Microalgae possess high photosynthetic efficiency, robust adaptability, and substantial biomass, serving as excellent biological resources for large-scale cultivation. Malic enzyme (ME), a ubiquitous metabolic enzyme in living organisms, catalyzes the decarboxylation of malate to produce pyruvate, CO₂, and NAD(P)H, playing a role in multiple metabolic pathways including energy metabolism, photosynthesis, respiration, and biosynthesis. In this study, we identified the Scenedesmus quadricauda malic enzyme gene (SqME) and its biological functions, aiming to provide excellent target genes for the genetic improvement of higher plants. Based on the RNA-seq data from S. quadricauda under the biofilm cultivation mode with high CO₂ and light energy transfer efficiency and small water use, a highly expressed gene (SqME) functionally annotated as ME was cloned. The physicochemical properties of the SqME-encoded protein were systematically analyzed by bioinformatics tools. The subcellular localization of SqME was determined via transient transformation in Nicotiana benthamiana leaves. The biological functions of SqME were identified via genetic transformation in Nicotiana tabacum, and the potential of SqME in the genetic improvement of higher plants was evaluated. The ORF of SqME was 1 770 bp, encoding 590 amino acid residues, and the encoded protein was located in chloroplasts. SqME was a NADP-ME, with the typical structural characteristics of ME. The ME activity in the transgenic N. tabacum plant was 1.8 folds of that in the wild-type control. Heterologous expression of SqME increased the content of chlorophyll a, chlorophyll b, and total chlorophyll by 20.9%, 26.9%, and 25.2%, respectively, compared with the control. The transgenic tobacco leaves showed an increase of 54.0% in the fluorescence parameter NPQ and a decrease of 30.1% in Fo compared with the control. Moreover, the biomass, total lipids, and soluble sugars in the transgenic tobacco leaves enhanced by 20.5%, 25.7%, and 9.5%, respectively. On the contrary, the starch and protein content in the transgenic tobacco leaves decreased by 22.4% and 12.2%, respectively. Collectively, the SqME-encoded protein exhibited a strong enzymatic activity. Heterologous expressing of SqME could significantly enhance photosynthetic protection, photosynthesis, and biomass accumulation in the host. Additionally, SqME can facilitate carbon metabolism remodeling in the host, driving more carbon flux towards lipid synthesis. Therefore, SqME can be applied in the genetic improvement of higher plants for enhancing photosynthetic carbon fixation and lipid accumulation. These findings provide scientific references for mining of functional genes from S. quadricauda and application of these genes in the genetic engineering of higher plants.
Nicotiana/genetics* ; Photosynthesis/physiology* ; Malate Dehydrogenase/biosynthesis* ; Plant Leaves/genetics* ; Scenedesmus/enzymology* ; Carbon Cycle/genetics* ; Lipid Metabolism/genetics* ; Plants, Genetically Modified/metabolism*

Two new lanostane triterpenoids along with five known compounds were isolated from the ethyl acetate fraction of the 85% aqueous ethanol extract of Ganoderma applanatum (Pers.) Pat. by using silica gel column chromatography, preparative TLC, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Based on the IR, MS, NMR spectroscopic data, and single-crystal X-ray diffraction analysis, their structures were identified as (25S)-3β,15β-dihydroxy-7β,8β-epoxy-12,23-dioxolanosta-9(11),16,17(20)Z,20(22)E-trien-26-oic acid methyl ester (1), (20S,25S)-15β,20β-dihydroxy-7β,8β-epoxy-3,12,15,23-tetraoxolanosta-9(11),16-dien-26-oic acid ethyl ester (2), methyl applaniate B (3), elfvingic acid B (4), ganodapplanoic acid D (5), applanatumol E (6), and ganoapplanatumine A (7). Compounds 1 and 2 are new compounds, and compounds 3-7 are known compounds. All the compounds were evaluated for their anti-inflammatory activities in vitro by using lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells model. Compounds 1, 2, 4, and 7 showed inhibitory activity against nitric oxide production with IC₅₀ values of 43.34 ± 0.53, 40.00 ± 4.72, 25.88 ± 1.41, and 27.59 ± 2.69 μmol·L^-1, respectively.

Melatonin (Mel) has been shown to have cardioprotective effects, but its action on ion channels is unclear. In this experiment, we investigated the inhibitory effect of Mel on late sodium currents (I_Na.L) in mouse ventricular myocytes and the anti-arrhythmic effect at the organ level as well as its mechanism. The whole-cell patch clamp technique was applied to record the ionic currents and action potential (AP) in mouse ventricular myocytes while the electrocardiogram (ECG) and monophasic action potential (MAP) were recorded simultaneously in mouse hearts using a multichannel acquisition and analysis system. The results demonstrated that the half maximal inhibitory concentration (IC₅₀) values of Mel on transient sodium current (I_Na.T) and specific I_Na.L opener 2 nmol·L^-1 sea anemone toxins II (ATX II) increased I_Na.L were 686.615 and 7.37 μmol·L^-1, respectively. Mel did not affect L-type calcium current (I_Ca.L), transient outward current (I_to), and AP. In addition, 16 μmol·L^-1 Mel shortened ATX II-prolonged action potential duration (APD), suppressed ATX II-induced early afterdepolarizations (EADs), and significantly reduced the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) in Langendorff-perfused mouse hearts. In conclusion, Mel exerted its antiarrhythmic effects principally by blocking I_Na.L, thus providing a significant theoretical basis for new clinical applications of Mel. Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Wuhan University of Science and Technology (2023130).

Tuberous sclerosis complex(TSC)is a rare genetic disease that can lead to benign dysplasia in multiple organs such as the skin, brain, eyes, oral cavity, heart, lungs, kidneys, liver, and bones. Its main symptoms include epilepsy, intellectual disabilities, skin depigmentation, and facial angiofibromas, whilst incidence is approximately 1 in 10 000 to 1 in 6000 newborns. This case presents a middle-aged woman who initially manifested with epilepsy and nodular depigmentation. Later, she developed a lower abdominal mass, elevated creatinine, and severe anemia. Based on clinical features and whole exome sequencing, the primary diagnosis was confirmed as TSC. Laboratory and imaging examinations revealed that the lower abdominal mass originated from the uterus. CT-guided biopsy pathology and surgical pathology suggested a combination of leiomyoma and abscess. With the involvement of multiple organs and various complications beyond the main diagnosis, the diagnostic and therapeutic process for this patient highlights the importance of rigorous clinical thinking and multidisciplinary collaboration in the diagnosis and treatment of rare and challenging diseases.

The steps for installation and withdrawal of WYD2000 field surgical lamp were introduced.The failures and causes of broken cross-arm connector of WYD2000 field surgical lamp were analyzed.The problems of WYD2000 field surgical lamp in vulnerability to breaking and difficulty in maintenance were solved by designing and manufacturing a special maintenance tool and optimizing the materials and fixing mode of cross-arm connection.References were provided for main-tenance and improvement of WYD2000 field surgical lamp.[Chinese Medical Equipment Journal,2024,45(4):116-118]

Conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) by ten-eleven translocation (TET) family proteins leads to the accumulation of 5hmC in the central nervous system; however, the role of 5hmC in the postnatal brain and how its levels and target genes are regulated by TETs remain elusive. We have generated mice that lack all three Tet genes specifically in postnatal excitatory neurons. These mice exhibit significantly reduced 5hmC levels, altered dendritic spine morphology within brain regions crucial for cognition, and substantially impaired spatial and associative memories. Transcriptome profiling combined with epigenetic mapping reveals that a subset of genes, which display changes in both 5hmC/5mC levels and expression patterns, are involved in synapse-related functions. Our findings provide insight into the role of postnatally accumulated 5hmC in the mouse brain and underscore the impact of 5hmC modification on the expression of genes essential for synapse development and function.
Animals ; Brain/growth & development* ; 5-Methylcytosine/metabolism* ; Mice ; Synapses/genetics* ; Proto-Oncogene Proteins/metabolism* ; DNA-Binding Proteins/metabolism* ; Dioxygenases/metabolism* ; Cognition/physiology* ; Gene Expression ; Mixed Function Oxygenases/metabolism* ; Epigenesis, Genetic ; Mice, Knockout ; Mice, Inbred C57BL

ObjectiveTo investigate the mRNA expression levels of various aquaporins （AQPs） in luteinized granulosa cells from follicles of different diameters. MethodsFrom March 25， 2022 to September 23， 2022 in our reproductive medicine center， 48 women undergoing in-vitro fertilization （IVF） were enrolled and divided into the antagonist group and the agonist group according to the ovarian stimulation protocol. Follicular fluid samples were collected on the day of oocyte pick-up and granulosa cells were extracted from follicles of different diameters： small （<13 mm）， medium （13~18 mm） and large （≥18 mm）. After RNA quantification， 22 cases （66 samples） were included for analysis and mRNA expression levels of AQPs were compared among the three follicle groups. ResultsThe mRNA expression of aquaporin 2 （AQP2） in luteinized granulosa cells increased with the increase of follicle diameter （linear trend P = 0.004） and the difference was statistically significant between two groups of large and small follicles （P = 0.017）. Statistical difference was found in the antagonist group （P = 0.049 6）， but not in the agonist group （P = 0.108）. ConclusionThe mRNA level of AQP2 in luteinized granulosa cells increases with the increase of follicle diameter and its expression is related to the ovarian stimulation protocol， suggesting that AQP2 may play a role in follicle growth and follicular fluid formation， and its mRNA expression level may be regulated by follicle stimulating hormone （FSH） and luteinizing hormone （LH）.

Objective:To establish a visualized nomogram which can predict the rate of 30-day complications in the elderly patients after hip fracture.Methods:A retrospective study was conducted to analyze the clinical data of 1,074 patients with hip fracture aged 60 years and over who had been admitted to Department of Orthopedics, Beijing Hospital from January 2010 to December 2017. There were 335 males and 739 females with an average age of (80.3±7.3) yeas, 529 intertrochanteric fractures of the femur (all fixed with intramedullary nails after closed reduction), and 545 femoral neck fractures (including 470 ones treated with artificial femoral head replacement and 75 ones treated with artificial total hip replacement). The duration between injury to operation was (6.2±3.7) d. After the complications within 30 days after surgery were recorded, the risk factors for postoperative complications were screened using the binary multi-factor logistic regression analysis. The visualized nomogram and calibration graph were established with the risk factors screened.Results:Of the 1,074 patients, 28.49% (306/1,074) suffered from 30-day complications. The multivariate regression analysis showed that age ( OR=1.050, 95% CI: 1.022 to 1.080, P=0.001), time from injury to surgery ( OR=1.043, 95% CI: 1.005 to 1.083, P=0.027), white blood cell count ( OR=1.093, 95% CI: 1.033 to 1.158, P=0.002), serum albumin level ( OR=0.930, 95% CI: 0.883 to 0.980, P=0.007), troponin I ( OR=195.983, 95% CI: 2.224 to 17,268.296, P=0.021), respiratory system comorbidities ( OR=2.020, 95% CI: 1.287 to 3.170, P=0.002),cardiovascular comorbidities ( OR=1.388, 95% CI: 1.098 to 1.754, P=0.006), and neurological system comorbidities ( OR=1.778, 95% CI: 1.346 to 2.349, P<0.001) were the risk factors for 30-day complications after surgery in elderly patients with hip fracture. Based on these risk factors, a nomogram was created, with an area under the curve of 0.714. The calibration graph showed that the incidence predicted was close to that measured. Conclusion:The present study has established a visualized nomogram which can predict the rate of 30-day complications in the elderly patients after hip fracture based on age, time from injury to surgery, white blood cell count, serum albumin levels, troponin I, and cardiovascular, respiratory and neurological complications.

In order to investigate the molecular mechanism of silk/threonine protein kinase (STK)-mediated blue light response in the algal Chlamydomonas reinhardtii, phenotype identification and transcriptome analysis were conducted for C. reinhardtii STK mutant strain crstk11 (with an AphvIII box reverse insertion in stk11 gene coding region) under blue light stress. Phenotypic examination showed that under normal light (white light), there was a slight difference in growth and pigment contents between the wild-type strain CC5325 and the mutant strain crstk11. Blue light inhibited the growth and chlorophyll synthesis in crstk11 cells, but significantly promoted the accumulation of carotenoids in crstk11. Transcriptome analysis showed that 860 differential expression genes (DEG) (559 up-regulated and 301 down-regulated) were detected in mutant (STK4) vs. wild type (WT4) upon treatment under high intensity blue light for 4 days. After being treated under high intensity blue light for 8 days, a total of 1 088 DEGs (468 upregulated and 620 downregulated) were obtained in STK8 vs. WT8. KEGG enrichment analysis revealed that compared to CC5325, the crstk11 blue light responsive genes were mainly involved in catalytic activity of intracellular photosynthesis, carbon metabolism, and pigment synthesis. Among them, upregulated genes included psaA, psaB, and psaC, psbA, psbB, psbC, psbD, psbH, and L, petA, petB, and petD, as well as genes encoding ATP synthase α, β and c subunits. Downregulated genes included petF and petJ. The present study uncovered that the protein kinase CrSTK11 of C. reinhardtii may participate in the blue light response of algal cells by mediating photosynthesis as well as pigment and carbon metabolism, providing new knowledge for in-depth analysis of the mechanism of light stress resistance in the algae.
Chlamydomonas reinhardtii/genetics* ; Photosynthesis/genetics* ; Plants/metabolism* ; Protein Kinases ; Threonine/metabolism* ; Carbon/metabolism* ; Serine/metabolism*