Knockdown of Arabidopsis ROOT UVB SENSITIVE4 Disrupts Anther Dehiscence by Suppressing Secondary Thickening in the Endothecium.

ROOT UV-B SENSITIVE4 (RUS4) encodes a protein with no known function that contains a conserved Domain of Unknown Function 647 (DUF647). The DUF647-containing proteins RUS1 and RUS2 have previously been associated with root UV-B-sensing pathway that plays a major role in Arabidopsis early seedling morphogenesis and development. Here, we show that RUS4 knockdown Arabidopsis plants, referred to as amiR-RUS4, were severely reduced in male fertility with indehiscent anthers. Light microscopy of anther sections revealed a significantly reduced secondary wall thickening in the endothecium of amiR-RUS4 anthers. We further show that the transcript abundance of the NAC domain genes NAC SECONDARY WALL THICKENING PROMOTING FACTOR1 (NST1) and NST2, which have been shown to regulate the secondary cell wall thickenings in the anther endothecium, were dramatically reduced in the amiR-RUS4 floral buds. Expression of the secondary cell wall-associated MYB transcription factor genes MYB103 and MYB85 were also strongly reduced in floral buds of the amiR-RUS4 plants. Overexpression of RUS4 led to increased secondary thickening in the endothecium. However, the rus4-2 mutant exhibited no obvious phenotype. Promoter-GUS analysis revealed that the RUS4 promoter was highly active in the anthers, supporting its role in anther development. Taken together, these results suggest that RUS4, probably functions redundantly with other genes, may play an important role in the secondary thickening formation in the anther endothecium by indirectly affecting the expression of secondary cell wall biosynthetic genes.

[Specific gene silencing of At1g13770 and At2g23470 by artificial mi-croRNAs in Arabidopsis].

DUF647 (domain of unknown function 647) protein family is found in diverse eukaryotic organisms and highly conserved in eukaryotes. It has 6 members in Arabidopsis genome. So far, the function of 4 members of Arabidopsis DUF647 family is unknown. In this report, using an endogenous Arabidopsis MIR319a precursor as the backbone, we constructed two artificial microRNAs (amiRNAs) to knock down the expression of two DUF647 family genes At1g13770 and At2g23470. Using the WMD (Web microRNA Designer) platform, we designed two amiRNAs targeting At1g13770 and At2g23470 genes, respectively. Both amiRNAs sequences were engineered into the MIR319a precursor using overlapping PCR and the amiRNAs backbones were transferred into the binary vector pCHF3. The resulting plasmids that harbor amiRNAs stem loop fragments were transformed into Arabidopsis by Agrobacterium-mediated floral diping. Upon constitutive expression of these two amiRNAs, the target genes were efficiently down-regulated in transgenic line. The decreased level of At2g23470 transcript in At2g23470-amiRNA transgenic plants resulted in severe sterility. This work will facilitate the functional analysis of At1g13770 and At2g23470 genes in Arabidopsis growth and development.

Synergistic effect of bortezomib and valproic acid treatment on the proliferation and apoptosis of acute myeloid leukemia and myelodysplastic syndrome cells.

The synergistic effect of proteasome inhibitor bortezomib and valproic acid (VPA), a histone deacetylase inhibitor, were investigated in this study. Co-treatment with VPA and bortezomib on acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) cell lines resulted in marked inhibition of proliferation and induction of apoptosis, including a striking increase in mitochondrial injury, caspase cascade activation, and altered expression of Bcl-2 family proteins. Moreover, combination treatment inhibited cyto-protective signaling pathways, including inactivation of nuclear factor κB (NF-κB), the extracellular signal-related kinase (ERK) and Akt pathways, and activated stress-related signaling pathway, including the c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38) pathways. In addition, this regimen significantly caused G2/M phase arrest, while downregulating the expression of phospho-CDC2 and CyclinD1 as well as increasing p21(cip1). Furthermore, combination treatment efficiently induced apoptosis in primary AML/MDS cells, with little effect on normal cells. In summary, these findings indicate that combination treatment with VPA and bortezomib may be a potent therapy for AML/MDS malignancies.

The prognostic value of immunohistochemical subtyping in Chinese patients with de novo diffuse large B-cell lymphoma undergoing CHOP or R-CHOP treatment.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with recognised variability in molecular aetiology and clinical outcome. Though the use of agents such as rituximab significantly improves outcome, intrinsic genetic and morphological factors greatly affect the response to treatment. The objective of this study was to evaluate the prognostic value of immunohistochemical subtyping and the International Prognostic Index (IPI) for predicting treatment outcome in Chinese DLBCL patients. We followed 108 cases of DLBCL and performed prognostic analyses based on molecular subtyping of the disease through immunostaining of tissue samples. The use of rituximab conferred a clinical benefit to DLBCL patients regardless of disease subtype. Importantly, this treatment regimen also improved outcomes in patients with the non-germinal centre B-cell-like (GCB) DLBCL subtype, frequently associated with poorer prognosis. Our results suggest that IPI was the best tool for the prediction of treatment outcome in our patient cohort, regardless of treatment regimen. Furthermore, the use of rituximab alongside classical chemotherapy regimens can improve the outcomes for DLBCL patients who exhibit both GCB and non-GCB subtypes of the disease.

Knockdown of the DUF647 family member RUS4 impairs stamen development and pollen maturation in Arabidopsis.

ROOT UV-B SENSITIVE4 (RUS4) encodes a Domain of Unknown Function647 (DUF647) protein, whose function is poorly understood. We have previously shown the artificial microRNA knockdown Arabidopsis RUS4 plants, referred to as amiR-RUS4, have severely reduced male fertility with a defect in anther dehiscence. Here, we show that amiR-RUS4 plants are also defective in pollen maturation and germination. Promoter-reporter analysis shows that RUS4 is highly expressed in tapetal layer, developing microspores, mature and germinating pollen, strongly suggesting its role in the process of pollen maturation. As the translational RUS4-GFP fusion protein has been localized to the chloroplasts where the first step of jasmonic acid (JA) biosynthesis takes place, leading to the hypothesis that RUS4 may be involved in JA-mediated stamen development. We show that expression of several JA metabolic genes increased markedly in flower buds of the amiR-RUS4 plants compared to that of the wild-type. We further show that transcript abundance of a clade of the JA-responsive MYB transcript factor genes, especially MYB108, reduced significantly in stamens of amiR-RUS4 plants relative to the wild-type; these MYB transcript factors have been shown to be required for JA-mediated stamen and pollen maturation. Our data suggest that RUS4 may play a role in coordinating anther dehiscence and pollen maturation by affecting the expression of JA-related genes.

Clinical significance of chemokine receptor CXCR4 and mammalian target of rapamycin (mTOR) expression in patients with diffuse large B-cell lymphoma.

To assess the relevance of C-X-C chemokine receptor type 4 (CXCR4) and mammalian target of rapamycin (mTOR) to large-B-cell lymphoma (DLBCL), levels of protein expression were measured in 56 DLBCL patients who had received rituximab-based therapy. Of these, 34 were positive for CXCR4 expression (60.7%) and 31 for mTOR (55.4%). CXCR4 expression was positively correlated with mTOR expression (r = 0.602; p = .000). CXCR4 expression was significantly associated with high lactate dehydrogenase (LDH) level (p = .009), high IPI score (p = .030) and non-GCB subtype (p = .006). Furthermore, the expression levels of CXCR4 and mTOR were negatively correlated with the chance of remission (p < .05). Kaplan-Meier analysis indicated significantly shorter progression-free survival (PFS) and overall survival (OS) in patients positive for CXCR4 and mTOR expression. The combination therapy with CXCR4 inhibitor WZ811 and mTOR inhibitor everolimus showed syncergistic effect in DLBCL cell lines. These results suggest that the expression of CXCR4 and mTOR may be suitable as biomarkers of the prognosis of DLBCL and for development of new therapeutic strategies.

[Signal pathways of flowering time regulation in plant].

The transition from vegetative to reproductive growth is the major developmental switch in plant life cycle. The timing of flower initiation is critical for a successful reproduction. Flowering is regulated by endogenous and environmental signals. Molecular genetic studies on Arabidopsis thaliana revealed four major flowering pathways: the photoperiod, the vernalization, the autonomous, and the gibberellin pathways. This paper reviews some research progresses in control of flowering time in Arabidopsis.

[G-CSF and Its Receptor in Hematonosis].

The granulocyte colony-stimulating factor (G-CSF), now referred to as CSF3, is a very important cell growth factor that supports the proliferation, survival, and differentiation of neutrophilic progenitor cells, and also is a strong immune regulator of T cells and a promising therapeutic tool in acute graft versus host disease (GVHD). G-CSF acts by binding to its receptor G-CSFR (also called CSF3R), a member of the cytokine receptor type I superfamily, which after binding with G-CSF activates the canonical Janus kinase (Jak)/signal transducer, activator of transcription (STAT)and Ras/Raf/MAP kinase pathways. G-CSF has been applied to the clinic to treat congenital and acquired neutropenia before or during courses of intensive chemotherapy. It has also been applied to mobilize hematopoietic stem cells into the peripheral blood for Auto-or allogeneic transplantation, and the priming strategies designed to enhance the sensitivity of leukemia stem cells to cytotoxic agents in protocols aimed to induce their differentiation, accompanying growth arrest, and cell death. With the rapid development of molecular genetics and clinical research, CSF3R mutations have been implicated in the progression of severe congenital neutropenia (SCN) to leukemia. Recently, CSF3R mutations have been discovered frequently in chronic neutrophilic leukemia (CNL). Such findings might provide the theoretical basis for the targeted therapy. In this review, the clinical application of G-CSF receptor in hematonosis is briefhy summarized.

[The introduction of chloroplast gene engineering].

Chloroplast is a kind of special cell organ in plant cells.Since 1988,Scientists have realized its advantages in plant gene engineering.It's high efficient expression and safety made it been attached more and more importance to. This paper introduces the chloroplast transformation,including its advantages,methods,uses and defects.

Studies on the rice LEAF INCLINATION1 (LC1), an IAA-amido synthetase, reveal the effects of auxin in leaf inclination control.

The angle of rice leaf inclination is an important agronomic trait and closely related to the yields and architecture of crops. Although few mutants with altered leaf angles have been reported, the molecular mechanism remains to be elucidated, especially whether hormones are involved in this process. Through genetic screening, a rice gain-of-function mutant leaf inclination1, lc1-D, was identified from the Shanghai T-DNA Insertion Population (SHIP). Phenotypic analysis confirmed the exaggerated leaf angles of lc1-D due to the stimulated cell elongation at the lamina joint. LC1 is transcribed in various tissues and encodes OsGH3-1, an indole-3-acetic acid (IAA) amido synthetase, whose homolog of Arabidopsis functions in maintaining the auxin homeostasis by conjugating excess IAA to various amino acids. Indeed, recombinant LC1 can catalyze the conjugation of IAA to Ala, Asp, and Asn in vitro, which is consistent with the decreased free IAA amount in lc1-D mutant. lc1-D is insensitive to IAA and hypersensitive to exogenous BR, in agreement with the microarray analysis that reveals the altered transcriptions of genes involved in auxin signaling and BR biosynthesis. These results indicate the crucial roles of auxin homeostasis in the leaf inclination control.

[Organic carbon storage in urban built-up areas of China in 1997-2006].

With the increase of greenhouse gases emission in urban regions, urban carbon cycle plays a more and more important role in global carbon cycle. To estimate urban carbon emission and carbon storage is crucial for understanding urban carbon cycle. By using China's statistics data and the results from recent publications, this paper estimated the organic carbon storage in China's urban built-up areas in 1997-2006. From 1997 to 2006, the total organic carbon storage in the urban built-up areas increased from 0.13-0.19 Pg C (averagely 0.16 Pg C) to 0.28-0.41 Pg C (averagely 0.34 Pg C), and the organic carbon density increased from 9.86-14.03 kg C x m(-2) (averagely 11.95 kg C x m(-2)) to 10.54-15.54 kg C x m(-2) (averagely 13.04 kg C x m(-2)). The total organic carbon storage in the urban built-up areas was mainly contributed by soils (78% in 1997 and 73% in 2006), followed by buildings (12% in 1997 and 16% in 2006) and green spaces (9% in 1997 and 10% in 2006), while the carbon storage in resident bodies only accounted for less than 1%, which could be neglected.

Rice leaf inclination2, a VIN3-like protein, regulates leaf angle through modulating cell division of the collar.

As an important agronomic trait, inclination of leaves is crucial for crop architecture and grain yields. To understand the molecular mechanism controlling rice leaf angles, one rice leaf inclination2 (lc2, three alleles) mutant was identified and functionally characterized. Compared to wild-type plants, lc2 mutants have enlarged leaf angles due to increased cell division in the adaxial epidermis of lamina joint. The LC2 gene was isolated through positional cloning, and encodes a vernalization insensitive 3-like protein. Complementary expression of LC2 reversed the enlarged leaf angles of lc2 plants, confirming its role in controlling leaf inclination. LC2 is mainly expressed in the lamina joint during leaf development, and particularly, is induced by the phytohormones abscisic acid, gibberellic acid, auxin, and brassinosteroids. LC2 is localized in the nucleus and defects of LC2 result in altered expression of cell division and hormone-responsive genes, indicating an important role of LC2 in regulating leaf inclination and mediating hormone effects.