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Heme oxygenase (HO)-1 is the inducible isoform of the heme-degrading enzyme HO, which is upregulated by multiple stress stimuli. HO-1 has major immunomodulatory and anti-inflammatory effects via its cell-type-specific functions in mononuclear cells. Contradictory findings have been reported on HO-1 regulation by the Toll-like receptor (TLR) 4 ligand lipopolysaccharide (LPS) in these cells. Therefore, we reinvestigated the effects of LPS on HO-1 gene expression in human and murine mononuclear cells in vitro and in vivo. Remarkably, LPS downregulated HO-1 in primary human peripheral blood mononuclear cells (PBMCs), CD14 + monocytes, macrophages, dendritic cells, and granulocytes, but upregulated this enzyme in primary murine macrophages and human monocytic leukemia cell lines. Furthermore, experiments with human CD14 + monocytes revealed that activation of other TLRs including TLR1, -2, -5, -6, -8, and -9 decreased HO-1 mRNA expression. LPS-dependent downregulation of HO-1 was specific, because expression of cyclooxygenase-2, NADP(H)-quinone oxidoreductase-1, and peroxiredoxin-1 was increased under the same experimental conditions. Notably, LPS upregulated expression of Bach1, a critical transcriptional repressor of HO-1. Moreover, knockdown of this nuclear factor enhanced basal and LPS-dependent HO-1 expression in mononuclear cells. Finally, downregulation of HO-1 in response to LPS was confirmed in PBMCs from human individuals subjected to experimental endotoxemia. In conclusion, LPS downregulates HO-1 expression in primary human mononuclear cells via a Bach1-mediated pathway. As LPS-dependent HO-1 regulation is cell-type- and species-specific, experimental findings in cell lines and animal models need careful interpretation. [ABSTRACT FROM AUTHOR]

Objective: To investigate a putative role of TSPYL1 in male idiopathic infertility. Design: Clinical article. Setting: University hospital. Patient(s): A total of 104 infertile men were selected with idiopathic nonobstructive azoospermia, cryptozoospermia, oligozoospermia, oligonecrozoospermia, and oligoasthenoteratozoospermia (OAT) syndrome, along with a control group of 106 men with proven paternity. Intervention(s): Mutation screening of the coding region and parts of the 5′ and 3′ untranslated regions of the TSPYL1 gene was performed by polymerase chain reaction and sequencing. Main Outcome Measure(s): Occurrence of TSPYL1 single-nucleotide polymorphisms (SNPs) and mutations. Result(s): In these cohorts, eight known TSPYL1 SNPs were identified, none of which was significantly associated with male infertility. Two potentially disease-causing variants were detected in the infertile cohort: one man with azoospermia was found to be heterozygous for the novel TSPYL1 variant c.419C>G (p.Ser140Cys), and the rare substitution c.1098C>A (p.Phe366Leu) was identified in a man with OAT syndrome in the heterozygous state. Additionally, one fertile man was found to be heterozygous for the rare variant c.487G>A (p.Val163Ile). In silico analyses predicted a nonpathogenic effect for all amino acid exchanges, although protein features might be affected by p.Ser140Cys and p.Phe366Leu, respectively. Conclusion(s): Mutations in the TSPYL1 gene do not seem to play a major role in the pathogenesis of idiopathic male infertility, and mutation screening of the TSPYL1 gene can currently not be recommended in routine diagnostics of idiopathic male infertility. [ABSTRACT FROM AUTHOR]