Diverse animal models for Chlamydia infections: unraveling pathogenesis through the genital and gastrointestinal tracts.

Chlamydia trachomatis is responsible for infections in various mucosal tissues, including the eyes, urogenital, respiratory, and gastrointestinal tracts. Chronic infections can result in severe consequences such as blindness, ectopic pregnancy, and infertility. The underlying mechanisms leading to these diseases involve sustained inflammatory responses, yet thorough comprehension of the underlying mechanisms remains elusive. Chlamydial biologists employ in multiple methods, integrating biochemistry, cell biology, and genetic tools to identify bacterial factors crucial for host cell interactions. While numerous animal models exist to study chlamydial pathogenesis and assess vaccine efficacy, selecting appropriate models for biologically and clinically relevant insights remains a challenge. Genital infection models in animals have been pivotal in unraveling host-microbe dynamics, identifying potential chlamydial virulence factors influencing genital pathogenicity. However, the transferability of this knowledge to human pathogenic mechanisms remains uncertain. Many putative virulence factors lack assessment in optimal animal tissue microenvironments, despite the diverse chlamydial infection models available. Given the propensity of genital Chlamydia to spread to the gastrointestinal tract, investigations into the pathogenicity and immunological impact of gut Chlamydia become imperative. Notably, the gut emerges as a promising site for both chlamydial infection vaccination and pathogenesis. This review elucidates the pathogenesis of Chlamydia infections and delineates unique features of prevalent animal model systems. The primary focus of this review is to consolidate and summarize current animal models utilized in Chlamydia researches, presenting findings, discussions on their contributions, and suggesting potential directions for further studies.

Feeding habits and foraging patch selection strategy of the giant panda in the Meigu Dafengding National Nature Reserve, Sichuan Province, China.

Despite retaining a digestive system with carnivorous characteristics, the giant panda has now specialized to eat bamboo. Therefore, research on its feeding habits and foraging strategies has always been an important field in the study of giant panda population ecology. Located in the core distribution area of the giant panda population in the Liangshan mountains, the Meigu Dafengding Nature Reserve acts as the link between the major panda reserves in the Liangshan mountains and the key corridor zone connecting the giant panda populations in the east and west. This study was performed in 2017 and aimed to determine the feeding habits of giant pandas in this region, the heterogeneity of food resources in different seasons, and the selection strategy for foraging patches. To achieve this, we used the line transect method to investigate the giant panda population, collected fresh feces, analyzed the nutritional composition of bamboo samples, and set up a sampling grid of foraging patches in different seasonal distribution areas. It was found that wild giant pandas in the region spend most of the year at lower elevations(1939-3296 m) foraging for Yushania maculata and Yushania ailuropodina, and only move to higher elevations(2844-3770 m) in summer for Bashania fangiana. Their preferred foraging patches(n = 65) had certain topographical features, such as gentle slopes(< 25°) and closer proximity to water sources(< 500 m), and the nutritional quality of bamboo resources in foraging patches was significantly better than in those they avoided or rarely used. The food habits and foraging patch selection strategies of giant pandas in the Liangshan and Qinling mountains are relatively similar, and the results of this study can help provide a scientific basis for the conservation and management of wild giant panda habitats in different mountain regions.

GOx-assisted synthesis of pillar[5]arene based supramolecular polymeric nanoparticles for targeted/synergistic chemo-chemodynamic cancer therapy.

BACKGROUND: Cancer is the most serious world's health problems on the global level and various strategies have been developed for cancer therapy. Pillar[5]arene-based supramolecular therapeutic nano-platform (SP/GOx NPs) was constructed successfully via orthogonal dynamic covalent bonds and intermolecular H-bonds with the assistance of glucose oxidase (GOx) and exhibited efficient targeted/synergistic chemo-chemodynamic cancer therapy. METHODS: The morphology of SP/GOx NPs was characterized by DLS, TEM, SEM and EDS mapping. The cancer therapy efficinecy was investigated both in vivo and in vitro. RESULTS: SP/GOx NPs can load drug molecules (Dox) and modify target molecule (FA-Py) on its surface conveniently. When the resultant FA-Py/SP/GOx/Dox NPs enters blood circulation, FA-Py will target it to cancer cells efficiently, where GOx can catalyst the overexpressed glucose to generate H2O2. Subsequently, the generated H2O2 in cancer cells catalyzed by ferrocene unit to form •OH, which can kill cancer cells. Furthermore, the loaded Dox molecules released under acid microenvironment, which can further achieve chemo-therapy. CONCLUSION: All the experiments showed that the excellent antitumor performance of FA-Py/SP/GOx/Dox NPs, which provided an new method for pillar[5]arene-based supramolecular polymer for biomedical applications.

NIR-II light triggered nitric oxide release nanoplatform combined chemo-photothermal therapy for overcoming multidrug resistant cancer.

The overexpression of P-glycoprotein (P-gp) in multidrug resistance (MDR) cancer cells increases the efflux of anticancer drugs thereby causing the failure of clinical chemotherapy. To address this obstacle, in this study, we rationally designed a near-infrared (NIR) light-responsive nitric oxide (NO) delivery nanoplatform for targeting the MDR tumors based on core-shell structured nanocomposites. The mesoporous silica shell provided abundant sites for modification of the NO donor, N-diazeniumdiolate, and tumor-targeting molecule, folic acid (FA), and enabled high encapsulation capacity for doxorubicin (DOX) loading. Under NIR light irradiation, the generation of NO gas can efficiently augment chemotherapeutic effects via the inhibition of P-gp expression. Simultaneously, the photothermal conversion agents of the Cu2-xSe core produce a large amount of heat for photothermal therapy (PTT). Finally, this combinational gas/chemo/PTT not only displays a superior and synergistic effect for overcoming MDR cancer, but also provides an efficient strategy to construct a multifunctional nano-drug delivery system with diversified therapeutic modalities.

Recent advances in the development of metal-organic framework-based gas-releasing nanoplatforms for synergistic cancer therapy.

Gas therapy as a burgeoning and promising research field has attracted considerable attention in biomedicine due to its high therapeutic efficacy, biocompatibility, and biosafety. However, the lack of tumor site accumulation and controlled release of therapeutic gas molecules limited the therapeutic efficacy. Therefore, the development of gas-releasing nanoplatforms to realize tumor targeting and controllable release is highly desired. The structural diversity and tailorability and ultrahigh surface area make metal-organic frameworks (MOFs) find potential applications in the delivery and release of gas or gas releasing molecules (GRMs). In this Frontier article, we provide an overview of the recent developments achieved in gas-involving cancer therapy using MOFs or MOF-based materials. The main emphasis is focused on the design of multifunctional MOF-based nanoplatforms for the delivery and release of therapeutic gas molecules, and emphasizing their synergistic mechanism against tumor. Moreover, the challenges, future trends, and prospects of gas-related cancer therapy are also discussed.

Pillar[6]arene-based supramolecular polymeric materials constructed via electrostatic interactions for rapid and efficient organic dye removal from water.

The first pillar[6]arene-based supramolecular polymeric material constructed from electrostatic interactions was designed and prepared successfully. Importantly, it can adsorb and remove organic dye from water efficiently.

Litter chemical traits strongly drove the carbon fractions loss during decomposition across an alpine treeline ecotone.

The decomposition of litter carbon (C) fraction is a major determinant of soil organic matter pool and nutrient cycling. However, knowledge of litter chemical traits regulate C fractions release is still relatively limited. A litterbag experiment was conducted using six plant functional litter types at two vegetation type (coniferous forest and alpine shrubland) in a treeline ecotone. We evaluated the relative importance of litter chemistry (i.e. Nutrient, C quality, and stoichiometry) on the loss of litter mass, non-polar extractables (NPE), water-soluble extractables (WSE), acid-hydrolyzable carbohydrates (ACID), and acid-unhydrolyzable residue (AUR) during decomposition. Litter nutrients contain nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), aluminium (Al), manganese (Mn), zinc (Zn), iron (Fe) and copper (Cu), litter C quality contains C, WSE, NPE, ACID, and AUR, and stoichiometry was defined by C:N, C:P; N:P, ACID:N, and AUR:N. The results showed single exponential model fitted decomposition rates of litter mass and C fractions better than double exponential or asymptotic decomposition, and the decomposition rates of C fractions were strongly correlated with initial litter nutrients, especially K, Na, Ca. Furthermore, the temporal dynamics of litter nutrients (Ca, Mg, Na, K, Zn, and Fe) strongly regulated C fractions loss during the decomposition process. Changes in litter C quality had an evident effect on the degradation of ACID and AUR, supporting the concept of "priming effect" of soluble carbon fraction. The significant differences were found in the release of NPE, WSE, and ACID rather than AUR among coniferous forest and alpine shrubland, and the vegetation type effects largely depend on the changes in litter stoichiometry, which is an important implication for the change in plant community abundance regulate decay. Collectively, elucidating the hierarchical drivers of litter chemistry on decomposition is critical to soil C sequestration in alpine ecosystems.

Ecoenzymatic stoichiometry and microbial nutrient limitations in rhizosphere soil along the Hailuogou Glacier forefield chronosequence.

Mountain glaciers retreat at an increased rate under global warming, resulting in exposed barren surfaces for primary succession. Soil microbes are an important driver of ecosystem processes. Although variations in soil microbes after deglaciation have been studied extensively, the roles of rhizosphere soil microbes in the biogeochemistry cycle during primary succession are less understood. In this study, Populus purdomii was present throughout the 123-year chronosequence as a representative tree species. We therefore investigated variations in the rhizosphere enzyme activity, microbial community structure, and ecoenzymatic stoichiometry of P. purdomii along Hailuogou Glacier chronosequences. The objective was to determinechanges in rhizosphere enzyme activities and microbial communities, as well as the effects of nutrient limitation on rhizosphere microbes. According to the results, the enzyme activities and microbial group biomass in rhizosphere soil all showed a bimodal trend and were highest at the 43rd or 123rd year, and enzyme activity varied with succession time but not microbial community structure. The rhizosphere soil bacterial community was the dominant community during the 123-year chronosequence. Ecoenzymatic stoichiometry indicated nitrogen restrictions on microbial activity throughout primary succession, with early succession stages (5-15 years) showing greater carbon restriction than late succession stages. Moreover, redundancy and correlation analyses demonstrated that soil microbial phospholipid fatty acid biomass was an important factor for increases in enzyme activities and that enzyme activities in turn played important roles in carbon, nitrogen and phosphorus cycling in rhizosphere soil. Additionally, rhizosphere soil microbial development significantly affected soil organic carbon, total nitrogen and dissolved organic carbon accumulation. Overall, our study links the rhizosphere microbial community and activity to successional chronosequences, providing a deeper understanding of the dynamics of ecosystem succession.

[Community Structure of Aquatic Community and Evaluation of Water Quality in Laovingyan Section of Dadu River].

In order to understand the aquatic community structure in the Laoyingyan section of the Dadu River, we collected samples from 9 aquatic sampling points along that section, and studied the phycophyta, zooplankton, benthic invertebrate and fish in them; we also used expert scoring method based on the actual situation of the river to weigh different biome. The water quality was evaluated using comprehensive evaluation of water quality index ( CEWI). The results showed that: (1) there were a total of 105 phycophyta species, belonging to 6 phyla,31 families, and 56 genera in the Laoyingyan section of the Dadu River, among which, diatom species had a higher richness than the others. The mean cell density of the phycophyta was 17.997 8 x 10(4) ind x L(-1), the mean biomass was 0.4463 mg x L(-1), and the highest population density sites were LTS, LYH and XSH. (2) there were a total of 26 zooplankton species, belonging to 3 phyla, 11 families, and 12 genera, among which, Protozoa had a higher richness than the others, accounting for 80.77% of all the zooplankton species; The mean density of the phycophyta was 40.89 ind x L(-1), and the mean biomass was 13.26 x 10(-3) mg x L(-1). The whole community composition was simple, characterized by few species and small population size. (3) there were a total of 14 benthic invertebrate species, belonging to 6 phyla,14 families, and 14 genera, among which, insecta had a higher richness than the others, accounting for 57.16% of the benthic invertebrate species. Benthic invertebrate had higher population densities in LYH and XSH. (4) The mean CEWI of the whole river water was 2. 698 28, characterized by slightly polluted water quality. The CEWI value between every collection point and the individual water quality evaluation index showed a significant positive correlation, manifesting a high consistency. In addition, the water quality of SLH and NYH was mesosaprobic (1 < CEWI < or = 2), and the water quality of LYH and LYY1 was clean (CEWI > 3), among which the worst was SLH with a lowest CEWI of 1.6207, and the best was LYH with a highest CEWI of 3.9545, all the other samples were subjected to different degrees of light pollution.