Pengzhenrongella phosphoraccumulans sp. nov., isolated from high Arctic glacial till, and emended description of the genus Pengzhenrongella.

A yellow pigmented, Gram-stain-positive, motile, facultatively anaerobic and irregular rod-shaped bacteria (strain M0-14T) was isolated from a till sample collected from the foreland of a high Arctic glacier near the settlement of Ny-Ålesund in the Svalbard Archipelago, Norway. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that M0-14T formed a lineage within the family Cellulomonadaceae, suborder Micrococcineae. M0-14T represented a novel member of the genus Pengzhenrongella and had highest 16S rRNA gene sequence similarity to Pengzhenrongella sicca LRZ-2T (97.3 %). Growth occurred at 4-25 °C (optimum 4-18 °C), at pH 6.0-9.0 (optimum pH 7.0), and in the presence of 0-5 % (w/v) NaCl. The predominant menaquinone was MK-9(H4) and the major fatty acids were anteiso-C15 : 0, C16 : 0 and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were phosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylinositol, one undefined phospholipid and five undefined phosphoglycolipids. The cell-wall diamino acid was l-ornithine whereas rhamnose and mannose were the cell-wall sugars. Polyphosphate particles were found inside the cells of M0-14T. Polyphosphate kinase and polyphosphate-dependent glucokinase genes were detected during genomic sequencing of M0-14. In addition, the complete pstSCAB gene cluster and phnCDE synthesis genes, which are important for the uptake and transport of phosphorus in cells, were annotated in the genomic data. According to the genomic data, M0-14T has a metabolic pathway related to phosphorus accumulation. The DNA G+C content of the genomic DNA was 70.8 %. On the basis of its phylogenetic relationship, phenotypic properties and chemotaxonomic distinctiveness, strain M0-14T represents a novel species of the genus Pengzhenrongella, for which the name Pengzhenrongella phosphoraccumulans sp. nov. is proposed. The type strain is M0-14T (= CCTCC AB 2012967T = NRRL B-59105T).

Achilles' Heel-The Significance of Maintaining Microenvironmental Homeostasis in the Nucleus Pulposus for Intervertebral Discs.

The dysregulation of intracellular and extracellular environments as well as the aberrant expression of ion channels on the cell membrane are intricately linked to a diverse array of degenerative disorders, including intervertebral disc degeneration. This condition is a significant contributor to low back pain, which poses a substantial burden on both personal quality of life and societal economics. Changes in the number and function of ion channels can disrupt the water and ion balance both inside and outside cells, thereby impacting the physiological functions of tissues and organs. Therefore, maintaining ion homeostasis and stable expression of ion channels within the cellular microenvironment may prove beneficial in the treatment of disc degeneration. Aquaporin (AQP), calcium ion channels, and acid-sensitive ion channels (ASIC) play crucial roles in regulating water, calcium ions, and hydrogen ions levels. These channels have significant effects on physiological and pathological processes such as cellular aging, inflammatory response, stromal decomposition, endoplasmic reticulum stress, and accumulation of cell metabolites. Additionally, Piezo 1, transient receptor potential vanilloid type 4 (TRPV4), tension response enhancer binding protein (TonEBP), potassium ions, zinc ions, and tungsten all play a role in the process of intervertebral disc degeneration. This review endeavors to elucidate alterations in the microenvironment of the nucleus pulposus during intervertebral disc degeneration (IVDD), with a view to offer novel insights and approaches for exploring therapeutic interventions against disc degeneration.

Candidatus Kaistella beijingensis sp. nov., Isolated from a Municipal Wastewater Treatment Plant, Is Involved in Sludge Foaming.

Biological foaming (or biofoaming) is a frequently occurring problem in wastewater treatment plants (WWTPs) and is attributed to the overwhelming growth of filamentous bulking and foaming bacteria (BFB). Biological foaming has been intensively investigated, with BFB like Microthrix and Skermania having been identified from WWTPs and implicated in foaming. Nevertheless, studies are still needed to improve our understanding of the microbial diversity of WWTP biofoams and how microbial activities contribute to foaming. In this study, sludge foaming at the Qinghe WWTP of China was monitored, and sludge foams were investigated using culture-dependent and culture-independent microbiological methods. The foam microbiomes exhibited high abundances of Skermania, Mycobacterium, Flavobacteriales, and Kaistella. A previously unknown bacterium, Candidatus Kaistella beijingensis, was cultivated from foams, its genome was sequenced, and it was phenotypically characterized. Ca. K. beijingensis exhibits hydrophobic cell surfaces, produces extracellular polymeric substances (EPS), and metabolizes lipids. Ca. K. beijingensis abundances were proportional to EPS levels in foams. Several proteins encoded by the Ca. K. beijingensis genome were identified from EPS that was extracted from sludge foams. Ca. K. beijingensis populations accounted for 4 to 6% of the total bacterial populations in sludge foam samples within the Qinghe WWTP, although their abundances were higher in spring than in other seasons. Cooccurrence analysis indicated that Ca. K. beijingensis was not a core node among the WWTP community network, but its abundances were negatively correlated with those of the well-studied BFB Skermania piniformis among cross-season Qinghe WWTP communities. IMPORTANCE Biological foaming, also known as scumming, is a sludge separation problem that has become the subject of major concern for long-term stable activated sludge operation in decades. Biological foaming was considered induced by foaming bacteria. However, the occurrence and deterioration of foaming in many WWTPs are still not completely understood. Cultivation and characterization of the enriched bacteria in foaming are critical to understand their genetic, physiological, phylogenetic, and ecological traits, as well as to improve the understanding of their relationships with foaming and performance of WWTPs.

High-Throughput Single-Cell Technology Reveals the Contribution of Horizontal Gene Transfer to Typical Antibiotic Resistance Gene Dissemination in Wastewater Treatment Plants.

The spread of antibiotic resistance genes (ARGs) has gained much attention worldwide, while the contribution of vertical gene transfer (VGT) and horizontal gene transfer (HGT) is still elusive. Here, we improved an emerging high-throughput single-cell-based technology, emulsion, paired isolation, and concatenation polymerase chain reaction (epicPCR), by lengthening the sequence of ARG in the fused ARG-16S rRNA fragments to cover the variance of both ARG and its hosts. The improved epicPCR was applied to track the hosts of a widely detected ARG, sul1 gene, in five urban wastewater treatment plants (UWTPs) during two seasons. The sul1 host bacteria were highly diverse and mostly classified as Proteobacteria and Bacteroidetes. Clear seasonal divergence of α-diversity and interaction networks were present in the host community. The consensus phylogenetic trees of the sul1 gene and their host demonstrated incorrespondence on the whole and regularity on abundant groups, suggesting the important role of both HGT and VGT, respectively. The relative importance of these two ways was further measured; HGT (54%) generally played an equal or even more important role as VGT (46%) in UWTPs. The application of the improved epicPCR technology provides a feasible approach to quantify the relative contributions of VGT and HGT in environmental dissemination of ARGs.

Niche width of above- and below-ground organisms varied in predicting biodiversity profiling along a latitudinal gradient.

Biodiversity is the foundation of all ecosystems across the planet, and having a better understanding of its global distribution mechanism could be important for biodiversity conservation under global change. A niche width model, combined with metabolic theory, has successfully predicted the increase of α-diversity and decrease of ß-diversity in the below-ground microbial community along an altitudinal mountain gradient. In this study, we evaluated this niche width model of above-ground plants (mainly trees and shrubs) and below-ground bulk soil microbial communities (i.e., bacteria and archaea) along a latitudinal gradient of forests in China. The niche widths of both plants and microbes increased with increasing temperature and precipitation, and with proximity to circumneutral pH. However, the α- and ß-diversities (observed richness and Bray-Curtis dissimilarity, respectively) could not be accurately predicted by a single niche width model alone, either temperature, precipitation or pH. Considering the interactions among different niche width models, all three niche width models were combined to predict biodiversity at the community level using structural equation modelling. The results showed that the niche width model of circumneutral pH was most important in predicting diversity profiling (i.e., α- and ß-diversity) for both plants and microbes, while niche width of precipitation and temperature showed both direct and indirect importance for microbe and plant biodiversity, respectively. Because the current niche width model neglects several scenarios related to taxon and environmental attributes, it still needs to be treated with caution in predicting biodiversity trends.

Giardia duodenalis induces extrinsic pathway of apoptosis in intestinal epithelial cells through activation of TNFR1 and K63 de-ubiquitination of RIP1 in vitro.

Giardia duodenalis is one of main causative agents of diarrhea that affects the health of millions of people on a global scale per year. It has been clear that attachment of G. duodenalis trophozoites to intestinal epithelium cells (IECs) can induce cell death, while the underlying cellular and molecular mechanisms remain to be explored. It was shown in this study that treatment of Caco-2 cells with Giardia trophozoites could result in reduced cell viability. RNA sequencing analysis demonstrated that expressions of many apoptosis-related genes and some deubiquitinase genes displayed marked changes in trophozoite-treated cells. Trophozoites activated the death-signaling receptor TNFR1 on the IEC surface and caspase-3/8 (CASP3/8) signaling pathways in Caco-2 cells. K63 ubiquitination level of RIP1 was reduced upon stimulation with trophozoites, in parallel, the expressions of deubiquitinases CYLD and A20 were increased. The caspase inhibitor Q-VD-OPH could rescue trophozoite-induced cell apoptosis. Likewise, TNFR1, CYLD, and A20 silencing decreased the levels of cleaved CASP3/8 in trophozoite-treated cells and reversed the pro-apoptosis induction effect of trophozoites. These data suggest that Giardia trophozoite stimulation can activate CASP3/8 signaling pathways via activation of TNFR1 and K63 de-ubiquitination of RIP1 caused by up-regulated expressions of CYLD and A20, and promote Caco-2 cell apoptosis. The present study deepens our understanding of the mechanism of interaction between Giardia and IECs.

Pseudolysobacter antarcticus gen. nov., sp. nov., isolated from soil in Fildes Peninsula, Antarctica.

A novel strain, designated AQ6-296T, was isolated from a soil sample collected in Fildes Peninsula, Antarctic. Cells were Gram-stain-negative, non-endospore-forming, non-motile, strictly aerobic and rod-shaped. Growth occurred at 4-28 °C (optimum, 20 °C) and at pH 6.0-7.0 (optimum, pH 7.0). NaCl was not obligatory for growth. Colonies were pale yellow after growth for 3 days at 20 °C on Reasoner's 2A agar. The strain was weakly positive for oxidase and the catalase test was negative. The only respiratory quinone was Q-8. The predominant cellular fatty acids were iso-C16 : 0, iso-C15 : 0, iso-C11 : 0 3OH, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and summed feature 9 (comprising iso-C17 : 1ω9c and/or C16 : 010-methyl). The major polar lipids were phosphatidylethanolamine, unknown aminolipids, phosphatidylglycerol and diphosphatidylglycerol. The results of phylogenetic analysis based on 16S rRNA gene sequences (the highest similarity at 92.4 % to Lysobacter dokdonensis) indicated that strain AQ6-296T is within the family Xanthomonadaceae. The DNA G+C content of the type strain was 58.6 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain AQ6-296T is considered to represent a novel genus and species in the family Xanthomonadaceae, for which the name Pseudolysobacter antarcticus gen. nov., sp. nov. is proposed. The type strain is AQ6-296T (CCTCC AB 2016313T=KCTC 52744T).

Correction to: Hymenobacter oligotrophus sp. nov., isolated from a contaminated agar plate.

In the original publication, the deposit number of strain sh-6T was incorrectly published as "CCTCC AB 2016064" throughout the article.

Prevalence and subtype diversity of Blastocystis in human and nonhuman primates in North China.

Blastocystis is of public health concern due to its global distribution in diverse animals including humans. Here, fecal specimens sampled from human and nonhuman primates were examined for Blastocystis by PCR and sequence analysis of the small subunit ribosomal RNA gene. Among age cohorts, the parasite was positive only for three of 126 (2.4%) adults admitted to a hospital in Harbin, Heilongjiang province, with a less common human subtype (ST), ST5, determined. Blastocystis was identified in 7.0% of nonhuman primates (NHPs), giving an infection rate of 6.8% (4/59) to zoo NHPs in Harbin and 7.1% (9/126) to lab NHPs in Beijing. No significant prevalence differences by macaque species, age, gender, and sample source were observed. Among the subtypes found in NHPs, seven belonged to ST1, three to ST2, one to ST3, and the remaining two to mixed ST1/ST3 and ST2/ST3. Although the data here showed no direct evidence linking human infections to Blastocystis of NHP origin, individuals might acquire colonization of ST5 from livestock sources judged by occurrence of this subtype also in cattle in Harbin and pigs and sheep in unspecified cities of Heilongjiang as noted in previous reports. In addition, given the nonrigid (but sometimes, perhaps cryptic) host specificity of ST1, ST2, and ST3 and their dominant role in human affections globally as discussed in a previous NHP report by Alfellani et al. (Parasitology 140:966-971, 2013a), precautions should be taken to minimize the possible transmission of those subtypes from NHPs to humans in North China.

Sphingomonas paeninsulae sp. nov., isolated from soil sampled at Fildes Peninsula, Antarctica.

Strain YZ-8T, isolated from soil sampled at Fildes Peninsula, Antarctica, was found to be a Gram-stain-negative, yellow-pigmented, oxidase- and catalase-positive, non-motile, non-spore-forming, rod-shaped and aerobic bacterium. Strain YZ-8T grewoptimally at pH 7.0 and 20 °C. Tolerance to NaCl was up to 0.3 % (w/v) with optimum growth in the absence of NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YZ-8T belonged to the family Sphingomonas. Strain YZ-8T showed the highest sequence similarities to Sphingomonas molluscorum KMM 3882T (94.4 %), Sphingomonas oligophenolica JCM 12082T (94.4 %), Sphingomonas gotjawalisoli SN6-9T (94.3 %) and Sphingomonas aquatica W1-2-1T (94.3 %). The predominant respiratory isoprenoid quinone and polyamine components were identified as ubiquinone Q-10 and sym-homospermidine, respectively. In addition, carotenoid were also found. The polar lipid profile of the strain YZ-8T was found to contain one phosphatidylethanolamine, an unidentified phospholipid, one diphosphatidylglycerol, one phosphatidylglycerol, two sphingophosphonolipids, one phosphatidylcholine and two unidentified alkali-stable lipids. The G+C content of the genomic DNA was determined to be 58.8 mol%. The main fatty acids were summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c; 35.4 %), summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c; 32.6 %) and C14 : 0 2-OH (7.7 %). On the basis of the evidence presented in this study, a novel species of the genus Sphingomonas, Sphingomonaspaeninsulae sp. nov., is proposed, with the type strain YZ-8T (=CCTCC AB 2017137T=LMG 31027T).

Hymenobacter oligotrophus sp. nov., isolated from a contaminated agar plate.

A taxonomic study of a Gram-stain negative, rod-shaped, motile, asporogenous, catalase- and oxidase-positive bacterium, sh-6T, forming pink-red colonies, isolated from a contaminated R2A plate in the laboratory was performed. Its optimum growth temperature was determined to be 28 °C in the absence of NaCl on R2A plates. On the basis of 16S rRNA gene sequence analysis, strain sh-6T belongs to the genus Hymenobacter and is closely related to Hymenobacter deserti ZLB-3T (95.05%), Hymenobacter paludis KBP-30T (94.96%), Hymenobacter coalescens WW84T (94.04%), Hymenobacter gummosus ANT-18T (93.38%), Hymenobacter ocellatus Myx2105T (93.70%), Hymenobacter jeollabukensis 1-3-3-8T (93.48%) and Hymenobacter koreensis GYR3077T (93.21%). Comparison of the genome of strain sh-6T and that of H. gummosus ANT-18T gave digital DNA-DNA hybridization and Average Nucleotide Identity values of 20.6% and 78.4%, respectively. The respiratory isoprenoid quinone and polyamine component were identified as MK-7 and sym-homospermidine, respectively. The major cellular fatty acids identified as iso-C15:0, summed feature 4 (iso-C17:1 I/anteiso B), iso-C16:0, iso-C17:0 3-OH and iso-C17:0. The major polar lipid of strain sh-6T determined to be phosphatidylethanolamine. The DNA G+C content was determined to be 60.5 mol%. On the basis of the evidence presented in this study, a novel species of the genus Hymenobacter, Hymenobacter oligotrophus sp. nov., is proposed, with the type strain sh-6T (= CCTCC AB 2016064T = KCTC 62345T).

Sphingomonas antarctica sp. nov., isolated from Antarctic tundra soil.

Strain 200T, isolated from a soil sample taken from Antarctic tundra soil around Zhongshan Station, was found to be a Gram-stain-negative, yellow-pigmented, catalase-positive, oxidase-negative, non-motile, non-spore-forming, rod-shaped and aerobic bacterium. Strain 200T grew optimally at pH 7.0 and in the absence of NaCl on R2A. Its optimum growth temperature was 20 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 200T belonged to the genus Sphingomonas. Strain 200T showed the highest sequence similarities to Sphingomonas kyeonggiense THG-DT81T (95.1 %) and Sphingomonas molluscorum KMM 3882T (95.1 %). Chemotaxonomic analysis showed that strain 200T had characteristics typical of members of the genus Sphingomonas. Ubiquinone 10 was the predominant respiratory quinone and sym-homospermidine was the polyamine. The major polar lipids were sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine. The G+C content of the genomic DNA was determined to be 60.9 mol%. Strain 200T contained C16 : 0 (31.6 %), summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c, 22.7 %), summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c, 11.2 %), C18 : 0 (7.8 %) and C14 : 0 2OH (6.7 %) as the major cellular fatty acids. On the basis of phylogenetic analysis, and physiological and biochemical characterization, strain 200T should be classified as representing a novel species of the genus Sphingomonas, for which the name Sphingomonasantarctica sp. nov. is proposed. The type strain is 200T (=CCTCC AB 2016064T=KCTC 52488T).

Deinococcus taklimakanensis sp. nov., isolated from desert soil.

A gamma- and UV radiation-tolerant, Gram-negative, short-rod-shaped bacterial strain, designated X-121T, was isolated from soil samples collected from the Taklimakan desert in Xinjiang, China. Strain X-121T showed the highest 16S rRNA gene sequence similarity with Deinococcus depolymerans TDMA-24T (94.7 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain X-121T is a member of a novel species belonging to the clade formed by members of the genus Deinococcus in the family Deinococcaceae. The DNA G+C content of strain X-121T was 63.6 mol%. The chemotaxonomic charateristics of strain X-121T were typical of members of the genus Deinococcus, with MK-8 being the predominant respiratory quinone, summed feature 3 (16 : 1ω7c,16 : 1ω6c), 16 : 0 and 17 : 1ω8c as major cellular fatty acid, several unidentified phosphoglycolipids and glycolipids as the dominant polar lipids, galactose as the predominant cell-wall sugar and the presence of peptidoglycan with l-ornithine. Strain X-121T is therefore identified as representing a novel species, for which the name Deinococcus taklimakanensis sp. nov. is proposed, with the type strain X-121T(=CCTCC AB 207228T=KCTC 33842T).

Flavitalea antarctica sp. nov., isolated from Fildes Peninsula, Antarctica.

A bright-yellow, Gram-stain-negative, rod-shaped, gliding and aerobic bacterium, designated strain AQ6-291T, was isolated from the Fildes Peninsula, Antarctica, and its taxonomic position was investigated by genotypic, phenotypic and chemotaxonomic analyses. Growth occurred at 4-28 °C (optimum 20 °C) and at pH 5.0-8.0 (optimum pH 7.0). Strain AQ6-291T contained iso-C15 : 1 G, iso-C15 : 0, C16 : 1ω5c, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) as the major cellular fatty acids. The main polar lipids were phosphatidylethanolamine, unknown aminophospholipids, unknown phospholipids, five unknown aminolipids and two unknown polar lipids. MK-7 was the major respiratory quinone. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain AQ6-291T belonged to the genus Flavitalea. The DNA G+C content was 48.1 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain AQ6-291T is considered to represent a novel species of the genus Flavitalea, for which the name Flavitalea antarctica sp. nov. is proposed. The type strain is AQ6-291T (=CCTCC AB 2016109T=KCTC 52491T).

Terrimonas crocea sp. nov., isolated from the till of a high Arctic glacier.

A yellow-pigmented bacterial strain, designated M1-33108T, was isolated from the till of high Arctic glacier Midtre Lovénbreen near Ny-Ålesund, in the West Svalbard Archipelago, Norway. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain M1-33108T belonged to the genus Terrimonas and its closest neighbour was Terrimonas arctica R9-86T with 96.12 % 16S rRNA gene sequence similarity. Cells of strain M1-33108T were Gram-reaction-negative, aerobic, non-spore-forming, rod-shaped bacteria that lacked motility. Cells contained iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 0 and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) as its major cellular fatty acids and menaquinone-7 as the sole respiratory quinone. The polar lipid profile of strain M1-33108T consisted of phosphatidylethanolamine, two unknown aminophospholipids, eight unknown aminolipids, an unknown glycolipid and three unknown polar lipids. The DNA G+C content was 45.0 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain M1-33108T is considered to represent a novel species in the genus Terrimonas, for which the name Terrimonas crocea sp. nov. is proposed. The type strain is M1-33108T (=CCTCC AB 2016103T=KCTC 52448T).

Hymenobacter rutilus sp. nov., isolated from marine sediment in the Arctic.

Strain K2-33028T, which appeared as a brick-red colony on an R2A plate, was isolated from a marine sediment sample from Kings Bay, Svalbard Archipelago, Norway. Phylogenetic analysis based on 16S rRNA gene sequences indicated that K2-33028T represented a member of the genus Hymenobacter. Cells were Gram-reaction-negative, non-spore-forming, aerobic, rod-shaped and without motility. Growth occurred at 4-37 °C (optimum 28 °C) and at pH 6.0-8.0 (optimum pH 7.0). Cells contained menaquinone-7 as the main respiratory quinone and iso-C15 : 0, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 1ω5c, summed feature 4 (comprising anteiso-C17 : 1B and/or iso-C17 : 1I) and anteiso-C15 : 0 as the major cellular fatty acids. Phosphatidylethanolamine was predominant in the polar lipid profile. The DNA G+C content was 64.3 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain K2-33028T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacterrutilussp. nov. is proposed. The type strain is K2-33028T (=CCTCC AB 2016091T=KCTC 52447T).

Notochordal cells: A potential therapeutic option for intervertebral disc degeneration.

Intervertebral disc degeneration (IDD) is a prevalent musculoskeletal degenerative disorder worldwide, and ~40% of chronic low back pain cases are associated with IDD. Although the pathogenesis of IDD remains unclear, the reduction in nucleus pulposus cells (NPCs) and degradation of the extracellular matrix (ECM) are critical factors contributing to IDD. Notochordal cells (NCs), derived from the notochord, which rapidly degrades after birth and is eventually replaced by NPCs, play a crucial role in maintaining ECM homeostasis and preventing NPCs apoptosis. Current treatments for IDD only provide symptomatic relief, while lacking the ability to inhibit or reverse its progression. However, NCs and their secretions possess anti-inflammatory properties and promote NPCs proliferation, leading to ECM formation. Therefore, in recent years, NCs therapy targeting the underlying cause of IDD has emerged as a novel treatment strategy. This article provides a comprehensive review of the latest research progress on NCs for IDD, covering their biological characteristics, specific markers, possible mechanisms involved in IDD and therapeutic effects. It also highlights significant future directions in this field to facilitate further exploration of the pathogenesis of IDD and the development of new therapies based on NCs strategies.

Bradykinin protects nucleus pulposus cells from tert-butyl hydroperoxide-induced damage and delays intervertebral disc degeneration.

Intervertebral disc degeneration (IVDD) is a leading cause of degenerative spinal disorders, involving complex biological processes. This study investigates the role of the kallikrein-kinin system (KKS) in IVDD, focusing on the protective effects of bradykinin (BK) on nucleus pulposus cells (NPCs) under oxidative stress. Clinical specimens were collected, and experiments were conducted using human and rat primary NPCs to elucidate BK's impact on tert-butyl hydroperoxide (TBHP)-induced oxidative stress and damage. The results demonstrate that BK significantly inhibits TBHP-induced NPC apoptosis and restores mitochondrial function. Further analysis reveals that this protective effect is mediated through the BK receptor 2 (B2R) and its downstream PI3K/AKT pathway. Additionally, BK/PLGA sustained-release microspheres were developed and validated in a rat model, highlighting their potential therapeutic efficacy for IVDD. Overall, this study sheds light on the crucial role of the KKS in IVDD pathogenesis and suggests targeting the B2R as a promising therapeutic strategy to delay IVDD progression and promote disc regeneration.

Organic fertilizer potentiates the transfer of typical antibiotic resistance gene among special bacterial species.

The propagation of antibiotic resistance genes (ARGs) in environments has evoked many attentions, however, how to identify their host pathogenic bacteria in situ remains a great challenge. Here we explored the bacterial host distribution and dissemination of a typical ARG, sul1 gene, in agricultural soils through the simultaneous detection of sul1 and its host 16S rRNA gene by emulsion paired isolation and concatenation PCR (epicPCR). Compared to chemical fertilizer, organic fertilizer (chicken manure) led to a higher prevalence of sul1 gene in the soil, and dominant bacterial hosts of sul1 gene were classified into Proteobacteria and Bacteroidetes phyla. Additionally, significant higher diversity of antibiotic resistance bacteria (ARB), higher rate of horizontal gene transfer (HGT), higher rate of mobile genetic elements (MGE) and higher proportion of pathogens were all observed in the treatment of organic fertilizer. This study alerts potential health risks of manure applications in agricultural soils.

The large-scale spatial patterns of ecological networks between phytoplankton and zooplankton in coastal marine ecosystems.

Although autotrophic phytoplankton and heterotrophic zooplankton both play important roles in the food web of marine ecosystem, their comprehensive interactions and spatial patterns at continental scale remain poorly studied. Here, we collected 251 seawater samples along 13,000 km of Chinese coastline, and microscopically investigated the latitudinal gradients of planktonic diversities. In total, 307 phytoplanktonic and 311 zooplanktonic species were visually identified. Using the newly developed Inter-Domain Ecological Networks (IDENs) approach, the phytoplankton-zooplankton interaction networks were constructed. We found that the phyto-zooplankton network structure was varied across three regions, more complex and numerous connections along the southern coast than in the north. In addition, some particular associations between zooplanktonic and phytoplanktonic groups were found to be localized in specific regions. Furthermore, the seawater temperature and salinity were the major driving force for shaping planktonic interaction networks. These results provide a deeper understanding of planktonic biogeography and phytoplankton-zooplankton interaction patterns.