High Mobility Group Box 1 Contributes to the Acute Rejection of Liver Allografts by Activating Dendritic Cells

Acute rejection induced by the recognition of donor alloantigens by recipient T cells leads to graft failure in liver transplant recipients. The role of high mobility group box 1 (HMGB1), an inflammatory mediator, in the acute allograft rejection of liver transplants is unknown. Here, rat orthotopic liver transplantation was successfully established to analyze the expression pattern of HMGB1 in liver allografts and its potential role in promoting the maturation of dendritic cells (DCs) to promote T cell proliferation and differentiation. Five and 10 days after transplantation, allografts showed a marked upregulation of HMGB1 expression accompanied by elevated levels of serum transaminase and CD3+ and CD86+ inflammatory cell infiltration. Furthermore, in vitro experiments showed HMGB1 increased the expressions of co-stimulatory molecules (CD80, CD83, and MHC class II) on bone marrow-derived DCs. HMGB1-pulsed DCs induced naive CD4+ T cells to differentiate to Th1 and Th17 subsets secreting IFN-γ and IL-17, respectively. Further in vivo experiments confirmed the administration of glycyrrhizic acid, a natural HMGB1 inhibitor, during donor liver preservation had therapeutic effects by reducing inflammation and hepatocyte damage reflected by a decline in serum transaminase and prolonged allograft survival time. These results suggest the involvement of HMBG1 in acute liver allograft rejection and that it might be a candidate therapeutic target to avoid acute rejection after liver transplantation

Sex differences in cold hardiness and desiccation tolerance of invasive apple snails in South China

Sex differences in stress responses may be a key factor that determines population structure. Sex ratios of Pomacea canaliculata populations usually average 1:1 at birth, but are often female-biased for adults. Low temperatures and drought are the main abiotic stresses affecting reproductive dispersal and population development. Therefore, we investigated whether Pomacea sp. (mainly P. canaliculata but might include P. maculata) exhibited sex differences in cold hardiness and desiccation tolerance. Results show that more females survived than males during cold-drought stress and overwintering. Following cold-drought stress, 58% of females and 40% of males survived at 3°C drought conditions for 6 days. With the development of cold-drought hardiness, increased amounts of bound water, glycerol and lipids were found in Pomacea sp. along with decreased free water levels. These physiological parameters exhibited sex differences in the snails, except for lipids, and the changes all showed tendencies favoring the survival of females under cold-drought stress. These results suggest that female Pomacea sp. may be more viable than males under cold and dry conditions.Fil: Guo, Jing. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de ChinaFil: Xu, Wubing. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de ChinaFil: Martín, Pablo Rafael. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Zhang, Chunxia. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de ChinaFil: Zhang, Jiaen. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de China. Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture; China. Ministry of Agriculture, Key Laboratory of Agro-Environment in the Tropics; Chin

Organophotoredox-catalyzed intermolecular formal Grob fragmentation of cyclic alcohols with activated allylic acetates

We have developed an efficient method that employs organophotoredox-catalyzed relay Grob fragmentation to facilitate the smooth ring-opening allylation of cyclic alcohols in an environmentally friendly manner. This protocol directly incorporates a wide spectrum of cyclic alcohols and activated allylic acetates into the cross-coupling reaction, eliminating the need for metal catalysts. The process yields a variety of distally unsaturated ketones with good to excellent outcomes and stereoselectivity, while acetic acid is the sole byproduct.We gratefully acknowledge financial support from the National Natural Science Foundation of China (21702108), the Natural Science Foundation of Jiangsu Province, China (BK20211257), and the Six Talent Peaks Project in Jiangsu Province (YY-033)

Sex differences in alarm response and predation risk in the fresh water snail Pomacea canaliculata

Many animals show alarm responses (ARs) to chemical cues released from predators or injured conspecifics. However, the prey often makes a trade-off between predation avoidance and reproduction, resulting in pronounced sex differences in AR and in sex-biased predation. This phenomenon has rarely been investigated in snails. The freshwater snail Pomacea canaliculata is reported to exhibit an AR to chemical cues released from predators or injured conspecifics. Here, we investigate the sex differences in AR in the snail to chemical cues released from its predator turtle Chinemys reevesii and injured conspecifics. By exposing adult females and males of equivalent size to turtles, we also evaluate the sex-biased predation in the snail. We find that females respond to chemical cues significantly more strongly than males. The predation experiment shows that more females survived than males after a week of predation. These results suggest that males may reduce their antipredator behaviour in order to increase the chance of mating, suggesting a trade-off between predation avoidance and reproduction

Nonholonomic dynamics and control of road vehicles: moving toward automation

Nonholonomic models of automobiles are developed by utilizing tools of analytical mechanics, in particular the Appellian approach that allows one to describe the vehicle dynamics with minimum number of time-dependent state variables. The models are categorized based on how they represent the wheel-ground contact, whether they incorporate the longitudinal dynamics, and whether they consider the steering dynamics. It is demonstrated that the developed models can be used to design low-complexity controllers that enable automated vehicles to execute a large variety of maneuvers with high precision

Synthesis of Pincer Hydrido Ruthenium Olefin Complexes for Catalytic Alkane Dehydrogenation

A series of new hydrido Ru­(II) olefin complexes supported by isopropyl-substituted pincer ligands have been synthesized and characterized. These complexes are thermally robust and active for catalytic transfer and acceptorless alkane dehydrogenation. Notably, the alkane dehydrogenation catalysts are tolerant of a number of polar functional species

Cobalt-Catalyzed Borylation of Aryl Halides and Pseudohalides

We report the first Co-catalyzed borylation of aryl halides and pseudohalides with bis­(pinacolato)­diboron (B₂pin₂). The synthesis of two new Co­(II) complexes of oxazolinylferrocenylphosphine ligands is described. Upon activation with LiMe, the Co complex catalyzes the borylation reactions of aryl bromides, iodides, sulfonates, arenediazonium salts, and even aryl chlorides under mild conditions, providing the borylated products in excellent to moderate yields and with high functional group tolerance

MetaTiME integrates single-cell gene expression to characterize the meta-components of the tumor immune microenvironment

Abstract Recent advances in single-cell RNA sequencing have shown heterogeneous cell types and gene expression states in the non-cancerous cells in tumors. The integration of multiple scRNA-seq datasets across tumors can indicate common cell types and states in the tumor microenvironment (TME). We develop a data driven framework, MetaTiME, to overcome the limitations in resolution and consistency that result from manual labelling using known gene markers. Using millions of TME single cells, MetaTiME learns meta-components that encode independent components of gene expression observed across cancer types. The meta-components are biologically interpretable as cell types, cell states, and signaling activities. By projecting onto the MetaTiME space, we provide a tool to annotate cell states and signature continuums for TME scRNA-seq data. Leveraging epigenetics data, MetaTiME reveals critical transcriptional regulators for the cell states. Overall, MetaTiME learns data-driven meta-components that depict cellular states and gene regulators for tumor immunity and cancer immunotherapy