Understanding HAT1: A Comprehensive Review of Noncanonical Roles and Connection with Disease

Histone acetylation plays a vital role in organizing chromatin, regulating gene expression and controlling the cell cycle. The first histone acetyltransferase to be identified was histone acetyltransferase 1 (HAT1), but it remains one of the least understood acetyltransferases. HAT1 catalyzes the acetylation of newly synthesized H4 and, to a lesser extent, H2A in the cytoplasm. However, 20 min after assembly, histones lose acetylation marks. Moreover, new noncanonical functions have been described for HAT1, revealing its complexity and complicating the understanding of its functions. Recently discovered roles include facilitating the translocation of the H3H4 dimer into the nucleus, increasing the stability of the DNA replication fork, replication-coupled chromatin assembly, coordination of histone production, DNA damage repair, telomeric silencing, epigenetic regulation of nuclear lamina-associated heterochromatin, regulation of the NF-κB response, succinyl transferase activity and mitochondrial protein acetylation. In addition, the functions and expression levels of HAT1 have been linked to many diseases, such as many types of cancer, viral infections (hepatitis B virus, human immunodeficiency virus and viperin synthesis) and inflammatory diseases (chronic obstructive pulmonary disease, atherosclerosis and ischemic stroke). The collective data reveal that HAT1 is a promising therapeutic target, and novel therapeutic approaches, such as RNA interference and the use of aptamers, bisubstrate inhibitors and small-molecule inhibitors, are being evaluated at the preclinical level.

[Autoimmunity and autoinflammation in pathogenesis of immunoinflammatory diseases]

Rheumatic diseases relate to the group of the immunoinflammatory diseases (IID), in pathogenesis of which have a value both autoimmune and autoinflammatory processes.

AIM

To present the heterogeneous pathogenesis of inflammation in IID.

MATERIALS AND METHODS

It is inspected 260 patients (pts) with IID: 242 pts with systemic autoimmune diseases (SAD): 65 systemic lupus erythematosis, 50 systemic sclerosis, 127 systemic vasculitides (SV) and 18 patients with autoinflammatory diseases (AID): 8 Behcets disease, 2 periodic disease, 5 familial cold fever, 2 idiopathic lobular panniculitis and 1 relapsing polychondritis. Is carried out a study of complement, antigen of von Willebrand factor (FW:AG), antinuclear antibodies, antibodies to DNA, anti-endothelial antibodies, antibodies to topoizomeraze I (anti-Scl-70), antineutrophilic cytoplasmic antibodies (ANCA), anticardiolipin antibodies (aCL IgG and aCL IgM), cryoglobulins, VS, CRP.

RESULTS

SAD were characterized by the synthesis of wide antibodies spectrum. As the basic serological marker at the screening it follows to consider antinuclear antibodies (75%). Practically in all groups it took place hypcomlemetemia with reduction of C3 and C4 complement. With systemic lupus erythematosis are revealed antibodies to DNA (71%), with ANCA-associated SV-ANCA (94%), aKL (14%); with SSD aScl-70 (17%). At Wegener granulomatosis ANCA are determined in 94% patients in the active stage. It is noted correlation ANCA with the index of the clinical activity of vasculitis. In the remaining SV groups ANCA were separated in the single cases. Cryoglobulins are noted in all patients with cryoglobulinemic vasculitis. aCL IgG and aCL IgM were the markers of antiphospholipid syndrome. Аnti-endothelial antibodies had significant oscillation spectrum. High indices FW:AG are noted with all above nosologic forms indicated, especially with Wegener granulomatosis and vasculitis hemorrhagic. Among the laboratory tests of inflammatory activity should be considered the determination of VS, CRP and FV:AG, which is also considered the marker of vascular wall defeat. Is given clinical characteristic and changes in the laboratory indices at AID: Conclusion.Isolation from the group IID of patients with AID serves as indication for a genetic study of this contingent with the approval of use for their treatment of biological therapy. Isolation from the group SAD patients with AID serves as indication for a genetic study of this contingent with the approval of use for their treatment of biological therapy.