Nitrogen inhibition of nitrogenase activity involves the modulation of cytosolic invertase in soybean nodule.

Legume symbiotic nitrogen fixation (SNF) is suppressed by inorganic N in the soil. High N inhibition of nitrogenase activity is associated with the deprivation of carbon allocation and metabolism in nodules. However, the underlying molecular mechanisms remain unclear. Here, we identify GmCIN1 which encodes a cytosolic invertase, as a gateway for the N-tuning of sucrose utilization in nodules. GmCIN1 is enriched in mature soybean nodules and its expression is regulated by nitrogen status. The knockout of GmCIN1 using genome editing partially mimicks the inhibitory effects of N on nitrogenase activity and sugar content and the impact of high N on nodule transcriptomes. This indicates that GmCIN1 partially mediates the high N inhibition of nodule activity. Moreover, ChIP-qPCR and EMSA reveal that SNAP1/2 transcription factors directly bind to the GmCIN1 promoter. In addition, SNAP1/2 may be involved in the repression of GmCIN1 expression in mature nodules at high N concentrations. Our findings provide insights into the involvement of the transcriptional tuning of C metabolism genes by N-signaling modulators in the N-induced inhibition of nitrogenase activity.

The copper transporter, SLC31A1, transcriptionally activated by ELF3, imbalances copper homeostasis to exacerbate cisplatin-induced acute kidney injury through mitochondrial dysfunction.

Acute kidney injury (AKI) is a common complication of cisplatin chemotherapy, which greatly limits its clinical effect and application. This study explored the function of solute Carrier Family 31 Member 1 (SLC31A1) in cisplatin-induced AKI and its possible mechanism. Mice and HK-2 cells were exposed to cisplatin to establish the in vivo and in vitro AKI models. Cell viability was detected by CCK-8. Mitochondrial and oxidative damage was determined by Mito-Tracker Green staining, mtROS level, ATP production, mitochondrial membrane potential, MDA content and CAT activity. AKI was evaluated by renal function and histopathological changes. Apoptosis was detected by TUNEL and caspase-3 expression. Molecule expression was measured by RT-qPCR, Western blotting, and immunohistochemistry. Molecular mechanism was studied by luciferase reporter assay and ChIP. SLC31A1 level was predominantly increased by cisplatin exposure in AKI models. Notably, copper ion (Cu+) level was enhanced by cisplatin challenge. Moreover, Cu+ supplementation intensified cisplatin-induced cell death, mitochondrial dysfunction, and oxidative stress in HK-2 cells, indicating the involvement of cuproptosis in cisplatin-induced AKI, whereas these changes were partially counteracted by SLC31A1 knockdown. E74 like ETS transcription factor 3 (ELF3) could directly bind to SLC31A1 promoter and promote its transcription. ELF3 was up-regulated and positively correlated with SLC31A1 expression upon cisplatin-induced AKI. SLC31A1 silencing restored renal function, alleviated mitochondrial dysfunction, and apoptosis in cisplatin-induced AKI mice. ELF3 transcriptionally activated SLC31A1 to trigger cuproptosis that drove cisplatin-induced AKI through mitochondrial dysfunction, indicating that SLC31A1 might be a promising therapeutic target to mitigate AKI during cisplatin chemotherapy.

Risk model for predicting mortality in patients with necrotizing soft tissue infections in the intensive care unit.

BACKGROUND: The goal of this study is to look into the factors that lead to death in patients with necrotizing soft tissue infections（NSTIs） in the intensive care unit and create a mortality risk model. METHODS: The clinical data of 106 patients with necrotizing soft tissue infections admitted to intensive care unit(ICU) of the First Affiliated Hospital of Wenzhou Medical University between January 2008 and December 2021 were retrospectively analyzed. Univariate analysis and multivariate analysis were performed to evaluate the risk factors impacting patient mortality. The regression coefficient in binary logistic regression analysis was converted into the item score in the model, and then the model score of each patient was calculated. Finally, an ROC curve was constructed to evaluate the efficiency of the model for predicting mortality. Thirteen patients with NSTIs admitted to ICU between January 2022 and November 2022 were used to validate the model. RESULTS: The death group had 44 patients, while the survival group had 62 patients. The overall mortality was 41.5%. Binary logistic regression analysis showed that risk factors for mortality were age≥ 60 years(OR:4.419; 95%CI:1.093-17.862; P = 0.037), creatinine ≥ 132µmol/L(OR:11.166; 95%CI:2.234-55.816; P = 0.003), creatine kinase ≥ 1104 U/L(OR:4.019; 95%CI:1.134-14.250; P = 0.031), prothrombin time ≥ 24.4 s(OR:11.589; 95%CI:2.510-53.506; P = 0.002), and invasive mechanical ventilation (OR:17.404; 95%CI:4.586-66.052; P＜0.000). The AUC of the model for predicting mortality was 0.940 (95% CI:0.894-0.986). When the cut-off value for the model was 4 points, the sensitivity was 95.5% and the specificity was 83.9%. CONCLUSION: The death risk model in this study for NSTIs patients in the intensive care unit shows high sensitivity and specificity. Patients with a score of ≥ 4 points have a higher risk of mortality.

Memory effect of spider major ampullate silk in loading-unloading cycles and the structural connotations.

Spider silk is repeatedly stretched while performing biological functions. There is a close relationship between the shape change of the fibre materials and their mechanical properties. However, the effect of the deformation and interval time on the structure and tensile behaviour properties of spider silk after repeatedly stretching by given strain value has been rarely reported. Here we found that major ampullate silk (MAS) can revert its tensile behaviour independent of its previous loading history via intervals of approximately 8 s to 5 min with constant and increased elongation, respectively, after being subjected to yield and hardening regions. The true stress-true strain curve beyond a given value of true strain is independent from the previous loading history of the sample. Even after longer intervals (≥1 h), MAS can reproduce the last tensile behaviour via one stretched. Despite recognizing the development of irreversible deformations in the material when tested in air, the reversible change in tensile behaviour outside the spider silk's elastic region has rarely been observed before. MAS has at least one proper ground state that allows it to present good shape and mechanical behaviour memory in terms of longitudinal stretching, functioning as a new strategy to achieve certain tensile properties. The analysis of the true stress-true strain curves was performed from a series of loading‒unloading tests to evaluate the evolution of those mechanical parameters with the cycle number. The elastic modulus measured in the loading steps increases monotonously with increasing values of true strain reached in the cycles. In contrast, a marginal variation is found in the values of the yield stress measured in the different cycles. The memory and variation in the mechanical behaviour and performance of MAS can be accounted for through the irreversible and reversible deformation micromechanisms and its combination in which the viscoelasticity of the material plays a leading role. These findings may be helpful to guide the biomimetic design of novel fibre materials such as spider silk gut via artificially stretching spider silk glands.

The NAC transcription factors SNAP1/2/3/4 are central regulators mediating high nitrogen responses in mature nodules of soybean.

Legumes can utilize atmospheric nitrogen via symbiotic nitrogen fixation, but this process is inhibited by high soil inorganic nitrogen. So far, how high nitrogen inhibits N2 fixation in mature nodules is still poorly understood. Here we construct a co-expression network in soybean nodule and find that a dynamic and reversible transcriptional network underlies the high N inhibition of N2 fixation. Intriguingly, several NAC transcription factors (TFs), designated as Soybean Nitrogen Associated NAPs (SNAPs), are amongst the most connected hub TFs. The nodules of snap1/2/3/4 quadruple mutants show less sensitivity to the high nitrogen inhibition of nitrogenase activity and acceleration of senescence. Integrative analysis shows that these SNAP TFs largely influence the high nitrogen transcriptional response through direct regulation of a subnetwork of senescence-associated genes and transcriptional regulators. We propose that the SNAP-mediated transcriptional network may trigger nodule senescence in response to high nitrogen.

Administration of protopine prevents mitophagy and acute lung injury in sepsis.

Introduction: Sepsis is a severe life-threatening infection that induces a series of dysregulated physiologic responses and results in organ dysfunction. Acute lung injury (ALI), the primary cause of respiratory failure brought on by sepsis, does not have a specific therapy. Protopine (PTP) is an alkaloid with antiinflammatory and antioxidant properties. However, the function of PTP in septic ALI has not yet been documented. This work sought to investigate how PTP affected septic ALI and the mechanisms involved in septic lung damage, including inflammation, oxidative stress, apoptosis, and mitophagy. Methods: Here, we established a mouse model induced by cecal ligation and puncture (CLP) and a BEAS-2B cell model exposed to lipopolysaccharide (LPS). Results: PTP treatment significantly reduced mortality in CLP mice. PTP mitigated lung damage and reduced apoptosis. Western blot analysis showed that PTP dramatically reduced the expression of the apoptosis-associated protein (Cleaved Caspase-3, Cyto C) and increased Bcl-2/Bax. In addition, PTP decreased the production of inflammatory cytokines (IL-6, IL-1ß, TNF-α), increased glutathione (GSH) levels and superoxide dismutase (SOD) activity, and decreased malondialdehyde (MDA) levels. Meanwhile, PTP significantly reduced the expression of mitophagy-related proteins (PINK1, Parkin, LC-II), and downregulated mitophagy by transmission electron microscopy. Additionally, the cells were consistent with animal experiments. Discussion: PTP intervention reduced inflammatory responses, oxidative stress, and apoptosis, restored mitochondrial membrane potential, and downregulated mitophagy. The research shows that PTP prevents excessivemitophagy and ALI in sepsis, suggesting that PTP has a potential role in the therapy of sepsis.

Glabridin Therapy Reduces Chronic Allodynia, Spinal Microgliosis, and Dendritic Spine Generation by Inhibiting Fractalkine-CX3CR1 Signaling in a Mouse Model of Tibial Fractures.

Patients undergoing bone fractures frequently suffer from irritating chronic pain after orthopedic repairs. Chemokine-mediated interactions between neurons and microglia are important steps for neuroinflammation and excitatory synaptic plasticity during the spinal transmission of pathological pain. Recently, glabridin, the main bioactive component of licorice, has been shown to exhibit anti-nociceptive and neuroprotective properties for inflammatory pain. This present study evaluated the therapeutic potential of glabridin and its analgesic mechanisms using a mouse model of tibial fracture-associated chronic pain. Repetitive injections of glabridin were delivered spinally daily for 4 continuous days from days 3 to 6 after the fractures. Herein, we discovered that repeated administrations of glabridin (10 and 50 µg, but not 1 µg) could prevent prolonged cold allodynia and mechanical allodynia following bone fractures. A single intrathecal intervention with glabridin (50 µg) relieved an existing chronic allodynia two weeks following the fracture surgeries. Systemic therapies with glabridin (intraperitoneal; 50 mg kg-1) were protective against long-lasting allodynia caused by fractures. Furthermore, glabridin restricted the fracture-caused spinal overexpressions of the chemokine fractalkine and its receptor CX3CR1, as well as the elevated number of microglial cells and dendritic spines. Strikingly, glabridin induced the inhibition of pain behaviors, microgliosis, and spine generation, which were abolished with the co-administration of exogenous fractalkine. Meanwhile, the exogenous fractalkine-evoked acute pain was compensated after microglia inhibition. Additionally, spinal neutralization of fractalkine/CX3CR1 signaling alleviated the intensity of postoperative allodynia after tibial fractures. These key findings identify that glabridin therapies confer protection against inducing and sustaining fracture-elicited chronic allodynia by suppressing fractalkine/CX3CR1-dependent spinal microgliosis and spine morphogenesis, suggesting that glabridin is a promising candidate in the translational development of chronic fracture pain control.

Variation in the Elastic Modulus and Increased Energy Dissipation Induced by Cyclic Straining of Argiope bruennichi Major Ampullate Gland Silk.

The trends exhibited by the parameters that describe the mechanical behaviour of major ampullate gland silk fibers spun by Argiope bruennichi spiders is explored by performing a series of loading-unloading tests at increasing values of strain, and by the subsequent analysis of the true stress-true strain curves obtained from these cycles. The elastic modulus, yields stress, energy absorbed, and energy dissipated in each cycle are computed in order to evaluate the evolution of these mechanical parameters with this cyclic straining. The elastic modulus is observed to increase steadily under these loading conditions, while only a moderate variation is found in the yield stress. It is also observed that a significant proportion of the energy initially absorbed in each cycle is not only dissipated, but that the material may recover partially from the associated irreversible deformation. This variation in the mechanical performance of spider silk is accounted for through a combination of irreversible and reversible deformation micromechanisms in which the viscoelasticity of the material plays a leading role.

PINK1 protects against dendritic cell dysfunction during sepsis through the regulation of mitochondrial quality control.

BACKGROUND: Dendritic cell (DC) dysfunction plays a central role in sepsis-induced immunosuppression. Recent research has indicated that collective mitochondrial fragmentation contributes to the dysfunction of immune cells observed during sepsis. PTEN-induced putative kinase 1 (PINK1) has been characterized as a guide for impaired mitochondria that can keep mitochondrial homeostasis. However, its role in the function of DCs during sepsis and the related mechanisms remain obscure. In our study, we elucidated the effect of PINK1 on DC function during sepsis and its underlying mechanism of action. METHODS: Cecal ligation and puncture (CLP) surgery and lipopolysaccharide (LPS) treatment were used as in vivo and in vitro sepsis models, respectively. RESULTS: We found that changes in mitochondrial PINK1 expression of DCs paralleled changes in DC function during sepsis. The ratio of DCs expressing MHC-II, CD86, and CD80, the mRNAs level of dendritic cells expressing TNF-α and IL-12, and the level of DC-mediated T-cell proliferation were all decreased, both in vivo and in vitro during sepsis, when PINK1 was knocked out. This suggested that PINK1 knockout prevented the function of DCs during sepsis. Furthermore, PINK1 knockout inhibited Parkin RBR E3 ubiquitin protein (Parkin)-dependent mitophagy and enhanced dynamin-related protein 1 (Drp1)-related mitochondrial fission, and the negative effects of PINK1 knockout on DC function following LPS treatment were reversed by Parkin activation and Drp1 inhibitor. Knockout of PINK1 also increased apoptosis of DCs and the mortality of CLP mice. CONCLUSION: Our results indicated that PINK1 protected against DC dysfunction during sepsis through the regulation of mitochondrial quality control.

Efficacy of DC-CIK-based immunotherapy combined with chemotherapy in the treatment of intermediate to advanced non-small cell lung cancer.

OBJECTIVE: To evaluate the efficacy of dendritic cell-cytokine-induced killer cell (DC-CIK)-based immunotherapy combined with chemotherapy in the treatment of intermediate to advanced non-small cell lung cancer (NSCLC) and its effect on the levels of serum carbohydrate antigen 199 (CA199), matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). METHODS: Sixty patients with intermediate to advanced NSCLC who were treated in the Department of Oncology of Jiangxi Cancer Hospital from January to June 2016 were grouped according to a randomized double-blind method, including the control group (CG, n=30) receiving a routine chemotherapy regimen and the experimental group (EG, n=30) receiving DC-CIK immunotherapy plus a routine chemotherapy regimen. The treatment efficacy, major adverse reactions, immune function, level of cytokines in peripheral blood, serum tumor markers and CA-199, MMP-9, TIMP-1 and vascular endothelial growth factor (VEGF) levels were compared between the two groups. RESULTS: The overall cancer control rate of treatment in the EG (70.00%) was slightly higher than that in the CG (56.67%) (P > 0.05). The peripheral blood CD4+ and natural killer (NK) cell levels in the EG after treatment were higher than those in the CG, while interleukin-4 (IL-4), interferon-γ (IFN-γ), transforming growth factor-ß (TGF-ß), tumor necrosis factor-α (TNF-α), CA199, carbohydrate antigen 125 (CA125), CYFRA211, carcinoembryonic antigen (CEA), MMP-9, TIMP-1, and VEGF levels in the EG were lower than those in the CG (P < 0.05). CONCLUSION: DC-CIK immunotherapy combined with routine chemotherapy in the treatment of intermediate to advanced NSCLC had significant efficacy in enhancing patients' cellular immune function, reducing the inflammatory response, regulating tumor marker levels, and inhibiting tumor invasion and metastasis, without increasing adverse reactions.

The complete chloroplast genome sequence of the mangrove associate species Talipariti tiliaceum.

Talipariti tiliaceum is an evergreen mangrove associate species distributed throughout the world. In this study, the complete chloroplast genome sequence of T. tiliaceum was assembled and characterized using high-throughput sequencing data. The chloroplast genome was found to be 161 766 bp in length, consisting of large single-copy (LSC) and small single-copy (SSC) regions of 89 273 and 19 551 bp, respectively, which were separated by a pair of 26 471 bp inverted repeat (IR) regions. The genome contained 129 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. A phylogenetic tree including 66 chloroplast genomes from various species revealed that T. tiliaceum was most related to T. hamabo of the same genus.

Hsa_circ_0001982 promotes the progression of breast cancer through miR-1287-5p/MUC19 axis under hypoxia.

BACKGROUND: Breast cancer (BC) is the most commonly malignant tumor among women worldwide. Many studies have reported that circular RNAs (circRNAs) were participated in the regulation of multiple cancers development. However, the mechanism underlying hsa_circ_0001982 in breast cancer development is still unclear. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the levels of circ_0001982, microRNA-1287-5p (miR-1287-5p), and mucin 19 (MUC19) in BC tissues and cells under hypoxia. Moreover, glycolysis was evaluated by glucose consumption, lactic acid production, and hexokinase II (HK2) protein levels. The protein levels of cyclin D1, proliferating cell nuclear antigen (PCNA), and HK2 were determined by western blot assay. Cell proliferation, migration, and invasion were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-h-tetrazolium bromide (MTT) and transwell assays, respectively. The relationship between miR-1287-5p and circ_0001982 or MUC19 was predicted using starbase v3.0 or Targetscan, and verified by dual-luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay. The xenograft model in nude mice was established to examine the effect of circ_0001982 in vivo. RESULTS: The levels of circ_0001982 and MUC19 were upregulated, while miR-1287-5p was downregulated in BC tissues and cells under hypoxia. Knockdown of circ_0001982 hindered glycolysis, cell viability, migration, and invasion of BC cells under hypoxia. Mechanistic studies discovered that circ_0001982 could act as a sponge for miR-1287-5p to enhance MUC19 expression in BC cells. In addition, circ_0001982 silencing reduced xenograft tumor growth by regulating miR-1287-5p/MUC19 axis. CONCLUSION: Circ_0001982 affected BC cells glycolysis, proliferation, migration, and invasion through miR-1287-5p/MUC19 axis under hypoxia.

LncRNA TTN-AS1 sponges miR-376a-3p to promote colorectal cancer progression via upregulating KLF15.

AIMS: Long non-coding RNAs (lncRNAs) play key roles in regulating multiple cancers. TTN-AS1 was reported to function in several human malignancies. However, the biological function of TTN-AS1 in colorectal cancer (CRC) has not been explored. In this study, we aimed to investigate the role and the underlying mechanisms of TTN-AS1 in CRC progression. MAIN METHODS: RT-qPCR was used to detect the expression levels of TTN-AS1, miR-376a-3p and KLF15 in colorectal cancer tissues and cells. CCK-8, colony formation, flow cytometry and transwell assays were performed to determine the cell proliferation, apoptotic rate and invasion ability. Target genes were predicted using bioinformatics methods. si-RNA and miRNA inhibitor were transfected into CRC cells to explore the underlying mechanisms. Tumor xenografts were created to confirm the function of TTN-AS-1 in vivo. KEY FINDINGS: TTN-AS1 upregulation was observed both in CRC tissues and cell lines. Functional investigation showed that knockdown of TTN-AS1 inhibited CRC cell proliferation and invasion, while enhanced cell apoptosis. Bioinformatics analysis identified miR-376a-3p as a target of TTN-AS1. Transfection of miR-376a-3p inhibitor mitigated the alterations induced by TTN-AS1 knockdown. Moreover, TTN-AS1 positively regulated KLF15 via sponging miR-376a-3p. Additionally, these findings were supported by in vivo experiments. SIGNIFICANCE: In conclusions, TTN-AS1 promoted CRC proliferation and invasion through miR-376a-3p/KLF15 axis. Our findings suggested that TTN-AS1 might be a potential therapeutic target in CRC treatment.

Combining solar irradiation with chlorination enhances the photochemical decomposition of microcystin-LR.

Microcystin-LR (MC-LR) generated by cyanobacteria is a potent toxin threatening human health. In this study the kinetics and mechanisms of MC-LR elimination from drinking water under solar irradiation with free chlorine (the solar/chlorine process) was evaluated. The rate of MC-LR degradation was dramatically enhanced in the solar/chlorine process (1.1 × 10-2 s-1) compared with chlorination alone (2.6 × 10-3 s-1) or solar irradiation alone (1.2 × 10-4 s-1) with a free chlorine dose of 42 µM (3.0 mg L-1 as Cl2). The enhancement was due to the presence of hydroxyl radicals, reactive chlorine species (RCS), and ozone during free chlorine photolysis. The second-order rate constants of Cl • and Cl2•- reacting with MC-LR were determined to be (2.25 ±â€¯0.07) × 1010 and (5.58 ±â€¯0.42) × 107 M-1s-1, respectively. Cl • was the major RCS contributing to MC-LR elimination. The highest MC-LR degradation rate was observed at pH 8.0. Free chlorine, HO •, Cl • and O3 together accounted for almost 95% of the MC-LR elimination. Hydroxyl- and chloro-MC-LR were generated in the process, followed by dechlorination, dehydration and cleavage of cyclic structures in MC-LR. Aldehyde- and ketone-MC-LR byproducts were also observed. The destruction of dienes led to a great reduction in MC-LR's toxicity. MC-LR removal in natural water samples under natural sunlight irradiation with free chlorine was demonstrated with limited formation of disinfection byproducts. The solar/chlorine process is an energy-efficient approach for MC-LR control, especially suitable for rural areas or where algal blooming threatens.

Pooled CRISPR/Cas9 reveals redundant roles of plastidial phosphoglycerate kinases in carbon fixation and metabolism.

Phosphoglycerate kinase (PGK) is a highly conserved reversible enzyme that participates in both glycolysis and photosynthesis. In Arabidopsis thaliana, one cytosolic PGK (PGKc) and two plastidial PGKs (PGKp) are known. It remains debatable whether the two PGKp isozymes are functionally redundant or specialized in plastidial carbon metabolism and fixation. Here, using a pooled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) strategy, we found that plants with single mutations in pgkp1 or pgkp2 were not significantly affected, whereas a pgkp1pgkp2 double mutation was lethal due to retarded carbon fixation, suggesting that PGKp isozymes play redundant functional roles. Metabolomic analysis demonstrated that the sugar-deficient pgkp1pgkp2 double mutation was partially complemented by exogenous sugar, although respiration intermediates were not rescued. Chloroplast development was defective in pgkp1pgkp2, due to a deficiency in glycolysis-dependent galactoglycerolipid biosynthesis. Ectopic expression of a plastid targeting PGKc did not reverse the pgkp1pgkp2 double-mutant phenotypes. Therefore, PGKp1 and PGKp2 play redundant roles in carbon fixation and metabolism, whereas the molecular function of PGKc is more divergent. Our study demonstrated the functional conservation and divergence of glycolytic enzymes.

CCL2 influences the sensitivity of lung cancer A549 cells to docetaxel.

Lung cancer is one of the most common malignant tumor types globally. Acquisition of chemoresistance in lung cancer cells is the primary cause of chemotherapy failure. Inflammatory chemokine C-C motif chemokine ligand 2 (CCL2) has been reported to be involved in the progression of cancer and drug resistance. However, its function in docetaxel (DTX) resistance of lung cancer remains unclear. In the present study, the mechanism underlying DTX-induced drug resistance was investigated. Reverse transcription-quantitative polymerase chain reaction and western blot analysis revealed that DTX treatment increased the mRNA and protein expression of CCL2 in lung cancer A549 cells. CCL2 was knocked down by small interfering RNA or was overexpressed by recombinant CCL2 lentivirus, and cell viability was determined. An MTT assay indicated that CCL2 downregulation decreased the viability of A549 cells and augmented the DTX-induced cytotoxicity, whereas CCL2 upregulation protected A549 cells from DTX-induced cytotoxicity. Additionally, it was revealed that CCL2 overexpression activated phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling and inhibited apoptosis-associated protein caspase-3 activation and B-cell lymphoma 2 (Bcl-2) phosphorylation at Ser70 induced by DTX, and enhanced DTX-induced Bcl-2-associated death promoter phosphorylation at Ser112. PI3K/AKT inhibitor LY294002 restored DTX-induced caspase-3 activation and Bcl-2 phosphorylation, reversed the effect of CCL2 on the viability of A549 cells and enhanced DTX-induced cytotoxicity. These results demonstrated that chemoresistance may be mediated by cell stress responses involving CCL2 expression, suggesting that CCL2 may be a potential target for enhancing the therapeutic effect of DTX in lung cancer.

Proteomic approach reveals that starch degradation contributes to anthocyanin accumulation in tuberous root of purple sweet potato.

UNLABELLED: A comparative proteomic approach was carried out to investigate anthocyanin biosynthesis in the tuberous roots of yellow sweet potato (YSP) and purple sweet potato (PSP) cultivars. More than 800 proteins were reproducibly detected through two-dimensional electrophoresis (2-DE), of which 50 proteins with 39 more and 11 less accumulated in PSP were identified through matrix-assisted laser desorption ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF-MS). Most of the analyzed proteins are annotated to be involved in starch metabolism and glycolysis. The more abundant starch phosphorylase (SP) and phosphoglucomutase (PGM) in PSP promoted the synthesis of precursors for anthocyanin synthesis. The results implied that starch degradation provided abundant substrates for anthocyanin biosynthesis in tuberous roots of PSP. 24kDa vacuolar protein (VP24) is related to anthocyanin transport and accumulation in vacuoles. Vacuole-associated annexin protein, VCaB42, is correlated with tonoplast biogenesis. Synergistic action of the two proteins is probably involved in the microautophagy and the intravacuolar trapping of anthocyanins. Interestingly, both VCaB42 and VP24 were more accumulated in PSP, suggesting that anthocyanins generated in the cytosol were transported into and became stored in the vacuoles of PSP. The present study provides new insights into the mechanism of tuberous root-specific anthocyanin accumulation in PSP. BIOLOGICAL SIGNIFICANCE: Sweet potato ranks as the seventh most important crop worldwide. Purple sweet potato, a special sweet potato cultivar, has been extensively investigated because large amounts of anthocyanin accumulate in its tuberous roots. Anthocyanin is well known for its free radical-scavenging activity and beneficial effects on human health. Its biosynthetic pathway has been well characterized in model plants. Although large-scale systematic studies have been performed to identify the proteins present in sweet potato, information on the regulation of anthocyanin synthesis in sweet potato is insufficient. Our proteome study demonstrated that starch degradation may contribute to anthocyanin accumulation in purple sweet potato. To our knowledge, this study is the first to propose that starch degradation may provide precursors of anthocyanin biosynthesis in sweet potato.