A study on the association between serum amyloid A and sperm concentration

High lipid diet and the expression of proinflammatory markers in testis

Abstract

Introduction: Obesity is defined as chronic low-grade inflammation which is manifestation of the cellular response to a variety of stressful situations leading to organ and tissue damage. А high lipid diet could be assumed to be the trigger mechanism for the development of inflammatory processes leading to a disorder in the immune tolerance in the testis.

Aim: The present study aimed at demonstrating the expression of inflammatory markers in the testis by a model of a high lipid diet and the possible effect on spermatogenesis.

Materials and methods: Male Wistar rats were used in the study divided into two groups: a control group fed standard rodent food and an experimental group receiving high lipid food for 14 weeks. Routine histological techniques, immunohistochemical reactions for proinflammatory markers and morphometric analysis were performed to examine the testis preparations.

Results: The high lipid diet caused a low-grade inflammation in the testis in the experimental group, which was confirmed by the increase of proinflammatory markers: the C-reactive protein, serum amyloid A, and interleukin-4, and by the elevated levels of angiotensin-converting enzyme in the experimental versus control groups in a rat experimental model.

Conclusions: Our results suggest that a high lipid diet might be a possible cause for the idiopathic infertility in men.

Genetic resistance to DEHP-induced transgenerational endocrine disruption

Di(2-ethylhexyl)phthalate (DEHP) interferes with sex hormones signaling pathways (SHP). C57BL/6J mice prenatally exposed to 300 mg/kg/day DEHP develop a testicular dysgenesis syndrome (TDS) at adulthood, but similarly-exposed FVB/N mice are not affected. Here we aim to understand the reasons behind this drastic difference that should depend on the genome of the strain. In both backgrounds, pregnant female mice received per os either DEHP or corn oil vehicle and the male filiations were examined. Computer-assisted sperm analysis showed a DEHP-induced decreased sperm count and velocities in C57BL/6J. Sperm RNA sequencing experiments resulted in the identification of the 62 most differentially expressed RNAs. These RNAs, mainly regulated by hormones, produced strain-specific transcriptional responses to prenatal exposure to DEHP; a pool of RNAs was increased in FVB, another pool of RNAs was decreased in C57BL/6J. In FVB/N, analysis of non-synonymous single nucleotide polymorphisms (SNP) impacting SHP identified rs387782768 and rs29315913 respectively associated with absence of the Forkhead Box A3 (Foxa3) RNA and increased expression of estrogen receptor 1 variant 4 (NM_001302533) RNA. Analysis of the role of SNPs modifying SHP binding sites in function of strain-specific responses to DEHP revealed a DEHP-resistance allele in FVB/N containing an additional FOXA1-3 binding site at rs30973633 and four DEHP-induced beta-defensins (Defb42, Defb30, Defb47 and Defb48). A DEHP-susceptibility allele in C57BL/6J contained five SNPs (rs28279710, rs32977910, rs46648903, rs46677594 and rs48287999) affecting SHP and six genes (Svs2, Svs3b, Svs4, Svs3a, Svs6 and Svs5) epigenetically silenced by DEHP. Finally, targeted experiments confirmed increased methylation in the Svs3ab promoter with decreased SEMG2 persisting across generations, providing a molecular explanation for the transgenerational sperm velocity decrease found in C57BL/6J after DEHP exposure. We conclude that the existence of SNP-dependent mechanisms in FVB/N inbred mice may confer resistance to transgenerational endocrine disruption.

Male Inflammatory Parameters Are not Useful to Predict the Outcomes of Intracytoplasmic Sperm Injection: Results from a Cross-Sectional Study

Purpose

The relationship between male systemic inflammation and fertility seems intriguing, but no data about its impact on the assisted reproductive technology outcomes has been reported. Here, we aimed to evaluate the prognostic role of male systemic inflammatory parameters in intracytoplasmic sperm injection (ICSI) outcomes prediction, in couples undergoing an ovum donation program.

Materials and Methods

From January 2016 to December 2017, one hundred-ten couples were considered for this cross-sectional study. Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-eosinophil ratio (MER), platelet-to-lymphocyte ratio (PLR), seminal parameters, fertilization rate (FR), cleavage rate (CR), pregnancy rate (PR) were evaluated. Male patients were divided into Group A with FR ≤70%, Group B with FR >70%.

Results

Overall, FR was 74.5%, CR 90.9%, PR 41.8%. Group A included 43 patients, Group B 67 men. Group A showed a median NLR of 1.55, PLR of 106.09, MER of 2.33. Group B reported a median NLR of 1.64, PLR 109.0, MER 2.76. We found no statistically differences between two groups with respect to NLR, PLR, MER (p=0.90, p=0.70, p=0.96, respectively). The age-adjusted linear regression analysis demonstrated only a relationship between NLR and sperm motility count (r=−0.02; p<0.05). Using the univariate logistic regression analysis, we found no significant associations.

Conclusions

We did not find any relationship between ICSI outcomes and male inflammation parameters.