Growth Regulatory Protein Research Articles

Evolution of a plant growth-regulatory protein interaction specificity

Specific protein–protein interactions (PPIs) enable biological regulation. However, the evolution of PPI specificity is little understood. Here we trace the evolution of the land-plant growth-regulatory DELLA–SLY1/GID2 PPI, revealing progressive increase in specificity of affinity of SLY1/GID2 for a particular DELLA form. While early-diverging SLY1s display relatively broad-range DELLA affinity, later-diverging SLY1s tend towards increasingly stringent affinity for a specific DELLA A’ form generated by the growth-promoting phytohormone gibberellin (GA). Our novel mutational strategy reveals amino acid substitutions contributing to the evolution of Arabidopsis thaliana SLY1 A’ specificity, also showing that routes permitting reversion to broader affinity became increasingly constrained over evolutionary time. We suggest that progressive affinity narrowing may be an important evolutionary driver of PPI specificity and that increase in SLY1/GID2-DELLA specificity enabled the enhanced flexibility of plant physiological environmental adaptation conferred by the GA-DELLA growth-regulatory mechanism.

Searching for Key Genes in Ulcerative Colitis: a Bioinformatics Study

Objective: The incidence of ulcerative colitis (UC) is increasing year by year, which leads to increasing cost of medical resources investment, and the exact pathogenesis of the disease is still unclear, leading to difficulties in clinical diagnosis and treatment. This study is based on a bioinformatics approach to search for possible key genes leading to the development of this disease, hoping to provide clinicians with new biomarkers that can be used for reference, so that patients can receive timely diagnosis and treatment.Methods: Peripheral blood-related information was first obtained from the Gene Expression Omnibus (GEO) database for UC patients and non-UC populations. Then differentially expressed genes were identified using R language (based on "Limma" software). Functional enrichment analysis was then performed, followed by screening of central genes, and finally correlations between the central genes were investigated using Spearman correlation analysis.Results: Fifty-nine up-regulated and 39 down-regulated DEGs were screened. These genes were involved in pathways such as viral protein-cytokine receptor interaction, cytokine-cytokine receptor interaction, biosynthesis of pantothenic acid and coenzyme A, IL-17 signaling pathway and chemokine signaling pathway. And growth regulatory alpha protein, C-X-C chemokine receptor 1, C-C patterned chemokine 2, and trigger receptor 1 expressed in bone marrow cells were found to be the top ten hub genes. The final correlation analysis showed a positive correlation between these ten hub genes.Conclusion The present study identified 10 DEGs as possible biomarkers for the diagnosis of patients with ulcerative colitis. Experiments are needed to validate the present study.

Osteopontin - The stirring multifunctional regulatory factor in multisystem aging.

Osteopontin (OPN) is a multifunctional noncollagenous matrix phosphoprotein that is expressed both intracellularly and extracellularly in various tissues. As a growth regulatory protein and proinflammatory immunochemokine, OPN is involved in the pathological processes of many diseases. Recent studies have found that OPN is widely involved in the aging processes of multiple organs and tissues, such as T-cell senescence, atherosclerosis, skeletal muscle regeneration, osteoporosis, neurodegenerative changes, hematopoietic stem cell reconstruction, and retinal aging. However, the regulatory roles and mechanisms of OPN in the aging process of different tissues are not uniform, and OPN even has diverse roles in different developmental stages of the same tissue, generating uncertainty for the future study and utilization of OPN. In this review, we will summarize the regulatory role and molecular mechanism of OPN in different tissues and cells, such as the musculoskeletal system, central nervous system, cardiovascular system, liver, and eye, during senescence. We believe that a better understanding of the mechanism of OPN in the aging process will help us develop targeted and comprehensive therapeutic strategies to fight the spread of age-related diseases.

FSTL1-knockdown improves neural oscillation via decreasing neuronal-inflammation regulating apoptosis in Aβ1–42 induced AD model mice

Follistatin like protein 1 (FSTL1) is a famous growth regulatory protein. FSTL1 has been noticed in many diseases, including heart and lung ischemia, cerebral ischemia, glioma, schizophrenia, and Autism. The role of FSTL1 has been declared in the genetics and development of the central nervous system. Therefore, we designed this study to investigate the function and the role of FSTL1 in Alzheimer's disease. Firstly, we noticed upregulated expression level of FSTL1 among four to six-month-old 5XFAD AD mice. Accordingly, we hypothesized that FSTL1-Knockdown improved AD model mice's cognitive function and recover from Alzheimer's disease. Thus, AD model mice were made by single intracerebroventricular injections of Aβ1–42 peptides in FSTL1+/− and CON mice. Next, our results concluded that FSTL1-knockdown effectively improved cognitive functions. FSTL1-knockdown enhanced the pattern of neural oscillations, and synaptic plasticity in Aβ1–42 treated FSTL1-Knockdown mice compared to Aβ1–42 induced AD model mice. Next, FSTL1-Knockdown inhibited the activation of microglia and binding of TLR-4 with microglia. Further, inactivated microglia stopped the formation of MyD88. Thus, our data revealed that FSTL1-Knockdown is slowing down the caspase/BAX/Bcl-2/TLR-4 regulating apoptosis pathway, and the expression of inflammatory cytokines in the hippocampus of Aβ1–42 inserted FSTL1-Knockdown mice. Overall, all these data illuminate the clinical significance role of down-regulated FSTL1. FSTL1-Knockdown reduced the amyloid-beta by affecting microglia, neural-inflammation and apoptosis in AD-like model mice. Finally, down regulation of FSTL1 improved synaptic plasticity, neural oscillations, and cognitive behaviours in the Aβ1–42 induced AD model mice.

Size and activity of the root meristem: A key for drought resistance and a key model of drought-related signaling.

Plants make many adjustments to their growth and development in response to even small changes in water availability. Under such conditions, root elongation can be actively restricted by stress-related signaling mechanisms. Here we look at how the Arabidopsis thaliana root meristem can be affected by moderate water limitation (low water potential, ψw ). Recent characterization of the clade E Growth-Regulating (EGR) protein phosphatases and Microtubule Associated Stress Protein 1 (MASP1) provides an example of how active restriction of root meristem size allows the plant to downregulate root elongation during low ψw stress. EGR2 protein accumulation in cortex cells of the transition zone at the distal end of the root meristem illustrates how the balance of cell division versus cell expansion signals at this critical location can determine meristem size and root elongation during low ψw . These characteristics of EGRs also raise the question of whether they may also be involved in hydrotropism, and, more broadly, whether hydrotropism is a distinct response or a specific manifestation of more general mechanisms used to adjust root growth under moderate severity low ψw whether or not a gradient of water availability is present. These questions, as well as a better understanding of how specific cell layers (cortex and endodermis) seem to have an outsized role in growth regulation and better understanding the roles of plasma membrane-based signaling and polar-localized proteins in the regulation of root meristem size and cell division activity are key to elucidating the cellular mechanisms that determine root growth behavior during soil drying.

Fabatin induce defense-related enzymes in cucumber against soil born pathogen, Fusarium oxysporum

Fusarium oxysporum is one of the most common soil borne pathogens over the world. This work tried to introduce safe and efficient agent in controlling this pathogen infection in cucumber plants, beside that understanding the mechanism at which fabitine enables the cucumber plants to fight wilt disease. Also, this works introduce a molecular modeling for the direct interaction between fabatin and the Fusarium oxysporum. We evaluated the impact of defensin isolated from broad bean debris (fabatin) against the Fusarium wilt disease in the greenhouse, followed by the analysis of defense-related enzymes, including superoxide dismutase, polyphenol oxidase, soluble peroxidase, cell wall-bound peroxidase, catalase, lactate dehydrogenase, phenylalanine ammonia-lyase, chitinase, and glucanase. Moreover, the growth-regulating protein of the fungus (Snt2, a BAH/PHD) was docked with the fabatin. Fabatin reduced the disease severity from 18.52 to 0.0% by 100% disease reduction, 30 days after transplanting, and from 66.67 to 33.33% by 50.01% disease reduction after 60 days. Interestingly fabatin spray induced upregulation of the studied defense enzymes. The sprayed group showed significant continuous increase in defense related enzymes under infection. Furthermore, fabatin showed a high binding affinity to the Bromo-adjacent domain (BAH) of the Snt2 by - 214.42 kacl/mol and this can prevent the transcriptional regulation processes of the fungus. The present study proved that the exogenous spray fabatin is an effective way in controlling cucumber Fusarium wilt. This is achieved through the enhancement the defense related enzymes which regulate the resistance mechanism in the plants. Moreover, fabatin can directly influence the fungal growth.

141 Translation and growth pathways are directly influenced by autoimmune regulator (Aire) in skin keratinocytes

Autoimmune regulator, Aire, is commonly known to function as a transcriptional regulator in medullary thymic epithelia. However, we and others have identified Aire to express and function in non-thymic tissues, including the skin, where it greatly influences inflammation and tumorigenesis. We report here that, within skin keratinocytes, Aire participates in a variety of cellular processes outside of its classically defined role in the nucleus. We employed a proximity based biotinylation screen (BioID) to examine the localization of Aire and its binding partners within keratinocytes. Aire is observed by structured illumination microscopy to localize in distinct subcellular compartments within the nucleus, cytoplasm, and along cytoskeletal tracks. Disease causing and function blocking mutations in Aire substantially alter these distribution patterns in keratinocytes, suggesting a link between Aire subcellular compartmentalization and pathogenesis. Using an isobaric labeling method (iTRAQ) coupled to tandem mass spectrometry, we identified 295 common Aire binding partners (99.0% probability), most of them novel, and quantitatively assessed the impact of Aire mutations on binding partner associations. Specifically, Aire binding partners associated with protein translation and cell growth (e.g. multiple 40S and 60S ribosomal protein subunits, cell growth-regulating nucleolar protein, eukaryotic translation initiation factors 4 and 5, elongation factor 1 alpha 1) were significantly altered in cells expressing mutant Aire compared to wild-type Aire. Serum pulse assays confirm a positive correlation between loss of wild-type Aire expression in keratinocytes and increased translation associated signaling (P-AKTS473, P-S6KT389, P-S6S235/S236, P-4EBP1S65, P-eIF4BS422, and P-eEF2KS366). These newly identified partners for Aire expand our understanding of Aire function in the skin and may provide a basis for the pro-tumorigenic role for Aire in skin cancers.

A low toxic CRM1 degrader: Synthesis and anti-proliferation on MGC803 and HGC27.

Chromosome region maintenance 1 (CRM1) is the sole nuclear exporter of several tumor suppressor, a growth regulatory protein as an attractive cancer drug target. In the present work, a novel CRM1 degrader was discovered from newly synthesized α, β-unsaturated-δ-lactone based on a natural product Goniothalamin. It induces apoptosis of both MGC803 and HGC27cell lines via degrading CRM1. Selective inhibition was observed for the proliferation of gastric cancer cell lines MGC803, HGC27 comparing to Human Gastric Mucosal Epithelial Cell Line (GES1). For the first time, CRM1 inhibitor or degrader inducing apoptosis in gastric carcinoma was investigated.

LYAR Suppresses Beta Interferon Induction by Targeting Phosphorylated Interferon Regulatory Factor 3.

The innate immune response is vital for host defense and must be tightly controlled, but the mechanisms responsible for its negative regulation are not fully understood. The cell growth-regulating nucleolar protein LYAR was found to promote replication of multiple viruses in our previous study. Here, we report that LYAR acts as a negative regulator of innate immune responses. We found that LYAR expression is induced by beta interferon (IFN-β) during virus infection. Further studies showed that LYAR interacts with phosphorylated IFN regulatory factor 3 (IRF3) to impede the DNA binding capacity of IRF3, thereby suppressing the transcription of IFN-β and downstream IFN-stimulated genes (ISGs). In addition, LYAR inhibits nuclear factor-κB (NF-κB)-mediated expression of proinflammatory cytokines. In summary, our study reveals the mechanism of LYAR in modulating IFN-β-mediated innate immune responses by targeting phosphorylated IRF3, which not only helps us to better understand the mechanisms of LYAR-regulated virus replication but also uncovers a novel role of LYAR in host innate immunity.IMPORTANCE Type I interferon (IFN-I) plays a critical role in the antiviral innate immune responses that protect the host against virus infection. The negative regulators of IFN-I are important not only for fine-tuning the antiviral responses to pathogens but also for preventing excessive inflammation. Identification of negative regulators and study of their modulation in innate immune responses will lead to new strategies for the control of both viral and inflammatory diseases. Here, we report for the first time that the cell growth-regulating nucleolar protein LYAR behaves as a repressor of host innate immune responses. We demonstrate that LYAR negatively regulates IFN-β-mediated immune responses by inhibiting the DNA binding ability of IFN regulatory factor 3 (IRF3). Our study reveals a common mechanism of LYAR in promoting different virus replication events and improves our knowledge of host negative regulation of innate immune responses.

Hematopoietic tissue of Macrobrachium rosenbergii plays dual roles as a source of hemocyte hematopoiesis and as a defensive mechanism against Macrobrachium rosenbergii nodavirus infection

White tail disease caused by Macrobrachium rosenbergii nodavirus (MrNV) infection takes place only in nauplii, not adults, of M. rosenbergii prawn. Hemocyte homeostasis and immune-related functions derived from the hematopoietic tissue (Hpt) in adult prawn are presumed to play roles in resisting viral infection. To elucidate the role of the Hpt cell response to MrNV, a comparative transcriptome analysis was performed with MrNV-infected prawn at various time intervals. The results showed that there were 462 unigenes that were differentially expressed between mock and infected samples. BlastX sequence analysis revealed that two proteins, crustacean hematopoietic factor (CHF) and cell growth-regulating zinc finger protein (Lyar), are involved in hemocyte hematopoiesis and are up-regulated during MrNV infection. In fact, genes involved in cell growth regulation and immunity were highly expressed at 6 h and decreased within 24 h post-infection. Localization studies in the Hpt tissue revealed the presence of anti-lipopolysaccharide factor (ALF) and CHF mRNAs in Hpt cells. Considering these findings, we concluded that resistance to MrNV infection in adult prawn is due to an increase in humoral immune factors and the acceleration of hemocyte homeostasis by the dual roles of the Hpt organ in M. rosenbergii.

The Nucleolar Protein LYAR Facilitates Ribonucleoprotein Assembly of Influenza A Virus.

Influenza A viral ribonucleoprotein (vRNP) is responsible for transcription and replication of the viral genome in infected cells and depends on host factors for its functions. Identification of the host factors interacting with vRNP not only improves understanding of virus-host interactions but also provides insights into novel mechanisms of viral pathogenicity and the development of new antiviral strategies. Here, we have identified 80 host factors that copurified with vRNP using affinity purification followed by mass spectrometry. LYAR, a cell growth-regulating nucleolar protein, has been shown to be important for influenza A virus replication. During influenza A virus infection, LYAR expression is increased and partly translocates from the nucleolus to the nucleoplasm and cytoplasm. Furthermore, LYAR interacts with RNP subunits, resulting in enhancing viral RNP assembly, thereby facilitating viral RNA synthesis. Taken together, our studies identify a novel vRNP binding host partner important for influenza A virus replication and further reveal the mechanism of LYAR regulating influenza A viral RNA synthesis by facilitating viral RNP assembly.IMPORTANCE Influenza A virus (IAV) must utilize the host cell machinery to replicate, but many of the mechanisms of IAV-host interaction remain poorly understood. Improved understanding of interactions between host factors and vRNP not only increases our basic knowledge of the molecular mechanisms of virus replication and pathogenicity but also provides insights into possible novel antiviral targets that are necessary due to the widespread emergence of drug-resistant IAV strains. Here, we have identified LYAR, a cell growth-regulating nucleolar protein, which interacts with viral RNP components and is important for efficient replication of IAVs and whose role in the IAV life cycle has never been reported. In addition, we further reveal the role of LYAR in viral RNA synthesis. Our results extend and improve current knowledge on the mechanisms of IAV transcription and replication.

Cytotoxicity of Zardaverine in Embryonal Rhabdomyosarcoma from a Costello Syndrome Patient.

Costello syndrome (CS) patients suffer from a very high 10% incidence of embryonal rhabdomyosarcoma (ERMS). As tools to discover targeted therapeutic leads, we used a CS patient-derived ERMS cell line (CS242 ERMS) harboring a homozygous p.G12A mutation in HRAS, and a control cell line derived from the same patient comprising non-malignant CS242 fibroblasts with a heterozygous p.G12A HRAS mutation. A library of 2,000 compounds with known pharmacological activities was screened for their effect on CS242 ERMS cell viability. Follow-up testing in a panel of cell lines revealed that various compounds originally developed for other indications were remarkably selective; notably, the phosphodiesterase (PDE) inhibitor zardaverine was at least 1,000-fold more potent in CS242 ERMS than in the patient-matched non-malignant CS242 fibroblasts, other ERMS, or normal fibroblasts. Chronic treatment with zardaverine led to the emergence of resistant cells, consistent with CS242 ERMS comprising a mixed population of cells. Many PDE inhibitors in addition to zardaverine were tested on CS242 ERMS, but almost all had no effect. Interestingly, zardaverine and analogs showed a similar cytotoxicity profile in CS242 ERMS and cervical carcinoma-derived HeLa cells, suggesting a mechanism of action common to both cell types that does not require the presence of an HRAS mutation (HeLa contains wild type HRAS). Two recent studies presented possible mechanistic explanations for the cytotoxicity of zardaverine in HeLa cells. One revealed that zardaverine inhibited a HeLa cell-based screen measuring glucocorticoid receptor (GR) activation; however, using engineered HeLa cells, we ruled out a specific effect of zardaverine on signaling through the GR. The second attributed zardaverine toxicity in HeLa cells to promotion of the interaction of phosphodiesterase 3A and the growth regulatory protein Schlafen 12. We speculate that this work may provide a possible mechanism for zardaverine action in CS242 ERMS, although we have not yet tested this hypothesis. In conclusion, we have identified zardaverine as a potent cytotoxic agent in a CS-derived ERMS cell line and in HeLa. Although we have ruled out some possibilities, the mechanism of action of zardaverine in CS242 ERMS remains to be determined.

Clinical implications of plasma Nogo-A levels in patients with coronary heart disease.

IntroductionNogo-A is an important neurite growth-regulatory protein in the adult and developing nervous system. Recently, increasing evidence has shown that Nogo-A plays important roles in cardiac development and may act as a potential indicator for heart failure. In addition, increased oxidative stress has been found in individuals with cardiovascular diseases. However, not much is known regarding the expression levels of Nogo-A and reactive oxygen species (ROS) in patients with coronary heart disease (CHD). Therefore, we sought to investigate the relationship between Nogo-A, ROS levels and CHD.Material and methodsThe plasma Nogo-A and ROS concentrations of 122 acute coronary syndrome (ACS), 101 unstable angina pectoris (UAP), and 21 acute myocardial infarction (AMI) patients and 56 healthy controls were measured by enzyme-linked immunosorbent assay (ELISA). We further generated a receiver operating characteristic (ROC) curve to assess the diagnostic accuracy of Nogo-A and ROS in CHD.ResultsThe Nogo-A and ROS levels were significantly higher in patients with CHD than those in healthy controls. In addition, multivariate logistic regression analysis revealed that the level of Nogo-A (odds ratio (OR) = 1.624, 95% confidence interval: 1.125–2.293, p = 0.009) is a risk factor for prediction of CHD. Nogo-A has diagnostic value, with an optimal threshold of 5.466 ng/ml for maximized diagnostic performance (59% sensitivity and 78.6% specificity, area under curve, p < 0.05). However, ROS concentration is not a risk factor for prediction of CHD (OR = 0.999, 95% confidence interval: 0.997–1.001, p = 0.320).ConclusionsIncreased plasma Nogo-A level may be associated with CHD.

P-Hydroxycinnamaldehyde Induces B16-F1 Melanoma Cell Differentiation via the RhoA-MAPK Signaling Pathway

Background/Aims: Due to its antitumor and gastroprotective properties, cochinchina momordica seed (CMS), has been widely used to treat cancer patients in Asia. Our previous reports have shown that CMS is able to induce the differentiation of B16-F1 melanoma cells. However, its functional component and mechanism remain unclear and are addressed in this study. Methods and Results: CMSP (p-hydroxycinnamaldehyde isolated from CMS) inhibited the proliferation, migration and invasiveness of B16-F1 cells both in vivo and in vitro. CMSP also induced the differentiation of B16-F1 cells, as characterized by dendrite-like outgrowth, increased melanogenesis and enhanced tyrosinase activity. Furthermore, CMSP treatment reduced the level of malignant markers of melanoma, specifically S-100B and melanoma-derived growth regulatory protein precursor (MIA), in a concentration-dependent manner. According to a western blot analysis, B16-F1 cells treated with CMSP exhibited a sustained increase in p-P38 and decreased activities of ERK and JNK. Our data further indicated that the downregulation of GTP-RhoA, which was mediated by increased cAMP release, was involved in CMSP-induced changes in MAPK, while LPA (Lysophosphatidic acid) partially reversed CMSP-induced B16 cell differentiation. Conclusion: These results demonstrated that CMSP-induced differentiation of B16F1 cells may occur through the RhoA-MAPK axis, which suggests a new potential strategy for melanoma treatment.

Mechanism of Breast Cancer Preventive Action of Pomegranate: Disruption of Estrogen Receptor and Wnt/β-Catenin Signaling Pathways.

A pomegranate emulsion (PE), containing various bioactive phytochemicals, has recently been found to exert substantial chemopreventive effect against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumorigenesis in rats via antiproliferative and proapoptotic actions. Nevertheless, the underlying mechanisms of action are not completely understood. The present study was designed to investigate the effects of PE treatment on intratumor expression of estrogen receptor (ER)-α, ER-β,β-catenin and cyclin D1 during DMBA rat mammary carcinogenesis. Mammary tumor sections were harvested from a chemopreventive study in which PE (0.2, 1.0 and 5.0 g/kg) exhibited inhibition of mammary tumorigenesis in a dose-response manner. The expressions of ER-α, ER-β, β-catenin and cyclin D1 were analyzed by immunohistochemical techniques. PE downregulated the expression of intratumor ER-α and ER-β and lowered ER-α:ER-β ratio. PE also decreased the expression, cytoplasmic accumulation, and nuclear translocation of β-catenin, an essential transcriptional cofactor for Wnt signaling. Moreover, PE suppressed the expression of cell growth regulatory protein cyclin D1, which is a downstream target for both ER and Wnt signaling. Our current results in conjunction with our previous findings indicate that concurrent disruption of ER and Wnt/β-catenin signaling pathways possibly contributes to antiproliferative and proapoptotic effects involved in PE-mediated chemoprevention of DMBA-inflicted rat mammary tumorigenesis.

Quantitative analysis of the genes affecting development of the hypopharyngeal gland in honey bees (Apis mellifera L.)

Royal jelly has many important biological functions, however the molecular mechanism of royal jelly secretion in hypopharyngeal gland (HG) is still not well understood. In our previously study, six genes (SV2C, eIF-4E, PDK1, IMP, cell growth-regulating nucleolar protein and TGF-βR1) have been shown to might be associated with royal jelly secretion. In this study, the relative expression levels of these genes were examined in the hypopharyngeal gland of workers at different developmental stages (nurse, forager and reversed nurse stages). The results indicated that the relative expression levels of SV2C, eIF-4E, IMP, cell growth-regulating nucleolar protein and TGF-βR1 were reversed at reversed nurse stage compared to forager stage. We concluded that these genes are possibly candidates related to hypopharyngeal gland development or royal jelly secretion.

Involvement of p53 in insulin-like growth factor binding protein-3 regulation in the breast cancer cell response to DNA damage.

Chemotherapy drugs that induce apoptosis by causing DNA double-strand breaks, upregulate the tumor suppressor p53. This study investigated the regulation of the growth-regulatory protein insulin-like growth factor binding protein-3 (IGFBP-3), a p53 target, by DNA-damaging agents in breast cancer cells. IGFBP-3 was upregulated 1.4- to 13-fold in response to doxorubicin and etoposide in MCF-10A, Hs578T, MCF-7 and T47D cells, which express low to moderate basal levels of IGFBP-3. In contrast, IGFBP-3 was strongly downregulated by these agents in cells with high basal levels of IGFBP-3 (MDA-MB-231, MDA-MB-436 and MDA-MB-468). In MDA-MB-468 cells containing the R273H p53 mutation, reported to display gain-of-function properties, chemotherapy-induced suppression of IGFBP-3 was not reversed by the p53 reactivating drug, PRIMA-1, or by p53 silencing, suggesting that the decrease in IGFBP-3 following DNA damage is not a mutant p53 gain-of-function response. SiRNA-mediated downregulation of endogenous IGFBP-3 modestly attenuated doxorubicin-induced apoptosis in MDA-MB-468 and Hs578T cells. IGFBP-3 downregulation in some breast cancer cell lines in response to DNA-damaging chemotherapy may have clinical implications because suppression of IGFBP-3 may modulate the apoptotic response. These observations provide further evidence that endogenous IGFBP-3 plays a role in breast cancer cell responsiveness to DNA damaging therapy.

Amygdalin isolated from Semen Persicae (Tao Ren) extracts induces the expression of follistatin in HepG2 and C2C12 cell lines.

BackgroundThe Chinese medicine formulation ISF-1 (also known as Bu-Yang-Huan-Wu-Tang) for post-stroke rehabilitation could increase the expression of growth-regulating protein follistatin by approximately 4-fold. This study aims to identify the active compounds of ISF-1 for the induction of follistatin expression.MethodsActive compounds in ISF-1 responsible for induction of follistatin were identified by a bioactivity-guided fractionation procedure involving liquid-liquid extraction, HPLC separation and RT-PCR detection. The aqueous extracts of seven ISF-1 ingredients including Semen Persicae (Tao Ren) and the S. Persicae-derived fractions were assayed for the induction of follistatin mRNA expression in human hepatocarcinoma HepG2 cells by RT-PCR. The concentrations of isolated compounds were proportionally normalized to the reported IC50 concentration (5.8 mg/mL) of the formulation ISF-1 in HepG2. The active fractions were characterized by reverse-phase HPLC on a C18 column and identified by mass spectrometry.ResultsThree ingredients of ISF-1, namely S. Persicae (Tao Ren), Pheretima (Di Long), and Flos Carthami (Hong Hua), induced the expression of follistatin mRNA. Among these, the ingredient S. Persicae were the most active, and amygdalin from S. Persicae extract was identified as a novel follistatin inducer. Amygdalin stimulated the growth of skeletal muscle cell line C2C12 cells in a concentration-dependent manner.ConclusionsAmygdalin isolated from S. Persicae extract in ISF-1 through a bioactivity-guided fractionation procedure induced the expression of follistatin in HepG2 and C2C12 cell lines.

Overexpression of the maize GRF10, an endogenous truncated growth-regulating factor protein, leads to reduction in leaf size and plant height.

It has long been thought that growth-regulating factors (GRFs) gene family members act as transcriptional activators to play important roles in multiple plant developmental processes. However, the recent characterization of Arabidopsis GRF7 showed that it functions as a transcriptional repressor of osmotic stress-responsive genes. This highlights the complex and diverse mechanisms by which different GRF members use to take action. In this study, the maize (Zea mays L.) GRF10 was functionally characterized to improve this concept. The deduced ZmGRF10 protein retains the N-terminal QLQ and WRC domains, the characteristic regions as protein-interacting and DNA-binding domains, respectively. However, it lacks nearly the entire C-terminal domain, the regions executing transactivation activity. Consistently, ZmGRF10 protein maintains the ability to interact with GRF-interacting factors (GIFs) proteins, but lacks transactivation activity. Overexpression of ZmGRF10 in maize led to a reduction in leaf size and plant height through decreasing cell proliferation, whereas the yield-related traits were not affected. Transcriptome analysis revealed that multiple biological pathways were affected by ZmGRF10 overexpression, including a few transcriptional regulatory genes, which have been demonstrated to have important roles in controlling plant growth and development. We propose that ZmGRF10 aids in fine-tuning the homeostasis of the GRF-GIF complex in the regulation of cell proliferation.

Lyar, a cell growth-regulating zinc finger protein, was identified to be associated with cytoplasmic ribosomes in male germ and cancer cells

Translational control is a basic mechanism for gene regulation in cells and important for tissue growth and development in mammals. Deregulation of the mechanism thus causes diseases such as cancer. Considering the importance of the ribosome as a factory of polypeptide synthesis, some new factors have been expected to be associated with the ribosome and involved in translational control. Our proteomic survey for these factors identified a zinc finger protein, Lyar, in cytoplasmic ribosomes of the rodent testis. Subcellular fractionation of the testis provided data supporting association of Lyar with ribosomes. Lyar was then suggested to be included in the 60S large subunit, but not in polysomes, by ultracentrifugation of testicular ribosomes. While analysis of tissue distribution of Lyar has indicated its testis-predominant expression, Lyar mRNA was expressed in the cancer cells originated from tissues other than testis, and Lyar promoted proliferation of NIH-3T3 cells. Furthermore, translation was increased by Lyar in vitro, pointing out the first experimental link between this protein and translation. Taken together, Lyar seems to be a new player in translational control and a potential target for cancer therapy.