Lactococcus lactis HkyuLL 10 suppresses colorectal tumourigenesis and restores gut microbiota through its generated alpha-mannosidase.

OBJECTIVE: Probiotic Lactococcus lactis is known to confer health benefits to humans. Here, we aimed to investigate the role of L. lactis in colorectal cancer (CRC). DESIGN: L. lactis abundance was evaluated in patients with CRC (n=489) and healthy individuals (n=536). L. lactis was isolated from healthy human stools with verification by whole genome sequencing. The effect of L. lactis on CRC tumourigenesis was assessed in transgenic Apc Min/+ mice and carcinogen-induced CRC mice. Faecal microbiota was profiled by metagenomic sequencing. Candidate proteins were characterised by nano liquid chromatography-mass spectrometry. Biological function of L. lactis conditioned medium (HkyuLL 10-CM) and functional protein was studied in human CRC cells, patient-derived organoids and xenograft mice. RESULTS: Faecal L. lactis was depleted in patients with CRC. A new L. lactis strain was isolated from human stools and nomenclated as HkyuLL 10. HkyuLL 10 supplementation suppressed CRC tumourigenesis in Apc Min/+ mice, and this tumour-suppressing effect was confirmed in mice with carcinogen-induced CRC. Microbiota profiling revealed probiotic enrichment including Lactobacillus johnsonii in HkyuLL 10-treated mice. HkyuLL 10-CM significantly abrogated the growth of human CRC cells and patient-derived organoids. Such protective effect was attributed to HkyuLL 10-secreted proteins, and we identified that α-mannosidase was the functional protein. The antitumourigenic effect of α-mannosidase was demonstrated in human CRC cells and organoids, and its supplementation significantly reduced tumour growth in xenograft mice. CONCLUSION: HkyuLL 10 suppresses CRC tumourigenesis in mice through restoring gut microbiota and secreting functional protein α-mannosidase. HkyuLL 10 administration may serve as a prophylactic measure against CRC.

Does obstructive sleep apnea-induced intermittent hypoxia increase the incidence of solitary pulmonary nodules, thyroid nodules, and other disorders? A retrospective study based on 750 cardiovascular disease patients.

BACKGROUND: Obstructive sleep apnea (OSA) has been shown to be an important risk factor for cardiovascular disease (CVD), and intermittent hypoxia is an important pathogenetic factor for it. In the clinic, it was found that most CVD patients combined with OSA were also combined with solitary pulmonary nodules (SPN) or thyroid nodules (TN). Are these disorders related to intermittent hypoxia? One study showed that intermittent hypoxia is a pathogenic factor for lung cancer in mice, but there have been no clinical reports. So we conducted a retrospective study to explore whether intermittent hypoxia caused by OSA increases the incidence of SPN, TN, and other disorders. METHODS: We selected 750 patients with cardiovascular disease (CVD), who were divided into the control group and the OSA group according to the result of portable sleep monitoring. Retrospectively analyzed the comorbidities that patients with OSA are prone to and explored the correlation between OSA and those comorbidities. RESULTS: The incidence of SPN, TN, cervical spondylosis, and carotid-artery plaques was higher in the OSA group than in the control group. These diseases are significantly associated with OSA (p < 0.05), and their incidence increased with an elevated apnea-hypopnea index. After excluding interference from age, gender, BMI, smoking history, history of lung disease, and history of tumors, OSA showed a significant correlation with SPN. After excluding age, gender, BMI, and thyroid disease, OSA was associated with TN. Patients with comorbidities have lower nocturnal oxygen saturation and more extended periods of apnea. Logistic multiple regression results revealed that male, advanced age, obesity, CS, and nasal septum deviation were independent risk factors for OSA. CONCLUSIONS: Patients combined with OSA may further develop more comorbidities, such as SPN, TN, and carotid-artery plaques. It may be related to intermittent hypoxia caused by OSA.

Limited ability of increased sequencing depth in detecting cases missed by noninvasive prenatal testing: a comparative analysis of 3 clinical cases.

Increased sequencing depth can improve the detection rate of noninvasive prenatal testing (NIPT) for chromosome aneuploidies and copy number variations (CNVs). However, due to the technical limitations of NIPT, false-positives and false-negatives are inevitable. False-positives for aneuploidy and CNVs have been widely reported, but few missed cases have been reported. In this study, we report 3 patients missed by NIPT, which were still missed after increasing the sequencing depth. To verify the detection efficiency of the platform, the results of NIPT in 32,796 patients treated in Yulin Women and Children Health Care Hospital from 2020 to 2022 were retrospectively analyzed. Data on false-negative cases found by postnatal follow-up or amniocentesis were collected, and the sequencing data, pregnancy examination data, and postnatal follow-up results of these missed patients were summarized. Five patients missed by NIPT were found, and they were missed again by retesting or increasing the sequencing depth. Except for hypospadias found in 1 patient, ultrasonography of the other 4 patients showed no obvious abnormalities during the whole pregnancy. Our results suggest that pregnant women should be fully informed of the benefits and limitations of NIPT before undergoing the examination to avoid unnecessary medical disputes.

A novel ADGRG2 truncating variant associated with X-linked obstructive azoospermia in a large Chinese pedigree.

PURPOSE: In this study, we aimed to identify sterility-related variants in a Chinese pedigree with male infertility and to reveal the different phenotypes and intracytoplasmic sperm injection (ICSI) outcomes of the affected members. METHODS: Physical examinations were performed on male patients. G-band karyotype analysis, copy number variation sequencing, and quantitative fluorescent PCR were conducted to detect common chromosomal disorders in the probands. Whole-exome sequencing and Sanger sequencing were applied to identify the pathogenic genes and the protein expression changes caused by the very mutation were identified by Western Blot in vitro. RESULTS: A novel nonsense mutation (c.908C > G: p.S303*) in the ADGRG2 was identified in all infertile male patients of the pedigree, which was inherited from their mothers. This variant was absent from the human genome databases. This mutation was also unexpectedly found in a male member with normal reproductive capability. Members with the mutation had different genitalia phenotypes, ranging from normal to dilated phenotypes of the vas deferens, spermatic veins and epididymis. There was a truncated ADGRG2 protein in vitro after mutation. Of the three patients' wives treated with ICSI, only one successfully gave birth. CONCLUSIONS: Our study is the first to report the c.908C > G: p.S303* mutation in the ADGRG2 in an X-linked azoospermia pedigree and is the first to report normal fertility in a member with this mutation, expanding the mutation spectrum and phenotype spectrum of this gene. In our study, ISCI had a success rate of only one-third in couples including men with azoospermia with this mutation.

The frequency of HKαα allele in silent deletional α-thalassemia carriers in the Yulin region of southern China using the third-generation sequencing.

OBJECTIVES: α-thalassemia is relatively prevalent in Yulin Region in southern China. In order to accurately detect α-globin gene aberrations for genetic counseling, the prevalence of HKαα (Hong Kong αα) allele in this subpopulation of silent deletional α-thalassemia were examined. MATERIALS AND METHODS: A total of 1845 subjects were selected in Yulin Region from January 2021 to March 2021. Peripheral blood was collected from each participant for routine genetic analysis of thalassemia. The HKαα allele was determined using the Single-molecule real-time (SMRT) technology for samples with -α3.7/αα, ßN/ßN genotype. RESULTS: Two samples were identified with HKαα allele from 100 samples with -α3.7/αα, ßN/ßN genotype. The frequency of HKαα allele was 2.0 % (2/100) in -α3.7/αα, ßN/ßN carriers in Yulin Region. One sample was identified with a novel variant of the α-globin gene cluster named αHKαα by SMRT technology. One rare HBA2 variant and six HBB variants were found by SMRT technology, including -α3.7/HBA2:c.300 + 34G > A, HBB:c.316-45G > C/ßN, HBB:c.315 + 180 T > C/ßN, HBB:c.316-179A > C/ßN. CONCLUSION: A certain proportion of HKαα allele had been detected in Yulin Region. SMRT technology plays a crucial role for improving the diagnostic accuracy and positive detection rate of thalassemia. The completion of this study has great meaning for strengthening the prevention and control of thalassemia in Yulin Region.

A novel rearrangement of the α-globin gene cluster containing both the -α3.7 and ααααanti4.2 crossover junctions in a Chinese family.

BACKGROUND: Thalassemia is one of the most common hemoglobinopathies. Thalassemia is mainly caused by the loss and/or deficiency of one or more globin chains in hemoglobin. The copy number variant (CNV) of α-globin gene is one of the important factors affecting the clinical phenotype of ß-thalassemia. The precise detection for this type of variation is needed. METHODS: Peripheral blood of a 33-year-old man and his family members were collected. Complete blood counts and serum iron levels were measured for participants. Genomic DNA was extracted from all family members. Routine genetic analysis of thalassemia was performed to determine the genotype. Additional PCR-electrophoresis and Multiplex ligation dependent probe amplification (MLPA) were conducted. Single-molecule real-time technology(SMRT) was then performed as a validation assay and further characterization of the variant for family members. RESULTS: PCR-electrophoresis and MLPA found a new variant, but the exact genotype could not be determined. At last, SMRT identified the new variant as a rearrangement of the α-globin gene cluster named αHKαα (NC_000016.9:g.169818_174075dup169818_174075dup173302_177105del), which contained both the -α3.7 and ααααanti4.2 crossover junctions. Carriers of the novel CNV show normal clinical phenotype according to the hematological results. CONCLUSION: We have identified an unreported CNV (αHKαα) in α-globin gene cluster. The novel CNV not only demonstrates the accuracy and efficiency of our combining strategy in detecting unknown CNVs, but also enriched the variant spectrum of thalassemia.

[The Genotypes and Clinical Characteristics of Thalassemia on Children in Wuhan Region].

OBJECTIVE: To investigate the genotypes and clinical characteristics of thalassemia on children in Wuhan region. METHODS: A total of 159 patients diagnosed as thalassemia in Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology from December 2017 to December 2019. The patients were retrospectively analyzed for their types of mutations, detection rates and clinical characteristics. RESULTS: Among the 422 samples, 159 samples were finally diagnosed as thalassemia through genetic testing, the total detection rate was 37.68%. The detection rate of α, ß and αß-thalassemia was 17.30%, 20.14% and 0.24% respectively. Among α-thalassemia, αα/-SEA was the most common one, with a composition ratio of 68.49%(50/73), followed by αα/-α3.7 (19.18%), αα/-α4.2 (6.85%) and αα/ QS (1.37%). 9 types of ß-thalassemia gene mutations were detected, and the most common three mutations were IVSII-654(C→T), with a composition ratio of 40.00%, CD41-42(-TTCT) (20.00%) and CD17(A→T)(16.47%). Two novel mutations of ß-thalassemia, HBB: c.92-2A＞T and HBB:c.-23A＞G were detected. Among all the positive patients, 134 (84.28%) were 0-3 years old, 19 (11.95%) were 4-6 years old, and 6 (3.77%) were 7 years of age or older. There were 147 patients with mild anemia (92.45%), 11 patients with moderate anemia (6.92%), and 1 patients with severe anemia (0.63%). The MCV of 94(59.12%) patients was lower than 65 fL, and that of 51(32.08%) patients was between 65 fL and 80 fL, while 14(8.81%) patients was higher than 80 fL. MCV in ß-thalassemia group was lower than that in α-thalassemia group, and the difference showed statistically significant (P<0.05). CONCLUSION: The genotypes of thalassemia in children in Wuhan area are diverse, and most of them are mild thalassemia, and diagnosed under 3 years old. Children with ß-thalassemia have smaller red blood cell volumes than those with α-thalassemia.

Conformational changes and binding property of the periplasmic binding protein BtuF during vitamin B12 transport revealed by collision-induced unfolding, hydrogen-deuterium exchange mass spectrometry and molecular dynamic simulation.

The periplasmic binding protein (PBP) BtuF plays a key role in transporting vitamin B12 from periplasm to the ATP-binding cassette (ABC) transporter BtuCD. Conformational changes of BtuF during transport can hardly be captured by traditional biophysical methods and the exact mechanism regarding B12 and BtuF recognition is still under debate. In the present work, conformational changes of BtuF upon B12 binding and release were investigated using hybrid approaches including collision-induced unfolding (CIU), hydrogen deuterium exchange mass spectrometry (HDX-MS) and molecular dynamics (MD) simulation. It was found that B12 binding increased the stability of BtuF. In addition, fast exchange regions of BtuF were localized. Most importantly, midpoint of hinge helix in BtuF was found highly flexible, and binding of B12 proceed in a manner similar to the Venus flytrap mechanism. Our study therefore delineates a clear view of BtuF delivering B12, and demonstrated a hybrid approach encompassing MS and computer based methods that holds great potential to the probing of conformational dynamics of proteins in action.

An overview of therapeutic potential of N-alkylated 1-deoxynojirimycin congeners.

Polyhydroxylated alkaloids display a wide range of biological activities, suggesting their use in the treatment of various diseases. Their most famous representative, 1-deoxynojirimycin (DNJ), is a natural product that shows α- and ß-glucosidase inhibition. This molecule has been since converted into two clinically approved drugs i.e., Zavesca® and Glyset®, targeting type I Gaucher's disease and type II diabetes mellitus, respectively. This review examines the therapeutic potential of important DNJ congeners reported in last decade and presents concise mechanism of glycosidase inhibition. A brief overview of substituents conjugation's impact on DNJ scaffold (including N-alkylated DNJ derivatives, mono-valent, di-valent and multivalent DNJ congeners, N-[5-(adamantan-1-yl-methoxy)-pentyl]-1-deoxynojirimycin (AMP-DNM) look alike DNJ based lipophilic derivatives, AMP-DNM based neoglycoconjugates, DNJ click derivatives with varying carboxylic acids and aromatic moieties, conjugates of DNJ and glucose, and N-bridged DNJ analogues) towards various enzymes such as α/ß glucosidase, porcine trehalase, as F508del-CFTR correctors, α-mannosidase, human placental ß-glucocerebrosidase, N370S ß-GCase, α-amylase and insect trehalase as potent and selective inhibitors have been discussed with potential bioactivities, which can provide inspiration for future studies.

An epigenetic gene silencing pathway selectively acting on transgenic DNA in the green alga Chlamydomonas.

Silencing of exogenous DNA can make transgene expression very inefficient. Genetic screens in the model alga Chlamydomonas have demonstrated that transgene silencing can be overcome by mutations in unknown gene(s), thus producing algal strains that stably express foreign genes to high levels. Here, we show that the silencing mechanism specifically acts on transgenic DNA. Once a permissive chromatin structure has assembled, transgene expression can persist even in the absence of mutations disrupting the silencing pathway. We have identified the gene conferring the silencing and show it to encode a sirtuin-type histone deacetylase. Loss of gene function does not appreciably affect endogenous gene expression. Our data suggest that transgenic DNA is recognized and then quickly inactivated by the assembly of a repressive chromatin structure composed of deacetylated histones. We propose that this mechanism may have evolved to provide protection from potentially harmful types of environmental DNA.

Efficacy of intravesical therapies on the prevention of recurrence and progression of non-muscle-invasive bladder cancer: A systematic review and network meta-analysis.

Intravesical instillation therapy is the mainstay of prophylaxis of tumor recurrence and progression in non-muscle-invasive bladder cancer. However, there is no study evaluating the superiority of monotherapy. The aim of this study is to compare the efficacy of preventing recurrence and progression of intravesical monotherapies via network meta-analysis (NMA) of randomized controlled trials. Database searches were conducted on Embase, Ovid Medline, Web of Science, ScienceDirect, Cochrane Library, and ClinicalTrials.com from the time of establishment to February 6, 2020. The monotherapies included Bacille Calmette-Guérin (BCG), mitomycin C (MMC), interferon (IFN), adriamycin, epirubicin, gemcitabine (GEM), and thiotepa (THP). A Bayesian consistency network model was generated under a random-effects model. The superiority of therapy was identified based on the surface under the cumulative ranking curve (SUCRA). Fifty-seven studies with 12462 patients are included. NMA shows that GEM (SUCRA = 0.92), BCG (SUCRA = 0.82), and IFN (SUCRA = 0.78) are the top three effective drugs to reduce recurrence. GEM (SUCRA = 0.87) is the most effective therapy to prevent progress, followed by BCG, MMC, THP, and IFN with similar efficacy. Subgroup analysis of pairwise meta-analysis and NMA was performed on publication year, trial initiation year, study origin, center involvement, sample size, drug schedule, tumor characteristics, and trial quality to address confounding factors, which suggests the robustness of the results with stable effect sizes. Network meta-regression also indicates consistent rank by analyzing year, sample size, and quality. Compared with BCG, GEM is also a promising therapy with favorable efficacy to reduce tumor recurrence and progression. IFN and MMC could be alternative therapies for BCG with slightly inferior efficacy in recurrence prevention and similar efficacy in progression prevention. However, the results of this study should be treated with caution since most of the included studies are of moderate to high risk of bias.

Photosynthesis without ß-carotene.

Carotenoids are essential in oxygenic photosynthesis: they stabilize the pigment-protein complexes, are active in harvesting sunlight and in photoprotection. In plants, they are present as carotenes and their oxygenated derivatives, xanthophylls. While mutant plants lacking xanthophylls are capable of photoautotrophic growth, no plants without carotenes in their photosystems have been reported so far, which has led to the common opinion that carotenes are essential for photosynthesis. Here, we report the first plant that grows photoautotrophically in the absence of carotenes: a tobacco plant containing only the xanthophyll astaxanthin. Surprisingly, both photosystems are fully functional despite their carotenoid-binding sites being occupied by astaxanthin instead of ß-carotene or remaining empty (i.e. are not occupied by carotenoids). These plants display non-photochemical quenching, despite the absence of both zeaxanthin and lutein and show that tobacco can regulate the ratio between the two photosystems in a very large dynamic range to optimize electron transport.

Most life on Earth depends on photosynthesis, the process used by plants and many other organisms to store energy from sunlight and produce oxygen. The first steps of photosynthesis, the capture and conversion of sunlight into chemical energy, happen in large assemblies of proteins containing many pigment molecules called photosystems. In plants, the pigments involved in photosynthesis are green chlorophylls and carotenoids. In addition to harvesting light, carotenoids have an important role in preventing damage caused by overexposure to sunlight There are over one thousand different carotenoids in living beings, but only one, ß-carotene, is present in every organism that performs the type of photosynthesis in which oxygen is released, and is thought to be essential for the process. However, this could never be proved because it is impossible to remove ß-carotene from cells using typical genetic approaches without affecting all other carotenoids. Xu et al. used genetic engineering to create tobacco plants that produced a pigment called astaxanthin in place of ß-carotene. Astaxanthin is a carotenoid from salmon and shrimp, not normally found in plants. These plants are the first living things known to perform photosynthesis without ß-carotene and demonstrate that this pigment is not essential for photosynthesis as long as other carotenoids are present. Xu et al. also show that the photosystems can adapt to using different carotenoids, and can even operate with a reduced number of them. Xu et al's findings show the high flexibility of photosynthesis in plants, which are able to incorporate non-native elements to the process. These results are also important in the context of increasing the photosynthetic efficiency, and thus the productivity of crops, since they show that a radical redesign of the photosynthetic machinery is feasible.

Rare partial trisomy and tetrasomy of 15q11-q13 associated with developmental delay and autism spectrum disorder.

BACKGROUND: Small supernumerary marker chromosomes (sSMCs), are additional abnormal chromosomes, which can't be detected accurately by banding cytogenetic analysis. Abnormal phenotypes were observed in about 30% of SMC carriers. Duplication of chromosome 15 and related disorders, characterized by hypotonia motor delays, autism spectrum disorder (ASD), intellectual disability, and epilepsy including infantile spasms, might be account for 50% of the total sSMCs. CASE PRESENTATION: An 11-month-old infant with an sSMC found by banding cytogenetics was referred to our clinic because of developmental retardation and autism spectrum disorder. After several months of rehabilitation treatment, the progress of motor development was obvious, but the consciousness was still far from satisfied. High-resolution karyotype analysis, multiplex ligation-dependent probe amplification and copy number variation sequencing (CNV-Seq) were conducted to confirm the identity of the sSMC. A bisatellited dicentric sSMC was observed clearly in high-resolution karyotype analysis and a 10.16-Mb duplication of 15q11.1q13.2 (3.96 copies) together with a 1.84-Mb duplication of 15q13.2q13.3 (3 copies) was showed by CNV-Seq in the proband. It suggested that the molecular cytogenetic karyotype was 47,XY,+dic(15;15)(q13.2;q13.3). Furthermore, the clinical symptoms of the proband mostly fit 15q duplication related disorders which are characterized by hypotonia motor delays, autism spectrum disorder (ASD), and intellectual disability. CONCLUSION: We reported for the first time using CNV-Seq to detect sSMCs and find a partial trisomy and tetrasomy of 15q11-q13 associated with developmental delay and autism spectrum disorder. Our report indicates that CNV-seq is a useful and economical way for diagnosis of dup15q and related disorders.

Impact of Endourological procedures with or without double-J stent on sexual function: a systematic review and meta-analysis.

BACKGROUND: Endourological procedures are widely used to treat benign urinary disorders and the double-J stent is routinely used. However, its potential impact on sexual function remains unclear. Therefore, we performed a quantitative systematic review to determine the relationship between endourological procedures with or without double-J stent and post-operative sexual function. METHODS: We conducted a search of PubMed, EMBASE, Web of Science, and Cochrane Library databases up to December 2018 for studies that compared sexual function before and after endourological procedures. The quality of the included studies was evaluated using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I). We performed subgroup analyses to explore heterogeneity. A random effects model was used to combine the results. RESULTS: Five prospective studies involving 485 sexually active participants were identified. Pooled results showed that, in patients without a double-J stent, the change in sexual function after endourological procedures was not significant in men (mean difference [MD]: - 0.61, 95% confidence interval [CI]: - 1.43 to 0.22, p = 0.148) or women (MD: 0.53, 95% CI: - 0.52 to 1.57, p = 0.322). However, in patients with indwelling double-J stent, sexual function scores significantly declined after the procedure in both men (MD: -4.25, 95% CI: - 6.20 to - 2.30, p < 0.001) and women (MD: -7.17, 95% CI: - 7.88 to - 6.47, p < 0.001). CONCLUSIONS: Our meta-analysis suggests that indwelling double-J stent after endourological procedures could be a crucial factor causing temporary sexual dysfunction post-operatively. Our results may be used to provide evidence-based advice to patients.

Circ_USP36/miR-182-5p/KLF5 axis regulates the ox-LDL-induced injury in human umbilical vein smooth muscle cells.

Atherogenesis is a chronic inflammatory process, closely related to high morbidity and mortality. Circular RNAs (circRNAs) were reported to function in atherosclerosis. However, the functional impact of circRNA ubiquitin-specific Protease 36 (circ_USP36) on atherosclerosis and the possible mechanism are still unclear. Serum specimens were collected from atherosclerosis patients and healthy volunteers. Human umbilical vein smooth muscle cells (HUVSMCs) exposed with 25 µg/mL oxidized low-density lipoprotein (ox-LDL) were utilized to simulate atherosclerosis. Expression of circ_USP36, microRNA (miR)-182-5p and Kruppel-like factor 5 (KLF5) was determined via quantitative real-time polymerase chain reaction or western blot assay. Cell viability and apoptosis were evaluated by Cell Counting Kit-8 and flow cytometry. Cell metastasis, including migration and invasion, was assessed via Transwell assay. Biomarker protein was analyzed by western blot. The relationship among circ_USP36, miR-182-5p and KLF5 was confirmed by dual-luciferase reporter and RNA pull-down assays. Circ_USP36 and KLF5 were up-regulated, while miR-182-5p was down-regulated in atherosclerosis patients and ox-LDL-induced HUVSMCs. Circ_USP36 knockdown inhibited proliferation and metastasis of ox-LDL-induced HUVSMCs by up-regulating miR-182-5p. MiR-182-5p targeted KLF5, and ameliorated ox-LDL-mediated injury of HUVSMCs. Circ_USP36 knockdown down-regulated KLF5 expression by sponging miR-182-5p. Knockdown of circ_USP36 alleviated ox-LDL-mediated injury of HUVSMCs by modulating miR-182-5p/KLF5 axis, potentially providing a treatment target for atherosclerosis.

Real-time monitoring of newly acidified organelles during autophagy enabled by reaction-based BODIPY dyes.

Real-time monitoring of newly acidified organelles during autophagy in living cells is highly desirable for a better understanding of intracellular degradative processes. Herein, we describe a reaction-based boron dipyrromethene (BODIPY) dye containing strongly electron-withdrawing diethyl 2-cyanoacrylate groups at the α-positions. The probe exhibits intense red fluorescence in acidic organelles or the acidified cytosol while exhibiting negligible fluorescence in other regions of the cell. The underlying mechanism is a nucleophilic reaction at the central meso-carbon of the indacene core, resulting in the loss of π-conjugation entailed by dramatic spectroscopic changes of more than 200 nm between its colorless, non-fluorescent leuco-BODIPY form and its red and brightly emitting form. The reversible transformation between red fluorescent BODIPY and leuco-BODIPY along with negligible cytotoxicity qualifies such dyes for rapid and direct intracellular lysosome imaging and cytosolic acidosis detection simultaneously without any washing step, enabling the real-time monitoring of newly acidified organelles during autophagy.

Protective effect of Qishen Yiqi dropping pills on the myocardium of rats with chronic heart failure.

Protective effect of Qishen Yiqi dropping pills on the myocardium of rats with chronic heart failure (CHF) was investigated. Sixty rats were divided into the sham operation (n=20), the model (n=20) and the Qishen Yiqi dropping pill treatment group (n=20) using the random table method. The treatment group received administration of Qishen Yiqi dropping pills. The model and the sham operation group were given the same amount of normal saline. Within 24 h after the last administration, the rats were sacrificed. The myocardia were used for reverse transcription-polymerase chain reaction, western blot analysis and histological examination. In the sham operation group, cardiomyocytes were stained evenly and arranged neatly and densely with clear structures. In the model group, the cell morphology was fuzzy, the myocytes were hypertrophied, the nuclear pyknosis was fragmented, the arrangement was disordered, the intercellular space was narrowed, and the cytoplasm was missing. The apoptosis rates of cardiomyocytes in the model and Qishen Yiqi dropping pill treatment group were significantly higher than that in the sham operation group (P<0.05). The myocardial infarction areas in the model group and the Qishen Yiqi dropping pill treatment group were larger than that in the sham operation group (P<0.05). The expression levels of transforming growth factor-ß1, mothers against decapentaplegic homolog 2 (Smad2), Smad3, and caspase-3 messenger ribonucleic acids and proteins in the model group and the Qishen Yiqi dropping pill treatment group were higher than those in the sham operation group (P<0.05). Qishen Yiqi dropping pills have an obvious myocardial protective effect on CHF rats, which may enhance the degree of myocardial fibrosis by inhibiting the TGF-ß1/Smads pathway and improve cardiomyocyte apoptosis by suppressing the caspase-3 signaling pathway, thus protecting the myocardium.

Revisiting the Role of Xanthophylls in Nonphotochemical Quenching.

Photoprotective nonphotochemical quenching (NPQ) of absorbed solar energy is vital for survival of photosynthetic organisms, and NPQ modifications significantly improve plant productivity. However, the exact NPQ quenching mechanism is obscured by discrepancies between reported mechanisms, involving xanthophyll-chlorophyll (Xan-Chl) and Chl-Chl interactions. We present evidence of an experimental artifact that may explain the discrepancies: strong laser pulses lead to the formation of a novel electronic species in the major plant light-harvesting complex (LHCII). This species evolves from a high excited state of Chl a and is absent with weak laser pulses. It resembles an excitonically coupled heterodimer of Chl a and lutein (or other Xans at site L1) and acts as a de-excitation channel. Laser powers, and consequently amounts of artifact, vary strongly between NPQ studies, thereby explaining contradicting spectral signatures attributed to NPQ. Our results offer pathways toward unveiling NPQ mechanisms and highlight the necessity of careful attention to laser-induced artifacts.

Different carotenoid conformations have distinct functions in light-harvesting regulation in plants.

To avoid photodamage plants regulate the amount of excitation energy in the membrane at the level of the light-harvesting complexes (LHCs). It has been proposed that the energy absorbed in excess is dissipated via protein conformational changes of individual LHCs. However, the exact quenching mechanism remains unclear. Here we study the mechanism of quenching in LHCs that bind a single carotenoid species and are constitutively in a dissipative conformation. Via femtosecond spectroscopy we resolve a number of carotenoid dark states, demonstrating that the carotenoid is bound to the complex in different conformations. Some of those states act as excitation energy donors for the chlorophylls, whereas others act as quenchers. Via in silico analysis we show that structural changes of carotenoids are expected in the LHC protein domains exposed to the chloroplast lumen, where acidification triggers photoprotection in vivo. We propose that structural changes of LHCs control the conformation of the carotenoids, thus permitting access to different dark states responsible for either light harvesting or photoprotection.