TIP60 acts as a regulator of genes involved in filopodia formation and cell migration during wound healing.

Wound healing is a complex phenomenon that requires coordination of numerous molecular and cellular changes to facilitate timely and efficient repair of the damaged tissue. Although many of these molecular pathways have been detailed, others remain to be elucidated. In the present work, we show for the first time, roles for the acetyltransferase TIP60 and nuclear receptor transcription factor PXR in this process, participating in wound healing by altering actin dynamics and cellular motility. We found that in response to wound-injury, TIP60 induces rapid formation of filopodia at the wounded cell front, leading to enhanced cell migration and faster closure of the wound. Further, qPCR analysis revealed heightened expression of Cdc42 and ROCK1 genes, key regulators involved in filopodia formation and actin reorganization, exclusively in TIP60-PXR-expressing cells upon wound-induction. We also performed ChIP assays to confirm the context-specific binding of TIP60 on the ROCK1 promoter and demonstrated that the TIP60 chromodomain is essential for loading of the TIP60-PXR complex onto the chromatin. Results from immunoprecipitation assays revealed that during the wounded condition, TIP60 alters the chromatin microenvironment by specifically acetylating histones H2B and H4, thereby modulating the expression of target genes. Overall, findings of this study show that TIP60 is a novel regulator of the wound healing process by regulating the expression of wound repair-related genes.

Characterization of Two Novel Variants of the Steroidogenic Acute Regulatory Protein Identified in a Girl with Classic Lipoid Congenital Adrenal Hyperplasia.

Congenital adrenal hyperplasia (CAH) consists of several autosomal recessive disorders that inhibit steroid biosynthesis. We describe a case report diagnosed with adrenal insufficiency due to low adrenal steroids and adrenocorticotropic hormone excess due to lack of cortisol negative feedback signaling to the pituary gland. Genetic work up revealed two missense variants, p.Thr204Arg and p.Leu260Arg in the STAR gene, inherited by both parents (non-consanguineous). The StAR protein supports CYP11A1 enzyme to cleave the side chain of cholesterol and synthesize pregnenolone which is metabolized to all steroid hormones. We used bioinformatics to predict the impact of the variants on StAR activity and then we performed functional tests to characterize the two novel variants. In a cell system we tested the ability of variants to support cholesterol conversion to pregnenolone and measured their mRNA and protein expression. For both variants, we observed loss of StAR function, reduced protein expression and categorized them as pathogenic variants according to guidelines of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. These results fit the phenotype of the girl during diagnosis. This study characterizes two novel variants and expands the list of missense variants that cause CAH.

Correction: Stereoselective synthesis of natural product inspired carbohydrate fused pyrano[3,2-c]quinolones as antiproliferative agents.

Correction for 'Stereoselective synthesis of natural product inspired carbohydrate fused pyrano[3,2-c]quinolones as antiproliferative agents' by Priti Kumari et al., Org. Biomol. Chem., 2018, DOI: 10.1039/c7ob03186f.

Stereoselective synthesis of natural product inspired carbohydrate fused pyrano[3,2-c]quinolones as antiproliferative agents.

Pyrano[3,2-c]quinolone structural motifs are commonly found in natural products with diverse biological activities. As part of a research programme aimed at developing the efficient synthesis of natural product-like small molecules, we designed and developed the microwave assisted, facile stereoselective synthesis of two series of carbohydrate fused pyrano[3,2-c]quinolone derivatives (n = 23) starting from 2-C-formyl galactal and 2-C-formyl glucal, reacting with various 4-hydroxyquinolones in shorter reaction times (15-20 min). The antiproliferative activity of these synthesized pyrano[3,2-c]quinolones was determined against MCF-7 (breast) and HepG2 (liver) cancer cells. The selected library members displayed low micromolar (3.53-9.68 µM) and selective antiproliferative activity. These findings on carbohydrate fused pyrano[3,2-c]quinolone derivatives are expected to provide new leads for anticancer drug discovery.

Secondary open-angle pigmentary glaucoma resulting from a single-piece hydrophobic intraocular lens in the sulcus.

The case report of a 68-year-old man with a single-piece hydrophobic intraocular lens (IOL) implanted in the sulcus with posterior capsular rent in the right eye inducing secondary open-angle pigmentary glaucoma without individual hereditary steroid susceptibility. The clinical and diagnostic evaluations of the patient were thoroughly and specifically carried out. The unilateral pseudophakic open-angle pigmentary glaucoma developed in the long course in the context of rubbing of the haptics and optic of a hydrophobic IOL implanted in the sulcus, against the posterior surface of the iris, resulting in pigment dispersion, trabecular inflammation, and aqueous outflow obstruction. Although the clinical findings of our case were very similar to that of pigmentary glaucoma, the distinction between the two conditions was still quite easy, considering that pigmentary glaucoma is a bilateral disorder predominantly affecting young myopic men with Krukenberg's spindle and increased incidence of steroid responsiveness. It has been clearly distinguished from steroid-induced glaucoma based on the pigmented trabecular meshwork.

Categoric prediction of metal ion mechanisms in the active sites of 17 select type II restriction endonucleases.

Recently determined crystal structures of type II restriction endonucleases have produced a plethora of information on the basis for target site sequence selectivity. The positioning and role of metal ions in DNA recognition sites might reflect important properties of protein-DNA interaction. Although acidic and basic groups in the active sites can be identified, and in some cases divalent-metal binding sites delineated, a convincing picture clarifying the way in which the attacking hydroxide ion is generated, and the leaving group stabilized, has not been elucidated for any of the enzymes. We have examined the interatomic distances between metal ions and proposed key catalytic residues in the binding sites of seventeen type II restriction endonucleases whose crystal structures are documented in literature. The summary and critical evaluation of structural assignments and predictions made earlier have been useful to group these enzymes. All the enzymes used for this study have been categorized on the basis of the number of metal ions identified in their crystal structures. Among 17 experimentally characterized (not putative) type II REases, whose apparently full-length sequences are available in REBASE, we predict 8 (47%) to follow the single metal ion mechanism, 5 to follow the two metal ion mechanism, 2, the three metal ion mechanism, 1, the four metal ion mechanism and 1 the six metal ion mechanism.

A Novel Single Domain Antibody Targeting FliC Flagellin of Salmonella enterica for Effective Inhibition of Host Cell Invasion.

The enteric pathogen, Salmonella enterica is a major cause of human gastroenteritis globally and with increasing bacterial resistance to antibiotics, alternative solutions are urgently needed. Single domain antibodies (sdAbs), the smallest antibody fragments that retain antigen binding specificity and affinity, are derived from variable heavy-chain only fragments (VHH) of camelid heavy-chain-only immunoglobulins. SdAbs typically contain a single disulfide bond simplifying recombinant protein production in microbial systems. These factors make sdAbs ideally suited for the development of effective anti-bacterial therapeutics. To this end, we generated an anti-Salmonella VHH library from which we screened for high affinity sdAbs. We present a novel sdAb (Abi-Se07) that targets the Salmonella virulence factor, FliC, required for bacterial motility and invasion of host cells. We demonstrate that Abi-Se07 bound FliC with a K D of 16.2 ± 0.1 nM. In addition, Abi-Se07 exhibited cross-serovar binding to whole cells of S. enterica serovar Typhimurium, Heidelberg, and Hadar. Abi-Se07 significantly inhibited bacterial motility and significantly reduced S. enterica colonization in a more native environment of chicken jejunum epithelium. Taken together, we have identified a novel anti-Salmonella sdAb and discuss future efforts toward therapeutic development.

Novel complex of HAT protein TIP60 and nuclear receptor PXR promotes cell migration and adhesion.

PXR is a member of nuclear receptor superfamily and a well-characterized mediator of xenobiotic metabolism. The classical mode of PXR activation involves its binding to appropriate ligand and subsequent heterodimerization with its partner RXR. However, various factors such as post-translational modifications and crosstalk with different cellular factors may also regulate the functional dynamics and behavior of PXR. In the present study, we have identified that TIP60, an essential lysine acetyltransferase protein interacts with unliganded PXR and together this complex promotes cell migration & adhesion. TIP60 utilizes its NR Box to interact with LBD region of PXR and acetylates PXR at lysine 170 to induce its intranuclear reorganization. Also, RXR is not required for TIP60-PXR complex formation and this complex does not induce ligand-dependent PXR target gene transactivation. Interestingly, we observed that PXR augments the catalytic activity of TIP60 for histones. This is the first report demonstrating the exclusive interaction of TIP60 with PXR and uncovers a potential role for the TIP60-PXR complex in cell migration and adhesion.