The transcription factor PagLBD3 contributes to the regulation of secondary growth in Populus.

LATERAL ORGAN BOUNDARIES DOMAIN (LBD) genes encode plant-specific transcription factors that participate in regulating various developmental processes. In this study, we genetically characterized PagLBD3 encoding an important regulator of secondary growth in poplar (Populus alba × Populus glandulosa). Overexpression of PagLBD3 increased stem secondary growth in Populus with a significantly higher rate of cambial cell differentiation into phloem, while dominant repression of PagLBD3 significantly decreased the rate of cambial cell differentiation into phloem. Furthermore, we identified 1756 PagLBD3 genome-wide putative direct target genes (DTGs) through RNA sequencing (RNA-seq)-coupled DNA affinity purification followed by sequencing (DAP-seq) assays. Gene Ontology analysis revealed that genes regulated by PagLBD3 were enriched in biological pathways regulating meristem development, xylem development, and auxin transport. Several central regulator genes for vascular development, including PHLOEM INTERCALATED WITH XYLEM (PXY), WUSCHEL RELATED HOMEOBOX4 (WOX4), Secondary Wall-Associated NAC Domain 1s (SND1-B2), and Vascular-Related NAC-Domain 6s (VND6-B1), were identified as PagLBD3 DTGs. Together, our results indicate that PagLBD3 and its DTGs form a complex transcriptional network to modulate cambium activity and phloem/xylem differentiation.

Genome-wide transcriptional adaptation to salt stress in Populus.

BACKGROUND: Adaptation to abiotic stresses is crucial for the survival of perennial plants in a natural environment. However, very little is known about the underlying mechanisms. Here, we adopted a liquid culture system to investigate plant adaptation to repeated salt stress in Populus trees. RESULTS: We first evaluated phenotypic responses and found that plants exhibit better stress tolerance after pre-treatment of salt stress. Time-course RNA sequencing (RNA-seq) was then performed to profile changes in gene expression over 12 h of salt treatments. Analysis of differentially expressed genes (DEGs) indicated that significant transcriptional reprogramming and adaptation to repeated salt treatment occurred. Clustering analysis identified two modules of co-expressed genes that were potentially critical for repeated salt stress adaptation, and one key module for salt stress response in general. Gene Ontology (GO) enrichment analysis identified pathways including hormone signaling, cell wall biosynthesis and modification, negative regulation of growth, and epigenetic regulation to be highly enriched in these gene modules. CONCLUSIONS: This study illustrates phenotypic and transcriptional adaptation of Populus trees to salt stress, revealing novel gene modules which are potentially critical for responding and adapting to salt stress.

Activation of Wnt/ß-catenin signalling is required for TGF-ß/Smad2/3 signalling during myofibroblast proliferation.

Fibrosis in animal models and human diseases is associated with aberrant activation of the Wnt/ß-catenin pathway. Despite extensive research efforts, effective therapies are still not available. Myofibroblasts are major effectors, responsible for extracellular matrix deposition. Inhibiting the proliferation of the myofibroblast is crucial for treatment of fibrosis. Proliferation of myofibroblasts can have many triggering effects that result in fibrosis. In recent years, the Wnt pathway has been studied as an underlying factor as a primary contributor to fibrotic diseases. These efforts notwithstanding, the specific mechanisms by which Wnt-mediated promotes fibrosis reaction remain obscure. The central role of the transforming growth factor-ß (TGF-ß) and myofibroblast activity in the pathogenesis of fibrosis has become generally accepted. The details of interaction between these two processes are not obvious. The present investigation was conducted to evaluate the level of sustained expression of fibrosis iconic proteins (vimentin, α-SMA and collagen I) and the TGF-ß signalling pathway that include smad2/3 and its phosphorylated form p-smad2/3. Detailed analysis of the possible molecular mechanisms mediated by ß-catenin revealed epithelial-mesenchymal transition and additionally demonstrated transitions of fibroblasts to myofibroblast cell forms, along with increased activity of ß-catenin in regulation of the signalling network, which acts to counteract autocrine TGF-ß/smad2/3 signalling. A major outcome of this study is improved insight into the mechanisms by which epithelial and mesenchymal cells activated by TGFß1-smad2/3 signalling through Wnt/ß-catenin contribute to lung fibrosis.

High-Mobility Group Box 1 Mediates Epithelial-to-Mesenchymal Transition in Pulmonary Fibrosis Involving Transforming Growth Factor-ß1/Smad2/3 Signaling.

Epithelial-to-mesenchymal transition (EMT) is a crucial event in the cellular origin of myofibroblasts that secrete extracellular matrix in the progression of pulmonary fibrosis (PF). High-mobility group box 1 (HMGB1) is a novel mediator of EMT. However, whether this process involves the recognized transforming growth factor-ß1 (TGF-ß1)/Smad signaling that also contributes to EMT in PF has not yet been elucidated. Here, we developed a model of PF induced by bleomycin (BLM) in rats and conducted several simulation experiments in A549 (human) and RLE-6TN (rat) alveolar epithelial cell (AEC) lines to unravel the role of TGF-ß1/Smad2/3 signaling in HMGB1-mediated EMT. We found that the levels of serum HMGB1 and lung hydroxyproline were severely elevated after BLM administration. Moreover, the protein expression of HMGB1, TGF-ß1, phosphorylated Smad2/3 (p-Smad2/3), and mesenchymal markers including α-smooth muscle actin, vimentin, and type I collagen were significantly increased with the reduced protein expression of an epithelial marker (E-cadherin) in the rat model by Western blot or immunohistochemical analysis. In addition, the uptake of both exogenous TGF-ß1 and HMGB1 by AECs could induce EMT; meanwhile, HMGB1 dramatically enhanced TGF-ß1 expression and triggered Smad2/3 phosphorylation. In contrast, TGF-ß1 deficiency evidently ameliorated HMGB1-mediated EMT with reduced p-Smad2/3 in A549 cells. It provides new insights that HMGB1 release from injured lungs promotes AEC damage through induction of the EMT process, in which TGF-ß1/Smad2/3 signaling is activated and contributes to PF. These results suggest that HMGB1 may constitute a therapeutic target for developing antifibrotic agents for abnormal lung remodeling.

Crosstalk of nervous and immune systems in pancreatic cancer.

Pancreatic cancer is a highly malignant tumor known for its extremely low survival rate. The combination of genetic disorders within pancreatic cells and the tumor microenvironment contributes to the emergence and progression of this devastating disease. Extensive research has shed light on the nature of the microenvironmental cells surrounding the pancreatic cancer, including peripheral nerves and immune cells. Peripheral nerves release neuropeptides that directly target pancreatic cancer cells in a paracrine manner, while immune cells play a crucial role in eliminating cancer cells that have not evaded the immune response. Recent studies have revealed the intricate interplay between the nervous and immune systems in homeostatic condition as well as in cancer development. In this review, we aim to summarize the function of nerves in pancreatic cancer, emphasizing the significance to investigate the neural-immune crosstalk during the advancement of this malignant cancer.

Parasitism and Suitability of Trichogramma chilonis on Large Eggs of Two Factitious Hosts: Samia cynthia ricini and Antheraea pernyi.

Trichogramma, an effective biological control agent, demonstrates promise in environmentally sustainable pest management through its parasitic action toward insect eggs. This study evaluates the parasitism fitness and ability of T. chilonis with regard to two factitious host eggs, aiming to develop a cost-effective biological control program. While T. chilonis demonstrated the ability to parasitize both host eggs, the results indicate a preference for ES eggs over COS eggs. The parasitism and emergence rates of T. chilonis regarding ES eggs (parasitism: 89.3%; emergence: 82.6%) surpassed those for COS eggs (parasitism: 74.7%; emergence: 68.8%), with a notable increase in the number of emergence holes observed in the ES eggs compared to the COS eggs. Moreover, the developmental time of T. chilonis for ES eggs (10.8 days) was shorter than that for COS eggs (12.5 days), resulting in a lower number of dead wasps produced. Notably, no significant difference was observed in the female ratios between the two species. A comprehensive analysis was conducted, comparing the size and shell thickness of the two factitious hosts. The ES eggs exhibited smaller dimensions (length: 1721.5 µm; width: 1178.9 µm) in comparison to the COS eggs (length: 2908.8 µm; width: 2574.4 µm), with the ES eggshells being thinner (33.8 µm) compared to the COS eggshells (47.3 µm). The different host species had an effect on the body length of the reared parasitoids, with T. chilonis reared on COS hosts exhibiting a larger body length (female: 626.9 µm; male: 556.7 µm) than those reared on ES hosts (female: 578.8 µm; male: 438.4 µm). Conclusively, the results indicate that ES eggs present a viable alternative to COS eggs for the mass production of Trichogramma species in biological control programs.

Comparison of liposome-polycation-DNA(LPD) and monophosphoryl lipid A(MPL) adjuvant formulations in BALB/c mice models.

It is of fundamental importance to use an appropriate adjuvant to generate a potent immune response for immunotherapy. In this study, we had a comparative investigation on the effectiveness of two adjuvant formulations, liposome-polycation-DNA (LPD) and monophosphoryl lipid A(MPL) in combination with a truncated peptide of bFGF(tbFGF) as antigen. LPD/tbFGF induced continuously increasing antibodies expression during the whole immunization period. In contrast, the level of antibodies was variable in MPL/tbFGF-immunized mice, MPL/tbFGF elicited potent antibodies response in the early-phase of immunization (during the first 3 immunizations), but the later immunizations did not produce a significant increase in the level of antibodies. Evaluation of IFN-γ and IL-4 responses revealed that both LPD/tbFGF and MPL/tbFGF demonstrated generation of higher level of IFN-γ, whereas no significant increase in IL-4 levels was detected in the two groups. In addition, histological analysis exhibited obvious germinal centers in the spleen tissues of LPD/tbFGF mice. The data suggested that LPD would be a promising long-effective adjuvant due to its potent and persistent immunostimulation and MPL could play an appropriate role in short-acting immunization.

Immobilization of R-ω-transaminase on MnO2 nanorods for catalyzing the conversion of (R)-1-phenylethylamine.

R-É·-transaminases transfer an amino group from an amino donor (e.g. (R)-1-phenylethylamine) onto an amino acceptor (e.g. pyruvate), resulting a co-product (e.g. d-alanine). This work intends to immobilize R-É·-Transaminase on MnO2 nanorods to achieve multienzyme catalysis. R-É·-Transaminase (RTA) and d-amino acid oxidase (DAAO) have been fused to an elastin-like polypeptide (ELP) separately through genetic engineering of the enzymes. ELP-RTA and ELP-DAAO have been separately immobilized on polydopamine-coated MnO2 nanorods. When the two immobilized enzymes were used together in one pot, the transformation of (R)-1-phenylethylamine was catalyzed by the immobilized ELP-RTA, and the co-product d-alanine was converted back to pyruvate under the catalysis of the immobilized ELP-DAAO, achieving the recycling of pyruvate in situ. Thus pyruvate was maintained at a low concentration in order to reduce its negative effect. On the other hand, the generated H2O2 of ELP-DAAO was decomposed by the MnO2 nanorods, and the evolved oxygen oxidized the reduced cofactors of ELP-DAAO. Forming the circles of hydrogen peroxide→oxygen→hydrogen peroxide accelerated the deamination reaction. The highly efficient conversion of the co-product d-alanine back to pyruvate accelerated the forming of the pyruvate→d-alanine→pyruvate cycle between the two immobilized enzymes. The coordination of the pyruvate→d-alanine→pyruvate and hydrogen peroxide→oxygen→hydrogen peroxide cycles accelerated the transformation of (R)-1-phenylethylamine. As a result, As a result, the immobilized enzymes achieved a conversion of 98±1.8% in comparison to 69.6±1.2% by free enzymes.

Astragaloside IV Improves Bleomycin-Induced Pulmonary Fibrosis in Rats by Attenuating Extracellular Matrix Deposition.

Pulmonary fibrosis is a devastating lung disorder with mysterious pathogenesis and limited treatment options. It is well-recognized that the uncontrolled proliferation of lung fibroblasts and differentiation of fibroblasts into myofibroblasts excessively produce extracellular matrix (ECM) proteins which contribute to the fibrosis change of the lungs. Thus, blocking ECM accumulation would delay fibrosis progression. In this study, we observed the effects of astragaloside IV (ASV) (10 mg/kg/d) on ECM proteins in bleomycin (BLM, 5 mg/kg)-treated rats. Our results showed that ASV not only ameliorated BLM-induced body weight loss, lung coefficient increase, histological changes and collagen secretion, but also reduced the levels of type III collagen (Col-III) in lung homogenate, laminin (LN) and hyaluronic acid (HA) in serum, as well as hydroxyproline (HYP) in lung tissue. Besides, ASV significantly down-regulated the levels of high-mobility group box1 (HMGB1) in serum and lung tissue, and inhibited the up-regulated expression of α-SMA (marker of myofibroblasts) in the lungs. Taken together, these findings indicate that ASV attenuates BLM-induced ECM deposition, supporting its use as a promising candidate to treat lung fibrosis.

Inositol-requiring protein 1 - X-box-binding protein 1 pathway promotes epithelial-mesenchymal transition via mediating snail expression in pulmonary fibrosis.

Epithelial-mesenchymal transition (EMT) is a complex biological program during which cells loss epithelial phenotype and acquire mesenchymal features. EMT is thought to be involved in the pathogenesis of various fibrotic diseases including pulmonary fibrosis (PF). Recent studies suggest that endoplasmic reticulum (ER) stress is associated with EMT in the progression of PF. However, the exact mechanism is unclear. Here, we developed a PF model with bleomycin (BLM) administration in rats and conducted several simulation experiments in alveolar epithelial cell (AECs) RLE-6TN to unravel the role of inositol-requiring protein 1 (IRE1) - X-box-binding protein 1 (XBP1) signal pathway in ER stress-induced EMT in PF. First, we observed that ER stress was occurred in type II AECs accompanied by EMT in BLM-induced PF. Then we explored the role of IRE1-XBP1-snail pathway in transforming growth factor (TGF)-ß1/tunicamycin (TM)-induced EMT. When TGF-ß1/TM was treated on AECs, IRE1 and XBP1 were overexpressed, meanwhile, snail expression was upregulated accompanied with EMT. However, when IRE1 or XBP1 was knockdown, TGF-ß1/TM-induced EMT were blocked while the expression of snail was inhibited. Then we silenced snail and found that TGF-ß1/TM-induced EMT were also suppressed, but it had no effect on the up-regulated expression of IRE1 and XBP1. Thus, we concluded that IRE1-XBP1 pathway promotes EMT via mediating snail expression in PF.

Total Glucosides of Danggui Buxue Tang Attenuate BLM-Induced Pulmonary Fibrosis via Regulating Oxidative Stress by Inhibiting NOX4.

Pulmonary fibrosis (PF) is a serious chronic lung disease with unknown pathogenesis. Researches have confirmed that oxidative stress which is regulated by NADPH oxidase-4 (NOX4), a main source of reactive oxygen species (ROS), is an important molecular mechanism underlying PF. Previous studies showed that total glucosides of Danggui Buxue Tang (DBTG), an extract from a classical traditional Chinese herbal formula, Danggui Buxue Tang (DBT), attenuated bleomycin-induced PF in rats. However, the mechanisms of DBTG are still not clear. We hypothesize that DBTG attenuates PF through regulating the level of oxidative stress by inhibiting NOX4. And we found that fibrosis indexes hydroxyproline (HYP) and type I collagen (Col-I) were lower in DBTG groups compared with the model group. In addition, the expression of transforming growth factor-ß1 (TGF-ß1) and expression of alpha smooth muscle actin (α-SMA) were also much more decreased than the model group. For oxidative stress indicators, DBTG blunted the decrease of superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC), and the increase in malondialdehyde (MDA), 8-iso-prostaglandin in lung homogenates. Treatment with DBTG restrained the expression of NOX4 compared to the model group. Present study confirms that DBTG inhibits BLM-induced PF by modulating the level of oxidative stress via suppressing NOX4.

[Role of tumor necrosis factor α in endothelial-mesenchymal transition in vitro].

OBJECTIVE: To observe the role of tumor necrosis factor α (TNF-α) in endothelial-mesenchymal transition (EnMT), and to explore the mechanism of fibrosis disease. METHODS: Human umbilical vein endothelial cells (HUVEC) from umbilical cord of healthy fetus were isolated by enzymatic digestion and identified by immunofluorescence assay. The third to fifth generations of cultured HUVEC in logarithmic phase were harvested and seeded in 12-well plates and 6-well plates, and they were divided into control group (ordinary culture without any stimulation), 5, 10, 25, 50, and 100 ng/mL TNF-α groups (5, 10, 25, 50, 100 ng/mL of TNF-α was respectively added into the nutrient solution) according to the random number table, with three samples in each group. After being cultured for 72 hours, the cell morphology was observed under inverted phase-contrast microscope; the expression levels of coagulation factor VIII and α smooth muscle actin (α-SMA) were detected by immunofluorescence assay, and the ratios of numbers (absorbance values) of cells with expression of both factors were calculated. The mRNA expression levels of cadherin, α-SMA, and type I collagen were detected by RT-PCR (denoted as gray value ratio). Data were processed with one-way analysis of variance and LSD test. RESULTS: (1) The shape of primary HUVEC was round, short-spindle, or flat, and cells grew vigorously in cobblestone appearance after passages. After being subcultured for 1, 2, 3, 4, 5 passage (s), the positive rate of coagulation factor VIII of HUVEC was respectively (85.5 ± 1.8)%, (88.1 ± 5.0)%, (93.6 ± 3.7)%, (92.9 ± 4.8)%, (89.5 ± 1.1)%, and they were significantly higher than that of primary HUVEC [(81.4 ± 3.8)%, with F values all equal to 7.481, P values all below 0.05]. (2) As compared with that in control group, the appearance of cells in 5, 10, 25, 50, and 100 ng/mL TNF-α groups was gradually transformed from round, short-spindle, or flat shape to long-spindle shape with reduced intercellular junction and larger intercellular gap along with the increase in the concentration of TNF-α. (3) The ratios of numbers and the absorbance values of coagulation factor VIII and α-SMA double positive cells in control group (0.055 ± 0.015, 0.078 ± 0.017) were significantly lower than those in 5, 10, 25, 50, and 100 ng/mL TNF-α groups (0.257 ± 0.106, 0.280 ± 0.129, 0.505 ± 0.059, 0.817 ± 0.035, 0.929 ± 0.101 and 0.437 ± 0.040, 0.456 ± 0.097, 0.496 ± 0.082, 0.787 ± 0.131, 0.885 ± 0.087, with F value respectively 45.009, 50.099, P values all below 0.01). (4) The expression levels of cadherin mRNA in 5, 10, 25, 50, and 100 ng/mL TNF-α groups were 0.70 ± 0.05, 0.63 ± 0.06, 0.60 ± 0.10, 0.45 ± 0.16, and 0.26 ± 0.14, and it was significantly lower in the latter four groups than in control group (0.83 ± 0.03, with F values all equal to 11.593, P < 0.05 or P < 0.01). The mRNA expression levels of α-SMA and collagen I in 5, 10, 25, 50, and 100 ng/mL TNF-α groups were 0.45 ± 0.10, 0.51 ± 0.16, 0.49 ± 0.12, 0.60 ± 0.09, 0.76 ± 0.03 and 0.38 ± 0.18, 0.45 ± 0.15, 0.52 ± 0.12, 0.66 ± 0.17, 0.76 ± 0.20, and they were significantly higher in the latter three groups than in control group (0.37 ± 0.14, 0.31 ± 0.12, with F value respectively 7.839, 2.898, P < 0.05 or P < 0.01). CONCLUSIONS: TNF-α can obviously promote EnMT in a dose-dependent manner. EnMT may be another significant source of myofibroblasts that contributes to fibrotic tissue in scar formation.

[Effect of granulocyte-macrophage colony-stimulating factor on the mammalian target of sirolimus signaling pathway in the wound of rat].

OBJECTIVE: To investigate the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) on wound healing and mammalian target of sirolimus (rapamycin) signaling pathway in rats. METHODS: Fifty SD rats were divided into control group (n = 25) and treatment group (n = 25) according to the random number table. All rats were inflicted with 2 cm × 2 cm full-thickness skin wound on the back. Recombinant human GM-CSF gel (10 µg/cm(2)) was applied onto the wounds in treatment group, and the actual quantity was 1 × 10(-4) µg/cm(2). Gel vehicle (10 µg/cm(2)) without any medicine was applied onto the wounds in control group. The treatment was conducted once a day up to the day of wound healing. Five rats from two groups were sacrificed on post injury day (PID) 1, 3, 5, 7, 14 respectively to observe and determine the wound healing rate. Wound tissue samples were collected at the former 4 time points to observe the histopathological changes with HE staining, and to detect the content of GM-CSF with enzyme-linked immunosorbent assay, and the expression levels of GM-CSF, CD31, and the mTOR signal pathway associated molecules P70S6K, phosphorylated (p-) P70S6K, 4E-BP1, p-4E-BP1, mTOR, p-mTOR with Western blotting. Data were processed with t test. RESULTS: (1) Wound healing rates in control group and treatment group were close on PID 1 (t = 0.307, P > 0.05). Wound healing rate in treatment group was obviously higher than that in control group on PID 3, 5, 7, and 14 (with t values from 2.704 to 4.030, P < 0.05 or P < 0.01). (2) Compared with those in control group, more abundant granulation tissue was observed in treatment group, in which an increase in the number of microvessels and obvious proliferation of keratinized epithelial cells in wound margin were observed at each time point. (3) The content and the protein expression level of GM-CSF peaked on PID 3 in two groups, and they were (720.9 ± 0.9) pg/mL, 2.45 ± 0.10 in control group and (910.5 ± 1.3) pg/mL, 2.80 ± 0.48 in treatment group. The content of GM-CSF in treatment group was significantly higher than that in control group at each time point (with t values from 105.743 to 298.971, P values all equal to 0.000). The protein expression level of GM-CSF in treatment group was significantly higher than that in control group on PID 1, 5, and 7 (with t values from 4.070 to 5.275, P values all below 0.01). (4) The expression level of CD31 in treatment group was obviously higher than that in control group on PID 1, 3, and 7 (with t values from 7.237 to 26.401, P values all below 0.01). (5) The expression levels of mTOR and p-mTOR in treatment group were significantly higher than those in control group at each time point (with t values from 2.921 to 23.143, P < 0.05 or P < 0.01). In treatment group, the expression level of P70S6K was obviously higher than that in control group on PID 3, 5, and 7 (with t values from 2.950 to 5.275, P < 0.05 or P < 0.01), and the expression level of p-P70S6K was significantly higher than that in control group on PID 1, 3, and 7 (with t values from 3.307 to 22.793, P < 0.05 or P < 0.01). In treatment group, the expression level of 4E-BP1 was significantly lower than that in control group on PID 1, 3, and 5 (with t values from 2.449 to 6.431, P < 0.05 or P < 0.01), but the expression level of p-4E-BP1 was significantly higher than that in control group on PID 1, 3, and 7 (with t values from 5.522 to 11.613, P values all below 0.01). CONCLUSIONS: GM-CSF can promote wound healing in rats by activating mTOR signaling pathway through phosphorylating mTOR proteins and its downstream signal molecules P70S6K and 4E-BP1.