Transcriptomic and genomic studies classify NKL54 as a histone deacetylase inhibitor with indirect influence on MEF2-dependent transcription

In leiomyosarcoma class IIa HDACs (histone deacetylases) bind MEF2 and convert these transcription factors into repressors to sustain proliferation. Disruption of this complex with small molecules should antagonize cancer growth. NKL54, a PAOA (pimeloylanilide o-aminoanilide) derivative, binds a hydrophobic groove of MEF2, which is used as a docking site by class IIa HDACs. However, NKL54 could also act as HDAC inhibitor (HDACI). Therefore, it is unclear which activity is predominant. Here, we show that NKL54 and similar derivatives are unable to release MEF2 from binding to class IIa HDACs. Comparative transcriptomic analysis classifies these molecules as HDACIs strongly related to SAHA/vorinostat. Low expressed genes are upregulated by HDACIs, while abundant genes are repressed. This transcriptional resetting correlates with a reorganization of H3K27 acetylation around the transcription start site (TSS). Among the upregulated genes there are several BH3-only family members, thus explaining the induction of apoptosis. Moreover, NKL54 triggers the upregulation of MEF2 and the downregulation of class IIa HDACs. NKL54 also increases the binding of MEF2D to promoters of genes that are upregulated after treatment. In summary, although NKL54 cannot outcompete MEF2 from binding to class IIa HDACs, it supports MEF2-dependent transcription through several actions, including potentiation of chromatin binding

Two cases of asbestosis and one case of rounded atelectasis due to non-occupational asbestos exposure

Asbestos is a well-known cause of several neoplastic (malignant mesothelioma, lung cancer) and non-neoplastic (asbestosis, pleuropathies) occupational diseases. Lower-level exposure in the general environment may induce pleural plaques and thickenings, and is associated with an increased mesothelioma risk. We present two patients (a 68-year-old man and a 72-year-old woman) who developed asbestosis (in association with pleural plaques and calcifications), and a 78-year-old man who developed rounded atelectasis (with pleural plaques and benign effusion), after living for several decades in the proximity of large Italian asbestos-cement plant. None of them had been exposed to asbestos occupationally. Besides living in a contaminated area, the woman used to clean the work clothes of her brother, who was employed in the local asbestos factory. The three cases indicate that non-neoplastic, long-latency asbestos-related diseases which are usually observed as a consequence of occupational exposures, may rarely develop in subjects living in contaminated geographical sites and buildings. These unusual environmental diseases raise the diagnostic problem of differentiating them from other, more common respiratory illnesses, and impose the duties of patient notification, assessment and follow-up, to assess the possibility of progression of disease and increased neoplastic risk

Rabdomiolisi in operaio esposto ad olii minerali paraffinici. Insolita associazione con bronchiolite obliterante e polmonite organizzativa (BOOP)

We describe a 29-year-old worker; exposed to metal dust, sawdust and paraffinic mineral oils in a factory producing accessories for leather articles and clothing, who came to observation with fever (39 degrees C), chest pain and marked increase of muscular enzymes. Chest computed tomography showed two areas of lung consolidation, that subsequently appeared enlarged with central escavation. Lung biopsy lead to the diagnosis of BOOP. The case has been reported to the judicial and workers' compensation authorities as probable occupational toxic myopathy. Indeed, exposure to paraffinic mineral oils is a known, though unusual, cause of rhabdomyolysis. The association with BOOP has never been previously described

Quiescent Platelets Stimulate Angiogenesis and Diabetic Wound Repair

Introduction Platelets partake in hemostasis, wound healing, and tumor growth. Although platelet-rich-plasma (PRP) has been used in surgery for several years, its mechanism of action and application methods are still poorly characterized. Materials and Methods A single unit of human platelets obtained by plateletpheresis was diluted in plasma and divided into three equal volumes. One volume was stored at room temperature as fresh platelets (RT), another volume was frozen by storage at –80°C (FZ), and the third volume was frozen at –80°C with 6% DMSO (FZ6). Plasma (PL) was used as control. Using flow cytometry, platelets were tested for platelet glycoprotein GPIb and annexin V binding, as survival and activation markers, respectively. Hemostatic function was assessed by thromboelastometry. In vivo, platelets were topically applied on 1 cm,2 full-thickness wounds on db/db mice (n = 10/group) and healing was staged microscopically and macroscopically. Results All platelet preparations showed hemostatic ability. RT platelets were GPIb positive (nonactivated-quiescent platelets) and stimulated angiogenesis by threefold, and cell proliferation by fourfold in vivo. FZ platelets were positive for annexin V, indicating activated platelets and, in vivo, increased only wound granulation. FZ6 platelets contained 30% nonactivated-quiescent and 50% activated platelets and stimulated granulation, angiogenesis, cell proliferation, and promoted re-epithelialization in vivo. Conclusions Platelets showed distinct mechanisms to induce hemostasis and wound healing. Quiescent platelets are required to induce angiogenesis in vivo. Platelets stored at room temperature and frozen with 6% DMSO and stored at –80°C achieved optimal wound healing in diabetic mice

Design, synthesis, and biological evaluation of sirtinol analogues as class III histone/protein deacetylase (sirtuin) inhibitors

In a search for potent inhibitors of class III histone/protein deacetylases (sirtuins), a series of sirtinol analogues have been synthesized and the degree of inhibition was assessed in vitro using recombinant yeast Sir2, human SIRT1, and human SIRT2 and in vivo with a yeast phenotypic assay. Two analogues, namely, 3- and 4-[(2-hydroxy-1-naphthalenylmethylene)amino] -N-(l-phenylethyl)benzamide (i.e., in- and p-sirtinol), were 2- to 10-fold more potent than sirtinol against human SIRT1 and SIRT2 enzymes. In yeast in vivo assay, these two small molecules were as potent as sirtinol. Compounds lacking the 2-hydroxy group at the naphthalene moiety or bearing several modifications at the benzene 2'-position of the aniline portion (carbethoxy, carboxy, and cyano) were 1.3-13 times less potent than sirtinol, whereas the 2'carboxamido analogue was totally inactive. Both (R)- and (S)-sirtinol had similar inhibitory effects on the yeast and human enzymes, demonstrating no enantioselective inhibitory effect