Israel Medical Association Journal

Background: Atherosclerosis is a well-established inflammatory disease in which T helper 1 (Th1) cells play a key role. Regulatory T (Treg) cells drive a shift from Th1 to Th2 response and were shown to be reduced in atherosclerosis. ST2/interleukin (IL)-33 signal was found to promote Th2 response, attenuating atherosclerotic plaque progression.

Objectives: To evaluated the effect of IL-33 on Treg cell number.

Methods: We employed flow cytometry to determine Treg cell number, as well as ST2 levels, among splenocytes of C57BL/6J vs ApoE-/- mice. Soluble ST2 (sST2) levels were detected by enzyme-linked immunosorbent assay. 

Results: IL-33 contributed to an increase in Treg cells, but this association was attenuated in ApoE knockout (ApoE-/-) atherosclerotic mice. As a possible mechanism we demonstrated a reduction in the levels of CD4+ST2+ cells by flow cytometry, which is cotemporary to the previously described decrease in Treg cells in ApoE-/- mice. Additionally, the serum level of the soluble ST2 (sST2) decoy receptor was higher in ApoE-/- mice than in control animals.

Conclusions: Our results suggest that a repressed ST2/IL-33 signaling may contribute to the decrease in Treg cells observed in atherosclerosis.
 

Background: Studies suggest that global semen quality is declining, but the debate remains open owing to geographic variation.

Objectives: To evaluate temporal trends of sperm parameters – namely concentration, motility and total motile sperm count – in sperm donated during the period 1995–2009.

Methods: In a retrospective longitudinal cohort study we analyzed the sperm count and motility of 2182 semen samples provided on a weekly basis by 58 young, healthy, fertile, university-educated, paid donors.

Results: Despite the lowering of criteria for sperm parameters satisfactory for donation that were implemented in 2004, 38% of applicants for sperm donation are now rejected based on semen quality as compared to a third of applicants 10–15 years ago (P < 0.001). If the old strict criteria were in place 88% of candidates would be rejected today (P < 0.0001). Over the study period, the average sperm parameters dropped from a concentration of 106 ± 25 million spermatozoa/ml with 79% ± 4.3% motility to 68 ± 14 million/ml with 66% ± 4.5% motile sperm (P < 0.0001, P < 0.0001, respectively). The total motile sperm count per ejaculate also decreased, from 66.4 ± 18.2 million to 48.7 ± 12 million (P < 0.005). When the previous criteria were implemented for the analysis of the latest group of sperm donors, only 18% of donors had an acceptable sperm quality, with an average concentration of 87 ± 12 million spermatozoa/ml, 73% ± 2.6% motile sperm and total motile sperm count of 53.1 ± 3.8 million per ejaculate – still significantly lower than 15 years ago (P = 0.01, P = 0.003, P = 0.058 respectively).

Conclusions: The rapid deterioration of sperm quality among fertile semen donors is alarming and may lead to cessation of sperm donation programs.