in this review were retrieved. Authors of relevant studies for the meta-analysis were contacted by email and asked to provide standardized data. RESULTS A total of 21 studies were included in the meta-analysis, resulting in a sample of 13 077 men from the general population and attending fertility clinics. Data were stratified according to the total sperm count as normozoospermia, oligozoospermia and azoospermia. Standardized weighted mean differences in sperm concentration did not differ significantly across BMI categories. There was a J-shaped relationship between BMI categories and risk of oligozoospermia or azoospermia. Compared with men of normal weight, the odds ratio (95% confidence interval) for oligozoospermia or azoospermia was 1.15 (0.93-1.43) for underweight, 1.11 (1.01-1.21) for overweight, 1.28 (1.06-1.55) for obese and 2.04 (1.59-2.62) for morbidly obese men. CONCLUSIONS Overweight and obesity were associated with an increased prevalence of azoospermia or oligozoospermia. The main limitation of this report is that studied populations varied, with men recruited from both the general population and infertile couples. Whether weight normalization could improve sperm parameters should be evaluated further.
Chronic inflammation of adipose tissue in obesity is by now an established phenomenon, but the initiating event(s) of the inflammatory cascade are still unknown. We hypothesized that neutrophil infiltration into adipose tissue may precede macrophage infiltration as in classical immune responses. Here we demonstrate that early (3 and 7 days) after initiating high-fat feeding of C57BL/6J mice, neutrophils transiently infiltrate the parenchyma of intra-abdominal adipose tissue. Mean periepdidymal fat myeloperoxidase expression (representing neutrophils) was significantly increased 3.5-fold (P , 0.01) and 2.9-fold (P , 0.03), at days 3 and 7 compared with day 0. Immunohystochemistry analysis demonstrated a physical binding between neutrophils and adipocytes, which was supported by in vitro adherence assay: mouse peritoneal neutrophils adhered to a monolayer of 3T3-L1 mouse adipocytes, in a manner dependent on their activation state, 41.9 6 3.7% or 29.5 6 2%, by PMA or the IL-8 analog CXCL1 (KC), respectively, compared with 24.8 6 1.5% in unstimulated neutrophils, respectively. The degree of surface exposure of CD11b (Mac-1) corresponded to the percentage of adhered neutrophils. The adherence was prevented by preincubating neutrophils or adipocytes with anti-CD11b or anti-ICAM-1 antibodies. Furthermore, immunoprecipitation of CD11b from lysates of a mixed neutrophil-adipocyte cell population resulted in coimmunoprecipitation of ICAM-1, indicating that the interaction is mediated by neutrophil CD11b and adipocyte ICAM-1.-Elgazar-Carmon, V., A. Rudich, N. Hadad, and R. Levy. Neutrophils transiently infiltrate intra-abdominal fat early in the course of high-fat feeding.
Arachidonic acid (AA) can trigger activation of the phagocyte NADPH oxidase in a cell-free assay. However, a role for AA in activation of the oxidase in intact cells has not been established, nor has the AA generating enzyme critical to this process been identified. The human myeloid cell line PLB-985 was transfected to express p85 cytosolic phospholipase A 2 (cPLA 2 ) antisense mRNA and stable clones were selected that lack detectable cPLA 2 The phagocyte NADPH oxidase is a multicomponent transport chain that transfers electrons from NADPH to molecular oxygen and generates superoxide, a precursor of microbicidal oxidants important to host defense. NADPH oxidase subunits include three cytoplasmic components, p47 phox , p67 phox , and Rac-2, and a membrane flavocytochrome b 558 composed of gp91 phox and p22 phox (1-9). In differentiated phagocytic cells stimulation results in translocation of the cytosolic NADPH oxidase components to the membrane where they interact with the flavocytochrome to form the activated oxidase leading to superoxide generation. The signals responsible for assembly and activation of the oxidase are not clearly defined. PLA 2 1 activity has been implicated in a variety of responses by stimulated phagocytes, including degranulation, phagocytosis, adhesion, cell spreading, and activation of NADPH oxidase (10 -16). Until recently, generation of AA had been viewed as a modulating event leading to oxidase activation but not as critical to the process. Recently we and others have used PLA 2 inhibitors to implicate generation of AA as important for activation of the NADPH oxidase activity in human neutrophils (17,18). Moreover, we have shown that AA increases the affinity of the assembled oxidase for NADPH (19). However, studies using inhibitors may not delineate the specific enzyme of a related group whose inhibition is responsible for the observed effect, and the inhibition seen may result from action on more than one enzyme.In the last decade, several secreted and cytosolic mammalian PLA 2 isozymes have been described (20 -24). The existence of several types of PLA 2 in phagocytic cells (25-30) complicates delineation of the PLA 2 responsible for release of the AA, which impacts on NADPH oxidase activation following phagocyte stimulation. In the present study, we used the RNA antisense technique to create in the human phagocyte myeloid cell line, PLB-985, a p85 cPLA 2 -deficient model cell line to demonstrate the role of this enzyme in NADPH oxidase activation. MATERIALS AND METHODSCell Culture-PLB-985 cells (31) were grown in stationary suspension culture in RPMI 1640 medium containing 10% bovine serum (Hyclone Laboratories, Inc. Logan, UT), 2 mM L-glutamine, 100 units/ml penicillin, 100 g/ml streptomycin, and 12.5 units/ml nystatin (Biological Industries, Beth Haemek, Israel) at 37°C in a humidified of 5% CO 2 atmosphere. Cell number and viability were determined by trypan blue exclusion. [ 3 H]Thymidine incorporation was determined as described earlier (32).
Cryopreservation induces many changes in sperm cells, including membrane disorders and cell death. We tested the hypothesis that apoptosis, a form of programmed cell death, can contribute to the fatal effect of cryopreservation on sperm cells. A multiparametric study of apoptosis on bovine sperm is proposed, using flow cytometry, including mitochondrial membrane potential (DeltaPsi(m)), caspase activation, membrane permeability, nucleus condensation, DNA fragmentation, and phosphatidylserine (PS) externalization. The relevance of each test was first validated on a human somatic cell line, U937. Cryopreservation and/or thawing induced significant changes in all apoptotic markers in living bull sperm cells except those concerning the nucleus. After cryopreservation, 44.9% +/- 17% (vs. 11.3% +/- 10.6% before cryopreservation) of sperm cells showed low DeltaPsi(m), 12% +/- 6.3% (vs. 2.2% +/- 1.0% before) contained active caspases, and 10.8% +/- 5.8% (vs. 1.4% +/- 1.1% before) exhibited high membrane permeability. However, cryopreservation had no effect on DNA fragmentation (9.1% +/- 7.7% before vs. 11.1% +/- 5.7% after cryopreservation) or on nucleus condensation (46% +/- 12.7% before vs. 43.8% +/- 13.1% after). Cryopreservation acts as an apoptotic mechanism inducer in bovine sperm cells, where the earliest but not the latest features of cells undergoing apoptosis occur. We have named this abortive process an apoptosis-like phenomenon.
Infantile neuroaxonal dystrophy (INAD) is an autosomal recessive progressive neurodegenerative disease that presents within the first 2 years of life and culminates in death by age 10 years. Affected individuals from two unrelated Bedouin Israeli kindreds were studied. Brain imaging demonstrated diffuse cerebellar atrophy and abnormal iron deposition in the medial and lateral globus pallidum. Progressive white-matter disease and reduction of the N-acetyl aspartate : chromium ratio were evident on magnetic resonance spectroscopy, suggesting loss of myelination. The clinical and radiological diagnosis of INAD was verified by sural nerve biopsy. The disease gene was mapped to a 1.17-Mb locus on chromosome 22q13.1 (LOD score 4.7 at recombination fraction 0 for SNP rs139897), and an underlying mutation common to both affected families was identified in PLA2G6, the gene encoding phospholipase A2 group VI (cytosolic, calcium-independent). These findings highlight a role of phospholipase in neurodegenerative disorders.
The early features of apoptosis appear as ordered events during the cryopreservation/thawing process of bovine sperm cells. Bovine spermatozoa contain the machinery necessary to proceed to apoptosis involving especially the mitochondrial pathway.
There has been a growing interest over the past few years in the impact of male nutrition on fertility. Infertility has been linked to male overweight or obesity, and conventional semen parameter values seem to be altered in case of high body mass index (BMI). A few studies assessing the impact of BMI on sperm DNA integrity have been published, but they did not lead to a strong consensus. Our objective was to explore further the relationship between sperm DNA integrity and BMI, through a 3-year multicentre study. Three hundred and thirty male partners in subfertile couples were included. Using the terminal uridine nick-end labelling (TUNEL) assay, we observed an increased rate of sperm DNA damage in obese men (odds ratio (95% confidence interval): 2.5 (1.2-5.1)).
Lycopene, the major tomato carotenoid, has been found to inhibit proliferation of several types of cancer cells, including those of breast, lung, and endometrium. By extending the work to the HL-60 promyelocytic leukemia cell line, we aimed to evaluate some mechanistic aspects of this effect. Particularly, the possibility was examined that the antiproliferative action of the carotenoid is associated with induction of cell differentiation. Lycopene treatment resulted in a concentration-dependent reduction in HL-60 cell growth as measured by [3H]thymidine incorporation and cell counting. This effect was accompanied by inhibition of cell cycle progression in the G0/G1 phase as measured by flow cytometry. Lycopene alone induced cell differentiation as measured by phorbol ester-dependent reduction of nitro blue tetrazolium and expression of the cell surface antigen CD14. Results of several recent intervention studies with beta-carotene, which have revealed no beneficial effects of this carotenoid, suggest that a single dietary component cannot explain the anticancer effect of diets rich in vegetables and fruits. Thus another goal of our study was to examine whether lycopene has the ability to synergize with other natural anticancer compounds, such as 1,25-dihydroxyvitamin D3, which when used alone are therapeutically active only at high and toxic concentrations. The combination of low concentrations of lycopene with 1,25-dihydroxyvitamin D3 exhibited a synergistic effect on cell proliferation and differentiation and an additive effect on cell cycle progression. Such synergistic antiproliferative and differentiating effects of lycopene and other compounds found in the diet and in plasma may suggest the inclusion of the carotenoid in the diet as a cancer-preventive measure.
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