Differential Pituitary Gene Expression Profiles Associated- To Aging and Spontaneous Tumors as Revealed by cDNA Expression Array

Abstract Abstract 2361 HOXB4 is a homeobox transcription factor that can induce hematopoietic stem cell (HSC) expansion both in vivo and in vitro. An interesting feature of HOXB4-induced HSC expansion is that HSC numbers do not exceed normal levels in vivo due to an unexplained physiological capping mechanism. To gain further insight into HOXB4 regulatory signals, we transplanted mice with bone marrow cells that had been transduced with a MSCV-HOXB4-ires-YFP vector and analyzed gene expression profiles in HSC-enriched populations 20 weeks after transplant, a time point at which HSC numbers have expanded to normal levels but no longer increasing beyond physiologic levels. We used Affymetrix arrays to analyze gene expression profiles in bone marrow cells sorted for a Lin−Sca-1+c-Kit+ (LSK), YFP+ phenotype. Using ANOVA, we identified1985 probe sets with >2 fold difference in expression (FDR<, 0.1) relative to a control vector-transduced LSK cells. A cohort of genes was identified that were known positive regulators of HSC self-renewal and proliferation. Hemgn, which we identified in a previous screen as a positive regulator of expansion and a direct transcriptional target of HOXB4, was 3.5 fold up-regulated in HOXB4 transduced LSKs. Other genes known to be important for HSCs survival, self-renewal and differentiation were upregulated to significant levels including N-myc, Meis1, Hoxa9, Hoxa10 and GATA2. Microarray data for selected genes was validated by quantitative real-time PCR on HOXB4 transduced CD34low LSK cells, a highly purified HSC population, obtained from another set of transplanted mice at the 20 week time point. In contrast, other gene expression changes were noted that would potentially limit or decrease stem cell numbers. PRDM16, a set domain transcription factor critical for HSC maintenance and associated with clonal hematopoietic expansions when inadvertently activated as a result of retroviral insertion, was dramatically down-regulated on the expression array and 7.6 fold decreased in the real time PCR assay of CD34low LSK cells. TFG-beta signaling is a well defined inhibitor HSC proliferation and utilize Smad proteins as downstream effectors. Expression of Smad1 and Smad7 were significantly upregulated on the LSK expression array and 8.1 and 3.5 fold up-regulated by qPCR in CD34low LSK cells. Another potential counter-regulatory signal was down regulation of Bcl3 mRNA, a potential anti-apoptotic effector in HSCs. We hypothesize that the HOXB4 expansion program involves activation of genes that lead to increased HSC numbers with later activation of counter-regulatory signals that limit expansion to physiologic numbers of HSCs in vivo. We are now examining how this program changes at various time points after transplantation and hypothesize the capping limits are set at relatively later time points during reconstitution. We also are studying the functional effects of these gene expression changes, and in particular, whether enforced expression of HOXB4 and PRMD16 will result in uncontrolled HSC proliferation and/or leukemia. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Differential Effects of Virulent versus AvirulentLegionella pneumophila on Chemokine Gene Expression in Murine Alveolar Macrophages Determined by cDNA Expression Array Technique

Infection and Immunity ◽

10.1128/iai.68.10.6069-6072.2000 ◽

2000 ◽

Vol 68 (10) ◽

pp. 6069-6072 ◽

Cited By ~ 16

Author(s):

Noriya Nakachi ◽

Kazuto Matsunaga ◽

Thomas W. Klein ◽

Herman Friedman ◽

Yoshimasa Yamamoto

Keyword(s):

Gene Expression ◽

Legionella Pneumophila ◽

Specific Gene ◽

Expression Array ◽

Cdna Expression Array ◽

Cdna Expression ◽

Inflammatory Protein ◽

Chemotactic Protein ◽

Differential Induction

ABSTRACT The cDNA expression array technique is a powerful tool to determine, at one time from many genes, specific gene messages modulated by infection. In the present study, we identified genes modulated in response to virulent versus avirulent Legionella pneumophila infection of the alveolar macrophage cell line MH-S by the cDNA expression array technique. Many macrophage genes were found to be modulated after 5 h of in vitro infection withL. pneumophila. In particular, it was found that the monocyte chemotactic protein 3 (MCP-3) gene expression was significantly induced by infection with virulent L. pneumophila but not with avirulent L. pneumophila. In contrast, other chemokine genes, such as macrophage inflammatory protein (MIP) 1α, were induced by both virulent and avirulentL. pneumophila. Reverse transcription (RT)-PCR assay of total RNA isolated from macrophages infected with the bacteria for 5 or 24 h confirmed the differential induction of the chemokine genes by virulent versus avirulent L. pneumophila. Thus, the cDNA expression array technique readily revealed differential induction byL. pneumophila infection of select chemokine genes of macrophages from more than 1,100 genes. These results also indicate that certain chemokine genes may be selectively induced by virulent bacteria.

Download Full-text

cDNA expression array (cDNA array; gene expression array;geneexpressionmicroarray, GEM, transcript array, mRNA expression array, RNA expression microarray, REM)

The Dictionary of Genomics, Transcriptomics and Proteomics ◽

10.1002/9783527678679.dg01451 ◽

2015 ◽

pp. 1-1

Keyword(s):

Gene Expression ◽

Mrna Expression ◽

Cdna Array ◽

Rna Expression ◽

Gene Expression Array ◽

Expression Microarray ◽

Expression Array ◽

Cdna Expression Array ◽

Cdna Expression

Download Full-text

TWENTY-FOUR GENES ARE UPREGULATED IN PATIENTS WITH HYPOSPADIAS

Balkan Journal of Medical Genetics ◽

10.2478/bjmg-2013-0030 ◽

2013 ◽

Vol 16 (2) ◽

pp. 39-43 ◽

Cited By ~ 6

Author(s):

R. Karabulut ◽

Z. Turkyilmaz ◽

K. Sonmez ◽

G. Kumas ◽

Sg. Ergun ◽

...

Keyword(s):

Gene Expression ◽

Expression Profiles ◽

Association Studies ◽

Gene Expression Profiles ◽

Ventral Surface ◽

Genome Wide Association Studies ◽

Expression Array ◽

Large Patient ◽

Expression Studies ◽

Genome Wide

ABSTRACT Hypospadias is a congenital hypoplasia of the penis, with displacement of the urethral opening along the ventral surface, and has been reported to be one of the most common congenital anomalies, occurring in approximately 1:250 to 1:300 live births. As hypospadias is reported to be an easily diagnosed malformation at the crossroads of genetics and environment, it is important to study the genetic component in order to elucidate its etiology. In this study, the gene expression profiles both in human hypospadias tissues and normal penile tissues were studied by Human Gene Expression Array. Twentyfour genes were found to be upregulated. Among these, ATF3 and CYR61 have been reported previously. Other genes that have not been previously reported were also found to be upregulated: BTG2, CD69, CD9, DUSP1, EGR1, EIF4A1, FOS, FOSB, HBEGF, HNRNPUL1, IER2, JUN, JUNB, KLF2, NR4A1, NR4A2, PTGS2, RGS1, RTN4, SLC25A25, SOCS3 and ZFP36 (p <0.05). Further studies including genome-wide association studies (GWAS) with expression studies in a large patient group will help us for identifiying the candidate gene(s) in the etiology of hypospadias

Download Full-text