Involvement In Regulation Of Growth Research Articles

Somatostatin Receptor Gene Functions in Growth Regulation in Bivalve Scallop and Clam.

Bivalves hold an important role in marine aquaculture and the identification of growth-related genes in bivalves could contribute to a better understanding of the mechanism governing their growth, which may benefit high-yielding bivalve breeding. Somatostatin receptor (SSTR) is a conserved negative regulator of growth in vertebrates. Although SSTR genes have been identified in invertebrates, their involvement in growth regulation remains unclear. Here, we identified seven SSTRs (PySSTRs) in the Yesso scallop, Patinopecten yessoensis, which is an economically important bivalve cultured in East Asia. Among the three PySSTRs (PySSTR-1, -2, and -3) expressed in adult tissues, PySSTR-1 showed significantly lower expression in fast-growing scallops than in slow-growing scallops. Then, the function of this gene in growth regulation was evaluated in dwarf surf clams (Mulinia lateralis), a potential model bivalve cultured in the lab, via RNA interference (RNAi) through feeding the clams Escherichia coli containing plasmids expressing double-stranded RNAs (dsRNAs) targeting MlSSTR-1. Suppressing the expression of MlSSTR-1, the homolog of PySSTR-1 in M. lateralis, resulted in a significant increase in shell length, shell width, shell height, soft tissue weight, and muscle weight by 20%, 22%, 20%, 79%, and 92%, respectively. A transcriptome analysis indicated that the up-regulated genes after MlSSTR-1 expression inhibition were significantly enriched in the fat digestion and absorption pathway and the insulin pathway. In summary, we systemically identified the SSTR genes in P. yessoensis and revealed the growth-inhibitory role of SSTR-1 in bivalves. This study indicates the conserved function of somatostatin signaling in growth regulation, and ingesting dsRNA-expressing bacteria is a useful way to verify gene function in bivalves. SSTR-1 is a candidate target for gene editing in bivalves to promote growth and could be used in the breeding of fast-growing bivalves.

Accumulation of Hydrogen Peroxide in Barley Seeds – A Key Factor for Malt Quality?

Hydrogen peroxide (H2O2) is a reactive oxygen species that contributes to undesired oxidation of barley ingredients that are crucial for beer production and quality. H2O2 reveals a dual role in plant physiology as it is involved in oxidative damage of biomolecules, but also actively synthesized for growth regulating processes. As H2O2 formation in barley and its consequences for malt quality have not been investigated before, a method for H2O2 quantification throughout malting is presented in this work to investigate this pathway's potential involvement in oxidative reactions in malt production. During germination, H2O2 steadily accumulated in the barley seeds reaching concentrations up to approximately 2.5 µmol/g (dm). Barley variety, aeration rate, as well as water content during steeping were significant impact factors for H2O2 formation. H2O2 strongly correlated with the barley acrospire lengths indicating its beneficial involvement in growth regulation. During withering and kilning, the majority of H2O2 was exponentially degraded. It is proposed that after its controlled synthesis during germination, H2O2 acts as a primary oxidant of malt ingredients during withering and kilning. The barley metabolism-derived H2O2 accumulation is discussed in relation to oxidative stability of malt, wort, and beer. The data of this work can be used as a fundament to control oxidative damage during malting.

Protein Kinase D Is Dispensable for Development and Survival of Drosophila melanogaster.

Members of the Protein Kinase D (PKD) family are involved in numerous cellular processes in mammals, including cell survival after oxidative stress, polarized transport of Golgi vesicles, as well as cell migration and invasion. PKD proteins belong to the PKC/CAMK class of serine/threonine kinases, and transmit diacylglycerol-regulated signals. Whereas three PKD isoforms are known in mammals, Drosophila melanogaster contains a single PKD homolog. Previous analyses using overexpression and RNAi studies indicated likewise multi-facetted roles for Drosophila PKD, including the regulation of secretory transport and actin-cytoskeletal dynamics. Recently, involvement in growth regulation has been proposed based on the hypomorphic dPKDH allele. We have generated PKD null alleles that are homozygous viable without apparent phenotype. They largely match control flies regarding fertility, developmental timing and weight. Males, but not females, are slightly shorter lived and starvation sensitive. Furthermore, migration of pole cells in embryos and border cells in oocytes appears normal. PKD mutants tolerate heat, cold and osmotic stress like the control but are sensitive to oxidative stress, conforming to the described role for mammalian PKDs. A candidate screen to identify functionally redundant kinases uncovered genetic interactions of PKD with Pkcδ, sqa and Drak mutants, further supporting the role of PKD in oxidative stress response, and suggesting its involvement in starvation induced autophagy and regulation of cytoskeletal dynamics. Overall, PKD appears dispensable for fly development and survival presumably due to redundancy, but influences environmental responses.

Erratum to “The Preventive Effect of Biochanin A on Bone Loss in Ovariectomized Rats: Involvement in Regulation of Growth and Activity of Osteoblasts and Osteoclasts”

Erratum to “The Preventive Effect of Biochanin A on Bone Loss in Ovariectomized Rats: Involvement in Regulation of Growth and Activity of Osteoblasts and Osteoclasts”

Desmoglein-3/γ-catenin and E-cadherin/ß-catenin differential expression in oral leukoplakia and squamous cell carcinoma

The purpose of this study was to investigate gene/protein expression alterations of intercellular connections' components in oral leukoplakia (OLs) and squamous-cell carcinoma (OSCCs). Expression of desmogleins-2,3 (Dsg2/Dsg3), E-cadherin, and their cytoplasmic ligand, β/γ-catenins were quantitatively assessed in HSC-3 cells growing as monolayer cultures (ML)/multicellular aggregates (MCAs), using RT-PCR/Western blot, whereas their localization was detected by immunofluorescence. Furthermore, their expression was semi-quantitatively investigated in tissues from 25 OLs/25 OSCCs, using automated immunohistochemistry. The steady-state levels of Dsg3 RNA transcripts increased as HSC-3 cells enter their exponential phase of growth, before a dramatic decrease to be observed as cells reached their plateau phase especially in MCAs. Upon the same period of time, Dsg2 levels have been increased. The expression of γ-catenin but not that of β-catenin was increased after 48h in both MLs and MCAs. In clinical samples, Dsg3, Ε-cadherin, β/γ-catenin down-regulation was observed to be associated with the grade of OLs-dysplasia and OSCCs. Importantly, a membrane-to-cytoplasmic switch of expression and strong perinuclear aggregation of Dsg3/γ-catenin was seen in both HSC-3 cells and OLs/OSCCs. The altered expression of Dsg3/γ-catenin and E-cadherin/β-catenin, in vitro and in ODs/OSCC imply their involvement in growth regulation and phenotype of dysplastic/malignant oral epithelial cells, contributing to the better understanding of epithelial dysplasia and OSCCs. The observed alterations of their expression suggest a role of Dsg3 and γ-catenin (additionally to E-cadherin/β-catenin) as biomarkers of malignant transformation risk of oral dysplasia and the biological behavior (aggressiveness) of oral cancer, respectively.

The Preventive Effect of Biochanin A on Bone Loss in Ovariectomized Rats: Involvement in Regulation of Growth and Activity of Osteoblasts and Osteoclasts

Biochanin A (BCA) is a major isoflavone abundant in red clover (Trifolium pretense). The protective effect of BCA on bone loss in an ovariectomized (OVX) animal model has never been clarified. The objective of this study was to investigate the biological effects of BCA on bone loss in OVX rats in vivo and on the development of osteoblasts and osteoclasts in vitro. Ovariectomy resulted in a marked increase in body weight and a decrease in femoral bone mineral density and trabecular bone volume that was prevented by BCA or 17β-estradiol (E2) treatment. However, an increase in uterine weight was observed in E2-treated OVX rats, but not in response to BCA treatment. Treatment with BCA increased the mRNA expression of osterix, collagen type I, alkaline phosphatase (ALP), and osteocalcin and decreased the mRNA expression of tartrate-resistant acid phosphatase (TRAP) and the receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio in the femur of OVX rats. Treatment with BCA or E2 prevented the OVX-induced increase in urinary deoxypyridinoline (DPD) and serum tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β). In vitro, BCA induced preosteoblasts to differentiate into osteoblasts and increased osteoblast mineralization. BCA inhibited preosteoclasts and osteoclast proliferation and decreased osteoclast bone resorption. These findings suggest that BCA treatment can effectively prevent the OVX-induced increase in bone loss and bone turnover possibly by increasing osteoblastic activities and decreasing osteoclastic activities.

SOX11 expression correlates to promoter methylation and regulates tumor growth in hematopoietic malignancies

BackgroundThe transcription factor SOX11 plays an important role in embryonic development of the central nervous system (CNS) and is expressed in the adult immature neuron but is normally not expressed in any other adult tissue. It has recently been reported to be implicated in various malignant neoplasms, including several lymphoproliferative diseases, by its specific expression and in some cases correlation to prognosis. SOX11 has been shown to prevent gliomagenesis in vivo but the causes and consequences of aberrant expression of SOX11 outside the CNS remain unexplained.ResultsWe now show the first function of SOX11 in lymphoproliferative diseases, by demonstrating in vitro its direct involvement in growth regulation, as assessed by siRNA-mediated silencing and ectopic overexpression in hematopoietic malignancies. Gene Chip analysis identified cell cycle regulatory pathways, including Rb-E2F, to be associated with SOX11-induced growth reduction. Furthermore, promoter analysis revealed that SOX11 is silenced through DNA methylation in B cell lymphomas, suggesting that its regulation is epigenetically controlled.ConclusionsThe data show that SOX11 is not a bystander but an active and central regulator of cellular growth, as both siRNA-mediated knock-down and ectopic overexpression of SOX11 resulted in altered proliferation. Thus, these data demonstrate a tumor suppressor function for SOX11 in hematopoietic malignancies and revealed a potential epigenetic regulation of this developmentally involved gene.

Mild salinity improves sugar beet (Beta vulgaris L.) quality

Sugar beet (Beta vulgaris L.) is cultivated mainly on saline soils. Low levels of salinity stimulate growth of this crop plant possibly due to production of broader leaves as sources of assimilates. In this work, six cultivars were studied under mild salinity (EC = 5.5 dS m−1) in a field experiment to analyse its effect on growth parameters and yield of storage root and sugar accumulation. An attempt was also made to determine the contributing role of photosynthetic gas exchange in response of sugar beet plants to salinity. Production of greater leaf area in salinized plants occurred only transitionally in the early growth period; in progression of the growing season it was decreased, and at 3rd harvest (100 days after treatment) it was significantly lower compared with control plants without cultivar differences. Leaf chlorophyll fluorescence, net photosynthesis rate, and stomatal conductance did not change by salinity significantly. Although, at the end of growth season, leaf area and potential photosynthesizing component of salinized plants on the basis of leaf area (LAR) or weight (LWR) were significantly lower than for control plants, weight of storage root and sugar content were up to 90 and 37% higher than in control plants, respectively. Consequently, a considerable higher yield under mild salinity conditions in sugar beet is not attributable to higher leaf area or, therefore, higher photosynthetic capacity of whole plants. Indeed, the storage roots benefit from lower dry matter and surface production of shoot during the late growing season (because of lower nitrogen assimilation and a slight drought stress of salinized plants) and a change in dry-matter partitioning in favor of roots takes place. However, a possible special effect of Na on carbon allocation for storage and structure and involvement of growth regulators in the change of root-shoot allometry could not be excluded.

Hormone-response Genes Are Direct in Vivo Regulatory Targets of Brahma (SWI/SNF) Complex Function

Metazoan SWI/SNF chromatin remodeling complexes exhibit ATP-dependent activation and repression of target genes. The Drosophila Brahma (SWI/SNF) complex subunits BRM and SNR1 are highly conserved with direct counterparts in yeast (SWI2/SNF2 and SNF5) and mammals (BRG1/hBRM and INI1/hSNF5). BRM encodes the catalytic ATPase required for chromatin remodeling and SNR1 is a regulatory subunit. Importantly, SNR1 mediates ATP-independent repression functions of the complex in cooperation with histone deacetylases and direct contacts with gene-specific repressors. SNR1 and INI1, as components of their respective SWI/SNF complexes, are important for developmental growth control and patterning, with direct function as a tumor suppressor. To identify direct regulatory targets of the Brm complex, we performed oligonucleotide-based transcriptome microarray analyses using RNA isolated from mutant fly strains harboring dominant-negative alleles of snr1 and brm. Steady-state RNA isolated from early pupae was examined, as this developmental stage critically requires Brm complex function. We found the hormone-responsive Ecdysone-induced genes (Eig) were strongly misregulated and that the Brm complex is directly associated with the promoter regions of these genes in vivo. Our results reveal that the Brm complex assists in coordinating hormone-dependent transcription regulation of the Eig genes.

Functional role of RhoA in growth regulation of primary hepatocytes.

The expression, activation and involvement in growth regulation of a small GTPase, RhoA, were examined in rat primary hepatocyte cultures. Hepatocytes freshly isolated from liver expressed RhoA protein at high levels. The total level of RhoA protein in the cells decreased markedly within a day in monolayer cultures. Thereafter, RhoA expression recovered as cell-cell attachment occurred during the culture. On the other hand, the level of the active form of RhoA decreased as the culture proceeded. Ca(2+) depletion in the medium to disrupt cadherin engagement triggered RhoA activation without de novo protein synthesis, indicating cadherin engagement regulates RhoA activation in hepatocytes. Hepatocyte growth stimulation by HGF was enhanced by Ca(2+) depletion or introduction of a constitutively active form of RhoA. The Clostridium botulinum C3 enzyme inhibited hepatocyte growth with stimulation by HGF. These results suggest that RhoA has a crucial role in hepatocyte growth control.

The Role of Adrenomedullin as a Growth Regulatory Peptide in the Normal and Malignant Setting

Adrenomedullin (AM) is a recently discovered pluripotent peptide initially isolated from a human adrenal gland tumor (pheochromocytoma). Adrenomedullin has been shown to have an ancient origin with immunoreactive species found in mammals, birds, reptiles, amphibians, fish, and echinoderms (starfish). Given its highly conserved evolutionary expression, AM is thought to play a critical role in species survival. This peptide has been shown to mediate a variety of physiological functions, of which its involvement in growth regulation will be the central focus of this paper. In the following text, we will review the cited literature in this area and include our own observations regarding AM expression in carcinogenesis, embryogenesis, and wound repair. Adrenomedullin will be shown to induce both growth promotion or growth suppression depending on the target cell examined and the surrounding nutritional environment in which the analysis was done. Its implied role as a mitogen, angiogenic factor, and apoptosis survival factor will be critiqued and evaluated relative to its importance in the cell proliferation process. Finally, we will review the antimicrobial effect AM has on several human pathogens (Escherichia coli and Candida albicans) and demonstrate its participation in the host immune response system as a first line defense peptide.

Effects of forskolin on growth and morphology of cultured glial and cerebrovascular endothelial and smooth muscle cells

The present experiments were designed to evaluate the effectiveness of forskolin on cAMP production, growth and morphology on cell cultures of glia, endothelium and smooth muscle derived from brain microvessels.Forskolin significantly increased formation of cAMP and decreased incorporation of thymidine in all three cell types. The thymidine incorporation was reduced dose-dependently with maximal growth inhibition at 100 μM forskolin. A 1 hr preincubation with forskolin abolished thymidine incorporation by cells grown in fetal calf serum (FCS)-containing media over the following 24 hr.In cerebromicrovascular endothelium and smooth muscle, forskolin caused drastic and immediate changes of cell morphology and F-actin composition that were reversible. In glial cells, morphological changes were visible only after exposure to forskolin for more than 24 hr. These changes were accompanied by increased staining with antibodies against glial fibrillary acidic protein (GFAP).These findings support the contention of cAMP involvement in growth regulation of these cells and indicate that forskolin might be used as a tool to induce growth arrest and possible differentiation in cell cultures from mammalian brain.

Organic acid synthesis and release of hydrogen ions in response to Fe deficiency stress of mono‐ and dicotyledonous plant species

Abstract Comparing three mono‐ and dicotyledonous plant species (barley, oat, millet; pea, sugar beet, bean) it will be shown that under Fe stress conditions monocots do not lower the pH of the nutrient solution if nitrate is the only form of nitrogen supplied, whereas dicots do. During the iron stress‐induced H+ excretion there is a striking increase in organic acids (particularly citrate and malate) in the roots of dicots. Therefore, it is proposed that these acids could be the source of hydrogen ions released by the roots. When severe chlorosis has developed the organic acid content of the monocots is raised too, but without any drop of the nutrient solution pH. The results are discussed in relation to a possible involvement of growth regulators and differences between the NO3 assimilation rate in roots of mono‐ and dicotyledonous plant species.