Erratum: Metabolomics analysis of stool in rats with type 2 diabetes mellitus after single-anastomosis duodenal-ileal bypass with sleeve gastrectomy.

[This corrects the article DOI: 10.3389/fendo.2022.1013959.].

Metabolomics analysis of stool in rats with type 2 diabetes mellitus after single-anastomosis duodenal-ileal bypass with sleeve gastrectomy.

Background: Single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) is one of the most effective bariatric procedures in the treatment of type 2 diabetes mellitus (T2DM). However, the mechanisms by which SADI-S improves T2DM are not well-known. Objective: To explore the effects of SADI-S on metabolites in the stool of rats with T2DM. Methods: Twenty rats were fed on high-fat diet and administered with a low-dose (30mg/kg) of streptozotocin to establish T2DM models. The rats were then randomly assigned to the SADI-S group (n=10) and sham operation group (n=9). Stool samples were collected from all rats at 8 weeks after surgery and stored at -80 °C. Metabolomics analysis was performed to identify differential metabolites through ultra- performance liquid chromatography-mass spectrometry. Results: At 8-week after surgery, rats of the SADI-S group showed significantly decreased fasting blood glucose, glucose tolerance test 2-hour, glycated haemoglobin, and body weight compared with those of the sham group. A total of 245 differential metabolites were identified between the two groups. Among them, 16 metabolites such as branched-chain amino acids (valine), aromatic amino acid (phenylalanine), bile acid (cholic acid, lithocholic acid, and ß-muricholic acid), short-chain fatty acid (isobutyric acid), and phospholipid [lysoPE(17:0), lysoPE(20:3) and lysoPS(16:0)] were associated to the T2DM remission after SADI-S. Conclusion: SADI-S improves T2DM in rats by regulating phenylalanine biosynthesis, valine, phenylalanine, alanine, glutamate, proline, bile acid, and phospholipid metabolism pathways.

Evaluation of the learning curve for robotic single-anastomosis duodenal-ileal bypass with sleeve gastrectomy.

Background: The robotic surgical system is being used in various bariatric procedures. However, only a few studies with very small sample size are present on robotic single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S). Moreover, to date, the learning curve of robotic SADI-S has been poorly evaluated yet. Objective: This retrospective study aimed to estimate the learning curve of robotic SADI-S. Methods: 102 consecutive patients who underwent robotic SADI-S between March 2020 and December 2021 were included. Textbook outcome standard was performed to comprehensively evaluate clinical outcome of robotic SADI-S. Based on the textbook outcome, we evaluated the learning curve of robotic SADI-S by the cumulative sum (CUSUM) method. Results: The mean operative time was 186.13 ± 36.91 min. No conversion to laparotomy or deaths occurred during the study period. The rate of complications was 6.9% (n = 7), of which major complications were identified in 2.9% (n = 3), including 2 gastric leakages and 1 respiratory failure. A total of 60 patients reached the textbook outcome standard. The rate of textbook outcome was positive and was steadily increasing after the number of surgical cases accumulated to the 58th case. Taking the 58th case as the boundary, all the patients were divided into the learning stage group (the first 58 patients) and mastery stage group (the last 44 patients). The rate of complications, proportion of abdominal drainage tubes and postoperative hospital stay were significantly higher in the learning stage group compared with the mastery stage group (P < 0.05). No significant difference was observed between the two groups in terms of patient demographic data, operative times, reoperations and readmission. Conclusion: Robotic SADI-S is a feasible and reproducible surgical technique with a learning curve of 58 cases.

OTP970 Is Required for RNA Editing of Chloroplast ndhB Transcripts in Arabidopsis thaliana.

RNA editing is essential for compensating for defects or mutations in haploid organelle genomes and is regulated by numerous trans-factors. Pentatricopeptide repeat (PPR) proteins are the prime factors that are involved in RNA editing; however, many have not yet been identified. Here, we screened the plastid-targeted PLS-DYW subfamily of PPR proteins belonging to Arabidopsis thaliana and identified ORGANELLE TRANSCRIPT PROCESSING 970 (OTP970) as a key player in RNA editing in plastids. A loss-of-function otp970 mutant was impaired in RNA editing of ndhB transcripts at site 149 (ndhB-C149). RNA-immunoprecipitation analysis indicated that OTP970 was associated with the ndhB-C149 site. The complementation of the otp970 mutant with OTP970 lacking the DYW domain (OTP970∆DYW) failed to restore the RNA editing of ndhB-C149. ndhB gene encodes the B subunit of the NADH dehydrogenase-like (NDH) complex; however, neither NDH activity and stability nor NDH-PSI supercomplex formation were affected in otp970 mutant compared to the wild type, indicating that alteration in amino acid sequence is not necessary for NdhB function. Together, these results suggest that OTP970 is involved in the RNA editing of ndhB-C149 and that the DYW domain is essential for its function.

The juxtamembrane domains of Arabidopsis CERK1, BAK1, and FLS2 play a conserved role in chitin-induced signaling.

Arabidopsis thaliana CERK1 is an essential receptor-like kinase in the chitin signal transduction pathway. The juxtamembrane (JM) domain of CERK1 regulates the kinase activity of this receptor. Here we demonstrate that the JM domains of LysM-RLKs, CERK1, and OsCERK1 play a functionally conserved role in the activation of chitin signaling in Arabidopsis. The C-termini of the JM domains of both CERK1 and OsCERK1 are indispensable for their function. Moreover, after replacing the JM domain of CERK1 with that of the nonhomologous RLK, BAK1 (CJBa) or FLS2 (CJFl), the chimeric CERK1 receptors maintained their ability to activate chitin signaling in Arabidopsis. Interestingly, the heterologous expression of CJBa and CJFl did not induce cell death in Nicotiana benthamiana leaves. These results suggest that the JM domains of CERK1, BAK1, and FLS2 play a conserved role in chitin signaling via a mechanism not related to sequence homology.

[Acupressure with activating blood and dissipating blood stasis prescription for early swelling of calcaneal fractures].

OBJECTIVE: To observe clinical effects of acupressure combined with activating blood and dissipating blood stasis prescription for the treatment of early swelling of calcaneal fractures. METHODS: From June 2016 to April 2018, 78 patients with calcaneus were divided into observation group and control group. There were 39 patients in observation group, including 36 males and 3 females aged from 28 to 61 years old with an average of(41.7±13.3) years old; 20 patients were caused by falling down, 10 patients were caused by traffic accident and 9 patients were caused by other injuries; The time from injury to medical treatment ranged from 0.5 to 10.5 h with an average of(4.6±3.2) h; 15 patients were type II, 17 patients were type III and 7 patients were type IV according to Sanders classification; the patients began to be pressed the three points of "Xuehai(SP 10)" "Sanyinjiao(SP 6)" "Zusanli(ST 36)" for 10 min from the day of hospital admission to the day of operation, 3 times a day, and taken prescription of activating blood and dissipating blood stasis prescription orally for 5 days, one dose per day and twice a day. There were 39 patients in control group, including 34 males and 5 females aged from 26 to 62 years old with an average of (43.3±12.3) years old; 19 patients were caused by falling down, 12 patients were caused by traffic accident and 8 patients were caused by other injuries; the time from injury to medical treatment ranged from 1 to 11 h with an average of (4.4±3.7) h; 15 patients were typeII, 18 patients were type III and 6 patients were type IV according to Sanders classification; patients were given 20% mannitol intravenously for 5 days, twice a day, 125 ml each time from hospital admission. During the 5 days of admission, the degree of swelling of the affected ankle was measured and calculated by water spillover method every day. The result which was measured and calculated on the first day of admission without treatment was the degree of swelling before treatment, compared degree of swelling before operation and 1st, 2nd, 3rd and 4th day after treatment; the time needed for the first positive skin fold sign in the affected ankle and the number of cases of tension blisters between two groups before operation were observed. RESULTS: The swelling of the affected ankle on the1st, 2nd, 3rd and 4th day after treatment in the observation group separately were(12.67±0.82)%, (11.87±0.88)%, (10.65±0.92)%, (9.47±0.96)%, and lower than control group which separately were(13.31±0.98)%, (13.51±0.84)%, (12.22±0.94)%, (11.38±1.01)%; The time for the first appearance of the skin fold sign was (6.41±1.74) days in the observation group was earlier than that of the control group (8.15±2.01) days; There was no significant difference in occurrence of tension blisters between observation group(3 patients) and control group(9 patients). CONCLUSIONS: Acupressure combined with activating blood and dissipating blood stasis prescription for the treatment of early swelling of calcaneal fractures could accelerate the decline of swelling of the affected ankle, shorten the time of the first skin fold sign, reduce the incidence of tension blisters in the ankle, shorten the waiting time of operation, and the surgical treatment as soon as possible.

Brain networks modeling for studying the mechanism underlying the development of Alzheimer's disease.

Alzheimer's disease is a primary age-related neurodegenerative disorder that can result in impaired cognitive and memory functions. Although connections between changes in brain networks of Alzheimer's disease patients have been established, the mechanisms that drive these alterations remain incompletely understood. This study, which was conducted in 2018 at Northeastern University in China, included data from 97 participants of the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset covering genetics, imaging, and clinical data. All participants were divided into two groups: normal control (n = 52; 20 males and 32 females; mean age 73.90 ± 4.72 years) and Alzheimer's disease (n = 45, 23 males and 22 females; mean age 74.85 ± 5.66). To uncover the wiring mechanisms that shaped changes in the topology of human brain networks of Alzheimer's disease patients, we proposed a local naïve Bayes brain network model based on graph theory. Our results showed that the proposed model provided an excellent fit to observe networks in all properties examined, including clustering coefficient, modularity, characteristic path length, network efficiency, betweenness, and degree distribution compared with empirical methods. This proposed model simulated the wiring changes in human brain networks between controls and Alzheimer's disease patients. Our results demonstrate its utility in understanding relationships between brain tissue structure and cognitive or behavioral functions. The ADNI was performed in accordance with the Good Clinical Practice guidelines, US 21CFR Part 50-Protection of Human Subjects, and Part 56-Institutional Review Boards (IRBs)/Research Good Clinical Practice guidelines Institutional Review Boards (IRBs)/Research Ethics Boards (REBs).

Effect of Laparoscopic Sleeve Gastrectomy on Type 2 Diabetes Mellitus in Patients with Body Mass Index less than 30 kg/m2.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has been proved to be the most effective treatment strategy for the treatment of type 2 diabetes mellitus (T2DM) with a body mass index ≥ 30 kg/m2 achieving high remission rates. However, there are few clinical studies on the treatment of T2DM patients with a body mass index less than 30 kg/m2 by LSG. This study aims to study the effect of LSG on type 2 diabetes mellitus(T2DM) in patients with a body mass index (BMI) less than 30 kg/m2. METHODS: The clinical data of 25 patients with type 2 diabetes mellitus (T2DM) and body mass index 23.23-29.97 kg/m2 who were treated by LSG at the Department of Bariatric and Metabolic Surgery in China-Japan Union Hospital of Jilin University from May 2016 to May 2017 were retrospectively analyzed. The changes of fasting plasma glucose, glycosylated hemoglobin, insulin resistance index, body weight, body mass index, waist circumference, blood pressure, heart rate, blood lipids, and uric acid were analyzed at 3 months, 6 months, and 12 months after operation, respectively. All the clinical data were analyzed by SPSS 22.0. They were tested with a single-sample K-S test to determine whether they were normal distribution data. The normal distribution data were analyzed by a matched t test, and the Mann-Whitney test was used to examine skewed data. RESULTS: All patients (9 males, 16 females) with a median age of 57(24~65) years were treated successfully by laparoscopic sleeve gastrectomy. The median duration of type 2 diabetes mellitus was 10(0~20)years. The preoperative fasting plasma glucose, glycosylated hemoglobin, body weight, body mass index, and waist circumference were 10.32 ± 2.66 mmol/L,8.20 ± 1.47%,76.54 ± 10.02 kg,27.92 ± 1.72 kg/m2, and 99.88 ± 5.38 cm, respectively. The meaning fasting plasma glucose was 7.26 ± 1.36 mmol/L, 6.90 ± 1.07 mmol/L, and 6.62 ± 0.97 mmol/L, respectively, at 3, 6, and 12 months after operation. The mean HbAlc in the same observation intervals was 6.88 ± 1.23%,6.54 ± 1.02%, and 6.51 ± 0.89%, respectively. The body weight was 62.18 ± 8.38 kg,59.07 ± 8.58 kg, and 58.62 ± 8.53 kg, respectively. The corresponding body mass index was 22.56 ± 1.56 kg/m2, 21.35 ± 1.58 kg/m2, and 21.24 ± 1.86 kg/m2, respectively. The waist circumference was 82.84 ± 5.10 cm,78.60 ± 5.21 cm, and 76.92 ± 5.21 cm, respectively. The complete remission rates of type 2 diabetes mellitus were 40%, 60%, and 68%, respectively, at 3, 6, and 12 months after operation. The complete remission rates for insulin resistance index were 52.4%, 80%, and 80%, postoperatively, at 3, 6, and 12 months, respectively. The complete remission rates of hypertension were 22.2%, 50%, and 75%,respectively, at 3,6, and 12 months after operation. The complete remission rates of hypertriglyceridemia were 66.7%, 66.7%, and 100%,and the complete remission rates of hypercholesterolemia were 41.7%, 60%, and 100%;the abnormal elevations of plasma cholesterol in two patients with normal cholesterol before operation were significantly higher, postoperatively, at 3 monthsand 6 months, respectively. The complete remission rates of hyperuricemia were 37.5%, 33.3%, and 100% in the same observation period, respectively. The abnormal elevations of uric acid in two patients with normal uricemia before operation were significantly higher at postoperative 3 months. CONCLUSION: LSG has a significant effect on patients with type 2 diabetes mellitus whose BMI less than 30 kg/m2 in a short time, but its long-term effectiveness needs to be further followed up.

[Current status and perspective of bariatric surgery in the treatment of type 1 diabetes with obesity].

With the development of social economy and the change of lifestyle and working environment, the number of obese and diabetic population has increased significantly. Obesity is closely related to diabetes mellitus with interaction. Among the patients with type 1 diabetes mellitus (T1DM), the cardiovascular risk of T1DM with obesity is significantly higher than those of lean T1DM. The mortality of T1DM with obesity is significantly higher than that of the general population, which poses a great threat to human health, making it become one of the serious public health problems we have to face at present. However, the traditional treatment method of obesity and diabetes has limited effects and fails to effectively solve obesity, diabetes mellitus and its complications. The birth of bariatric surgery brings a new hope to the treatment of obesity and diabetes. After more than half of a century progress, bariatric surgery has become an effective way to cure or relieve obesity, type 2 diabetes and other metabolic syndromes, which is included in the diabetes treatment guidelines. In patients with diabetes, there are a large number of T1DM patients with obesity being in urgent need of surgical treatment, but only a few patients were reported. From the existing papers and case reports , we can see parameters in many aspects, such as BMI, insulin requirement per day, blood pressure and blood plasma lipid, were significantly reduced after bariatric surgery as well as insulin resistance, diabetic complications, polycystic ovarian syndrome and obstructive sleep apnea hypopnea syndrome were improved or even reversed. However, bariatric surgery in treating T1DM with obesity has not yet reached a consensus in the medical community and not been written to diabetes treatment guidelines. In this paper, the operation methods and mechanism, curative effects, disadvantages and its preventive measures, current status and perspective of bariatric surgery in treating T1DM with obesity are reviewed so as to provide reference for clinical practice.

LOW PHOTOSYNTHETIC EFFICIENCY 1 is required for light-regulated photosystem II biogenesis in Arabidopsis.

Photosystem II (PSII), a multisubunit protein complex of the photosynthetic electron transport chain, functions as a water-plastoquinone oxidoreductase, which is vital to the initiation of photosynthesis and electron transport. Although the structure, composition, and function of PSII are well understood, the mechanism of PSII biogenesis remains largely elusive. Here, we identified a nuclear-encoded pentatricopeptide repeat (PPR) protein LOW PHOTOSYNTHETIC EFFICIENCY 1 (LPE1; encoded by At3g46610) in Arabidopsis, which plays a crucial role in PSII biogenesis. LPE1 is exclusively targeted to chloroplasts and directly binds to the 5' UTR of psbA mRNA which encodes the PSII reaction center protein D1. The loss of LPE1 results in less efficient loading of ribosome on the psbA mRNA and great synthesis defects in D1 protein. We further found that LPE1 interacts with a known regulator of psbA mRNA translation HIGH CHLOROPHYLL FLUORESCENCE 173 (HCF173) and facilitates the association of HCF173 with psbA mRNA. More interestingly, our results indicate that LPE1 associates with psbA mRNA in a light-dependent manner through a redox-based mechanism. This study enhances our understanding of the mechanism of light-regulated D1 synthesis, providing important insight into PSII biogenesis and the functional maintenance of efficient photosynthesis in higher plants.

Enhancing the functional output of transplanted islets in diabetic mice using a drug-eluting scaffold.

BACKGROUND: Islet transplantation is increasingly used in the diabetic patients to control the blood glucose level. However, the functional output of transplanted islets remains hampered due to the local inflammation, loss of islets, etc. To that end, in this study we explored to enhance the functional output of transplanted islets in diabetic mice by employing a drug-eluting scaffold with a payload of interleukin 4 (IL-4). RESULTS: According to the in vitro studies, the scaffold showed no cytotoxicity, a rapid release of IL-4 within a week and the IL-4 retained its bioactivity. During the 4-week time window after the islet transplantation, in vivo studies showed that the levels of blood insulin and C-peptide 2 in diabetic mice in the drug-eluting scaffold group significantly increased since week 2, which effectively reduced the blood glucose level. In addition, these mice demonstrated a stronger capability to withstand a rapid glucose spike as evidenced by the tolerance of sudden oral glucose challenge test result. A further mechanistic study suggested that the enhanced functional output could be attributed to the M2 polarization of macrophages as evidenced by the increase of CD163+/CD68+ macrophages in the islet tissues. A M2 polarization of macrophages is widely believed to exert an anti-inflammatory influence on local tissues, which could accelerate the resolution of local inflammation following the islet transplantation. CONCLUSION: Our study shed a new light on the hyperglycemia management of diabetic patients following the islet transplantation.

A Tyrosine Phosphorylation Cycle Regulates Fungal Activation of a Plant Receptor Ser/Thr Kinase.

Plants initiate immunity by cell-surface pattern-recognition receptors (PRRs), which perceive non-self molecules. PRRs are predominantly receptor serine/threonine (Ser/Thr) kinases that are evolutionarily related to animal interleukin-1 receptor-associated kinase (IRAK)/Pelle-soluble kinases. However, how the activity of these receptor kinases is modulated remains poorly understood. We report that the Arabidopsis PRR chitin elicitor receptor kinase 1 (CERK1) is autophosphorylated in unstimulated cells at tyrosine428 (Tyr428), a modification that is required for CERK1 activation upon binding to the fungal cell wall component chitin. Upon chitin activation, CERK1 recruits the CERK1-interacting protein phosphatase 1 (CIPP1), a predicted Ser/Thr phosphatase, to dephosphorylate Tyr428 and dampen CERK1 signaling. CIPP1 subsequently dissociates from Tyr428-dephosphorylated CERK1, allowing CERK1 to regain Tyr428 autophosphorylation and return to a standby state. This work sheds light onto plant chitin signaling and shows that a receptor kinase and phosphatase can coordinately regulate signal transduction of a receptor kinase through a phosphorylation cycle.

M-type thioredoxins are involved in the xanthophyll cycle and proton motive force to alter NPQ under low-light conditions in Arabidopsis.

KEY MESSAGE: M-type thioredoxins are required to regulate zeaxanthin epoxidase activity and to maintain the steady-state level of the proton motive force, thereby influencing NPQ properties under low-light conditions in Arabidopsis. Non-photochemical quenching (NPQ) helps protect photosynthetic organisms from photooxidative damage via the non-radiative dissipation of energy as heat. Energy-dependent quenching (qE) is a major constituent of NPQ. However, the mechanism underlying the regulation of qE is not well understood. In this study, we demonstrate that the m-type thioredoxins TRX-m1, TRX-m2, and TRX-m4 (TRX-ms) interact with the xanthophyll cycle enzyme zeaxanthin epoxidase (ZE) and are required for maintaining the redox-dependent stabilization of ZE by regulating its intermolecular disulfide bridges. Reduced ZE activity and accumulated zeaxanthin levels were observed under TRX-ms deficiency. Furthermore, concurrent deficiency of TRX-ms resulted in a significant increase in proton motive force (pmf) and acidification of the thylakoid lumen under low irradiance, perhaps due to the significantly reduced ATP synthase activity under TRX-ms deficiency. The increased pmf, combined with acidification of the thylakoid lumen and the accumulation of zeaxanthin, ultimately contribute to the elevated stable qE in VIGS-TRX-m2m4/m1 plants under low-light conditions. Taken together, these results indicate that TRX-ms are involved in regulating NPQ-dependent photoprotection in Arabidopsis.

Thioredoxin and NADPH-Dependent Thioredoxin Reductase C Regulation of Tetrapyrrole Biosynthesis.

In chloroplasts, thioredoxin (TRX) isoforms and NADPH-dependent thioredoxin reductase C (NTRC) act as redox regulatory factors involved in multiple plastid biogenesis and metabolic processes. To date, less is known about the functional coordination between TRXs and NTRC in chlorophyll biosynthesis. In this study, we aimed to explore the potential functions of TRX m and NTRC in the regulation of the tetrapyrrole biosynthesis (TBS) pathway. Silencing of three genes, TRX m1, TRX m2, and TRX m4 (TRX ms), led to pale-green leaves, a significantly reduced 5-aminolevulinic acid (ALA)-synthesizing capacity, and reduced accumulation of chlorophyll and its metabolic intermediates in Arabidopsis (Arabidopsis thaliana). The contents of ALA dehydratase, protoporphyrinogen IX oxidase, the I subunit of Mg-chelatase, Mg-protoporphyrin IX methyltransferase (CHLM), and NADPH-protochlorophyllide oxidoreductase were decreased in triple TRX m-silenced seedlings compared with the wild type, although the transcript levels of the corresponding genes were not altered significantly. Protein-protein interaction analyses revealed a physical interaction between the TRX m isoforms and CHLM. 4-Acetoamido-4-maleimidylstilbene-2,2-disulfonate labeling showed the regulatory impact of TRX ms on the CHLM redox status. Since CHLM also is regulated by NTRC (Richter et al., 2013), we assessed the concurrent functions of TRX m and NTRC in the control of CHLM. Combined deficiencies of three TRX m isoforms and NTRC led to a cumulative decrease in leaf pigmentation, TBS intermediate contents, ALA synthesis rate, and CHLM activity. We discuss the coordinated roles of TRX m and NTRC in the redox control of CHLM stability with its corollary activity in the TBS pathway.

OsRLCK 57, OsRLCK107 and OsRLCK118 Positively Regulate Chitin- and PGN-Induced Immunity in Rice.

BACKGROUND: The receptor-like cytoplasmic kinase, OsRLCK176 has been reported to participate in both chitin- and PGN-induced immunity in rice. Here, we further researched the function of the homologous proteins, OsRLCK57, OsRLCK107 and OsRLCK118, in chitin- and PGN immunity in rice. FINDINGS: Silencing of OsRLCK57,OsRLCK107 and OsRLCK118 suppressed chitin- and PGN-induced immunity responses, including reactive oxygen species generation, defense gene expression. Furthermore, OsRLCK107 could interact with OsCERK1 in a MAMP induced way, which suggested a possible physiological relevance of OsRLCKs107 to OsCERK1 pathway. CONCLUSIONS: OsRLCK57, OsRLCK107 and OsRLCK118, positively regulate chitin- and PGN- induced responses in rice, similar to that observed in OsRLCK176.

BIK1 cooperates with BAK1 to regulate constitutive immunity and cell death in Arabidopsis.

In Arabidopsis, both the membrane-anchored receptor-like kinase (RLK) BAK1 and the receptor-like cytoplasmic kinase (RLCK) BIK1 are important mediators of transmembrane signal transduction that regulate plant development and immunity. However, little attention has been paid to their genetic association. This study found the bak1 bik1 double mutant of Arabidopsis displayed a severe dwarfism phenotype due to constitutive immunity and cell death in developing plants. These data suggest that BIK1 cooperates with BAK1 to regulate constitutive immunity and cell death.

DELAYED GREENING 238, a Nuclear-Encoded Chloroplast Nucleoid Protein, Is Involved in the Regulation of Early Chloroplast Development and Plastid Gene Expression in Arabidopsis thaliana.

Chloroplast development is an essential process for plant growth that is regulated by numerous proteins. Plastid-encoded plastid RNA polymerase (PEP) is a large complex that regulates plastid gene transcription and chloroplast development. However, many proteins in this complex remain to be identified. Here, through large-scale screening of Arabidopsis mutants by Chl fluorescence imaging, we identified a novel protein, DELAYED GREENING 238 (DG238), which is involved in regulating chloroplast development and plastid gene expression. Loss of DG238 retards plant growth, delays young leaf greening, affects chloroplast development and lowers photosynthetic efficiency. Moreover, blue-native PAGE (BN-PAGE) and Western blot analysis indicated that PSII and PSI protein levels are reduced in dg238 mutants. DG238 is mainly expressed in young tissues and is regulated by light signals. Subcellular localization analysis showed that DG238 is a nuclear-encoded chloroplast nucleoid protein. More interestingly, DG238 was co-expressed with FLN1, which encodes an essential subunit of the PEP complex. Bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP) assays showed that DG238 can also interact with FLN1. Taken together, these results suggest that DG238 may function as a component of the PEP complex that is important for the early stage of chloroplast development and helps regulate PEP-dependent plastid gene expression.

Optimization of Light-Harvesting Pigment Improves Photosynthetic Efficiency.

Maximizing light capture by light-harvesting pigment optimization represents an attractive but challenging strategy to improve photosynthetic efficiency. Here, we report that loss of a previously uncharacterized gene, HIGH PHOTOSYNTHETIC EFFICIENCY1 (HPE1), optimizes light-harvesting pigments, leading to improved photosynthetic efficiency and biomass production. Arabidopsis (Arabidopsis thaliana) hpe1 mutants show faster electron transport and increased contents of carbohydrates. HPE1 encodes a chloroplast protein containing an RNA recognition motif that directly associates with and regulates the splicing of target RNAs of plastid genes. HPE1 also interacts with other plastid RNA-splicing factors, including CAF1 and OTP51, which share common targets with HPE1. Deficiency of HPE1 alters the expression of nucleus-encoded chlorophyll-related genes, probably through plastid-to-nucleus signaling, causing decreased total content of chlorophyll (a+b) in a limited range but increased chlorophyll a/b ratio. Interestingly, this adjustment of light-harvesting pigment reduces antenna size, improves light capture, decreases energy loss, mitigates photodamage, and enhances photosynthetic quantum yield during photosynthesis. Our findings suggest a novel strategy to optimize light-harvesting pigments that improves photosynthetic efficiency and biomass production in higher plants.

Laparoscopic gastrectomy versus open gastrectomy for elderly patients with gastric cancer: a systematic review and meta-analysis.

BACKGROUND: The objective of this study was to evaluate the feasibility, safety, and potential benefits of laparoscopic gastrectomy (LG) comparing with open gastrectomy (OG) in elderly population. METHODS: Studies comparing LG with OG for elderly population with gastric cancer, published between January 1994 and July 2015, were identified in the PubMed, Embase, and ISI Web of Science databases. Operative outcomes (intraoperative blood loss, operative time, and the number of lymph nodes harvested) and postoperative outcomes (time to first ambulation, time to first flatus, time to first oral intake, postoperative hospital stay, postoperative morbidity) were included and analyzed. The Newcastle-Ottawa Scale was used to assess the quality of the pooled study. A funnel plot was used to evaluate the publication bias. RESULTS: Seven studies totaling 845 patients were included in the meta-analysis. LG in comparison to OG showed less intraoperative blood loss (weighted mean difference (WMD) -127.47; 95% confidence interval (CI) -202.79 to -52.16; P < 0.01), earlier time to first ambulation (WMD -2.07; 95% CI -2.84 to -1.30; P < 0.01), first flatus (WMD -1.04; 95% CI -1.45 to -0.63; P < 0.01), and oral intake (WMD -0.94; 95% CI -1.11 to -0.77; P < 0.01), postoperative hospital stay (WMD -5.26; 95% CI -7.58 to -2.93; P < 0.01), lower overall postoperative complication rate (odd ratio (OR) 0.39; 95% CI 0.28 to 0.55; P < 0.01), less surgical complications (OR 0.47; 95% CI 0.32 to 0.69; P < 0.01), medical complication (OR 0.35; 95% CI 0.22 to 0.56; P < 0.01), incisional complication (OR 0.40; 95% CI 0.19 to 0.85; P = 0.02), and pulmonary infection (OR 0.49; 95% CI 0.26 to 0.93; P = 0.03). No significant differences were observed between LG and OG for the number of harvested lymph nodes. However, LG had longer operative times (WMD 15.73; 95% CI 6.23 to 25.23; P < 0.01). CONCLUSIONS: LG is a feasible and safe approach for elderly patients with gastric cancer. Compared with OG, LG has less blood loss, faster postoperative recovery, and reduced postoperative morbidity.

The bHLH transcription factor bHLH104 interacts with IAA-LEUCINE RESISTANT3 and modulates iron homeostasis in Arabidopsis.

Iron (Fe) is an indispensable micronutrient for plant growth and development. The regulation of Fe homeostasis in plants is complex and involves a number of transcription factors. Here, we demonstrate that a basic helix-loop-helix (bHLH) transcription factor, bHLH104, belonging to the IVc subgroup of bHLH family, acts as a key component positively regulating Fe deficiency responses. Knockout of bHLH104 in Arabidopsis thaliana greatly reduced tolerance to Fe deficiency, whereas overexpression of bHLH104 had the opposite effect and led to accumulation of excess Fe in soil-grown conditions. The activation of Fe deficiency-inducible genes was substantially suppressed by loss of bHLH104. Further investigation showed that bHLH104 interacted with another IVc subgroup bHLH protein, IAA-LEUCINE RESISTANT3 (ILR3), which also plays an important role in Fe homeostasis. Moreover, bHLH104 and ILR3 could bind directly to the promoters of Ib subgroup bHLH genes and POPEYE (PYE) functioning in the regulation of Fe deficiency responses. Interestingly, genetic analysis showed that loss of bHLH104 could decrease the tolerance to Fe deficiency conferred by the lesion of BRUTUS, which encodes an E3 ligase and interacts with bHLH104. Collectively, our data support that bHLH104 and ILR3 play pivotal roles in the regulation of Fe deficiency responses via targeting Ib subgroup bHLH genes and PYE expression.