A Comprehensive Study of the Effects by Sequence Truncation within Inverted Terminal Repeats (ITRs) on the Productivity, Genome Packaging, and Potency of AAV Vectors.

One of the primary challenges in working with adeno-associated virus (AAV) lies in the inherent instability of its inverted terminal repeats (ITRs), which play vital roles in AAV replication, encapsidation, and genome integration. ITRs contain a high GC content and palindromic structure, which occasionally results in truncations and mutations during plasmid amplification in bacterial cells. However, there is no thorough study on how these alterations in ITRs impact the ultimate AAV vector characteristics. To close this gap, we designed ITRs with common variations, including a single B, C, or D region deletion at one end, and dual deletions at both ends of the vector genome. These engineered ITR-carrying plasmids were utilized to generate AAV vectors in HEK293 cells. The crude and purified AAV samples were collected and analyzed for yield, capsid DNA-filled percentage, potency, and ITR integrity. The results show that a single deletion had minor impact on AAV productivity, packaging efficiency, and in vivo potency. However, deletions on both ends, except A, showed significant negative effects on the above characteristics. Our work revealed the role of ITR regions, A, B, C, and D for AAV production and DNA replication, and proposes a new strategy for the quality control of ITR-bearing plasmids and final AAV products.

UHPLC-MS/MS-based central carbon metabolism unveils the biomarkers related to colon cancer.

Even though colon cancer ranks among the leading causes of cancer mortality, early detection dramatically increases survival rates. Many studies have been conducted to determine whether altered metabolite levels may serve as a potential biomarker of cancer that affects key metabolic pathways. The goal of the study was to detect metabolic biomarkers in patients with colon cancer using liquid chromatography-mass spectrometry (LC-MS). This study consisted of 30 patients with colon cancer. An analysis of the metabolomes of cancer samples and para-carcinoma tissues was conducted. We identified a series of important metabolic changes in colon cancer by analyzing metabolites in cancerous tissues compared to their normal counterparts. They are mainly involved in the pentose phosphate pathway, the TCA cycle, glycolysis, galactose metabolism, and butanoate metabolism. As well, we observed dysregulation of AMP, dTMP, fructose, and D-glucose in colon cancer. Additionally, the AUCs for AMP, dTMP, fructose, and D-glucose were greater than 0.7 for the diagnosis of colon cancer. In conclusion, AMP, dTMP, fructose, and D-glucose showed excellent diagnostic performance and could serve as novel disease biomarkers for colon cancer diagnosis.

The effects of nutrient loading from different sources on eutrophication in a large shallow lake in Southeast China.

Lake water eutrophication has become one of the leading obstacles to sustainable economic development in China. Research on the effects of mainstream currents on reservoirs has been relatively underdeveloped compared with research on tributaries, though changes in the water-sediment transport regime in a downstream river may affect nutrient transport behavior in a lake connected to that river. This is particularly problematic because certain wastewater sources, including runoff from agricultural wastes and industrial discharges, adversely affect lake water. Our study focused on Sanshiliujiao Lake, a significant drinking water source in Fujian, Southeast China, that has suffered considerably from eutrophication over the past few decades. This study aimed to estimate the phosphorus and nitrogen loads to the lake, exploring their sources and their ecologic effects using in situ observation and the export coefficient model. Our results showed that the pollution loads of total phosphorus (TP) and total nitrogen (TN) were 2.390 and 46.040 t/year, respectively, most of which were derived from the water diversion (TP 45.7%, TN 29.2%) and non-point source (TP 30.2%, TN 41.6%). The TN input was the highest in East river (3.557 kg/d), followed by Red river (2.524 kg/d). During the wet season, the input of TP and TN increased by 14.6 and 18.7 times, respectively, but produced only slight variations in concentration. Water diversion enriched the nutrients inputs and altered the structure and abundance of phytoplankton communities. In addition, when water flows from the main river directly to Sanshiliujiao Lake, algal blooms in river-connected lakes are significantly exacerbated, so our study may also serve as a theoretical basis to regulate eutrophication in Sanshiliujiao Lake.