Simultaneous Mapping of the Nanoscale Organization and Redox State of Extracellular Space in Living Brain Tissue.

The spatial organization characteristics and redox status of the extracellular space (ECS) are crucial in the development of brain diseases. However, it remains a challenge to simultaneously capture dynamic changes in microstructural features and redox states at the submicron level within the ECS. Here, we developed a reversible glutathione (GSH)-responsive nanoprobe (RGN) for mapping the spatial organization features and redox status of the ECS in brain tissues with nanoscale resolution. The RGN is composed of polymer nanoparticles modified with GSH-responsive molecules and amino-functionalized methoxypoly(ethylene glycol), which exhibit exceptional single-particle brightness and excellent free diffusion capability in the ECS of brain tissues. Tracking single RGNs in acute brain slices allowed us to dynamically map spatial organizational features and redox levels within the ECS of brain tissues in disease models. This provides a powerful super-resolution imaging method that offers a potential opportunity to study the dynamic changes in the ECS microenvironment and to understand the physiological and pathological roles of the ECS in vivo.

Comparison between AWGC-cachexia and GLIM-malnutrition in patients with gastric cancer.

BACKGROUND: The newly released Asian Working Group for Cachexia (AWGC) criteria share similar diagnostic items with the Global Leadership Initiative on Malnutrition (GLIM) criteria. This study aims to compare the AWGC cachexia and GLIM malnutrition in patients with gastric cancer and investigate whether one diagnosis continues to be a prognostic factor in individuals diagnosed with the other condition. METHODS: Data of patients who underwent radical gastrectomy for gastric adenocarcinoma were prospectively collected from 2013 to 2019. The AWGC and GLIM criteria were applied to diagnosis cachexia and malnutrition, respectively. Univariate and multivariate logistic and Cox regression were used to verify the effect of relevant factors on postoperative complications and overall survival. RESULTS: A total of 1420 patients were included, among whom 174 (12.3 %) were diagnosed with AWGC-cachexia alone, 85 (6.0 %) were diagnosed with GLIM-malnutrition alone, and 324 (22.8 %) had both AWGC-cachexia and GLIM-malnutrition. Both AWGC-cachexia and GLIM-malnutrition were independent risk factors for complications and overall survival. When they coexisted, the odds ratios (OR) and hazard ratios (HR) tended to be higher. In the AWGC-cachexia subset, GLIM-malnutrition remained an independent risk factor (HR = 1.544, 95 % CI = 1.098-2.171, P = 0.012) for overall survival after the adjustment of confounding factors. Similarly, in the GLIM-malnutrition subset, AWGC-cachexia remained an independent risk factor for overall survival (HR = 1.697, 95 % CI = 1.087-2.650, P = 0.020). Patients with both cachexia and malnutrition had the worst overall survival. CONCLUSION: AWGC-cachexia and GLIM-malnutrition criteria were two non-redundancy tools in reflecting mortality risk in preoperative nutritional assessment.

Inborn errors of immunity and its clinical significance in children with lymphoma in China: a single-center study

Abstract Objective: To investigate the incidence, clinical and genetic characteristics of pediatric lymphoma patients of China with inborn errors of immunity (IEI)-related gene mutations, which have not been fully studied. Method: From Jan. 2020 to Mar. 2023, IEI-related genetic mutations were retrospectively explored in 108 children with lymphomas admitted to Beijing Children's Hospital by NGS. Genetic rule and clinical characteristics as well as treatment outcomes were compared between patients with or without IEI-related gene mutations. Results: A total of 17 patients (15.7 %) harbored IEI-associated mutations, including 4 cases with X-linked lymphoproliferative syndrome (XLP), 3 cases had mutations in tumor necrosis factor receptor superfamily 13B (TNFRSF13B), 2 cases with Activated p110 syndrome (APDS). Patients with IEI all had alteration of immunocompetence with decreased levels of immunoglobulin and lymphocyte subsets. Recurrent infection existed in 41.2 % of patients. The 18-month event-free survival (EFS) and the overall response rate (ORR) of patients with IEI are significantly lower than those without IEI (33.86% vs. 73.26 %, p = 0.011; 52.94% vs. 87.91 %, p = 0.002, respectively). In addition, patients with IEI had a higher progression disease (PD) rate of 23.5 % than those without IEI of 4.4% (p = 0.006). Conclusion: The present study demonstrated that IEI-associated lymphomas were much more common than originally appreciated in pediatric lymphomas, and those were insensitive to treatment and more likely to progress or relapse. The genomic analysis and a thorough review of the medical history of IEI can be used to distinguish them from pediatric lymphomas without IEI, which are beneficial for the early diagnosis and direct intervention.

Life at the conservative end of the leaf economics spectrum: intergeneric variation in the allocation of phosphorus to biochemical fractions in species of Banksia (Proteaceae) and Hakea (Proteaceae).

In severely phosphorus (P)-impoverished environments, plants have evolved to use P very efficiently. Yet, it is unclear how P allocation in leaves contributes to their photosynthetic P-use efficiency (PPUE) and position along the leaf economics spectrum (LES). We address this question in 10 species of Banksia and Hakea, two highly P-efficient Proteaceae genera. We characterised traits in leaves of Banksia and Hakea associated with the LES: leaf mass per area, light-saturated photosynthetic rates, P and nitrogen concentrations, and PPUE. We also determined leaf P partitioning to five biochemical fractions (lipid, nucleic acid, metabolite, inorganic and residual P) and their possible association with the LES. For both genera, PPUE was negatively correlated with fractional allocation of P to lipids, but positively correlated with that to metabolites. For Banksia only, PPUE was negatively correlated with residual P, highlighting a strategy contrasting to that of Hakea. Phosphorus-allocation patterns significantly explained PPUE but were not linked to the resource acquisition vs resource conservation gradient defined by the LES. We conclude that distinct P-allocation patterns enable species from different genera to achieve high PPUE and discuss the implications of different P investments. We surmise that different LES axes representing different ecological strategies coexist in extremely P-impoverished environments.

[Corrigendum] Ginsenoside Rg1 inhibits inflammatory responses via modulation of the nuclear factor­κB pathway and inhibition of inflammasome activation in alcoholic hepatitis.

Following the publication of the above article, the authors drew to the attention of the Editorial Office that, after having reviewed all the figures and the data of their drawing software, they discovered that the pictures in the 'Control' and 'DEX' groups of Fig. 4D on p. 904 had been incorrectly imported into Fig. 6 on p. 905 when assembling this figure, effectively replacing the original and correctly placed images in Fig. 6D and E. The original (and correct) version of Fig. 6 is shown on the next page. All the authors agree with the publication of this Corrigendum, and express their gratitude to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this; furthermore, they apologize to the readership of the Journal for any inconvenience caused. [International Journal of Molecular Medicine 41: 899­907, 2018; DOI: 10.3892/ijmm.2017.3297].

Concentration of IL-1ß, IL-7, IL-12, IL-17, CX3CL1, ITAC and relation with the seizure severity and sudden unexpected death in epilepsy patient.

OBJECTIVE: Inflammation plays an important role in epilepsy. There is evidence for the relationship between proinflammatory cytokines and epilepsy. We aimed to detect the serum levels of multiple cytokines in epilepsy patients, looking for biological indicators, and providing a theoretical basis for the clinical diagnosis, treatment, and prognosis of epilepsy. MATERIALS AND METHODS: In this study, 30 patients with drug-resistant epilepsy (DRE), 30 patients with well-controlled epilepsy (WCE), and 29 healthy controls (HC) were enrolled. Multi-proinflammatory cytokines were measured by LUMINX multi-factor detection. RESULTS: The levels of IL-1ß, IL-7, IL-12, and IL-17 were significantly elevated, and the levels of CX3CL1 and ITAC were significantly decreased in epilepsy patients compared with healthy controls. Furthermore, the level of IL-17 was significantly higher in the DRE group compared to WCE. We also found the ratio of IL-7/CX3CL discriminates accurately between patients and controls, with a ROC Area Under the Curve (AUC) of 0.963 (P<0.001). The levels of IL-1ß, IL-7, IL-12, and IL-17 in the DRE group were positively correlated with the National Hospital Seizure Severity Scale (NHS3) scores (IL-1ß, P = 0.029; IL-12, P = 0.039; IL-17, P = 0.004). IL-17 was positively correlated with seizure frequency (P = 0.050), while ITAC was negatively correlated with seizure frequency (P = 0.012) and Sudden Unexpected Death in Epilepsy-3 (SUDEP-3) scores (P = 0.023). CONCLUSIONS: IL-1ß, IL-12, and IL-17 may be used to predict seizure severity and the IL-7/CX3CL1 ratio may be a candidate biomarker for predicting epileptic seizures. While CX3CL1 and ITAC play anti-epileptic effects, ITAC may be used to assess the risk of SUDEP.

Efficacy and safety of batroxobin in patients with acute ischemic stroke: A multicenter retrospective analysis.

AIMS: The objective of this study was to evaluate the effectiveness of batroxobin in improving functional outcomes and reducing stroke recurrence among patients with acute ischemic stroke beyond the therapeutic time window for thrombolytic therapy. METHODS: This multicenter, retrospective study enrolled 492 patients with acute moderate-to-severe ischemic stroke within 24 h. 238 patients were given standard (basic) therapy. On the basis of standard treatment, 254 patients received an initial intravenous infusion of batroxobin 10 U on day 1, followed by subsequent infusions of batroxobin 5 U on the 3rd and 5th days, respectively. RESULTS: In the batroxobin group, 8.3% of patients experienced recurrence stroke, compared to 17.2% in the control group (HR, 0.433; 95% CI, 0.248 to 0.757; p = 0.003). Furthermore, intravenous batroxobin significantly improved the distribution of 90-120 day disability. Moderate-to-severe bleeding events were reported in three patients (1.2%) in the batroxobin group and one patient (0.4%) in the control group (p = 0.369). CONCLUSIONS: Among patients with acute moderate-to-severe ischemic stroke beyond the time window for thrombolytic therapy, treatment with intravenous batroxobin had a lower risk of stroke recurrence and a better recovery of function outcome without increasing bleeding events. Prospective studies are needed to further confirm.

Rapid detection of human cytomegalovirus by multienzyme isothermal rapid amplification and lateral flow dipsticks.

Introduction: Human cytomegalovirus (HCMV) is the most common viral infection seen in newborns. The major route of transmission for acquired human cytomegalovirus infection is breast milk from mothers who are HCMV seropositive to the infants. Thus, a rapid, economical, and simple method to perform HCMV test in breast milk is crucial and necessary for preventing acquired HCMV infection, especially in underdeveloped regions with limited laboratory resources. Methods: In this study, an effective technique for the detection of HCMV was constructed by combining multienzyme isothermal rapid amplification (MIRA) and lateral flow chromatography strip (LFD). Primers for the conserved HCMV sequence UL83 were utilized for MIRA-LFD testing. Results: Our results showed that the entire MIRA reaction could be completed in 12 minutes at 37°C, and LFD outcomes could be observed visibly after 10 minutes. The detection sensitivity of this method reached 50 copy/µl. Samples of breast milk were examined to compare MIRA-LFD and conventional qPCR. The accuracy of MIRA-LFD was 100%. Discussion: The straightforward, rapid, economic features of the test can provide the significant advantages for the prevention of breast milk-acquired cytomegalovirus infection, particularly in resource-limited locations with high seroprevalence of cytomegalovirus.

Computational study of associations between the synaptic conductance of STN and GPe and the development of Parkinson's disease.

There is evidence that the subthalamic nucleus (STN) and globus pallidus pars externa (GPe) involve in the development of Parkinson's disease, a neurodegenerative disorder characterized by motor and non-motor symptoms and loss of dopaminergic neurons in which the error index (EI) in firing patterns is widely used to address the related issues. Whether and how this interaction mechanism of STN and GPe affects EI in Parkinson's disease is uncertain. To account for this, we propose a kind of basal ganglia-thalamic network model associated with Parkinson's disease coupled with neurons, and investigate the effect of synaptic conductance of STN and GPe on EI in this network, as well as their internal relationship under EI as an index. The results show a relationship like a piecewise function between the error index and the slope of the state transition function of synaptic conductance from STN to GPe ( g snge ) and from GPe to STN ( g gesn ). And there is an approximate negative correlation between EI and g gesn . Increasing g snge and decreasing g gesn can improve the fidelity of thalamus information transmission and alleviate Parkinson's disease effectively. These obtained results can give some theoretical evidence that the abnormal synaptic releases of STN and GPe may be the symptoms of the development of Parkinson's disease, and further enrich the understanding of the pathogenesis and treatment mechanism of Parkinson's disease.

Cost-Effectiveness Analysis of Hepatic Arterial Chemotherapy for Advanced Hepatocellular Carcinoma in China: A Comparative Analysis of HAIC-FO and Sorafenib.

BACKGROUND The FOHAIC-1 trial showed hepatic arterial infusion chemotherapy with infusional fluorouracil, leucovorin, and oxaliplatin (HAIC-FO) improved survival, compared with sorafenib, in patients with advanced hepatocellular carcinoma (HCC). The aim of this study was to conduct a cost-effectiveness comparison between HAIC-FO and sorafenib from the perspective of the Chinese healthcare system. MATERIAL AND METHODS The economic evaluation was conducted between July 2023 and February 2024, spanning a 10-year investment horizon. A Markov model was developed to perform a cost-effectiveness analysis of HAIC-FO vs sorafenib. Health states incorporated in the model comprised progression-free disease, progressed disease, and death. Transition probabilities were derived from data obtained from the FOHAIC-1 trial. Incremental cost-effectiveness ratio (ICER) was calculated to evaluate cost-effectiveness. Additionally, one-way and probabilistic sensitivity analyses assessed the model's robustness. RESULTS The HAIC-FO group accrued a total cost of $22,781, whereas the sorafenib group totaled $18,795. In terms of effectiveness, the HAIC-FO group achieved 1.06 quality-adjusted life years (QALYs), whereas the sorafenib group attained 0.65 QALYs. Compared with sorafenib, HAIC-FO yielded an additional 0.41 QALYs at a cost of additional $3,985, resulting in an incremental cost of $9,720 per QALY gained. The one-way sensitivity analysis revealed the final ICER remained below the willingness-to-pay (WTP) threshold of $30,492 per QALY, when considering parameter fluctuations. Additionally, probabilistic sensitivity analysis indicated a 99.8% probability that the ICER for HAIC-FO compared with sorafenib would fall below the WTP threshold. CONCLUSIONS Compared with sorafenib, HAIC-FO emerged as a cost-effective first-line treatment option for patients facing advanced HCC in China.

A small molecule compound targeting hemagglutinin inhibits influenza A virus and exhibits broad-spectrum antiviral activity.

Influenza A virus (IAV) is a widespread pathogen that poses a significant threat to human health, causing pandemics with high mortality and pathogenicity. Given the emergence of increasingly drug-resistant strains of IAV, currently available antiviral drugs have been reported to be inadequate to meet clinical demands. Therefore, continuous exploration of safe, effective and broad-spectrum antiviral medications is urgently required. Here, we found that the small molecule compound J1 exhibited low toxicity both in vitro and in vivo. Moreover, J1 exhibits broad-spectrum antiviral activity against enveloped viruses, including IAV, respiratory syncytial virus (RSV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human coronavirus OC43 (HCoV-OC43), herpes simplex virus type 1 (HSV-1) and HSV-2. In this study, we explored the inhibitory effects and mechanism of action of J1 on IAV in vivo and in vitro. The results showed that J1 inhibited infection by IAV strains, including H1N1, H7N9, H5N1 and H3N2, as well as by oseltamivir-resistant strains. Mechanistic studies have shown that J1 blocks IAV infection mainly through specific interactions with the influenza virus hemagglutinin HA2 subunit, thereby blocking membrane fusion. BALB/c mice were used to establish a model of acute lung injury (ALI) induced by IAV. Treatment with J1 increased survival rates and reduced viral titers, lung index and lung inflammatory damage in virus-infected mice. In conclusion, J1 possesses significant anti-IAV effects in vitro and in vivo, providing insights into the development of broad-spectrum antivirals against future pandemics.

Population structure and selection signal analysis of indigenous sheep from the southern edge of the Taklamakan Desert.

Analyzing the genetic diversity and selection characteristics of sheep (Ovis aries) holds significant value in understanding their environmental adaptability, enhancing breeding efficiency, and achieving effective conservation and rational utilization of genetic resources. In this study, we utilized Illumina Ovine SNP 50 K BeadChip data from four indigenous sheep breeds from the southern margin of the Taklamakan Desert (Duolang sheep: n = 36, Hetian sheep: n = 74, Kunlun sheep: n = 27, Qira black sheep: n = 178) and three foreign meat sheep breeds (Poll Dorset sheep: n = 105, Suffolk sheep: n = 153, Texel sheep: n = 150) to investigate the population structure, genetic diversity, and genomic signals of positive selection within the indigenous sheep. According to the Principal component analysis (PCA), the Neighbor-Joining tree (NJ tree), and Admixture, we revealed distinct clustering patterns of these seven sheep breeds based on their geographical distribution. Then used Cross Population Extended Haplotype Homozygosity (XP-EHH), Fixation Index (FST), and Integrated Haplotype Score (iHS), we identified a collective set of 32 overlapping genes under positive selection across four indigenous sheep breeds. These genes are associated with wool follicle development and wool traits, desert environmental adaptability, disease resistance, reproduction, and high-altitude adaptability. This study reveals the population structure and genomic selection characteristics in the extreme desert environments of native sheep breeds from the southern edge of the Taklimakan Desert, providing new insights into the conservation and sustainable use of indigenous sheep genetic resources in extreme environments. Additionally, these findings offer valuable genetic resources for sheep and other mammals to adapt to global climate change.

Optimized microbial fuel cell-powered electro-Fenton processes to enhance electricity and bisphenol A removal by varying external resistance and electrolyte concentrations.

This study is the first to investigate the effects of external resistance and electrolyte concentration on the performance of a bioelectro-Fenton (BEF) system, involving measurements of power density, H2O2 generation, and bisphenol A (BPA) removal efficiency. With optimized operating conditions (external resistance of 1.12 kΩ and cathodic NaCl concentration of 1,657 mg/L), the BEF system achieved a maximum power density of 38.59 mW/m2, which is about 3.5 times higher than with 1 kΩ external resistance and no NaCl. This system featured a 71.7 % reduction in total internal resistance. The optimized BEF also accelerated the oxygen reduction reaction rate, increasing H2O2 generation by 4.4 times compared to the unoptimized system. Moreover, it exhibited superior BPA degradation performance, removing over 99 % of BPA within 14 hs, representing a 1.1 to 3.3-fold improvement over the unoptimized BEF. By the fifth cycle (70 h), the optimized BEF still removed 70 % of BPA. Optimizing the operating conditions significantly increased the abundance of electrochemically active bacteria (Pseudomonadaceae) from 2.2 % to 20 %, facilitating rapid acclimation. The study demonstrates the strong potential of an optimized BEF system for removing persistent pollutants.

Landscape of clinical drug development of ADCs used for the pharmacotherapy of cancers: an overview of clinical trial registry data from 2002 to 2022.

BACKGROUND: To provide reference for clinical development of ADCs in the industry, we analyzed the landscape and characteristics of clinical trials about antibody-drug conjugates (ADCs). METHOD: Clinical trials to study ADCs used for the pharmacotherapy of cancers initiated by the sponsor were searched in the Cite line Pharma Intelligence (Trialtrove database), and the landscape and characteristics of these clinical trials were analyzed from multiple perspectives, such as the number, phases, status, indications, and targets of the clinical trials. RESULT: As of December 31, 2022, a total of 431 clinical trials have been initiated to study ADCs used for the pharmacotherapy of cancers, and the number of the last 10 years was 5.5 times as large as the first 11 years. These clinical trials involved 47 indications, including breast cancer, lymphoma (lymphoma, non-Hodgkin's and lymphoma, Hodgkin's), unspecified solid tumor, bladder cancer and lung cancer (lung, non-small cell cancer and lung, small cell cancer). As for each of these five indications, 50 + clinical trials have been carried out, accounting for as high as 48.50% (454/936). ADCs involve 38 targets, which are relatively concentrated. Among them, ERBB2 (HER2) and TNFRSF8 (CD30) involve in 100 + registered clinical trials, and TNFRSF17 (BCMA), NECTIN4 and CD19 in 10 + trials. The clinical trials for these five targets account for 79.02% (354/448) of the total number. Up to 93.97% (405/431) of these clinical trials explored the correlation between biomarkers and efficacy. Up to 45.91% (292/636) of Lots (lines of treatment) applied in the clinical trials were the second line. Until December 31, 2022, 54.52% (235/431) of the clinical trials have been completed or terminated. CONCLUSION: ADCs are a hotspot of research and development in oncology clinical trials, but the indications, targets, phases, and Lot that have been registered are seemingly relatively concentrated at present. This study provides a comprehensive analysis which can assist researchers/developer quickly grasp relevant knowledge to assess a product and also providing new clues and ideas for future research.

True or false? Alzheimer's disease is type 3 diabetes: Evidences from bench to bedside.

Globally, Alzheimer's disease (AD) is the most widespread chronic neurodegenerative disorder, leading to cognitive impairment, such as aphasia and agnosia, as well as mental symptoms, like behavioral abnormalities, that place a heavy psychological and financial burden on the families of the afflicted. Unfortunately, no particular medications exist to treat AD, as the current treatments only impede its progression.The link between AD and type 2 diabetes (T2D) has been increasingly revealed by research; the danger of developing both AD and T2D rises exponentially with age, with T2D being especially prone to AD. This has propelled researchers to investigate the mechanism(s) underlying this connection. A critical review of the relationship between insulin resistance, Aß, oxidative stress, mitochondrial hypothesis, abnormal phosphorylation of Tau protein, inflammatory response, high blood glucose levels, neurotransmitters and signaling pathways, vascular issues in AD and diabetes, and the similarities between the two diseases, is presented in this review. Grasping the essential mechanisms behind this detrimental interaction may offer chances to devise successful therapeutic strategies.

Carex meyeriana Kunth Extract Is a Novel Natural Drug against Candida albicans.

As a widely distributed plant in Northeast China, Carex meyeriana Kunth (CMK) is generally considered to have antibacterial properties; however, there is a lack of scientific evidence for this. Therefore, we investigated the chemical composition of CMK extract and its effect against C. albicans. A total of 105 compounds were identified in the alcohol extracts of CMK by UPLC-Q-TOF-MS. Most were flavonoids, with Luteolin being the most represented. Among them, 19 compounds are found in the C. albicans lysates. After treatment with CMK ethanol extract, a significant reduction in the number of C. albicans colonies was observed in a vaginal douche solution from day 5 (p < 0.05). Furthermore, the CMK extract can reduce the number of C. albicans spores. The levels of IL-4, IL-6, IL-10, IL-1ß, and TNF-α in vaginal tissues all exhibited a significant decrease (p < 0.05) compared to those in the model group as determined by ELISA. The results of HE staining showed that CMK extract can eliminate vaginal mucosa inflammation. CMK adjusts the vaginal mucosa cells by targeting twenty-six different metabolites and five specific metabolic pathways in order to effectively eliminate inflammation. Simultaneously, the CMK regulates twenty-three types of metabolites and six metabolic pathways against C. albicans infection. So, CMK strongly inhibits the growth of C. albicans and significantly reduces vaginal inflammation, making it a promising candidate for treating C. albicans infection.

Unraveling the chemical constituents, absorption characteristics, and metabolic profile of Codonopsis Radix based on UPLC-Q- Orbitrap MS.

Codonopsis Radix (CR), a traditional tonic medicinal material in China, has been proven to possess a variety of bioactive functions. However, its chemical composition and in vivo metabolic pattern have not been fully elucidated. In this study, AB-8 macroporous resin column chromatography was employed for the enrichment of small molecular components in CR. Furthermore, a method combining ultra-performance liquid chromatography-quadrupole-orbitrap mass spectrometry with Acquire X intelligent data acquisition technology software was developed for the preliminary screening and identification of the chemical composition of CR in vitro and their metabolites in vivo. As a result, a total of 116 components were preliminarily characterized in the CR extract, including 28 polyacetylenes, 33 organic acids, 4 amino acids, 23 alkaloids, 9 phenylpropanoids, 6 terpenoids, 2 nucleosides, and 11 others. Additionally, a total of 84 compounds, including 37 prototype components and 47 metabolites, were identified in the plasma, urine, and feces of rats after oral administration of CR. Specifically, 11, 24, 19, 32, and 25 constituents were identified in the heart, liver, spleen, lung, and kidney, respectively. Of note, the lung and spleen are the organs with the highest distribution of CR compounds. These findings will serve as valuable data for future research on the correlation between the chemical composition and pharmacological effects of CR.

Genomic analysis of Alteromonas sp. M12 isolated from the Mariana Trench reveals its role in dimethylsulfoniopropionate cycling.

Dimethylsulfoniopropionate (DMSP) is a ubiquitous organosulfur molecule in marine environments with important roles in stress tolerance, global carbon and sulfur cycling, and chemotaxis. It is the main precursor of the climate active gas dimethyl sulfide (DMS), which is the greatest natural source of bio­sulfur transferred from ocean to atmosphere. Alteromonas sp. M12, a Gram-negative and aerobic bacterium, was isolated from the seawater samples collected from the Mariana Trench at the depth of 2500 m. Here, we report the complete genome sequence of strain M12 and its genomic characteristics to import and utilize DMSP. The genome of strain M12 contains one circular chromosome (5,012,782 bp) with the GC content of 40.88%. Alteromonas sp. M12 can grow with DMSP as a sole carbon source, and produced DMS with DMSP as a precursor. Genomic analysis showed that strain M12 contained a set of genes involved in the downstream steps of DMSP cleavage, but no known genes encoding DMSP transporters or DMSP lyases. The results indicated that this strain contained novel DMSP transport and cleavage genes in its genome which warrants further investigation. The import of DMSP into cells may be a strategy of strain M12 to adapt the hydrostatic pressure environment in the Mariana Trench, as DMSP can be used as a hydrostatic pressure protectant. This study sheds light on the catabolism of DMSP by deep-sea bacteria.