Functional Characterisation of the Transcription Factor GsWRKY23 Gene from Glycine soja in Overexpressed Soybean Composite Plants and Arabidopsis under Salt Stress.

WRKY proteins are a superfamily of transcription factors (TFs) that play multiple roles in plants' growth, development, and environmental stress response. In this study, a novel WRKY gene called GsWRKY23 that is specifically upregulated in salt-tolerant Glycine soja accession BB52 seedlings was identified by transcriptomic analysis under salt stress. How the physiological functions and mechanisms of the GsWRKY23 gene affect salt tolerance was investigated using transformations of soybean hairy roots and Arabidopsis, including wild-type (WT) and atwrky23-mutant plants. The results showed that GsWRKY23 in the roots, stems, and leaves of BB52, along with its promoter in the cotyledons and root tips of GsWRKY23pro::GUS Arabidopsis seedlings, displayed enhanced induction under salt stress. GsWRKY23 localises to the nucleus and shows transcriptional activation ability in yeast cells. Compared to GsWRKY23-RNAi wild soybean hairy-root composite plants under salt stress, obvious improvements, such as superior growth appearance, plant height and fresh weight (FW), and leaf chlorophyll and relative water content (RWC), were displayed by GsWRKY23-overexpressing (OE) composite plants. Moreover, their relative electrolytic leakage (REL) values and malondialdehyde (MDA) contents in the roots and leaves declined significantly. Most of the contents of Na+ and Cl- in the roots, stems, and leaves of GsWRKY23-OE plants decreased significantly, while the content of K+ in the roots increased, and the content of NO3- displayed no obvious change. Ultimately, the Na+/K+ ratios of roots, stems, and leaves, along with the Cl-/NO3- ratios of roots and stems, decreased significantly. In the transgenic WT-GsWRKY23 and atwrky23-GsWRKY23 Arabidopsis seedlings, the salt-induced reduction in seed germination rate and seedling growth was markedly ameliorated; plant FW, leaf chlorophyll content, and RWC increased, and the REL value and MDA content in shoots decreased significantly. In addition, the accumulation of Na+ and Cl- decreased, and the K+ and NO3- levels increased markedly to maintain lower Na+/K+ and Cl-/NO3- ratios in the roots and shoots. Taken together, these results highlight the role of GsWRKY23 in regulating ionic homeostasis in NaCl-stressed overexpressed soybean composite plants and Arabidopsis seedlings to maintain lower Na+/K+ and Cl-/NO3- ratios in the roots and shoots, thus conferring improved salt tolerance.

Controlling amorphous silicon in scratching for fabricating high-performance micromixers.

As core parts of microfluidic chip analysis systems, micromixers show robust applications in wide fields. However, restricted by the fabrication technology, it remains challenging to achieve high-quality micromixers with both delicately designed structure and efficient mixing. In this study, based on the theory of chaotic mixing, sinusoidal structures with variable phases were designed and then fabricated through scanning probe lithography (SPL) and post-selective etching. It was found that scratches with phase differences can lead to the periodic formation of amorphous silicon (a-Si), which can resist etching. Consequentially, misaligned sine channels with thick-thin alternating 3D shapes can be generated in situ from the scratched traces after the etching. Further analysis showed that a thicker a-Si layer can be obtained by reducing the line spacing in the scratching, confirmed by Raman detections and simulations. With the proposed method, the misaligned sine micromixer was achieved with higher mixing efficiency than ever. The duplicating process was also investigated for high-precision production of micromixers. The study provided strategies for the miniaturization of high-performance microfluidic chips.

Nanoscratch-induced formation of metallic micro/nanostructures with resin masks.

Metallic micro/nanostructures present a wide range of applications due to the small size and superior performances. In order to obtain high-performance devices, it is of great importance to develop new methods for preparing metallic micro/nanostructures with high quality, low cost, and precise position. It is found that metallic micro/nanostructures can be obtained by scratch-induced directional deposition of metals on silicon surface, where the mask plays a key role in the process. This study is focused on the preparation of keto-aldehyde resin masks and their effects on the formation of scratch-induced gold (Au) micro/nanostructures. It is also found that the keto-aldehyde resin with a certain thickness can act as a satisfactory mask for high-quality Au deposition, and the scratches produced under lower normal load and less scratching cycles are more conducive to the formation of compact Au structures. According to the proposed method, two-dimensional Au structures can be prepared on the designed scratching traces, providing a feasible path for fabricating high-quality metal-based sensors.

Lateral Bending of Ag Nanowires toward Controllable Manipulation.

Nanowires (NWs) provide opportunities for building high-performance sensors and devices at micro-/nanoscales. Directional movement and assembly of NWs have attracted extensive attention; however, controllable manipulation remains challenging partly due to the lack of understanding on interfacial interactions between NWs and substrates (or contacting probes). In the present study, lateral bending of Ag NWs was investigated under various bending angles and pushing velocities, and the mechanical performance corresponding to microstructures was clarified based on high-resolution transmission electron microscope (HRTRM) detections. The bending-angle-dependent fractures of Ag NWs were detected by an atomic force microscope (AFM) and a scanning electron microscope (SEM), and the fractures occurred when the bending angle was larger than 80°. Compared with an Ag substrate, Ag NWs exhibited a lower system stiffness according to the nanoindentation with an AFM probe. HRTRM observations indicated that there were grain boundaries inside Ag NWs, which would be contributors to the generation of fractures and cracks on Ag NWs during lateral bending and nanoindentation. This study provides a guide to controllably manipulate NWs and fabricate high-performance micro-/nanodevices.

Clinical characteristics and risk factors of organ failure and death in necrotizing pancreatitis.

BACKGROUND: Organ failure (OF) and death are considered the most significant adverse outcomes in necrotizing pancreatitis (NP). However, there are few NP-related studies describing the clinical traits of OF and aggravated outcomes. PURPOSE: An improved insight into the details of OF and death will be helpful to the management of NP. Thus, in our research, we addressed the risk factors of OF and death in NP patients. METHODS: We performed a study of 432 NP patients from May 2017 to December 2021. All patients with NP were followed up for 36 months. The primary end-points were risk factors of OF and death in NP patients. The risk factors were evaluated by logistic regression analysis. RESULTS: NP patients with OF or death patients were generally older, had a higher APACHE II score, longer hospital stay, longer ICU stay, as well as a higher incidence of severe acute pancreatitis (SAP), shock and pancreatic necrosis. Independent risk factors related to OF included BMI, APACHE II score and SAP (P < 0.05). Age, shock and APACHE II score (P < 0.05) were the most significant factors correlated with the risk of death in NP patients. Notably, increased mortality was linked to the number of failed organs. CONCLUSIONS: NP is a potentially fatal disease with a long hospital or ICU stay. Our study indicated that the incidence of OF and death in NP patients was 69.9% and 10.2%, respectively. BMI, SAP, APACHE II score, age and shock are potential risk factors of OF and death in NP patients. Clinicians should focus on these factors for early diagnosis and appropriate therapy.

Elevated hypertriglyceridemia and decreased gallstones in the etiological composition ratio of acute pancreatitis as affected by seasons and festivals: A two-center real-world study from China.

Objective: The purpose of this study was to observe the annual variation in the etiology of acute pancreatitis (AP) and its relationship with seasons and festivals. Methods: From 2011 to 2017, 5146 adult patients with AP were studied, including 4110 patients from the First Affiliated Hospital of Nanchang University (South center) and 1036 patients from the First Affiliated Hospital of Harbin Medical University (North center). We analyzed the overall annual variation in the etiology of AP and then compared the differences in etiology between the two regions, as well as the effects of seasons and festivals on the etiology of AP. Results: Gallstones, hypertriglyceridemia (HTG) and alcohol were the top three etiologies of AP. Gallstone AP showed a downward trend (P<0.001), and HTG-AP and alcohol AP showed an upward trend (both P<0.01). Among the etiologies of AP, gallstones and HTG were affected by seasons and festivals. The composition ratio of HTG-AP increased, while gallstone AP decreased in winter and in months with long holidays (all P<0.01). The composition ratio of gallstone AP in the south center was higher than that in the north center (59.5% vs. 49%), especially in summer (62.9% vs. 44.0%) and autumn (61.5% vs. 45.7%, all P<0.001). Conclusions: The composition ratio of HTG-AP increased while gallstone AP decreased in the past 7 years, and they were affected by seasons and festivals.

Toward Controllable Wet Etching of Monocrystalline Silicon: Roles of Mechanically Driven Defects.

Wet chemical etching is essential not only for processing silicon (Si) wafers but also for forming diverse structures, significantly promoting the development of the semiconductor industry. However, tight control of etched topography at the nanoscale and even atom-scale in a controllable and reproducible fashion can be hardly achieved in either laboratory research or industrial production, seriously hindering further enhancement of high-performance Si-based electronic devices. Herein, the roles of mechanically driven defects in wet etching were systematically investigated toward promoting controllable wet etching of monocrystalline Si. The role of antietching of mechanically driven amorphous Si (a-Si) and the role of promoting etching of distorted Si (including dislocations and stacking faults) were revealed in anisotropic or isotropic etchants. It was also found that the nucleation of nanocrystals in the a-Si area with increasing contact pressure can lead to deactivation of the antietching mask, and the required contact pressure for deactivation in KOH and tetramethyl ammonium hydroxide solutions was much higher than that in HF/HNO3 mixtures. The selective etching mechanisms for every defect including a-Si, distorted Si, and nanocrystals were further addressed down to the atom-scale based on the proposed dissolution model. This study provides insights into deeply understanding the role of defects in wet etching and pushes forward the idea of controllable wet chemical etching in the Si-based semiconductor industry.

GsCLC-c2 from wild soybean confers chloride/salt tolerance to transgenic Arabidopsis and soybean composite plants by regulating anion homeostasis.

The responses of the GsCLC-c2 gene and its promoter to NaCl stress, as well as the Cl- /salt tolerance of GsCLC-c2-transgenic Arabidopsis and overexpressed or RNAi wild soybean hairy root composite plants, were investigated. Results showed that both GsCLC-c2 and its promoter display enhanced induction under salt stress. In the transgenic Arabidopsis WT-GsCLC-c2 and atclc-c-GsCLC-c2 seedlings, the salt-induced growth reduction was markedly ameliorated; plant fresh weight, leaf area, and relative water content (RWC) increased; relative electrolytic leakage (REL), and malondialdehyde (MDA) content in shoots decreased significantly. In addition, accumulation of Cl- and K+ , especially Cl- , increased markedly in roots to minimize Cl- transport to shoots and maintain higher and lower Cl- /NO3 - ratios in roots and shoots, respectively. When compared to GsCLC-c2-RNAi wild soybean composite plants under salt stress, clear advantages, such as growth appearance, plant height, and leaf area, were displayed by GsCLC-c2-overexpressing composite plants. Moreover, their REL values in roots and leaves declined significantly. The accumulation of absorbed Cl- and Na+ in the roots increased, as the transportation to the stems and leaves decreased, the NO3 - content in roots, stems, and leaves significantly increased, and the changes in K+ contents were small, which resulted in the maintenance of a low Cl- /NO3 - ratio in all plant parts and low Na+ /K+ ratio in stems and leaves. Taken together, these results highlight the role of GsCLC-c2 in regulating anionic homeostasis in NaCl-stressed transgenic Arabidopsis and soybean composite plants to maintain lower Cl- /NO3 - ratios in shoots, thus conferring enhanced Cl- /salt tolerance.

Genome-wide analysis of chloride channel-encoding gene family members and identification of CLC genes that respond to Cl-/salt stress in upland cotton.

Chloride channels (CLCs) are kinds of anion transport protein family members that are mainly distributed in cell endomembrane systems of prokaryotic and eukaryotic organisms and mediate anion (Cl-, as a representative) transport and homeostasis. Some CLC genes have been reported to be involved in Cl-/salt tolerance of plants exposed to NaCl stress. Through BLAST in cotton database, a total of 22 CLCs were identified in genomes A and D in upland cotton (Gossypium hirsutum L.), and except for GhCLC6 and GhCLC17, they formed highly similar homologous genes pairs. According to the prediction in PlantCARE database, many cis-acting elements related to abiotic stress responses, including ABREs, AREs, GT-1s, G-boxes, MYBs, MYCs, etc., were found in the promoters of GhCLCs. qRT-PCR revealed that most GhCLC gene expression was upregulated in the roots and leaves of cotton seedlings under salt stress, and those of homologous GhCLC4/15, GhCLC5/16, and GhCLC7/18 displayed more obvious expression. Furthermore, according to leaf virus-induced gene silencing (VIGS) assay and compared with the salt-stressed GhCLC4/15- and GhCLC7/18-silenced cotton plants, the salt-stressed GhCLC5/16-silenced plants displayed relatively better growth with significant increases in both Cl- content and Cl-/NO3- ratio in the roots and drop of the same parameters in the leaves. These results indicate that homologous GhCLC5/16, with the highest NaCl-induced upregulation of expression and the maximum number of MYC cis-acting elements, might be the key members contributing to cotton Cl-/salt tolerance by regulating the transport, interaction and homeostasis of Cl- and NO3-.

Low-Molecular-Weight Heparin Combined With Insulin Versus Insulin Alone in the Treatment of Hypertriglyceridemic Pancreatitis (LIHTGP Trial): Study Protocol for a Multicenter, Prospective, Single-Blind, Randomized Controlled Trial.

OBJECTIVE: Currently, insulin and/or heparin/low-molecular-weight heparin (LMWH) serve as an early lipid-lowering treatment for hypertriglyceridemic pancreatitis (HTGP). However, whether the clinical prognosis of combining LMWH with insulin is superior to using insulin alone remains unknown. This trial will compare the clinical outcomes of LMWH with insulin and an insulin regimen for emergency lipid-lowering treatment in HTGP patients. METHODS: In total, 476 eligible participants will be recruited from 18 hospitals throughout China. Participants in the LMWH group will receive LMWH combined with insulin, whereas insulin alone will be administered to those in the insulin group. The patients will be followed up at 3 and 6 months after discharge. Adverse reactions will be evaluated by the safety monitoring committee. Safety outcomes and adverse events will also be recorded. RESULTS: The study is registered in the Chinese Clinical Trial Registry (No: ChiCTR1900023640). Recruitment will begin in August 2019 and will be completed in December 2021 (http://www.chictr.org.cn/index.aspx). No data are available now. CONCLUSIONS: The trial will investigate the efficacy of using LMWH combined with insulin as an emergency lipid-lowering treatment in reducing new organ failure, mortality, hospital stays, and expenses compared using with insulin alone for patients with HTGP.

The Clinical Characteristics of Acute Pancreatitis in Gerontal Patients: A Retrospective Study.

BACKGROUND: The incidence of acute pancreatitis (AP) in ageing patients has increased in recent years, and results regarding the clinical outcomes of these patients are controversial. The aim of this study was to compare the clinical outcomes of AP in ageing patients over 60 years old. METHODS: Eighty patients aged ≥80 years (oldest group) were compared to 393 patients aged 60 to 79 years (older group). The clinical course and biochemical and radiological data were evaluated. The primary endpoints were mortality rate, intensive care unit (ICU) admission rate and in-hospital length of stay (LOS). The secondary endpoints were the incidence of operative treatment and complications of AP. RESULTS: Abdominal pain (61.3% vs 46.3%, P=0.013) was less common in the oldest group. Jaundice (17.5% vs 8.9%, P=0.021) and dyspnoea (26.3% vs 11.5%, P=0.001) were more obvious in the oldest group than in the older group. The mean BMI was lower in the oldest group than in the older group (21.07±3.18 vs 22.36±2.89, P = 0.001). Age over 80 years (P=0.011) and organ failure (P<0.05) were independent risk factors for mortality. More severe AP (P=0.001), abdominal pain (P=0.033) and organ failure (P<0.05) were associated with the ICU admission rate. Age over 80 years (P=0.001), more severe AP (P=0.001), female sex (P=0.018), jaundice (P=0.038), operative treatment (P<0.05) and organ failure (P<0.05) were risk factors for increased LOS. CONCLUSION: The oldest group had a higher death rate and longer LOS than the older group. More attention should be given to the clinical symptoms of this frail population. We propose that more comprehensive and goal-directed attendant diagnostic procedures should be performed to detect the disease early and to improve the outcomes of ageing patients.

Progression to recurrent acute pancreatitis after a first attack of acute pancreatitis in adults.

PURPOSE: Patients with a first attack of acute pancreatitis (AP) can develop recurrent acute pancreatitis (RAP). Hence, this study aimed to investigate the clinical features of the disease and the risk factors for RAP. METHODS: We performed a retrospective study of 522 patients from Jan 1 to Dec 31, 2006. All patients with AP were followed for 36 months. The primary end point was the rate of RAP. The secondary end points were the risk factors that were evaluated by Cox regression analysis. The cumulative risk of RAP was assessed using Kaplan-Meier analysis. RESULTS: 56 of the 522 patients (10.7%) developed RAP. Among those RAP patients, 37 (7.1%) experienced one relapse, 10 (1.9%) experienced two relapses, and 9 (1.7%) experienced three or more relapses. Univariate analysis indicated that age (p = 0.016), male sex, etiology of AP (p = 0.001), local complications (p = 0.001) and Length of stay (LOS) (p = 0.007) were associated with RAP. Multivariate analysis with the Cox proportional hazards model showed that male sex (HR = 2.486, 95% CI, 0.169-0.960, p = 0.04), HTG-associated etiology (HR = 5.690, 95% CI, 2.138-15.146, p = 0.001), alcohol-associated etiology (HR = 5.867, 95% CI, 1.446-23.803, p = 0.013) and current local complications at index admission (HR = 8.917, 95% CI, 3.650-21.789, p = 0.001) were significant independent risk factors for RAP. CONCLUSIONS: A first attack of AP led to RAP in 10.7% of patients within 3 years. Male sex was significantly associated with RAP. The etiologies of alcohol and HTG and local complications were the strongest risk factors for recurrent disease. Patients with these characteristics should be given special attention and followed-up closely.

Risk Factors for Acute Kidney Injury in Acute Pancreatitis: A 7-Year Retrospective Analysis of Patients in a Large Tertiary Hospital.

OBJECTIVE: The aim of our study was to investigate the risk factors for acute kidney injury (AKI) in patients with acute pancreatitis (AP). METHODS: Acute pancreatitis patients were retrospectively divided into 2 groups: AKI and non-AKI. We used logistic regression analysis to investigate the risk factors for AP patients with AKI. We also compared the incidence of complications and mortality between the non-AKI and AKI groups. RESULTS: A total of 1255 AP patients without AKI and 430 AP patients with AKI were included. The risk factors for AKI in AP were hypertriglyceridemia (P = 0.001), severity (P = 0.001), etiology (P = 0.001), and Acute Physiology and Chronic Health Evaluation II scores (P = 0.001). The incidences of organ failure (P = 0.001), pancreatic necrosis (P = 0.001), and mortality (P = 0.001) were greater in the AKI group than in the non-AKI group. CONCLUSIONS: Hypertriglyceridemia, severity, etiology, and Acute Physiology and Chronic Health Evaluation II scores are independent risk factors for AKI in AP patients. Those patients have serious outcomes such as high rate of organ failure, pancreatic necrosis, and debridement of necrosis.

Pancreatic necrosis and severity are independent risk factors for pancreatic endocrine insufficiency after acute pancreatitis: A long-term follow-up study.

BACKGROUND: Pancreatic endocrine insufficiency after acute pancreatitis (AP) has drawn increasing attention in recent years. AIM: To assess the impact of risk factors on the development of pancreatic endocrine insufficiency after AP. METHODS: This retrospective observational long-term follow-up study was conducted in a tertiary hospital. Endocrine function was evaluated by the oral glucose tolerance test. The data, including age, sex, body mass index, APACHE II score, history of smoking and drinking, organ failure, pancreatic necrosis, debridement of necrosis (minimally invasive and/or open surgery), and time interval, were collected from the record database. RESULTS: A total of 361 patients were included in the study from January 1, 2012 to December 30, 2018. A total of 150 (41.6%) patients were diagnosed with dysglycemia (including diabetes mellitus and impaired glucose tolerance), while 211 (58.4%) patients had normal endocrine function. The time intervals (mo) of the above two groups were 18.73 ± 19.10 mo and 31.53 ± 27.27 mo, respectively (P = 0.001). The morbidity rates of pancreatic endocrine insufficiency were 46.7%, 28.0%, and 25.3%, respectively, in the groups with different follow-up times. The risk factors for pancreatic endocrine insufficiency after AP were severity (odds ratio [OR] = 3.489; 95% confidence interval [CI]: 1.501-8.111; P = 0.004) and pancreatic necrosis (OR = 4.152; 95%CI: 2.580-6.684; P = 0.001). CONCLUSION: Pancreatic necrosis and severity are independent risk factors for pancreatic endocrine insufficiency after AP. The area of pancreatic necrosis can affect pancreatic endocrine function.

Rapid identification of ultrathin amorphous damage on monocrystalline silicon surface.

Amorphous silicon (a-Si) is a type of common surface damages during the ultra-precision machining of monocrystalline Si. However, it is difficult to identify the amorphous damage of several nanometers by traditional detection methods, which severely hinders the performance improvement of Si-based products. In this study, ultrathin a-Si was found to act as a mask against etching in HF/HNO3 mixtures, resulting in the formation of protrusive hillocks. Reciprocating sliding on an atomic force microscope (AFM) was employed to simulate a material removal event in surface manufacturing. The effects of normal load, etching time and etchant concentration on selective etching were investigated to optimize the parameters for amorphous damage detection. The mechanisms for selective etching were further addressed based on high-resolution transmission electron microscopy (HRTEM) detection and comparative etching of different surface structures. Further analysis demonstrated that a lower dangling bond density of a-Si could result in the reduction of the dissolution rate, while deformed Si lattices, including stacking faults, dislocations and microcracks, could facilitate rapid selective etching. By the proposed selective etching, ultrathin amorphous damage and its spatial distributions can be rapidly identified with high resolution and low destruction. This study sheds new light on achieving a high-quality Si surface in ultra-precision machining.

Superoxide Dismutase Predicts Persistent Circulation Failure and Mortality in the Early Stage of Acute Pancreatitis.

OBJECTIVES: Oxidative stress is an important event in the pathogenesis of acute pancreatitis. Superoxide dismutase is a major antioxidant enzyme in the body. The aim of this study was to investigate the changes in superoxide dismutase activity early in the onset of acute pancreatitis and its value in predicting the risk of organ failure and mortality. METHODS: Data for 2549 patients hospitalized from 2013 to 2017 were extracted from the prospective database, and we selected 854 adult patients who were admitted within 24 h of disease onset with complete data. Serum superoxide dismutase activities on the first, second, and third days of hospital admission for patients with different severities, organ failure, and mortality were compared. The areas under the curve for the prediction of organ failure, pancreatic necrosis, and mortality were estimated using receiver operating characteristic curves. RESULTS: Among the 854 adult patients, superoxide dismutase activities were significantly different among patients with mild acute pancreatitis, moderately severe acute pancreatitis, and severe acute pancreatitis (P = 0.005). Superoxide dismutase activity was significantly decreased in patients with persistent renal failure (77.8 ± 37.2), persistent circulatory failure (66.2 ± 14.9), and mortality (64.3 ± 16.0). The accuracy of superoxide dismutase with regard to predicting persistent circulatory failure and mortality was high, and the areas under the receiver operating characteristic curves were 0.83 and 0.84, respectively. CONCLUSIONS: Superoxide dismutase activity was negatively correlated with the severity and clinical outcome of AP. Superoxide dismutase activity is highly accurate at predicting persistent circulation failure and mortality in the early stage of AP.

Dependence of water adsorption on the surface structure of silicon wafers aged under different environmental conditions.

Most materials exposed to ambient air can adsorb water molecules and the adsorption capability strongly depends on the surface property. The water contact angle has been widely used as a measure for surface wettability; however, a question can still be asked whether the water contact angle can be used as an adequate sole predictor for water adsorption on the surface in humid air. In this paper, HF-etched silicon wafers were aged (oxidized) under different environmental conditions at room temperature to grow surface layers with varying water contact angles from ∼0° (fully hydrophilic) to ∼83° (highly hydrophobic), and water adsorption as a function of relative humidity (RH) was studied on such surfaces. The thickness and structure of the adsorbed water layer were found to depend on not only the surface wettability on each surface, but also the history of surface oxidation conditions. In particular, the silicon wafer surface oxidized in liquid water uptakes significantly more water from humid air than the fully-hydroxylated native oxide surface (SiOx/OH), even though its water contact angle is higher than that on the SiOx/OH surface. This could be attributed to the formation of a gel-like structure during oxidation in liquid water.

Large triglyceride-rich lipoproteins in hypertriglyceridemia are associated with the severity of acute pancreatitis in experimental mice.

Hypertriglyceridemia severity is linked to acute pancreatitis prognosis, but it remains unknown why a portion of severe hypertriglyceridemia patients do not develop severe acute pancreatitis. To investigate whether hypertriglyceridemia subtypes affect acute pancreatitis progression, we analyzed two genetically modified hypertriglyceridemia mouse models-namely, glycosylphosphatidylinositol high-density lipoprotein binding protein 1 knockout (Gpihbp1-/-) and apolipoprotein C3 transgenic (ApoC3-tg) mice. Acute pancreatitis was induced by 10 intraperitoneal caerulein injections. Biochemical assays and pathological analysis were performed for the severity evaluation of acute pancreatitis. Plasma triglyceride-rich lipoproteins (TRLs), including chylomicrons and very low-density lipoprotein (VLDL), were collected via ultracentrifugation to evaluate their cytotoxic effects on primary pancreatic acinar cells (PACs). We found that the particle sizes of Gpihbp1-/- TRLs were larger than ApoC3-tg TRLs. Severe pancreatic injury with large areas of pancreatic necrosis in the entire lobule was induced in Gpihbp1-/- mice when plasma triglyceride levels were greater than 2000 mg/dL. However, ApoC3-tg mice with the same triglyceride levels did not develop large areas of pancreatic necrosis, even upon the administration of poloxamer 407 to further increase triglyceride levels. Meanwhile, in the acute pancreatitis model, free fatty acids (FFAs) in the pancreas of Gpihbp1-/- mice were greater than in ApoC3-tg mice. TRLs from Gpihbp1-/- mice released more FFAs and were more toxic to PACs than those from ApoC3-tg mice. Chylomicrons from patients showed the same effects on PACs as TRLs from Gpihbp1-/- mice. Gpihbp1-/- mice with triglyceride levels below 2000 mg/dL had milder pancreatic injury and less incidence of pancreatic necrosis than those with triglyceride levels above 2000 mg/dL, similar to Gpihbp1-/-mice with triglyceride levels above 2000 mg/dL but with fenofibrate administration. These findings demonstrated that hypertriglyceridemia subtypes with large TRL particles could affect acute pancreatitis progression and that chylomicrons showed more cytotoxicity than VLDL by releasing more FFAs.

The Recretohalophyte Tamarix TrSOS1 Gene Confers Enhanced Salt Tolerance to Transgenic Hairy Root Composite Cotton Seedlings Exhibiting Virus-Induced Gene Silencing of GhSOS1.

The salt overly sensitive 1 (SOS1) gene encodes the plasma membrane Na+/H+ antiporter, SOS1, that is mainly responsible for extruding Na+ from the cytoplasm and reducing the Na+ content in plants under salt stress and is considered a vital determinant in conferring salt tolerance to the plant. However, studies on the salt tolerance function of the TrSOS1 gene of recretohalophytes, such as Tamarix, are limited. In this work, the effects of salt stress on cotton seedlings transformed with tobacco-rattle-virus-based virus-induced gene silencing (VIGS) of the endogenous GhSOS1 gene, or Agrobacterium rhizogenes strain K599-mediated TrSOS1-transgenic hairy root composite cotton plants exhibiting VIGS of GhSOS1 were first investigated. Then, with Arabidopsis thaliana AtSOS1 as a reference, differences in the complementation effect of TrSOS1 or GhSOS1 in a yeast mutant were compared under salt treatment. Results showed that compared to empty-vector-transformed plants, GhSOS1-VIGS-transformed cotton plants were more sensitive to salt stress and had reduced growth, insufficient root vigor, and increased Na+ content and Na+/K+ ratio in roots, stems, and leaves. Overexpression of TrSOS1 enhanced the salt tolerance of hairy root composite cotton seedlings exhibiting GhSOS1-VIGS by maintaining higher root vigor and leaf relative water content (RWC), and lower Na+ content and Na+/K+ ratio in roots, stems, and leaves. Transformations of TrSOS1, GhSOS1, or AtSOS1 into yeast NHA1 (Na+/H+ antiporter 1) mutant reduced cellular Na+ content and Na+/K+ ratio, increased K+ level under salt stress, and had good growth complementation in saline conditions. In particular, the ability of TrSOS1 or GhSOS1 to complement the yeast mutant was better than that of AtSOS1. This may indicate that TrSOS1 is an effective substitute and confers enhanced salt tolerance to transgenic hairy root composite cotton seedlings, and even the SOS1 gene from salt-tolerant Tamarix or cotton may have higher efficiency than salt-sensitive Arabidopsis in regulating Na+ efflux, maintaining Na+ and K+ homeostasis, and therefore contributing to stronger salt tolerance.

Identification and functional characterization of the chloride channel gene, GsCLC-c2 from wild soybean.

BACKGROUND: The anionic toxicity of plants under salt stress is mainly caused by chloride (Cl-). Thus Cl- influx, transport and their regulatory mechanisms should be one of the most important aspects of plant salt tolerance studies, but are often sidelined by the focus on sodium (Na+) toxicity and its associated adaptations. Plant chloride channels (CLCs) are transport proteins for anions including Cl- and nitrate (NO3-), and are critical for nutrition uptake and transport, adjustment of cellular turgor, stomatal movement, signal transduction, and Cl- and NO3- homeostasis under salt stress. RESULTS: Among the eight soybean CLC genes, the tonoplast-localized c2 has uniquely different transcriptional patterns between cultivated soybean N23674 and wild soybean BB52. Using soybean hairy root transformation, we found that GsCLC-c2 over-expression contributed to Cl- and NO3- homeostasis, and therefore conferred salt tolerance, through increasing the accumulation of Cl- in the roots, thereby reducing their transportation to the shoots where most of the cellular damages occur. Also, by keeping relatively high levels of NO3- in the aerial part of the plant, GsCLC-c2 could reduce the Cl-/NO3- ratio. Wild type GsCLC-c2, but not its mutants (S184P, E227V and E294G) with mutations in the conserved domains, is able to complement Saccharomyces cerevisiae △gef1 Cl- sensitive phenotype. Using two-electrode voltage clamp on Xenopus laevis oocytes injected with GsCLC-c2 cRNA, we found that GsCLC-c2 transports both Cl- and NO3- with slightly different affinity, and the affinity toward Cl- was pH-independent. CONCLUSION: This study revealed that the expression of GsCLC-c2 is induced by NaCl-stress in the root of wild soybean. The tonoplast localized GsCLC-c2 transports Cl- with a higher affinity than NO3- in a pH-independent fashion. GsCLC-c2 probably alleviates salt stress in planta through the sequestration of excess Cl- into the vacuoles of root cells and thus preventing Cl- from entering the shoots where it could result in cellular damages.