Parab Sweta, Shetty Omshree, Gaonkar Reshma, Balasinor Nafisa, Khole Vrinda, Parte Priyanka
Department of Gamete Immunobiology, National Institute for Research in Reproductive Health (ICMR), Mumbai, 400012, India.
Department of Neuroendocrinology and Confocal Microscopy Lab, National Institute for Research in Reproductive Health (ICMR), Mumbai, 400012, India.
Cell Tissue Res. 2015 Feb;359(2):665-678. doi: 10.1007/s00441-014-2039-x. Epub 2014 Nov 20.
Histone deacetylase 6 (HDAC6) is an alpha (α)-tubulin deacetylase and its over-expression has been demonstrated to promote chemotactic cell movement. Motility in sperm is driven by the flagella, the cytoskeletal structure comprising the microtubules, which are heterodimers of α- and β-tubulins. We have hypothesized that HDAC6, by virtue of being an α-tubulin deacetylase, might modulate sperm motility. However, the presence of HDAC6 on sperm has hitherto not been reported. In this study, we have demonstrated, for the first time, the presence of HDAC6 transcript and protein in the testicular and caudal sperm of rat. We have observed a significantly overlapping expression of HDAC6 with acetyl α-tubulin (Ac α-tubulin) in the mid-piece and principal piece of sperm flagella, and the co-precipitation of α-tubulin and Ac α-tubulin together with HDAC6 and vice versa in sperm lysates. This indicates that HDAC6 interacts with α-tubulin. The HDAC6 activity of sperm, sperm motility and status of Ac α-tubulin investigated in the presence of HDAC inhibitors Trichostatin A, Tubastatin A and sodium butyrate demonstrate that HDAC6 in sperm is catalytically active and that inhibitors of HDAC6 increase acetylation and restrict sperm motility. Thus, we show that (1) active HDAC6 enzyme is present in sperm, (2) HDAC6 in sperm is able to deacetylate α-tubulin, (3) inhibition of HDAC6 results in increased Ac α-tubulin expression and (4) HDAC6 inhibition affects sperm motility. This evidence suggests that HDAC6 is involved in modulating sperm movement.
组蛋白去乙酰化酶6（HDAC6）是一种α-微管蛋白去乙酰化酶，其过表达已被证明可促进趋化性细胞运动。精子的运动由鞭毛驱动，鞭毛是由微管组成的细胞骨架结构，微管是α-微管蛋白和β-微管蛋白的异二聚体。我们推测，由于HDAC6是一种α-微管蛋白去乙酰化酶，它可能会调节精子的运动。然而，迄今为止尚未有关于精子上存在HDAC6的报道。在本研究中，我们首次证明了HDAC6转录本和蛋白在大鼠睾丸和尾部精子中的存在。我们观察到HDAC6与乙酰化α-微管蛋白（Ac α-微管蛋白）在精子鞭毛的中段和主段有明显的重叠表达，并且在精子裂解物中α-微管蛋白和Ac α-微管蛋白与HDAC6共沉淀，反之亦然。这表明HDAC6与α-微管蛋白相互作用。在存在HDAC抑制剂曲古抑菌素A、Tubastatin A和丁酸钠的情况下，对精子的HDAC6活性、精子运动和Ac α-微管蛋白状态进行研究，结果表明精子中的HDAC6具有催化活性，并且HDAC6抑制剂会增加乙酰化并限制精子运动。因此，我们表明：（1）精子中存在活性HDAC6酶；（2）精子中的HDAC6能够使α-微管蛋白去乙酰化；（3）抑制HDAC6会导致Ac α-微管蛋白表达增加；（4）抑制HDAC6会影响精子运动。这些证据表明HDAC6参与调节精子运动。
