Animals ; Cell Differentiation ; physiology ; Cell Proliferation ; Hepatocytes ; transplantation ; Humans ; Transcription Factors ; genetics ; Transcription, Genetic

OBJECTIVEA novel bHLH-like gene, designated SmbHLH1, was isolated from Salvia miltiorrhiza, in order to identify a bHLH gene in related to danshinone biosysnthesis.

METHODSmbHLH1 was isolated by RT-PCR,and Semi-quantitative RT-PCR was used to detect the gene expression level.

RESULTThe full length of SmbHLH1 cDNA has an open reading frame of 999 bp. The deduced amino acid sequence of SmbHLH1 has 332 amino acid residues which forms a 36 kDa polypeptide with a calculated pI of 5.4. SmbHLH1 gene was expressed at high level in root, but low level in stem, leaf and flower of S. miltiorrhiza. The transcripts of SmbHLH1 was suppressed when the plants were treated with exogenous MeJA, Yeast + Ag+. The transcripts of SmbHLH1 constitutively accumulated in response to exogenous ABA and low concentration of salicylic acid.

CONCLUSIONSmbHLH is a new member of the S. miltiorrhiza bHLH family, and its possible roles in brassinosteriods signaling responses.

Basic Helix-Loop-Helix Transcription Factors ; genetics ; physiology ; Cloning, Molecular ; Plant Proteins ; genetics ; physiology ; Salvia miltiorrhiza ; genetics

Transformation growth factor β -inducible gene 22 (TSC-22) is a putative negative growth regulation and tumor suppressor gene. It has the ability to combine with other transcription factors to regulate the cell growth and apoptosis. TSC-22 is lowly expressed in many types of tumors,which may be related to the tumorgenesis and development.
Animals ; Genes, Tumor Suppressor ; Humans ; Leucine Zippers ; genetics ; Neoplasms ; physiopathology ; Repressor Proteins ; genetics ; physiology ; Transcription Factors

Gondadal differentiation is genetically determined in humans. Sex is determined when the bipotential embryologic tissues differentiate into testes or ovary. SRY, a gene located on the Y chromosome, triggers a complex genetic cascade leading to testicular differentiation. However, only a minority of 46, XY sex reversal patients can be explained by SRY mutations, suggesting that other genes influencing sex determination are to be discovered. Recent studies show that testis differentiation requires insulin receptor family function in mice. SRY normally requires two distinct NLS-dependent nuclear import pathways to reach sufficient levels in the nucleus for gonadal differentiation.
Active Transport, Cell Nucleus ; Female ; Gene Expression Regulation ; Genes, sry ; physiology ; High Mobility Group Proteins ; genetics ; physiology ; Humans ; Male ; SOX9 Transcription Factor ; Sex Differentiation ; Transcription Factors ; genetics ; physiology

The sleep-wake cycle displays a characteristic 24-hour periodicity, providing an opportunity to dissect the endogenous circadian clock through the study of aberrant behaviour. This article surveys the properties of circadian clocks, with emphasis on mammals. Information was obtained from searches of peer-reviewed literature in the PUBMED database. Features that are highlighted include the known molecular components of clocks, their entrainment by external time cues and the output pathways used by clocks to regulate metabolism and behaviour. A review of human circadian rhythm sleep disorders follows, including recent discoveries of their genetic basis. The article concludes with a discussion of future approaches to the study of human circadian biology and sleep-wake behaviour.
ARNTL Transcription Factors ; Animals ; Basic Helix-Loop-Helix Transcription Factors ; physiology ; CLOCK Proteins ; Circadian Rhythm ; genetics ; physiology ; Humans ; Neurons, Afferent ; physiology ; Neurons, Efferent ; physiology ; Polymorphism, Single Nucleotide ; Sleep Disorders, Circadian Rhythm ; genetics ; physiopathology ; Suprachiasmatic Nucleus ; cytology ; physiology ; Trans-Activators ; physiology

Post-translational modifications (PTMs) of transcription factors play a crucial role in regulating metabolic homeostasis. These modifications include phosphorylation, methylation, acetylation, ubiquitination, SUMOylation, and O-GlcNAcylation. Recent studies have shed light on the importance of lysine acetylation at nonhistone proteins including transcription factors. Acetylation of transcription factors affects subcellular distribution, DNA affinity, stability, transcriptional activity, and current investigations are aiming to further expand our understanding of the role of lysine acetylation of transcription factors. In this review, we summarize recent studies that provide new insights into the role of protein lysine-acetylation in the transcriptional regulation of metabolic homeostasis.
Acetylation ; Animals ; Diabetes Mellitus, Type 2 ; metabolism ; Homeostasis ; genetics ; physiology ; Humans ; Protein Processing, Post-Translational ; genetics ; physiology ; Transcription Factors ; metabolism

Atoh1 gene encodes a helix-loop-helix transcription factor which is involved in the generation and differentiation of mammalian auditory hair cells and supporting cells, and regulation of the proliferation of cochlear cells, therefore plays an important role in the pathogenesis and recovery of sensorineural deafness. This study reviews the progress of the Atoh1 gene in hair cell regeneration, with the aim of providing a reference for the study of hair cell regeneration gene therapy for sensorineural deafness.
Animals ; Humans ; Basic Helix-Loop-Helix Transcription Factors/genetics* ; Hair Cells, Auditory/physiology* ; Transcription Factors ; Hearing Loss, Sensorineural ; Cell Differentiation ; Deafness ; Regeneration/genetics* ; Mammals

BACKGROUNDFolic acid is very important for embryonic development and dihydrofolate reductase is one of the key enzymes in the process of folic acid performing its biological function. Therefore, the dysfunction of dihydrofolate reductase can inhibit the function of folic acid and finally cause the developmental malformations. In this study, we observed the abnormal cardiac phenotypes in dihydrofolate reductase (DHFR) gene knock-down zebrafish embryos, investigated the effect of DHFR on the expression of heart and neural crest derivatives expressed transcript 2 (HAND2) and explored the possible mechanism of DHFR knock-down inducing zebrafish cardiac malformations.

METHODSMorpholino oligonucleotides were microinjected into fertilized eggs to knock down the functions of DHFR or HAND2. Full length of HAND2 mRNA which was transcribed in vitro was microinjected into fertilized eggs to overexpress HAND2. The cardiac morphologies, the heart rates and the ventricular shortening fraction were observed and recorded under the microscope at 48 hours post fertilization. Whole-mount in situ hybridization and real-time PCR were performed to detect HAND2 expression.

RESULTSDHFR or HAND2 knock-down caused the cardiac malformation in zebrafish. The expression of HAND2 was obviously reduced in DHFR knock-down embryos (P < 0.05). Microinjecting HAND2 mRNA into fertilized eggs can induce HAND2 overexpression. HAND2 overexpression rescued the cardiac malformation phenotypes of DHFR knock-down embryos.

CONCLUSIONSDHFR plays a crucial role in cardiac development. The down-regulation of HAND2 caused by DHFR knock-down is the possible mechanism of DHFR knock-down inducing the cardiac malformation.

Animals ; Basic Helix-Loop-Helix Transcription Factors ; genetics ; physiology ; Female ; Heart ; embryology ; Heart Defects, Congenital ; etiology ; Tetrahydrofolate Dehydrogenase ; genetics ; physiology ; Zebrafish ; Zebrafish Proteins ; genetics ; physiology

Self-renewal and multilineage differentiation of hematopoietic stem cell (HSC) are their functional characteristics. The regulation of HSC self-renewal is governed by a balance between positive regulatory signals promoting growth and negative regulatory signals resulting in apoptosis. Among the positive regulatory signals, HOXB4 activates distinct pathways that enhance self-renewal divisions of HSC without overriding the regulatory mechanisms that maintain normal steady-state hemopoiesis. The upregulation of HOXB4 gene expression can greatly promote the HSC self-renewal, but does not affect the HSC differentiation, the morphology and function of linage-specific cells and terminally-differentiated blood cells. Furthermore, HOXB4 can enhance the hematopoietic potential of embryonic stem cell (ESC), promoting the differentiation of ESC into hematopoietic cells. As a consequence, upregulation of HOXB4 expression and/or corresponding HOXB4 target genes can have enormous therapeutical potential for human HSC in the stem cell transplantation and gene therapy. In this review the regulatory role of HOXB4 in HSC self-renewal, "zero" effect of HOXB4 on differentiation specificity of HSC lines and terminal differentiation cells, and molecular mechanisms of regulating HSC self-renewal by HOXB4 are summarised.
Animals ; Apoptosis ; genetics ; Cell Differentiation ; genetics ; Cell Proliferation ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; cytology ; metabolism ; Homeodomain Proteins ; genetics ; physiology ; Humans ; Transcription Factors ; genetics ; physiology

Myostatin (Mstn) is a member of the transforming growth factor-beta superfamily that functions as a negative regulator of skeletal muscle growth and differentiation in mammals. The transcriptional regulation of Mstn is controlled by multiple genes including MEF2, which raise the importance of identifying the binding sites of MEF2 on myostatin promoter region and mechanisms underlying. In this study, we investigated the transcriptional regulation of MEF2 on porcine Mstn promoter activity in C2C12 cells. Sequence analysis of the 1 969 bp porcine Mstn promoter region revealed that it contained three potential MEF2 motifs. Using a serial deletion strategy, we tested the activity of several promoter fragments by luciferase assay. Overexpression of MEF2C, but not MEF2A increased Mstn promoter activity in all the promoter fragments with MEF2 motifs by two to six folds, in both C2C12 myoblasts and myotubes. When we transfected exogenous MEF2C, Mstn mRNA level was also upregulated in C2C12 cells, but the protein level was only significantly increased in myotubes. Thus, we propose that MEF2C could modulate and restrain myogenesis by Mstn activation and Mstn-dependent gene processing in porcine. Our research also provided potential targets and an effective molecule to regulate Mstn expression and gave a new way to explore the functional performance of Mstn.
Animals ; Cells, Cultured ; Gene Expression Regulation ; MEF2 Transcription Factors ; Mice ; Muscle, Skeletal ; metabolism ; Myoblasts ; cytology ; Myogenic Regulatory Factors ; genetics ; physiology ; Myostatin ; genetics ; physiology ; Promoter Regions, Genetic ; Swine