Gene in Hereditary Non-syndromic Hearing Loss: Recurrence and Incomplete Penetrance of the p.C113Y Mutation in Northwest Africa.

Inherited hearing loss is extremely heterogeneous both clinically and genetically. In addition, the spectrum of deafness-causing genetic variants differs greatly among geographical areas and ethnicities. The identification of the causal mutation in affected families allows early diagnosis, clinical follow-up, and genetic counseling.

Tranylcypromine-Based LSD1 Inhibitors: Structure-Activity Relationships, Antiproliferative Effects in Leukemia, and Gene Target Modulation.

LSD1 is a lysine demethylase highly involved in initiation and development of cancer. To design highly effective covalent inhibitors, a strategy is to fill its large catalytic cleft by designing tranylcypromine (TCP) analogs decorated with long, hindered substituents. We prepared three series of TCP analogs, carrying aroyl- and arylacetylamino (1 a-h), Z-amino acylamino (2 a-o), or double-substituted benzamide (3 a-n) residues at the C4 or C3 position of the phenyl ring.

Tuning mTORC1 activity dictates the response of acute myeloid leukemia to LSD1 inhibition.

Lysine specific demethylase-1 (LSD1) has been shown to be critical in acute myeloid leukemia (AML) pathogenesis and this has led to the development of LSD1 inhibitors (LSD1i) which are currently tested in clinical trials. Nonetheless, preclinical studies reported that AML cells frequently exhibit intrinsic resistance to LSD1 inhibition, and the molecular basis for this phenomenon is largely unknown. We explored the potential involvement of mammalian target of rapamycin (mTOR) in mediating the resistance of leukemic cells to LSD1i.

A Method to Convert mRNA into a Guide RNA (gRNA) Library without Requiring Previous Bioinformatics Knowledge of the Organism.

While the diversity of species represents a diversity of special biological abilities, many of the genes that encode those special abilities in a variety of species are untouched, leaving an untapped gold mine of genetic information; however, despite current advances in genome bioinformatics, annotation of that genetic information is incomplete in most species, except for well-established model organisms, such as human, mouse, or yeast. A guide RNA (gRNA) library using the clustered regularly interspersed palindromic repeats (CRISPR)/Cas9 (CRISPR-associated protein 9) system can be used for the phenotypic screening of uncharacterized genes by forward genetics. The construction of a gRNA library usually requires an abundance of chemically synthesized oligos designed from annotated genes; if one wants to convert mRNA into gRNA without prior knowledge of the target DNA sequences, the major challenges are finding the sequences flanking the protospacer adjacent motif (PAM) and cutting out the 20-bp fragment.

A double-strand break can trigger immunoglobulin gene conversion.

All three B cell-specific activities of the immunoglobulin (Ig) gene re-modeling system-gene conversion, somatic hypermutation and class switch recombination-require activation-induced deaminase (AID). AID-induced DNA lesions must be further processed and dissected into different DNA recombination pathways. In order to characterize potential intermediates for Ig gene conversion, we inserted an I-SceI recognition site into the complementarity determining region 1 (CDR1) of the Ig light chain locus of the AID knockout DT40 cell line, and conditionally expressed I-SceI endonuclease.

A method to convert mRNA into a gRNA library for CRISPR/Cas9 editing of any organism.

The clustered regularly interspersed palindromic repeats (CRISPR)/Cas9 (CRISPR-associated protein 9) system is a powerful tool for genome editing that can be used to construct a guide RNA (gRNA) library for genetic screening. For gRNA design, one must know the sequence of the 20-mer flanking the protospacer adjacent motif (PAM), which seriously impedes experimentally making gRNA. I describe a method to construct a gRNA library via molecular biology techniques without relying on bioinformatics.

Dietary restriction with and without caloric restriction for healthy aging.

Caloric restriction is the most effective and reproducible dietary intervention known to regulate aging and increase the healthy lifespan in various model organisms, ranging from the unicellular yeast to worms, flies, rodents, and primates. However, caloric restriction, which in most cases entails a 20-40% reduction of food consumption relative to normal intake, is a severe intervention that results in both beneficial and detrimental effects. Specific types of chronic, intermittent, or periodic dietary restrictions without chronic caloric restriction have instead the potential to provide a significant healthspan increase while minimizing adverse effects.

Alternative Okazaki Fragment Ligation Pathway by DNA Ligase III.

Higher eukaryotes have three types of DNA ligases: DNA ligase 1 (Lig1), DNA ligase 3 (Lig3) and DNA ligase 4 (Lig4). While Lig1 and Lig4 are present in all eukaryotes from yeast to human, Lig3 appears sporadically in evolution and is uniformly present only in vertebrates. In the classical, textbook view, Lig1 catalyzes Okazaki-fragment ligation at the DNA replication fork and the ligation steps of long-patch base-excision repair (BER), homologous recombination repair (HRR) and nucleotide excision repair (NER).

Wnt activation of immortalized brain endothelial cells as a tool for generating a standardized model of the blood brain barrier in vitro.

Reproducing the characteristics and the functional responses of the blood-brain barrier (BBB) in vitro represents an important task for the research community, and would be a critical biotechnological breakthrough. Pharmaceutical and biotechnology industries provide strong demand for inexpensive and easy-to-handle in vitro BBB models to screen novel drug candidates. Recently, it was shown that canonical Wnt signaling is responsible for the induction of the BBB properties in the neonatal brain microvasculature in vivo.

Characterization of the regulatory region of the zebrafish Prep1.1 gene: analogies to the promoter of the human PREP1.

Prep1 is a developmentally essential TALE class homeodomain transcription factor. In zebrafish and mouse, Prep1 is already ubiquitously expressed at the earliest stages of development, with important tissue-specific peculiarities. The Prep1 gene in mouse is developmentally essential and has haploinsufficient tumor suppressor activity [1].