ABSTRACT
Since 2012, the "Mountain Excavation and City Construction" (MECC) project has been implemented extensively on the Loess Plateau of China, transforming gullies into flat land for urban sprawl by leveling loess hilltops to fill in valleys. However, this unprecedented human activity has caused widespread controversy over its unknown potential ecological impacts. Quantitative assessment of the impacts of the MECC project on the vegetation is key to ecological management and restoration. Taking the largest MECC project area on the Loess Plateau, Yan'an New District (YND), as the study area, this study investigated the spatiotemporal pattern of vegetation dynamics before and after the implementation of the MECC project using a multitemporal normalized difference vegetation index (NDVI) time series from 2009 to 2023 and explored the response of vegetation dynamics to the large-scale MECC project. The results showed that the vegetation dynamics in the YND exhibited significant spatial and temporal heterogeneity due to the MECC project, with the vegetation in the project-affected areas showing rapid damage followed by slow recovery. Vegetation damage occurred only in the project-affected area, and 84 % of these areas began recovery within 10 years, indicating the limited impact of the large-scale MECC project on the regional vegetation. The strong correlation between vegetation dynamics and the MECC project suggested that the destruction and recovery of vegetation in the project-affected areas was mainly under anthropogenic control, which highlights the importance of targeted ecological policies. Specifically, the MECC project induced local anthropogenic damage to the plant population structure during the land creation period, but regeneration and rational allocation of the vegetation were achieved through urbanization, gradually forming a new balanced ecological environment. These findings will contribute to a full understanding of the response of vegetation to such large-scale engineering activities and help local governments adopt projects or policies that facilitate vegetation recovery.
ABSTRACT
Background: Shashi-Pena syndrome (SHAPNS) is a developmental disorder caused by mutations in additional sex combs-like Protein 2 (ASXL2). Since 2016, only 12 cases from 10 families have been reported. However, neonatal period characteristics remain largely unknown. Herein, we report a case with a pathogenic variant in ASXL2 in a newborn. Case Description: A newborn was diagnosed with a previously unreported de novo truncating mutation in ASXL2 (NM_018263.6) at 21 days and the clinical characteristics of all probands with ASXL2-related SHAPNS was reported in the literature. He had persistent hypoglycemia caused by inappropriate insulin levels and achieved stable glucose levels after octreotide treatment. Magnetic resonance imaging (MRI) revealed a small cerebellum, and fundoscopy showed bilateral retinal paving-stone-like white lesions. The results of trio-based whole exome sequencing (WES) were returned on the 21st day of life, and a heterozygous de novo truncating pathogenic c.1792C>T (p.Gln598*) variant in exon 11 of the ASXL2 gene was identified. The clinical features of our patient and another 10 probands with ASXL2-related SHAPNS reported in the literature were included in this review. More than half shared recognizable clinical features, including hypertelorism (11/11), broad nasal tip (10/11), arched eyebrows (9/11), a large V-shaped glabellar nevus flammeus on the forehead (9/11), low-set ears (8/11), posteriorly rotated ears (7/11), proptosis (6/11) and deep palm creases (6/11). Major clinical issues included feeding difficulties (10/11), developmental delay (10/11), skeletal and/or extremity abnormalities (8/11), progressive macrocephaly (8/11), hypotonia (8/11), hypoglycemia (6/11) and seizures (6/11). Neurodevelopmental regression was possible in patients (2/11) with normal MRI findings who later developed nonfebrile seizures. Conclusions: We present a newborn diagnosing the SHAPNS by trio-WES, which is the earliest age of diagnosis. The application of octreotide for hypoglycemia, the small cerebellum and bilateral paving-stone-like white lesions of the retinas are described for the first time in an individual with ASXL2-related SHAPNS. Additional clinical reports of neonates with damaging ASXL2 variants are necessary to verify the mechanism and optimal treatment of ASXL2-related hypoglycemia, neurological damage and optic impairment. Neurological, endocrinological, ophthalmological, and rehabilitative follow-ups of these patients are necessary and important.
ABSTRACT
Our previous research showed that capsaicin exhibits hypoglycemic effects by activating the transient receptor potential vanilloid 1 (TRPV1) channel in diabetic rats. Interestingly, capsiate was also able to activate the TRPV1 channel, but with a non-significant hypoglycemic effect. This study aimed to investigate the effect of capsaicin on the glycometabolism of streptozotocin (STZ)-induced diabetic rats by blocking the TRPV1 channel. After a 4-week capsaicin treatment (6 mg/kg·bw), the serum insulin level of STZ-induced diabetic rats increased from 15.2 to 22.1 mIU/L, the content of hepatic glycogen and muscle glycogen increased by 81.2 and 20.2%, respectively, and the blood glucose level decreased significantly from 19.3 to 14.7 mmol/L. When the TRPV1 channel was blocked, capsaicin lost the above-mentioned effects, and the hypoglycemic effect was no longer significant. It was concluded that a combined up-regulation of both TRPV1 receptors and pancreatic duodenal homeobox-1 (PDX-1) led to the hypoglycemic effect of capsaicin, which partially explains our previous observation: capsiate activating TRPV1 without showing a significant hypoglycemic effect was due to the lack of a significant up-regulation of PDX-1. Based on the experimental results, we speculated that two signaling pathways [TRPV1-(PDX1)-(GLUT2/GK) and TRPV1-(PDX-1)-(IRS1/2)] exist in the pancreas of STZ-induced diabetic rats.
ABSTRACT
Functionalized drug delivery systems against malignant lung metastasis of breast cancer have been extensively studied, while metastasis remains a challenging issue. We propose a new strategy to achieve eradication of primary breast cancer cells and inhibition of pulmonary metastasis. A cathepsin B/pH dual-sensitive block copolymer with a molecular weight of 92 kDa was synthesized to conjugate with doxorubicin (DOX). The copolymer-DOX was further loaded with nifuroxazide (NFX) to self-assemble co-prodrug-loaded micelles (CLM). CLM displayed a drug release pattern in response to pH/enzyme dual stimuli and was enzymatically biodegradable. CLM was demonstrated to reduce viability and inhibit migration and invasion of 4T1 murine breast cancer cells in vitro. After i.v. injection of CLM, its nanoscale size and stimuli-responsiveness facilitated delivery of drugs to the tumor site in mice. Enhanced anti-tumor efficacy and great anti-metastatic effects were found in both orthotropic and lung metastasis 4T1 breast cancer mice models. Meanwhile, histological immunofluorescence and immunohistochemical analyses revealed a high level of apoptosis, suppressed expression of matrix metalloproteinases and reduction in MDSCs infiltration, and all these contributed to inhibit pulmonary metastasis. CLM may be explored as a potential nanomedicine against breast cancer metastasis.
