Loss-of-function of PGL10 impairs photosynthesis and tolerance to high-temperature stress in rice.

High temperature (HT) affects the production of chlorophyll (Chl) pigment and inhibits cellular processes that impair photosynthesis, and growth and development in plants. However, the molecular mechanisms underlying heat stress in rice are not fully understood yet. In this study, we identified two mutants varying in leaf color from the ethylmethanesulfonate mutant library of indica rice cv. Zhongjiazao-17, which showed pale-green leaf color and variegated leaf phenotype under HT conditions. Mut-map revealed that both mutants were allelic, and their phenotype was controlled by a single recessive gene PALE GREEN LEAF 10 (PGL10) that encodes NADPH:protochlorophyllide oxidoreductase B, which is required for the reduction of protochlorophyllide into chlorophyllide in light-dependent tetrapyrrole biosynthetic pathway-based Chl synthesis. Overexpression-based complementation and CRISPR/Cas9-based knockout analyses confirmed the results of Mut-map. Moreover, qRT-PCR-based expression analysis of PGL10 showed that it expresses in almost all plant parts with the lowest expression in root, followed by seed, third leaf, and then other green tissues in both mutants, pgl10a and pgl10b. Its protein localizes in chloroplasts, and the first 17 amino acids from N-terminus are responsible for signals in chloroplasts. Moreover, transcriptome analysis performed under HT conditions revealed that the genes involved in the Chl biosynthesis and degradation, photosynthesis, and reactive oxygen species detoxification were differentially expressed in mutants compared to WT. Thus, these results indicate that PGL10 is required for maintaining chloroplast function and plays an important role in rice adaptation to HT stress conditions by controlling photosynthetic activity.

Genome-Wide Analysis and Functional Characterization of Pyruvate Kinase (PK) Gene Family Modulating Rice Yield and Quality.

Pyruvate kinase (PK) is one of the three rate-limiting enzymes of glycolysis, and it plays a pivotal role in energy metabolism. In this study, we have identified 10 PK genes from the rice genome. Initially, these genes were divided into two categories: cytoplasmic pyruvate kinase (PKc) and plastid pyruvate kinase (PKp). Then, an expression analysis revealed that OsPK1, OsPK3, OsPK4, OsPK6, and OsPK9 were highly expressed in grains. Moreover, PKs can form heteropolymers. In addition, it was found that ABA significantly regulates the expression of PK genes (OsPK1, OsPK4, OsPK9, and OsPK10) in rice. Intriguingly, all the genes were found to be substantially involved in the regulation of rice grain quality and yield. For example, the disruption of OsPK3, OsPK5, OsPK7, OsPK8, and OsPK10 and OsPK4, OsPK5, OsPK6, and OsPK10 decreased the 1000-grain weight and the seed setting rate, respectively. Further, the disruption of OsPK4, OsPK6, OsPK8, and OsPK10 through the CRISPR/Cas9 system showed an increase in the content of total starch and a decrease in protein content compared to the WT. Similarly, manipulations of the OsPK4, OsPK8, and OsPK10 genes increased the amylose content. Meanwhile, the grains of all CRISPR mutants and RNAi lines, except ospk6, showed a significant increase in the chalkiness rate compared to the wild type. Overall, this study characterizes the functions of all the genes of the PK gene family and shows their untapped potential to improve rice yield and quality traits.

TLR4 rs1927914 polymorphism contributes to serum TLR4 levels in patients with aortic aneurysm.

Toll-like receptor 4 (TLR4) is a crucial regulator of inflammatory reactions and vascular remodeling. Elevated TLR4 expression has been proved to be correlated with an increased risk of aortic aneurysm (AA). This study aimed to explore the influence of TLR4 gene polymorphisms on TLR4 expression levels and its probable functional significance in AA disease. A total of 294 AA patients and 285 controls were enrolled in the study and serum TLR4 levels were detected by ELISA. All the participants were genotyped for two tag-SNPs in TLR4 (rs1927914 in the promoter region and rs11536889 in the 3'-untranslated region) using the KASP method. Relative luciferase activity was measured by the dual-luciferase reporter assay system. The rs1927914 TC, TC/CC genotypes and C allele showed associations with increased serum TLR4 levels in the total population and AA patients (all P<0.05). Further stratified analysis demonstrated that AA subjects with TC or TC/CC genotype of rs1927914 had significantly higher serum levels of TLR4 than those with TT genotype in male, age>60y, hypertension, diabetes, TAA type and size>5.0 cm subgroups (all P<0.05). In binary logistic analysis, rs1927914 TC genotype and dominant model presented significant associations with high TLR4 levels (OR = 1.579 and 1.431, P = 0.020 and 0.049, respectively) after adjusting age, hypertension and diabetes. However, rs11536889 polymorphism had no significant influence on serum TLR4 levels. Regarding rs1927914, luciferase activity of the C allele construct was significantly increased in comparison with the T allele construct (0.589 ± 0.004 vs. 0.340 ± 0.014, P<0.001). Our results provided evidence that rs1927914 polymorphism contributed to serum TLR4 levels, possibly by influencing promoter activity of TLR4, and could be a novel genetic factor in the formation of AA.

PGC-MG7 combination could be used as a follow-up panel for monitoring dynamical progression of gastric precancerous diseases.

OBJECTIVE: The aim of this study was to investigate the value of the combined expression of the gastric mucosal differentiation protein pepsinogen C (PGC) and gastric cancer (GC)-associated antigen MG7 for the diagnosis of GC and prediction of the development from precancerous conditions to GC. METHODS: The gastric mucosal biopsies of 285 subjects enrolled from a region with a high incidence of GC were obtained and histopathologically examined. Subjects testing negative for GC (n=208) were followed up from 1998 to 2015. The levels of PGC and MG7 in the biopsies were determined by immunohistochemistry. RESULTS: PGC was positive in 91.4% of the non-atrophic gastritis, 26.5% of the atrophic gastritis, and 0% of the GC. MG7 was positive in 15.0% of the non-atrophic gastritis, 82.4% of the atrophic gastritis, and 94.8% of the GC. The non-atrophic gastritis group was predominantly "PGC+MG7-". The atrophic gastritis and GC groups were predominantly "PGC-MG7+". The rate of GC in subjects with "PGC-MG7+" staining was 113.4-fold higher [95% confidence interval (95% CI): 15.3-869.4, P<0.001] than that in subjects with other staining patterns. The sensitivity and specificity of the "PGC-MG7+" pattern were 92.2% and 78.8% for the detection of GC and 77.2% and 97.9% for GC and precancerous disease, respectively. In the follow-up cohort of non-GC subjects, the risk of developing GC was higher in those with the "PGC-MG7+" staining pattern. CONCLUSIONS: Our data suggest that the "PGC-MG7+" pattern can be employed as a useful follow-up panel for detecting individuals with a high risk of GC, and the dynamic assessment of the follow-up panel needs multi-centre large-scale validation in the future.

[Clinical features and prognosis of malignancy-associated hemophagocytic lymphohistiocytosis in children: a clinical analysis of 24 cases].

OBJECTIVE: To investigate the clinical features and prognosis of malignancy-associated hemophagocytic lymphohistiocytosis (MAHS) in children. METHODS: A retrospective analysis was performed for the primary diseases, clinical features, and prognosis of 24 children with MAHS. RESULTS: Among the 24 children, 11 (46%) had MAHS induced by tumor and 13 (54%) had chemotherapy-associated MAHS. As for primary diseases, 17 children had acute leukemia, 6 had lymphoma, and 1 had neuroblastoma. The most common clinical manifestations were pyrexia, respiratory symptoms, and hepatosplenomegaly. The most common laboratory abnormalities were hemocytopenia, elevated serum ferritin, and elevated lactate dehydrogenase. Of the 24 children, 22 were treated according to the HLH-2004 protocol and 2 gave up treatment; 18 children died, 1 was lost to follow-up, and 5 survived. The survival time ranged from 3 days to 2 years and 4 months (median 28 days). CONCLUSIONS: Children with MAHS have various clinical features and extremely poor treatment outcomes.

A comprehensive evaluation of fasting serum gastrin-17 as a predictor of diseased stomach in Chinese population.

BACKGROUND AND AIM: Fasting serum gastrin-17 (FsG17) is considered as a noninvasive biomarker reflecting the structure and functional status of gastric mucosa, but its clinical utility remains unclear. This study aimed to evaluate FsG17 comprehensively: establish the ranges and cut-off points of FsG17 levels in different gastric diseases, identify their influencing factors, and investigate the accuracy of FsG17 for identifying diseased stomach. METHODS: The study included 4064 participants from Northern China between 2008 and 2013. FsG17 and serum Helicobacter pylori IgG antibody levels were measured by enzyme-linked immunosorbent assay. Diagnostic accuracy was assessed by receiver operator characteristic curves. Multivariate logistic regression analysis was performed to determine the best predictors of gastric histopathological conditions. RESULTS: Median FsG17 levels in healthy, non-atrophic, atrophic, and cancerous stomachs were 1.8, 4.0, 3.8, and 6.1 pmol/l, respectively. Age, smoking status, alcohol consumption, H. pylori infection, and predominant lesion site were factors that affected FsG17 levels. The optimal cut-off values for FsG17 were 3.0 pmol/l (sensitivity of 59.3% and specificity of 67.3%) for discriminating between healthy stomach and diseased stomach and 10.7 pmol/l (sensitivity of 37% and specificity of 83.7%) for discriminating between cancerous stomach and cancer-free stomach; the screening accuracy was higher (sensitivity of 50.0% and specificity of 83.0%) for gastric cancer in the corpus. Multivariate analysis showed that FsG17, gender, age, and H. pylori infection were independent predictors of cancerous stomach. CONCLUSION: With the progression from health stomach to malignancy, FsG17 levels significantly increased and were influenced by other factors. FsG17 combined with age, gender, and H. pylori infection could distinguish between cancerous stomach and cancer-free stomach. The results will enhance our understanding of the potential clinical utility of FsG17.

Prevalence and anatomic associations of middle mesial canals and isthmi in mandibular first molars: A CBCT-based study in a Northern Chinese population.

This study investigated the prevalence of the middle mesial canal (MMC) and isthmus in a northern Chinese subpopulation using cone-beam computed tomography (CBCT). CBCT images of 1060 mandibular first molars (MFMs) were analysed. Data analysis was performed using the chi-square test, t-test, and multiple logistic regression analysis (p < 0.05). The prevalence of MMC and isthmus was 15.2% and 40.6%, respectively. The average dentinal thickness in the danger zone was 1.61 ± 0.14 mm. Patients younger than 40 years were two times more likely to have MMC (odds ratio [OR] = 2.204). Additionally, for every 1 mm reduction in the MB-ML orifice distance, the likelihood of detection of MMC in MFM nearly doubled (OR = 1.738). Furthermore, MFMs with MB-ML isthmus were five times more likely to exhibit MMC than those without it (OR = 4.756). The findings revealed that the prevalence of MMC and isthmus in MFMs is high and suggested that anatomical and demographic variables can serve as valuable indicators for clinicians in anticipating their presence.

Uncommon Presentation of Systemic Lupus Erythematosus: Intracranial Mass Lesions as the First Manifestation.

BACKGROUND Multi-system damage is a hallmark of systemic lupus erythematosus (SLE), a chronic systemic autoimmune disease. The typical initial symptoms of SLE are arthritis and dermatosis, whereas the presence of intracranial mass lesions as the first manifestation of systemic lupus erythematosus is very rare. This report describes an 18-year-old woman with intracranial mass lesions associated with SLE. CASE REPORT An 18-year-old woman was initially admitted to the hospital because of headache for 3 days, weakness in left arm, and blurred vision for 1 day. Magnetic resonance imaging (MRI) of her brain showed multiple abnormal occupying lesions in the right frontoparietal lobe. However, no evidence of tumor or infection was found. One month later, she was readmitted with right limb weakness and aphasia for 1 day. Brain MRI showed obvious and new abnormal signal shadows in both the right parietal lobe and the left frontotemporal parieto-occipital lobes compared with the previous MRI. She responded positively to immunotherapy, which, in a woman of child-bearing age, supports the diagnosis of SLE. Ultimately, the presence of focal neurological symptoms, abnormal autoantibodies (such as antinuclear antibodies, anti-dsDNA antibodies, anti-SSA autoantibodies, and anti-ribosomal P protein antibodies), as well as her positive response to immunotherapy, contributed to the diagnosis of SLE with intracranial mass lesions. No recurrence was seen during 1 year of follow-up. CONCLUSIONS It is unusual for SLE to present with intracranial mass lesions as the initial symptoms. The pathogenesis of the neurological symptoms of the patient may be small vessel thrombosis or vasculitis leading to cerebral mass-like necrosis.

Integrated Omics Approach: Revealing the Mechanism of Auxenochlorella pyrenoidosa Protein Extract Replacing Fetal Bovine Serum for Fish Muscle Cell Culture.

The process of producing cell-cultured meat involves utilizing a significant amount of culture medium, including fetal bovine serum (FBS), which represents a considerable portion of production expense while also raising environmental and safety concerns. This study demonstrated that supplementation with Auxenochlorella pyrenoidosa protein extract (APE) under low-serum conditions substantially increased Carassius auratus muscle (CAM) cell proliferation and heightened the expression of Myf5 compared to the absence of APE. An integrated intracellular metabolomics and proteomics analysis revealed a total of 13 and 67 differentially expressed metabolites and proteins, respectively, after supplementation with APE in the medium containing 5%FBS, modulating specific metabolism and signaling pathways, which explained the application of APE for passage cell culture under low-serum conditions. Further analysis revealed that the bioactive factors in the APE were protein components. Moreover, CAM cells cultured in reconstructed serum-free media containing APE, l-ascorbic acid, insulin, transferrin, selenium, and ethanolamine exhibited significantly accelerated growth in a scale-up culture. These findings suggest a promising alternative to FBS for fish muscle cell culture that can help reduce production costs and environmental impact in the production of cultured meat.

Evaluation of choroidal thickness and retinal nerve fiber layer thickness in Chinese pregnant women and healthy non-pregnant women.

Purpose: To evaluate choroidal thickness and retinal nerve fiber layer (RNFL) thickness in different trimesters using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: A prospective comparative study included 45 healthy pregnant women in the first trimester, 45 women in the second, 45 women in the third and 45 healthy non-pregnant women as the control group. Macular choroidal thickness was measured at three locations: The subfoveal, 1 â€‹mm temporal, and 1 â€‹mm nasal from the fovea with EDI-OCT. Peripapillary choroidal thickness (PPCT) and RNFL thickness parameters were automatically calculated by the Spectralis OCT. Results: The subfoveal, temporal and nasal macular choroidal thickness were all significantly thicker in the second trimester, compared with those parameters in the first, the third trimesters and the control group (all P â€‹< â€‹0.05). The PPCT was significantly increased in the second trimeter compared with the control group at global, temporal, temporal inferior, nasal and nasal inferior positions (all P â€‹< â€‹0.05). The RNFL thickness was also significantly increased in pregnant women at nasal superior and nasal inferior quadrants (all P â€‹< â€‹0.05). Conclusions: The choroidal thickness in pregnant women was found to be thicker than the control group, regardless of macular or optic disc location. Findings of RNFL thickening might indicate subclinical involvement of the central nervous system.

OsLESV and OsESV1 promote transitory and storage starch biosynthesis to determine rice grain quality and yield.

Transitory starch is an important carbon source in leaves, and its biosynthesis and metabolism are closely related to grain quality and yield. The molecular mechanisms controlling leaf transitory starch biosynthesis and degradation and their effects on rice (Oryza sativa) quality and yield remain unclear. Here, we show that OsLESV and OsESV1, the rice orthologs of AtLESV and AtESV1, are associated with transitory starch biosynthesis in rice. The total starch and amylose contents in leaves and endosperms are significantly reduced, and the final grain quality and yield are compromised in oslesv and osesv1 single and oslesv esv1 double mutants. Furthermore, we found that OsLESV and OsESV1 bind to starch, and this binding depends on a highly conserved C-terminal tryptophan-rich region that acts as a starch-binding domain. Importantly, OsLESV and OsESV1 also interact with the key enzymes of starch biosynthesis, granule-bound starch synthase I (GBSSI), GBSSII, and pyruvate orthophosphote dikiase (PPDKB), to maintain their protein stability and activity. OsLESV and OsESV1 also facilitate the targeting of GBSSI and GBSSII from plastid stroma to starch granules. Overexpression of GBSSI, GBSSII, and PPDKB can partly rescue the phenotypic defects of the oslesv and osesv1 mutants. Thus, we demonstrate that OsLESV and OsESV1 play a key role in regulating the biosynthesis of both leaf transitory starch and endosperm storage starch in rice. These findings deepen our understanding of the molecular mechanisms underlying transitory starch biosynthesis in rice leaves and reveal how the transitory starch metabolism affects rice grain quality and yield, providing useful information for the genetic improvement of rice grain quality and yield.

Helicobacter pylori-related host gene polymorphisms associated with susceptibility of gastric carcinogenesis: a two-stage case-control study in Chinese.

Stomach carcinogenesis progresses stepwise from normal mucosa/superficial gastritis, atrophic gastritis (GA) to gastric cancer (GC). Host factors independent of or combined with Helicobacter pylori infection may modulate the carcinogenesis process. In this two-stage study, we selected 24 putative functional tag single-nucleotide polymorphisms (tagSNPs) for six H.pylori-related host genes, MUC1, toll-like receptor 4 (TLR4), protein tyrosine phosphatase, non-receptor type 11 (PTPN11), IL-1B, PGC and PGA3-5, and analyzed their influence and interaction with H.pylori on the GA and GC risks. Using high-throughput genotyping, the 24 tagSNPs were preliminarily assessed in a screening population of 552 controls, 254 GA and 236 GC subjects; subsequently, five candidate tagSNPs for gastric diseases risk in the TLR4, PGC and PTPN11 genes were re-evaluated in a larger population of 1276 controls, 907GA and 714 GC subjects. We observed that PGC rs6458238, PGC rs4711690 and PTPN11 rs12229892 were associated with susceptibilities to GA and/or GC. Moreover, rs4711690 and rs12229892 and H.pylori demonstrated significant interaction effects on GA risk. In gastric cancerous specimens, we observed significantly higher messenger RNA level in the subjects carrying the PGC rs6458238 GA genotype than that in subjects with the common GG genotype. These findings indicated that genetic variations of two crucial H.pylori-related host genes, H.pylori's mucosal effecter PGC gene and H.pylori's cellular messenger PTPN11 gene, either dependent or independent of interaction with H.pylori, were associated with the risks of GC and/or GA that precede carcinoma. Functional studies and further independent large-scale studies especially in other ethnic populations are still needed to confirm our results.

The biological activity of H. pylori SlyD in vitro.

AIM: To investigate the biological activity of the H. pylori SlyD in vitro. METHODS: Helicobacter pylori (H.pylori) slyD prokaryotic expression vector was carried out in Escherichia coli (E.coli), and recombination SlyD (rSlyD) was purified by immobilized metal affinity chromatography. The proliferation, apoptosis, invasion, transformation effects of rSlyD on AGS cells was detected by CCK-8, cell cycle, caspase-3 activity, matrigel invasion assay, and double-deck soft agar colony forming efficiency. In addition, the expressions of PCNA, KI-67, caspase-3, and MMP-9 were detected by western blot and immunofluorescence assay, respectively. RESULTS: The CCK-8 assay revealed that cell proliferation was increased in a time and dose-dependent manner in AGS + rSlyD group compared with that of AGS or AGS + PBS group (p < .05). There are significant difference of PCNA and KI67 expressions among AGS, AGS + PBS, AGS + rSlyD groups (p < .05). Soft agar colony formation assay revealed the colony number (foci>100 µm) in AGS + rSlyD group was 26.3 ± 7.09, whereas 5.6 ± 1.15 in AGS and 5.0 ± 1.0 in AGS + PBS groups, respectively (p < .01). Colorimetric enzyme assay revealed the activity of caspase-3 was decreased to 31.45 ± 0.49 after treatment with rSlyD, whereas 55.5 ± 0.43 in AGS and 55.1 ± 0.25 in AGS + PBS group, respectively (p < .001). Similar caspase-3 expression also was confirmed by Western blot. The number of invasive cells in transwell chambers assay is 196.66 ± 40.41 in AGS + rSlyD group higher than 85 ± 22.9 in AGS or 81.66 ± 15.27 in AGS + PBS group, respectively (p < .001). The MMP-9 expression in AGS + rSlyD group was also higher than that of AGS or AGS + PBS group. CONCLUSION: These results suggest that the HpSlyD may play an important role in disturbing cell proliferation, apoptosis, and enhancing cell transformation and invasion in the AGS cell line. HpSlyD might contribute to gastric pathogenicity in H.pylori-associated diseases.

Pepsinogen I and II expressions in situ and their correlations with serum pesignogen levels in gastric cancer and its precancerous disease.

BACKGROUND: Serum pepsinogen (PG) I/II ratio has been widely used as "serological biopsy" for the screening of gastric cancer (GC) and atrophic gastritis (GA). However, study concerning in situ expression of PGs is currently insufficient, particularly for their relationship with serum PGs levels. This study was designed to investigate in situ expression of PGI and PGII in subjects with normal mucosa (NOR), superficial gastritis (GS), GA and GC, and to evaluate the correlations between PGs expressions in situ and in serum. METHODS: 185 subjects were enrolled for the study, including 30 NOR, 70 GS, 54 GA and 31 GC. PGI and PGII expressions in situ and in serum were detected by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) respectively. H. pylori immunoglobulin (Ig) G was also determined by ELISA. RESULTS: In situ expressions of PGI, PGII and PGI/II ratio consistently decreased in sequence of NOR/GS- > GA- > GC. The expressions of PGI, PGII and PGI/II ratio in situ were statistically higher in youngers than in olders (P < 0.05). In the NOR subjects, PGI staining was statistically higher in males than that in females (p = 0.02). For the correlations between in situ and serum expressions of PGI, PGII and PGI/II ratio, a borderline correlation in the total study sample (r = 0.131, P = 0.076) and a statistical correlation in GA cases (r = 0.307, P = 0.027) were observed for the PGI/II ratio. The PGI expression correlated well with that of PGII in situ and in serum. CONCLUSIONS: The in situ levels of PGI, PGII and PGI/II ratio sharply decreased in the GA and GC cases. The youngers exhibited higher levels of PGI, PGII and PGI/II ratios than the olders. The in situ PGI/II ratio rather than PGI and PGII alone showed certain correlation with that in serum, and the PGI expression correlated well with PGII expression. Further studies with large-scale samples are still required to validate our findings.

Auxenochlorella pyrenoidosa extract supplementation replacing fetal bovine serum for Carassius auratus muscle cell culture under low-serum conditions.

Cultured meat production requires large-scale cell proliferation in vitro with the supplementation of necessary media especially serum. This study investigated the capacity of Auxenochlorella pyrenoidosa extract (APE) to replace fetal bovine serum (FBS) for cell culture under low-serum conditions using Carassius auratus muscle (CAM) cells. Supplementation with APE and 5% FBS in the culture media significantly promoted the proliferation of CAM cells and increased the expression of MyoD in cells compared to that with 5% FBS through cell counting kit-8 and immunofluorescence staining assay. In addition, CAM cells in the media containing 5% FBS and APE could be continually cultured for 4 passages, and the cell number was 1.58 times higher than the counterpart without APE in long-term culture. Moreover, supplementation with APE realized large-scale culture on microcarriers under low-serum conditions, and more adherent cells were observed on microcarriers in 2% FBS supplemented with APE, compared with those in 2% FBS and 10% FBS without APE. These findings highlighted a potentially promising application of APE in muscle cell culture under low-serum conditions for cultured meat production.

OsLEA1b Modulates Starch Biosynthesis at High Temperatures in Rice.

High temperatures accelerate the accumulation of storage material in seeds, often leading to defects in grain filling. However, the mechanisms regulating grain filling at high temperatures remain unknown. Here, we want to explore the quality factors influenced by the environment and have identified a LATE EMBROYGENESIS ABUNDANT gene, OsLEA1b, a heat-stress-responsive gene in rice grain filling. OsLEA1b is highly expressed in the endosperm, and its coding protein localizes to the nucleus and cytoplasm. Knock-out mutants of OsLEA1b had abnormal compound starch granules in endosperm cells and chalky endosperm with significantly decreased grain weight and grain number per panicle. The oslea1b mutants exhibited a lower proportion of short starch chains with degrees of polymerization values from 6 to 13 and a higher proportion of chains with degrees from 14 to 48, as well as significantly lower contents of starch, protein, and lipid compared to the wild type. The difference was exacerbated under high temperature conditions. Moreover, OsLEA1b was induced by drought stress. The survival rate of oslea1b mutants decreased significantly under drought stress treatment, with significant increase in ROS levels. These results indicate that OsLEA1b regulates starch biosynthesis and influences rice grain quality, especially under high temperatures. This provides a valuable resource for genetic improvement in rice grain quality.

Sensitive and Enzyme-Free Pathogenic Bacteria Detection Through Self-Circulation of Molecular Beacon.

This research exhibits the design of a feasible, enzyme-free and sensitive fluorescent sensing assay for the detection of Staphylococcus aureus (S. aureus), using self-circulation of molecular beacons. With protein A on S. aureus as identifying target, the capture probe binds on the surface of S. aureus based on interaction between its aptamer section and protein A. Recognition of protein A by aptamer section in capture probe leads to allosterism of capture probe, exposing initiator section to activate the following self-circulation. After multiple circulation-based signal amplification, the method exhibits a favorable detection sensitivity and shows a promising prospect for the keratitis-related pathogenic bacteria detection. The highlights of the sensing assay are as follows: (i) capture probe is designed with aptamer section which endows the method a high selectivity; (ii) signal of bacteria is converted to nucleic acid signal after recognition of target bacteria by capture probe; and (iii) high sensitivity of method is derived from the self-circulation process. Therefore, we believe that the strategy can provide a useful platform for target bacteria detection and thus contribute to the diagnosis of infectious diseases.

The Arabidopsis Receptor-like Kinase CAP1 Promotes Shoot Growth under Ammonium Stress.

High levels of ammonium (NH4+) in soils inhibit plant growth and nitrogen utilization efficiency. Elucidating the underlying mechanisms of NH4+ toxicity is essential for alleviating the growth inhibition caused by high NH4+. Our previous work showed that [Ca2+]cyt-associated protein kinase 1 (CAP1) regulates root hair growth in response to NH4+ in Arabidopsis thaliana, and the cap1-1 mutant produces short root hairs under NH4+ stress conditions. However, it is unclear whether CAP1 functions in other physiological processes in response to NH4+. In the present study, we found that CAP1 also plays a role in attenuating NH4+ toxicity to promote shoot growth. The cap1-1 mutant produced smaller shoots with smaller epidermal cells compared with the wild type in response to NH4+ stress. Disruption of CAP1 enhanced the NH4+-mediated inhibition of the expression of cell enlargement-related genes. The cap1-1 mutant showed elevated reactive oxygen species (ROS) levels under NH4+ stress, as well as increased expression of respiratory burst oxidase homologue genes and decreased expression of catalase genes compared with the wild type. Our data reveal that CAP1 attenuates NH4+-induced shoot growth inhibition by promoting cell wall extensibility and ROS homeostasis, thereby highlighting the role of CAP1 in the NH4+ signal transduction pathway.

OPAQUE3, encoding a transmembrane bZIP transcription factor, regulates endosperm storage protein and starch biosynthesis in rice.

Starch and storage proteins are the main components of rice (Oryza sativa L.) grains. Despite their importance, the molecular regulatory mechanisms of storage protein and starch biosynthesis remain largely elusive. Here, we identified a rice opaque endosperm mutant, opaque3 (o3), that overaccumulates 57-kDa proglutelins and has significantly lower protein and starch contents than the wild type. The o3 mutant also has abnormal protein body structures and compound starch grains in its endosperm cells. OPAQUE3 (O3) encodes a transmembrane basic leucine zipper (bZIP) transcription factor (OsbZIP60) and is localized in the endoplasmic reticulum (ER) and the nucleus, but it is localized mostly in the nucleus under ER stress. We demonstrated that O3 could activate the expression of several starch synthesis-related genes (GBSSI, AGPL2, SBEI, and ISA2) and storage protein synthesis-related genes (OsGluA2, Prol14, and Glb1). O3 also plays an important role in protein processing and export in the ER by directly binding to the promoters and activating the expression of OsBIP1 and PDIL1-1, two major chaperones that assist with folding of immature secretory proteins in the ER of rice endosperm cells. High-temperature conditions aggravate ER stress and result in more abnormal grain development in o3 mutants. We also revealed that OsbZIP50 can assist O3 in response to ER stress, especially under high-temperature conditions. We thus demonstrate that O3 plays a central role in rice grain development by participating simultaneously in the regulation of storage protein and starch biosynthesis and the maintenance of ER homeostasis in endosperm cells.

Serum pepsinogen II: a neglected but useful biomarker to differentiate between diseased and normal stomachs.

BACKGROUND AND AIM: Serum pepsinogen II (sPGII) is underutilized and considered an inconspicuous biomarker in clinical practice. We refocused on this neglected but novel biomarker and conducted the present study, aiming to elucidate the normal level of sPGII in healthy Chinese patients and to investigate the clinical utility of sPGII for gastric disease screening. METHODS: In 2008-2009, a total of 2022 participants from northern China were selected and enrolled in the study. sPGII and Helicobacter pylori (H. pylori)-immunoglobulin G were measured with ELISA. RESULTS: sPGII showed a normal value of 6.6 microg/L in a total of 466 patients with endoscopically- and histologically-normal stomachs. A small sex difference was observed: the average value of sPGII was 7 microg/L and 6 microg/L in males and females, respectively (P < 0.001). In the differentiation between healthy and diseased (endoscopically-diseased stomach or gastritis/atrophic gastritis in endoscopic biopsies) stomach mucosae, the best sPGII cut-off value was 8.25 microg/L (sensitivity 70.6%, specificity 70.8%). In screening the H. pylori seropositivity, the optimum cut-off sPGII value was 10.25 microg/L (sensitivity 71.6%, specificity 70.1%). CONCLUSIONS: We demonstrated that the mean values of sPGII in a healthy Chinese population are 7 microg/L and 6 microg/L for males and females, respectively. sPGII significantly increases in diseased and H. pylori-infected stomach, and the best sPGII cut-off value is 8.25 microg/L in the differentiation between patients with healthy and diseased stomach mucosae. Furthermore, Chinese patients with sPGII greater than 10.25 microg/L are at greater risk of various H. pylori-related gastropathies, and are therefore prior candidates for gastro-protection therapy.