TaMYB44-5A reduces drought tolerance by repressing transcription of TaRD22-3A in the abscisic acid signaling pathway.

MAIN CONCLUSION: TaMYB44-5A identified as a transcription factor negatively regulates drought tolerance in transgenic Arabidopsis. Drought can severely reduce yields throughout the wheat-growing season. Many studies have shown that R2R3-MYB transcription factors are involved in drought stress responses. In this study, the R2R3-MYB transcription factor MYB44-5A was identified in wheat (Triticum aestivum L.) and functionally analyzed. Three homologs of TaMYB44 were isolated, all of which localized to the nucleus. Overexpression of TaMYB44-5A reduced drought tolerance in Arabidopsis thaliana. Further analysis showed that TaMYB44-5A reduced the sensitivity of transgenic Arabidopsis to ABA. Genetic and transcriptional regulation analyses demonstrated that the expression levels of drought- and ABA-responsive genes were downregulated by TaMYB44-5A, and TaMYB44-5A directly bound to the MYB-binding site on the promoter to repress the transcription level of TaRD22-3A. Our results provide insights into a novel molecular pathway in which the R2R3-MYB transcription factor negatively regulates ABA signaling in response to drought stress.

E3 ubiquitin ligase TaSDIR1-4A activates membrane-bound transcription factor TaWRKY29 to positively regulate drought resistance.

Drought is a deleterious abiotic stress factor that constrains crop growth and development. Post-translational modification of proteins mediated by the ubiquitin-proteasome system is an effective strategy for directing plant responses to stress, but the regulatory mechanisms in wheat remain unclear. In this study, we showed that TaSDIR1-4A is a positive modulator of the drought response. Overexpression of TaSDIR1-4A increased the hypersensitivity of stomata, root length and endogenous abscisic acid (ABA) content under drought conditions. TaSDIR1-4A encodes a C3H2C3-type RING finger protein with E3 ligase activity. Amino acid mutation in its conserved domain led to loss of activity and altered the subcellular localization. The membrane-bound transcription factor TaWRKY29 was identified by yeast two-hybrid screening, and it was confirmed as interacting with TaSDIR1-4A both in vivo and in vitro. TaSDIR1-4A mediated the polyubiquitination and proteolysis of the C-terminal amino acid of TaWRKY29, and its translocation from the plasma membrane to the nucleus. Activated TaWRKY29 bound to the TaABI5 promoter to stimulate its expression, thereby positively regulating the ABA signalling pathway and drought response. Our findings demonstrate the positive role of TaSDIR1-4A in drought tolerance and provide new insights into the involvement of UPS in the wheat stress response.

Size-Switchable Ru Nanoaggregates for Enhancing Phototherapy: Hyaluronidase-Triggered Disassembly to Alleviate Deep Tumor Hypoxia.

Hypoxia is a critical factor for restricting photodynamic therapy (PDT) of tumor, and it becomes increasingly severe with increasing tissue depth. Thus, the relief of deep tumor hypoxia is extremely important to improve the PDT efficacy. Herein, tumor microenvironment (TME)-responsive size-switchable hyaluronic acid-hybridized Ru nanoaggregates (HA@Ru NAs) were developed via screening reaction temperature to alleviate deep tumor hypoxia for improving the tumor-specific PDT by the artful integration multiple bioactivated chemical reactions in situ and receptor-mediated targeting (RMT). In this nanosystem, Ru NPs not only enabled HA@Ru NAs to have near infrared (NIR)-mediated photothermal/photodynamic functions, but also could catalyze endogenous H2O2 to produce O2 in situ. More importantly, hyaluronidase (HAase) overexpressed in the TME could trigger disassembly of HA@Ru NAs via the hydrolysis of HA, offering the smart size switch capability from 60 to 15 nm for enhancing tumor penetration. Moreover, the RMT characteristics of HA ensured that HA@Ru NAs could specially enter CD44-overexpressed tumor cells, enhancing tumor-specific precision of phototherapy. Taken together these distinguishing characteristics, smart HA@Ru NAs successfully realized the relief of deep tumor hypoxia to improve the tumor-specific PDT.

MiR-24-3p regulates the differentiation of adipose-derived stem cells toward pericytes and promotes fat grafting vascularization.

Adipose-derived stem cells (ADSCs) enhance fat graft survival by promoting neovascularization. The mechanism that promotes ADSCs differentiation toward pericytes was not known. We treated ADSCs with conditional medium (CM) from endothelial cells (ECs) or human recombinant transforming growth factor ß (TGF-ß) to induce differentiation into pericytes. Pericytes markers, including platelet-derived growth factor receptor ß (PDGFRß), alpha-smooth muscle actin (α-SMA), and desmin, were examined. Pericytes differentiation markers, migration, and their association with ECs were examined in ADSCs transfected with miR-24-3p mimics and inhibitors. Bioinformatics target prediction platforms and luciferase assays were used to investigate whether PDGFRß was directly targeted by miR-24-3p. In vivo, fat mixed with ADSCs transfected with miR-24-3p mimics or inhibitors was implanted subcutaneously on the lower back region of nude mice. Fat grafts were harvested and analyzed at 2, 4, 6, and 8 weeks. Results showed that endogenous TGF-ß derived from CM from EC or human recombinant TGF-ß promoted migration, association with ECs, and induced expression of pericyte markers (PDGFRß, α-SMA, Desmin) in ADSCs. MiR-24-3p directly targeted PDGFRß in ADSCs by lucifer reporter assays. Inhibition of miR-24-3p promoted pericytes differentiation, migration, and association with ECs in ADSCs. Inhibition of miR-24-3p in ADSCs promoted survival, integrity, adipocyte viability, vascularization, pericytes association with ECs, and reduced fibrosis, whereas overexpression of miR-24-3p in ADSCs yielded the opposite results. Collectively, TGF-ß released by ECs induced ADSCs differentiation toward pericytes through miR-24-3p. Downregulation of miR-24-3p in ADSCs induced survival, integrity, adipocyte viability, vascularization, pericytes association with ECs, and reduced fibrosis after fat grafting.

Studies on the effect and mechanism of CD147 on melanoma stem cells.

BACKGROUND: Melanoma is the most aggressive form of skin cancer. Melanoma stem cells (MSCs) are one of the driving forces of melanoma invasion and metastasis. Therefore, it is of great significance to explore the mechanisms that maintain the stemness of MSCs. In this study, CD147-positive (CD147+) MSCs derived from A375 cell line were characterized. METHODS: Side population (SP) and non-SP cells were sorted from A375 cells. Quantitative real-time polymerase chain reaction and Western blot analysis were conducted to determine the expression of CD147 in SP and non-SP cells. Subsequently, CD147+ and CD147-negative (CD147-) cells were isolated from SP cells. Stem cell characteristics and metastatic potential of CD147+/- antigen-presenting cells were identified by sphere-forming, wound-healing, and transwell assays. Western blot analysis was performed to evaluate the protein levels of transforming growth factor-beta1 (TGFß1) and neurogenic locus notch homolog protein 1 (Notch1) signaling pathway. Xenograft tumor experiments were conducted to investigate the tumorigenic capacity of CD147+ cells in vivo. RESULTS: CD147 was highly expressed in SP cells of A375 cell line. CD147+ cells have stronger abilities for sphere forming, migration, and invasion in vitro. The protein levels of TGFß1, notch1, jagged1, and Hes1 were higher in CD147+ cells than in CD147- cells. Moreover, the CD147+ cells showed stronger tumorigenic and metastatic potential in vivo. CONCLUSION: SP cells of A375 cell line expressed high levels of CD147, and CD147+ SP cells possessed much stronger stem-like characteristics and motility, which is linked to the activation of TGFß and notch pathways.

Revealing the mechanism of 755-nm long-pulsed alexandrite laser in inhibiting infantile hemangioma endothelial cells through transcriptome sequencing.

Laser therapy has shown promising outcomes in treating infantile hemangiomas. However, the molecular mechanisms underlying laser treatment for IH remain incompletely elucidated. This study aimed to unravel the molecular mechanisms of laser therapy in IH treatment. We evaluated the inhibitory effects of laser treatment on the proliferation and promotion of apoptosis in human hemangioma endothelial cells (HemECs) through cell counting kit-8 (CCK-8) assay, Hoechst 33342 staining, and flow cytometric analysis. Transcriptome sequencing analysis of HemECs following laser treatment revealed a significant decrease in the expression level of the GSTM5 gene. The qRT-PCR and western blot analysis also showed that GSTM5 expression in HemECs was downregulated compared to human umbilical vein endothelial cells (HUVECs), and concomitantly, the p62-Nrf2 pathway was suppressed. Using siRNA to downregulate GSTM5 expression, we observed that inhibiting GSTM5 expression could restrain cell proliferation, elevate intracellular ROS levels, and induce apoptosis in HemECs. Furthermore, upon inhibition of the p62-Nrf2 pathway using p62-specific siRNA, a significant decrease in GSTM5 expression and an elevation in intracellular ROS levels were noted in laser-treated HemECs. These findings suggested that laser treatment may operate by inhibiting the p62-Nrf2 pathway, thereby downregulating GSTM5 expression, elevating ROS levels, and consequently inducing apoptosis in HemECs.

TaFDL2-1A confers drought stress tolerance by promoting ABA biosynthesis, ABA responses, and ROS scavenging in transgenic wheat.

Plants have developed various protective mechanisms to survive drought stress. Previously, it was shown that a wheat bZIP transcription factor gene TaFD-Like2-1A (TaFDL2-1A) can confer drought tolerance in Arabidopsis. However, the biological functions related to drought stress tolerance of TaFDL2-1A in wheat (Triticum aestivum L.) remain unclear. In the present study, overexpression of TaFDL2-1A in the wheat cultivar Fielder improved drought resistance and conferred abscisic acid (ABA) hypersensitivity. Further analysis showed that overexpression of TaFDL2-1A increased the hypersensitivity of stomata to drought stress and endogenous ABA content under drought conditions. Genetic analysis and transcriptional regulation analysis indicated that TaFDL2-1A binds directly to the promoter fragments of TaRAB21s and TaNCED2s via ACGT core cis-elements, thereby activating their expression, leading to enhanced ABA responses and endogenous ABA accumulation. In addition, our results demonstrate that overexpression of TaFDL2-1A results in higher SOD and GPX activities in wheat under drought conditions by promoting the expression of TaSOD1 and TaGPx1-D, indicating enhanced reactive oxygen species (ROS) scavenging. These results imply that TaFDL2-1A positively regulates ABA biosynthesis, ABA responses, and ROS scavenging to improve drought stress tolerance in transgenic wheat. Our findings improve our understanding of the mechanisms that allow the wheat bZIP transcription factor to improve drought resistance and provide a useful reference gene for breeding programs to enhance drought resistance.

Transmission Pattern of Measles Virus Circulating in China During 1993-2021: Genotyping Evidence Supports That China Is Approaching Measles Elimination.

BACKGROUND: To provide useful insights into measles elimination progress in China, measles surveillance data were reviewed, and the transmission patterns of measles viruses circulating in China during 1993-2021 were analyzed. METHODS: Measles incidence data from the National Notifiable Disease Reporting System of the China Center for Disease Control and Prevention were analyzed. A total of 17 570 strains were obtained from 30 of 31 provinces in mainland China during 1993-2021. The recommended genotyping window was amplified. Genotyping analysis was conducted for comparison with the reference strains. Phylogenetic analyses were performed to identify genetic relationships among different lineages within the genotypes. RESULTS: With high coverage of routine immunization and intensive supplementary immunization activities, measles incidence has shown a downward trend since 1993, despite 2 resurgences, reaching a historic low level in 2020-2021 (average 0.5 per million). During 1993-2021, 9 genotypes including domestic genotype H1; imported genotypes B3, D4, D8, D9, D11, G3, and H2; and vaccine-associated genotype A were identified. Among them, the genotype H1 strain circulated endemically in China for more than 25 years; the last strain was detected in Yunnan Province in September 2019. Multiple imported genotypes have been identified since 2009 showing different transmission patterns. Since April 2020, no imported strains have been detected, while vaccine-associated genotype A continues to be detected. CONCLUSIONS: The evidence of low incidence during 2020-2021 and virological surveillance data in this study confirm that China is currently approaching measles elimination.

Aberrant Activation of Notch1 Signaling in Glomerular Endothelium Induces Albuminuria.

RATIONALE: Glomerular capillaries are lined with a highly specialized fenestrated endothelium and contribute to the glomerular filtration barrier. The Notch signaling pathway is involved in regulation of glomerular filtration barrier, but its role in glomerular endothelium has not been investigated due to the embryonic lethality of animal models with genetic modification of Notch pathway components in the endothelium. OBJECTIVE: To determine the effects of aberrant activation of the Notch signaling in glomerular endothelium and the underlying molecular mechanisms. METHODS AND RESULTS: We established the ZEG-NICD1 (notch1 intracellular domain)/Tie2-tTA/Tet-O-Cre transgenic mouse model to constitutively activate Notch1 signaling in endothelial cells of adult mice. The triple transgenic mice developed severe albuminuria with significantly decreased VE-cadherin (vascular endothelial cadherin) expression in the glomerular endothelium. In vitro studies showed that either NICD1 (Notch1 intracellular domain) lentiviral infection or treatment with Notch ligand DLL4 (delta-like ligand 4) markedly reduced VE-cadherin expression and increased monolayer permeability of human renal glomerular endothelial cells. In addition, Notch1 activation or gene knockdown of VE-cadherin reduced the glomerular endothelial glycocalyx. Further investigation demonstrated that activated Notch1 suppression of VE-cadherin was through the transcription factors SNAI1 (snail family transcriptional repressor 1) and ERG (Ets related gene), which bind to the -373 E-box and the -134/-118 ETS (E26 transformation-specific) element of the VE-cadherin promoter, respectively. CONCLUSIONS: Our results reveal novel regulatory mechanisms whereby endothelial Notch1 signaling dictates the level of VE-cadherin through the transcription factors SNAI1 and ERG, leading to dysfunction of glomerular filtration barrier and induction of albuminuria. Graphic Abstract: A graphic abstract is available for this article.

Transmission Dynamics of the Rubella Virus Circulating in China During 2010-2019: 2 Lineage Switches Between Genotypes 1E and 2B.

BACKGROUND: To provide a better understanding of the progress on rubella control and elimination in China, a genetic analysis was conducted to examine the transmission pattern of the endemic rubella virus in China during 2010-2019. METHODS: A total of 4895 strains were obtained from 29 of the 31 provinces in mainland China during 2010-2019. The genotyping regions of the strains were amplified, determined, and assembled. Genotyping analysis and lineage division were performed by comparisons with the World Health Organization reference strains and reported lineage reference strains, respectively. Further phylogenetic analyses were performed to compare the genetic relationship. RESULTS: During 2010-2019, the domestic lineage 1E-L1 and multiple imported lineages of rubella viruses including 2B-L1, 1E-L2, and 2B-L2c were identified. Further analysis of the circulation trend of the different lineages indicated that 2 switches occurred among the lineages. The first shift was from lineage 1E-L1 to 2B-L1, which occurred around 2015-2016, followed by the lowest rubella incidence in 2017. The second shift was from lineage 2B-L1 to 1E-L2 and 2B-L2c, which occurred around 2018-2019, coinciding with rubella resurgence and the subsequent nationwide epidemic during 2018-2019. Insufficient genomic information worldwide made it impossible to trace the origin of the imported viruses. CONCLUSIONS: China was moving toward rubella elimination, as evidenced by the fact that previous endemic lineages were not detected. However, rubella reemerged in 2018 2019 due to the newly imported rubella viruses. Therefore, to realize the rubella elimination goal, joint efforts are required for all countries worldwide.

Cadmium Induces Glomerular Endothelial Cell-Specific Expression of Complement Factor H via the -1635 AP-1 Binding Site.

Cadmium (Cd) is an environmental toxin that induces nephrotoxicity. Complement factor H (CFH), an inhibitor of complement activation, is involved in the pathogenesis of various renal diseases. In this study, we investigated the effects of Cd on CFH production by the kidney. In C57B6/J mice, an increased CFH level was found in renal blood and glomerular endothelial cells after Cd treatment. In vitro, Cd induces an increased CFH secretion and mRNA expression in human renal glomerular endothelial cells but not in human podocytes or human mesangial cells. Cd activates the JNK pathway and increases c-Jun and c-Fos in human renal glomerular endothelial cells. A JNK inhibitor, SP600125, specifically abolishes Cd-induced CFH production. By chromatin immunoprecipitation assay and EMSA, the -1635 AP-1 motif on human CFH promoter was identified as the binding element for c-Jun and c-Fos. In a luciferase activity assay, mutation of the AP1 site eliminates Cd-induced increase of CFH promoter activity. Thus, the -1635 AP-1 motif on the CFH promoter region mediates Cd-inducible CFH gene expression.

Genome-wide identification and abiotic stress response patterns of abscisic acid stress ripening protein family members in Triticum aestivum L.

ASR (ABA-stress-ripening) genes play important roles in regulating plant growth and stress responses. This study identified 29 ASR genes in wheat. 23 pairs of tandem duplication genes and six pairs of segmental duplication genes were found in wheat ASR (TaASR) gene family, respectively. It is speculated that gene duplication event is the main driving force of TaASR genes evolution. Using published RNA-seq data and the qRT-PCR results of 12 TaASR genes, we analyzed the expression profiles for TaASR genes under abiotic stresses. It found that most of the genes mainly responded to salt and low temperature stress. Finally, subcellular localization and self-activation experiments showed that the proteins encoded by 12 TaASR genes were all located in the nucleus and cell membrane, and the full-length proteins had self-activation activity, which supported their role as transcription factors. This study provides a scientific basis for a comprehensive understanding of the TaASR gene family.

Genome-Wide Identification and Analysis of the Growth-Regulating Factor (GRF) Gene Family and GRF-Interacting Factor Family in Triticum aestivum L.

Growth-regulating factors (GRFs) are unique transcription factors in plants. GRFs can interact with SNH (SYT N-terminal homology) domains in GRF-interacting factor (GIF) proteins via the N-terminal QLQ (Gln, Leu, Gln) domain to form functional complexes and participate in the regulation of downstream gene expression. In this study, we systematically identified the GRF gene family and GIF gene family in wheat and its relatives comprising Triticum urartu, Triticum dicoccoides, and Aegilops tauschii. Thirty GRF gene members are present in wheat, which are distributed on 12 chromosomes and they have 2-5 protein-coding regions. They all contain QLQ and WRC (Trp, Arg, Cys) conserved domains. Wheat possesses only eight members of the GIF gene family, which are distributed on six chromosomes. All wheat GIF (TaGIF) proteins have highly conserved SNH and QG (Gln, Gly) domains. The wheat GRF (TaGRF) gene family has 13 pairs of segmental duplication genes and no tandem duplication genes; the TaGIF gene family has two pairs of segmental duplication genes and no tandem duplication genes. It is speculated that segmental duplication events may be the main reason for the amplification of TaGRF gene family and TaGIF gene family. Based on published transcriptome data and qRT-PCR results of 8 TaGRF genes and 4 TaGIF genes, all of the genes responded strongly to osmotic stress, and the expression levels of TaGRF21 and TaGIF5 were also significantly upregulated under drought and cold stress conditions. The results obtained in this study may facilitate further investigations of the functions of TaGRF genes and TaGIF genes in order to identify candidate genes for use in stress-resistant wheat breeding programs.

Absence of Dx2 at Glu-D1 Locus Weakens Gluten Quality Potentially Regulated by Expression of Nitrogen Metabolism Enzymes and Glutenin-Related Genes in Wheat.

Absence of high-molecular-weight glutenin subunit (HMW-GS) Dx2 weakens the gluten quality, but it is unclear how the absence of Dx2 has these effects. Thus, we investigated the gluten quality in terms of cytological, physicochemical, and transcriptional characteristics using two near-isogenic lines with Dx2 absent or present at Glu-D1 locus. Cytological observations showed that absence of Dx2 delayed and decreased the accumulation of protein bodies (PBs), where fewer and smaller PBs formed in the endosperm. The activity and gene expression levels of nitrogen assimilation and proteolysis enzymes were lower in HMW-D1a without Dx2 than HMW-D1p with Dx2, and thus less amino acid was transported for protein synthesis in the grains. The expression pattern of genes encoding Glu-1Dx2+1Dy12 was similar to those of three transcription factors, where these genes were significantly down-regulated in HMW-D1a than HMW-D1p. Three genes involving with glutenin polymerization were also down-regulated in HMW-D1a. These results may explain the changes in the glutenin and glutenin macropolymer (GMP) levels during grain development. Therefore, we suggest that the lower nitrogen metabolism capacity and expression levels of glutenin synthesis-related genes in HMW-D1a accounted for the lower accumulation of glutenin, GMP, and PBs, thereby weakening the structural‒thermal properties of gluten.

Stromal vascular fraction cells plus sustained release VEGF/Ang-1-PLGA microspheres improve fat graft survival in mice.

Autologous fat transplantation is increasingly applied in plastic and reconstructive surgery. Stromal vascular fraction cells (SVFs) combined with angiogenic factors, such as VEGF (vascular endothelial growth factor A) and Ang-1 (angiogenin-1), can improve angiogenesis, which is a critical factor for graft survival. However, direct transplant with such a mixture is insufficient owing to the short half-life of angiogenic factors. In this study, we evaluated whether a double sustained release system of VEGF/ANG-1-PLGA (poly (lactic-co-glycolic acid)) microspheres plus SVFs can improve angiogenesis and graft survival after autologous fat transplantation. VEGF/ANG-1-PLGA-sustained release microspheres were fabricated by a modified double emulsion-solvent evaporation technique. Human aspirated fat was mixed with SVF suspension plus VEGF/ANG-1 sustained release microspheres (Group C), SVF suspension (Group B) alone, or Dulbecco's modified Eagle's medium as the control (Group A). Eighteen immunocompromised nude mice were injected with these three mixtures subcutaneously at random positions. After 8 weeks, the mean volume of grafts was greater in the SVFs plus VEGF/ANG-1-PLGA group than in the control and SVFs groups (1.08 ± 0.069 ml vs. 0.62 ± 0.036 ml, and 0.83 ± 0.059 ml, respectively). Histological assessments showed that lower fibrosis, but greater microvascular density in the SVFs plus VEGF/ANG-1-PLGA group than in the other groups, though the SVFs group also had an appropriate capillary density and reduced fibrosis. Our findings indicate that SVFs plus VEGF/ANG-1-PLGA-sustained release microspheres can improve angiogenesis and graft survival after autologous fat transplantation.

Dihydroartemisinin up-regulates VE-cadherin expression in human renal glomerular endothelial cells.

The antimalarial agent dihydroartemisinin (DHA) has been shown to be anti-inflammatory. In this study, we found that DHA increased the expression of the junctional protein vascular endothelial (VE)-cadherin in human renal glomerular endothelial cells. In addition, DHA inhibited TGF-ß RI-Smad2/3 signalling and its downstream effectors SNAIL and SLUG, which repress VE-cadherin gene transcription. Correspondingly, DHA decreased the binding of SNAIL and SLUG to the VE-cadherin promoter. Together, our results suggest an effect of DHA in regulating glomerular permeability by elevation of VE-cadherin expression.

Effects of VEGF-ANG-1-PLA nano-sustained release microspheres on proliferation and differentiation of ADSCs.

The improvement of fat graft viability might depend on the presence of multipotent resident adipose derived stem cells (ADSCs) which is the important component of stromal vascular fraction (SVF). Vascular endothelial growth factor (VEGF) and angiogenin-1 (Ang-1) are responsible for neovascularization. However, their half-life is too short to produce a biological effect. We thus investigated whether VEGF-ANG-1-polylactic acid (PLA) microspheres could enhance the angiogenic properties of ADSCs. PLA microspheres containing VEGF and ANG-1 were prepared by in vitro ultrasonic emulsification and characterized according to their encapsulation efficiency (EE), drug-loading rate (DL), particle size, and drug release. The systemic toxicity of empty loaded nanospheres (NPs) and the ability of these microspheres to promote the proliferation and differentiation of ADSCs were evaluated. The EE and DL were above 86% and 0.0288%, respectively [corrected].The drug release was completed after 20 days. Systemic toxicity was verified in ADSCs that received the unloaded NPs. It was observed that ADSCs treated with VEGF-ANG-1-PLA microspheres had an increase in the proliferation and the number of CD31 positive cells. ADSCs proliferation and differentiation toward endothelial cells (ECs) could be enhanced by the addition of VEGF-ANG-1-PLA nano-sustained release microspheres.

Rapamycin Promotes the Survival and Adipogenesis of Ischemia-Challenged Adipose Derived Stem Cells by Improving Autophagy.

BACKGROUND/AIMS: Ischemia is one of the main causes of the high rate of absorption of transplanted autologous fat. Autophagy allows cells to survive by providing energy under starvation. Rapamycin has been found to play a role in promoting autophagy. In this study, we investigated whether rapamycin participates in the survival and adipogenesis of ischemia-challenged adipose-derived stem cells (ADSCs) by regulating autophagy. METHODS: Before the cells were exposed to oxygen-glucose deprivation (OGD), a simulated ischemic microenvironment, the level of autophagy was reduced or increased by lentiviral transfection with short hairpin RNA targeting microtubule-associated protein 1-light chain 3 gene (shRNA-LC3) or treatment with rapamycin, respectively. The level of autophagy was assessed by western blotting, transmission electron microscopythen the apoptosis ratio was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and flow cytometry. Adipogenesis was further evaluated by oil red O staining and the expressions level of some specific proteins for adipocytes. RESULTS: shRNA-LC3 and rapamycin treatment effectively decreased and improved the level of autophagy in cells with or without OGD challenge, respectively. In addition, autophagy inhibition increased the apoptosis rate and activated caspase-3 expression level in response to OGD, and these were markedly inhibited by rapamycin preconditioning. During adipogenesis, autophagy inhibition decreased not only oil droplet accumulation but also lipoprotein lipase (LPL) and peroxisome proliferator-activated receptor gamma (PPARγ) expression in cells with or without OGD challenge. However, autophagy promotion by rapamycin increased oil droplet accumulation and LPL and PPARγ expression. CONCLUSIONS: Rapamycin may promote the survival and adipogenesis of ischemia-challenged ADSCs by upregulating autophagy.

TaGW2-6A allelic variation contributes to grain size possibly by regulating the expression of cytokinins and starch-related genes in wheat.

MAIN CONCLUSION: Functional allelic variants of TaGW2 - 6A produce large grains, possibly via changes in endosperm cells and dry matter by regulating the expression of cytokinins and starch-related genes via the ubiquitin-proteasome system. In wheat, TaGW2-6A coding region allelic variants are closely related to the grain width and weight, but how this region affects grain development has not been fully elucidated; thus, we explored its influence on grain development based mainly on histological and grain filling analyses. We found that the insertion type (NIL31) TaGW2-6A allelic variants exhibited increases in cell numbers and cell size, thereby resulting in a larger (wider) grain size with an accelerated grain milk filling rate, and increases in grain width and weight. We also found that cytokinin (CK) synthesis genes and key starch biosynthesis enzyme AGPase genes were significantly upregulated in the TaGW2-6A allelic variants, while CK degradation genes and starch biosynthesis-negative regulators were downregulated in the TaGW2-6A allelic variants, which was consistent with the changes in cells and grain filling. Thus, we speculate that TaGW2-6A allelic variants are linked with CK signaling, but they also influence the accumulation of starch by regulating the expression of related genes via the ubiquitin-proteasome system to control the grain size and grain weight.

Short-term, low-dose cadmium exposure induces hyperpermeability in human renal glomerular endothelial cells.

The kidney is the principal organ targeted by exposure to cadmium (Cd), a well-known toxic metal. Even at a low level, Cd damages glomerular filtration. However, little is known about the effects of Cd on the glomerular endothelium, which performs the filtration function and directly interacts with Cd in blood plasma. In this study, we cultured human renal glomerular endothelial cells (HRGECs) in the presence of serum with treatment of a short term (1 h) and low concentration (1 µm) of Cd, which mimics the pattern of glomerular endothelium exposure to Cd in vivo. We found that this short-term, low-dose Cd exposure does not induce cytotoxicity, but increases permeability in HRGECs monolayers and redistributes adherens junction proteins vascular endothelial-cadherin and ß-catenin. Though short-term, low-dose Cd exposure activates all three major mitogen activated protein kinases, only the inhibitor of p38 mitogen activated protein kinase partially prevents Cd-induced hyperpermeability in HRGECs. Our data indicate that the presence of Cd in blood circulation might directly disrupt the glomerular endothelial cell barrier and contribute to the development of clinical symptoms of glomerular diseases.