Impact of alcoholic extract from sea cucumber(Holothuria parva)on letrozole-induced polycystic ovary syndrome in adult female rats

Objective:To explore the potential therapeutic impact of an alcoholic extract derived from the sea cucumber(Holothuria parva)on letrozole-induced polycystic ovary syndrome(PCOS)in adult female Sprague-Dawley rats.Methods:Sixteen female rats,aged 8 to 10 weeks,with a mean weight of(200±20)g,were randomly assigned to four groups:the control,PCOS,and two treatment groups receiving sea cucumber extract and metformin,respectively.PCOS was induced by administering letrozole at a dose of 1 mg/kg to initiate the treatment period at 60 days of age.The study spanned four weeks,during which ovarian and uterine tissues were collected for histological examination,and blood samples were collected for hormonal levels.Results:Significant decreases in luteinizing hormone/follicle stimulating hormone(LH/FSH)and testosterone and increases progesterone levels among groups treated with sea cucumber extract were observed.While no significant differences were observed in follicle-stimulating hormone(FSH)and testosterone levels,the distinctive variations in key hormones suggested a potential role for sea cucumber alcoholic extract in ameliorating PCOS symptoms.Conclusions:This research highlights the moderate efficacy of sea cucumber extract as a therapeutic intervention for PCOS,providing a novel perspective in the search for effective remedies.The observed hormonal alterations,particularly in LH,estradiol,and progesterone,underscore the need for further exploration into the underlying mechanisms and for optimizing the application of sea cucumber extract in PCOS management.

Family-level diversity of extracellular proteases of sedimentary bacteria from the South China Sea

Protease-producing bacteria and their extracellular proteases are key players in degrading organic nitrogen to drive marine nitrogen cycling and yet knowledge on both of them is still very limited. This study screened protease-producing bacteria from the South China Sea sediments and analyzed the diversity of their extracellular proteases at the family level through N-terminal amino acid sequencing. Results of the 16 S rRNA gene sequence analysis showed that all screened protease-producing bacteria belonged to the class Gammaproteobacteria and most of them were affiliated with different genera within the orders Alteromonadales and Vibrionales. The Nterminal amino acid sequence analysis for fourteen extracellular proteases from fourteen screened bacterial strains revealed that all these proteases belonged to the M4 family of metalloproteases or the S8 family of serine proteases. This study presents new details on taxa of marine sedimentary protease-producing bacteria and types of their extracellular proteases, which will help to comprehensively understand the process and mechanism of the microbial enzymatic degradation of marine sedimentary organic nitrogen.

Gene cloning and sequence analysis of the cold-adapted chaperones DnaK and DnaJ from deep-sea psychrotrophic bacterium Pseudoalteromonas sp. SM9913

Pseudoalteromonas sp. SM9913 is a phychrotmphic bacterium isolated from the deep-sea sediment. The genes encoding chaperones DnaJ and DnaK of P. sp. SM9913 were cloned by normal PCR and TAIL - PCR （GenBank accession Nos DQ640312, DQ504163 ）. The chaperones DnaJ and DnaK from the strain SM9913 contain such conserved domains as those of many other bacteria, and show some cold-adapted characteristics in their structures when compared with those from psychro-, meso-and themophilic bacteria. It is indicated that chaperones DnaJ and DnaK of P. sp. SM9913 may be adapted to low temperature in deep-sea and function well in assisting folding, assembling and translocation of proteins at low temperature. This research lays a foundation for the further study on the cold-adapted mechanism of chaperones DnaJ and DnaK of cold-adapted microorganisms.

Winter distribution of diatom assemblages along the coastline of R.O.Korea in 2010

Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external wall.The relationship between their valve morphology and habitat means that diatoms can be used as bioindicators to characterize the aquatic environment.To estimate the differential distribution and diversity of diatom assemblages along the coastal line,we collected phytoplankton samples from 114 coastal sites of waters of R.O.Korea.We applied the unweighted pair-group technique using the arithmetic averages clustering method to cluster the sampling sites,apart from those where the biota consisted of other groups,such as dinoflagellates,into four regions:the Yellow Sea,South Sea,southern East Sea,and northern East Sea.Indicator species analysis in each region led to the selection of tychoplanktonic,chain-forming,attached species to substrates and psychrophilic indicator diatoms,respectively,each of which represented a planktonic lifestyle associated with one of the four regions.This study shows the diatom assemblages to serve as bioindicators of Korean coastal water in winter,and the subsequent seasonal survey will provide a starting point for the improved understanding of Korean diatom-based ecoregions,in both time and space.

The relationship between <i>Helicobacter pylori</i>disease and bacterial count in stomach

Several studies showed significant relationships between bacterial counts and the severity and type of disease in patients. The aim of this study was to evaluate the relationship between Helicobacter pylori disease and bacterial count. In this study, 287 patients with dyspeptic symptoms were evaluated. Three variables including patient-reported data, clinical signs and bacterial load of gastric specimens were analyzed. Biopsy samples were collected from patients who were referred for endoscopies because of dyspeptic symptoms. Initially, the clinical status was evaluated and recorded by a questionnaire. DNA extraction was performed and H. pylori was analyzed for bacterial count by Real-time PCR assay and specific primers and probe. The variety range of bacteria in specimens was 104 to 1012. The results revealed that a greater relationships existed between 1012 and gastric cancer (p = 0.036), also 104 and acid reflux (p = 0.006) and vomiting (p = 0.047). Real-time PCR assay provides a highly accurate, rapid and precise method for detection of H. pylori and determination of progressive disease due to this bacterium.

Evaluation of Association between <i>Chlamydophila pneumoniae</i>and Atherosclerotic Plaques in Coronary Artery Disease Patients with Abnormal Angiography

The role of Chlamydophila pneumoniae in pathogenesis of atherosclerosis is one of the most important discussions in coronary artery diseases. In this study, the relationship between C. pneumoniae seropositivity and atherosclerotic plaque was evaluated among two groups: one group with significant coronary stenosis and one group with normal coronary angiography. Serum C. pneumonia IgM and IgG were evaluated and compared in case and control groups. The seropositivity rates of IgM and IgG antibodies were not statistically differ between case and control groups, although the incidences of positivity were more in case group. The results of our study did not show a correlation between C. pneumonia infection and atherosclerotic plaque or coronary artery stenosis neither in acute nor in chronic infection. More precise studies are needed to clarify the probable inflammatory cascade that starts with C. pneumonia infection and lead to development of atherosclerotic plaque.

The Association between Waterpipe Smoking and Metabolic Syndrome: A Cross-Sectional Study of the Bushehr Elderly Health Program

Waterpipe(WP),a less common method of tobacco smoking than cigarette smoking(CS),has become increasingly popular over the last decade.Contrary to popular belief,WP smoking is far from harmless and has multiple health risks similar to,or even exceeding,those seen in CS[1,2].

Exosomes in viral infection:Effects for pathogenesis and treatment strategies

Exosomes are small vesicles that carry molecules from one cell to another.They have many features that make them interesting for research,such as their stability,low immunogenicity,size of the nanoscale,toxicity,and selective delivery.Exosomes can also interact with viruses in diverse ways.Emerging research highlights the significant role of exosomes in viral infections,particularly in the context of diseases like COVID-19,HIV,HBV and HCV.Understanding the intricate interplay between exosomes and the human immune system holds great promise for the development of effective antiviral therapies.An important aspect is gaining clarity on how exosomes influence the immune system and enhance viral infectivity through their inherent characteristics.By leveraging the innate properties of exosomes,viruses exploit the machinery involved in exosome biogenesis to set replication,facilitate the spread of infection,and eliminate immune responses.They can either help or hinder viral infection by modulating the immune system.This review summarizes the recent findings on how exosomes mediate viral infection and how they can be used for diagnosis or therapy.This could lead to new clinical applications of exosomes in disease management.

Mechanistic insights into the key marine dimethylsulfoniopropionate synthesis enzyme DsyB/DSYB

Marine algae and bacteria produce approximately eight billion tonnes of the organosulfur molecule dimethylsulfoniopropionate(DMSP)in Earth's surface oceans annually.DMSP is an antistress compound and,once released into the environment,a major nutrient,signaling molecule,and source of climate-active gases.The methionine transamination pathway for DMSP synthesis is used by most known DMSP-producing algae and bacteria.The S-directed S-adenosylmethionine(SAM)-dependent 4-methylthio-2-hydroxybutyrate(MTHB)S-methyltransferase,encoded by the dsyB/DSYB gene,is the key enzyme of this pathway,generating S-adenosylhomocysteine(SAH)and 4-dimethylsulfonio-2-hydroxybutyrate(DMSHB).DsyB/DSYB,present in most haptophyte and dinoflagellate algae with the highest known intracellular DMSP concentrations,is shown to be far more abundant and transcribed in marine environments than any other known S-methyltransferase gene in DMSP synthesis pathways.Furthermore,we demonstrate in vitro activity of the bacterial DsyB enzyme from Nisaea denitrificans and provide its crystal structure in complex with SAM and SAH-MTHB,which together provide the first important mechanistic insights into a DMSP synthesis enzyme.Structural and mutational analyses imply that DsyB adopts a proximity and desolvation mechanism for the methyl transfer reaction.Sequence analysis suggests that this mechanism may be common to all bacterial DsyB enzymes and also,importantly,eukaryotic DSYB enzymes from e.g.,algae that are the major DMSP producers in Earth's surface oceans.

Sequence analysis of the Microcystis aeruginosa FACHB-912 phytochrome gene supports positive selection in cyanobacteria

The phytochrome gene from Microcystis aeruginosa FACHB-912,isolated from algal blooms in Taihu Lake in China,was sequenced and found to code for a wavelength transition light receptor protein.The gene was composed of five distinct domains:a PAS fold domain,a GAF domain,a phytochrome domain,a His Kinase A(phosphoacceptor) domain,and a histidine kinase domain.Red-absorbing phytochrome,far-red-absorbing phytochrome,and photoconversion kinetics were monitored via the spectral characteristics of the protein.To detect positive selection,homologous sequences from cyanobacterium phytochrome genes were obtained from GenBank.Potential selective pressure was identified by phylogenetic analysis with maximum likelihood analyses.The frequency of the phytochrome gene being subjected to selective constraints suggests that positive selection is a potentially important mechanism that promotes the evolution of the cyanobacteria phytochrome gene.The sites identified in this study provide targets for further research on the structural-functional role of these residues,and on the correlation with the mechanism of algal blooms.

Cryoelectron Microscopy Delineates the In Situ Structure of the Thylakoid Network

Photosynthesis is conceivably the most important biological process on Earth.By performing oxygenic photosynthesis,cyanobacteria,algae,and plants can use solar energy to power their metabolism and produce sugars and oxygen for life on the planet.These photosynthetic organisms have evolved a specialized intracellular membrane system,the thylakoid membrane,inside the cytoplasmic membrane to carry out the reactions of photosynthesis.

Exploration of sea anemone-inspired high-performance biomaterials with enhanced antioxidant activity

Antioxidant biomaterials have attracted much attention in various biomedical fields because of their effective inhibition and elimination of reactive oxygen species(ROS)in pathological tissues.However,the difficulty in ensuring biocompatibility,biodegradability and bioavailability of antioxidant materials has limited their further development.Novel bioavailable antioxidant materials that are derived from natural resources are urgently needed.Here,an integrated multi-omics method was applied to fabricate antioxidant biomaterials.A key cysteine-rich thrombospondin-1 type Ⅰ repeat-like(TSRL)protein was efficiently discovered from among 1262 adhesive components and then used to create a recombinant protein with a yield of 500 mg L^(-1).The biocompatible TSRL protein was able to self-assemble into either a water-resistant coating through Ca^(2+)-mediated coordination or redox-responsive hydrogels with tunable physical properties.The TSRL-based hydrogels showed stronger 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging rates than glutathione(GSH)and ascorbic acid(Aa)and protected cells against external oxidative stress significantly more effectively.When topically applied to mice skin,TSRL alleviated epidermal hyperplasia and suppressed the degradation of collagen and elastic fibers caused by ultraviolet radiation B(UVB)irradiation,confirming that it enhanced antioxidant activity in vivo.This is the first study to successfully characterize natural antioxidant biomaterials created from marine invertebrate adhesives,and the findings indicate the excellent prospects of these biomaterials for great applications in tissue regeneration and cosmeceuticals.

Fluorescence recovery after photobleaching:analyses of cyanobacterial phycobilisomes reveal intrinsic fluorescence recovery

Fluorescence recovery after photobleaching(FRAP)has been used to study the dynamics of the cyanobacterial photosynthesis apparatus since 1997.Fluorescence recovery of cyanobacteria during FRAP was conventionally interpreted as a result of phycobilisome(PBS)diffusion on the surface of the thylakoid membrane.The mechanism of state transition in cyanobacteria has been widely attributed to PBS diffusion.However,in red algae,another PBS-containing group,the intrinsic photoprocess was found to contribute greatly to the fluorescence recovery of PBS,which raises questions concerning the role of FRAP in red algal PBS.Therefore,it is important to re-evaluate the nature of PBS fluorescence recovery in cyanobacteria.In the present study,four cyanobacterial strains with different phenotypes and PBS compositions were used to investigate their FRAP characteristics.Fluorescence recovery of PBS was observed in wholly photobleached cells in all four cyanobacterial strains,in which the contribution of PBS diffusion to the fluorescence recovery was not possible.Moreover,the fluorescence recovered in isolated PBSs and PBS-thylakoid membranes after photobleaching further demonstrated the intrinsic photoprocess nature of fluorescence recovery.These findings suggest that the intrinsic photoprocess contributed to the fluorescence recovery following photobleaching when measured by the FRAP method.

A study of the protein-protein interactions in the phycocyanin monomer from Synechocystis sp.PCC 6803 using a bacterial two-hybrid system

Investigations into the intramolecular interactions of the native protein in solution are important to understand its structural stability as well as its potential uses in future applications.In this study,we used a bacterial two-hybrid system to investigate the interaction between the phycocyanin𝛼and𝛽subunits that form the phycocyanin monomer.Key amino acid residues responsible for the interaction between the subunits were identified,providing direct experimental evidence for the intramolecular interaction.

Correction to:Fluorescence recovery after photobleaching:analyses of cyanobacteria!phycobilisomes reveal intrinsic fluorescence recovery

The original version of this article unfortunately contained a mistake.A funding number was incorrect in the Acknowledgements section.The correct funding number is:Natural Science Foundation of Shandong(no.ZR2017LD013).The original article has been corrected.