Non-enzymatic chitinase-3 like-protein-1 (CHI3L1) belongs to glycoside hydrolase family 18. It binds to chitin, heparin, and hyaluronic acid, and is regulated by extracellular matrix changes, cytokines, growth factors, drugs, and stress. CHI3L1 is synthesized and secreted by a multitude of cells including macrophages, neutrophils, synoviocytes, chondrocytes, fibroblast-like cells, smooth muscle cells, and tumor cells. It plays a major role in tissue injury, inflammation, tissue repair, and remodeling responses. CHI3L1 has been strongly associated with diseases including asthma, arthritis, sepsis, diabetes, liver fibrosis, and coronary artery disease. Moreover, following its initial identification in the culture supernatant of the MG63 osteosarcoma cell line, CHI3L1 has been shown to be overexpressed in a wealth of both human cancers and animal tumor models. To date, interleukin-13 receptor subunit alpha-2, transmembrane protein 219, galectin-3, chemo-attractant receptor-homologous 2, and CD44 have been identified as CHI3L1 receptors. CHI3L1 signaling plays a critical role in cancer cell growth, proliferation, invasion, metastasis, angiogenesis, activation of tumor-associated macrophages, and Th2 polarization of CD4+ T cells. Interestingly, CHI3L1-based targeted therapy has been increasingly applied to the treatment of tumors including glioma and colon cancer as well as rheumatoid arthritis. This review summarizes the potential roles and mechanisms of CHI3L1 in oncogenesis and disease pathogenesis, then posits investigational strategies for targeted therapies.

Forest aboveground biomass (AGB) plays an important role in the study of the carbon cycle and climate change in the global terrestrial ecosystem. AGB estimation based on remote sensing is an effective method for regional scale. In this study, Landsat 8 Operational Land Imager and Sentinel-1A data and China’s National Forest Continuous Inventory data in combination with three algorithms, either the linear regression (LR), random forest (RF), or the extreme gradient boosting (XGBoost), were used to estimate biomass of the subtropical forests in Hunan Province, China. XGBoost is a scalable tree boosting system that is widely used by data scientists and provides state-of-the-art results for many problems. It can process an entire dataset with billions of examples using a minimal amount of computational resources through the particular way of cache access patterns, data compression, and data fragmentation. The results include: (1) The combination of Landsat 8 and Sentinel-1A images as predictor variables in the XGBoost model provided the best AGB estimation. (2) In contrast to the LR method, the F-test results indicated that a significant improvement in AGB estimation was achieved with the RF and XGBoost algorithms. (3) The effect of parameter optimization was found to be more significant on XGBoost than on RF. (4) The XGBoost model is an effective method for AGB estimation and can reduce the problems of overestimation and underestimation. This research provides a new way of estimating AGB for the subtropical forest based on remote sensing through the synergy of different sensors datasets and modeling algorithms.

Climate change significantly influences changes in ecological phenomena and processes, such as species distribution and phenology, thus accelerating the rate of species extinction or prosperity. Climate change is considered to be one of the most important threats to global biodiversity in the 21st century and will pose significant challenges to biodiversity conservation in the future. The use of niche modelling to predict changes in the suitable distribution of species under climate change scenarios is becoming a hot topic of biological conservation. In this study, we use data from China's National Forest Continuous Inventory as well as specimen collection data of Cunninghamia lanceolata (Lamb.) Hook to run optimized Maxent models to predict potential suitable distribution of the species in the present day, 2050s, and 2070s under different climate change scenarios in China. In the modeling process, the most important uncorrelated variables were chosen, and the sample-size-adjusted Akaike information criterion (AICc) was used to select the optimal combination of feature type and regularization multiplier. Variable selection reduced the number of variables used and the complexity of the model, and the use of the AICc reduced overfitting. Variables relating to precipitation were more important than temperature variables in predicting C. lanceolata distribution in the optimal model. The predicted suitable distribution areas of C. lanceolata were different for the different periods under different climate change scenarios, with the centroids showing a degree of northward movement. The suitable distribution area is predicted to become more fragmented in the future. Our results reveal the climate conditions required for the suitable distribution of C. lanceolata in China and the likely changes to its distribution pattern in the future, providing a scientific basis for the sustainable management, protection, and restoration of the suitable habitat of this economically important tree species in the context of climate change.Forests 2020, 11, 302 2 of 25 have shown that climate change has caused or is causing significant changes to ecological processes, including distribution ranges, morphological characteristics, and phenology that are accelerating species extinction or prosperity [7][8][9]. Because of this, quantitative analysis of climate factors and predictions of climate change impacts on potential suitable species distributions have become key to biogeography and global change research [8,10,11].Niche modelling (also known as species distribution modelling or habitat suitability modelling) uses statistical or biophysical methods to infer the environmental requirements for the survival of a species based on the environmental variables taken from the known distribution areas, and then predicts their potential or future distribution [12][13][14]. Niche modelling has been widely used in ecology, biogeography, and conservation biology studies, such as the adaptive analysis of invasive alien species [15,16], conservation o...

Forest biomass is a major store of carbon and plays a crucial role in the regional and global carbon cycle. Accurate forest biomass assessment is important for monitoring and mapping the status of and changes in forests. However, while remote sensing-based forest biomass estimation in general is well developed and extensively used, improving the accuracy of biomass estimation remains challenging. In this paper, we used China’s National Forest Continuous Inventory data and Landsat 8 Operational Land Imager data in combination with three algorithms, either the linear regression (LR), random forest (RF), or extreme gradient boosting (XGBoost), to establish biomass estimation models based on forest type. In the modeling process, two methods of variable selection, e.g., stepwise regression and variable importance-base method, were used to select optimal variable subsets for LR and machine learning algorithms (e.g., RF and XGBoost), respectively. Comfortingly, the accuracy of models was significantly improved, and thus the following conclusions were drawn: (1) Variable selection is very important for improving the performance of models, especially for machine learning algorithms, and the influence of variable selection on XGBoost is significantly greater than that of RF. (2) Machine learning algorithms have advantages in aboveground biomass (AGB) estimation, and the XGBoost and RF models significantly improved the estimation accuracy compared with the LR models. Despite that the problems of overestimation and underestimation were not fully eliminated, the XGBoost algorithm worked well and reduced these problems to a certain extent. (3) The approach of AGB modeling based on forest type is a very advantageous method for improving the performance at the lower and higher values of AGB. Some conclusions in this paper were probably different as the study area changed. The methods used in this paper provide an optional and useful approach for improving the accuracy of AGB estimation based on remote sensing data, and the estimation of AGB was a reference basis for monitoring the forest ecosystem of the study area.

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Concurrent/adjuvant cisplatin-based chemoradiotherapy is regarded as the standard of treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, patients who do not respond to cisplatin suffer, rather than benefit, from chemotherapy treatment. The goal of this study was to identify molecules involved in cisplatin resistance and to clarify their molecular mechanisms, which would help in the discovery of potential therapeutic targets and in developing a personalized and precise treatment approach for NPC patients. We previously generated a cisplatin-sensitive NPC cell line, S16, from CNE2 cells and found that eIF3a, ASNS and MMP19 are upregulated in S16 cells, which contributes to their cisplatin sensitivity. In this study, we found that BST2 is downregulated in cisplatin-sensitive S16 cells compared with CNE2 cells. Knockdown of BST2 in NPC cells sensitized their response to cisplatin and promoted cisplatin-induced apoptosis, whereas exogenous overexpression of BST2 increased their cisplatin resistance and inhibited cisplatin-induced apoptosis. Further investigation demonstrated that BST2-mediated cisplatin resistance depended on the activation of the NF-κB signaling pathway and consequent upregulation of anti-apoptotic genes, such as Bcl-XL and livin. Moreover, an analysis of clinical data revealed that a high BST2 level might serve as an independent indicator of poor prognosis in patients with locally advanced NPC treated with platinum-based chemoradiotherapy. These findings suggest that BST2 likely mediates platinum resistance in NPC, offering guidance for personalized and precise treatment strategies for patients with NPC.

Background: Lysine succinylation is an emerging posttranslational modification that has garnered increased attention recently, but its role in gastric cancer (GC) remains underexplored. Methods: Proteomic quantification of lysine succinylation was performed in human GC tissues and adjacent normal tissues by mass spectrometry. The mRNA and protein levels of lactate dehydrogenase A (LDHA) in GC and adjacent normal tissues were analyzed by qRT-PCR and western blot, respectively. The expression of K222-succinylated LDHA was measured in GC tissue microarray by the K222 succinylation-specific antibody. The interaction between LDHA and sequestosome 1 (SQSTM1) was measured by co-immunoprecipitation (co-IP) and proximity ligation assay (PLA). The binding of carnitine palmitoyltransferase 1A (CPT1A) to LDHA was determined by co-IP. The effect of K222succinylated LDHA on tumor growth and metastasis was evaluated by in vitro and in vivo experiments. Results: Altogether, 503 lysine succinylation sites in 303 proteins were identified. Lactate dehydrogenase A (LDHA), the key enzyme in Warburg effect, was found highly succinylated at K222 in GC. Intriguingly, this modification did not affect LDHA ubiquitination, but reduced the binding of ubiquitinated LDHA to SQSTM1, thereby decreasing its lysosomal degradation. We demonstrated that CPT1A functions as a lysine succinyltransferase that interacts with and succinylates LDHA. Moreover, high K222-succinylation of LDHA was associated with poor prognosis in patients with GC. Finally, overexpression of a succinylation-mimic mutant of LDHA promoted cell proliferation, invasion, and migration. Conclusions: Our data revealed a novel lysosomal pathway of LDHA degradation, which is mediated by the binding of K63-ubiquitinated LDHA to SQSTM1. Strikingly, CPT1A succinylates LDHA on K222, which thereby reduces the binding and inhibits the degradation of LDHA, as well as promotes GC invasion and proliferation. This study thus uncovers a new role of lysine succinylation and the mechanism underlying LDHA upregulation in GC.

Forest aboveground biomass (AGB) estimation modeling based on remote sensing is an important method for large-scale biomass estimation; the accuracy of the estimation models has been a topic of broad and current interest. In this study, we used permanent sample plot data and Landsat 8 Operational Land Imager (OLI) images of western Hunan. Remote-sensing-based models were developed for different vegetation types, and different crown density classes were incorporated. The linear model, linear dummy variable model, and linear mixed-effects model were used to determine the most effective and accurate method for remote-sensing-based AGB estimation. The results show that the adjusted coefficient of determination (R2adj) and root mean square error (RMSE) of the linear dummy model and linear mixed-effects model were significantly better than those of the linear model; the R2adj increased more than 0.16 and the RMSE decreased more than 2.12 for each vegetation type, and the F-test also showed significant differences between the linear model and linear dummy variable model and between the linear model and linear mixed-effects model. The accuracies of the AGB estimations of the linear dummy variable model and the linear mixed-effects model were significantly better than those of linear model in the thin and dense crown density classes. There were no significant differences in the AGB estimation performance between the linear dummy variable model and linear mixed-effects model; these two models were more flexible and more suitable than the linear model for remote-sensing-based AGB estimation. The results of this study provide a new approach for solving the low-accuracy estimations of linear models.