Adeno-associated virus (AAV)-mediated gene delivery holds great promise for gene therapy. However, the non-invasive delivery of AAV for lung tissues has not been adequately established. Here, we revealed that the intratracheal administration of an appropriate amount of AAV2/8 predominantly targets lung tissue. AAV-mediated gene delivery that we used in this study induced the expression of the desired protein in lung parenchymal cells, including alveolar type II cells. We harnessed the technique to develop severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-susceptible mice. Three kinds of immune function-relevant gene knockout (KO) mice were transduced with AAV encoding human angiotensin-converting enzyme 2 (hACE2) and then injected with SARS-CoV-2. Among these mice, type I interferon receptor (IFNAR) KO mice showed increased viral titer in the lungs compared to that in the other KO mice. Moreover, nucleocapsid protein of SARS-CoV-2 and multiple lesions in the trachea and lung were observed in AAV-hACE2-transduced, SARS-CoV-2-infected IFNAR KO mice, indicating the involvement of type I interferon signaling in the protection of SARS-CoV-2. In this study, we demonstrate the ease and rapidness of the intratracheal administration of AAV for targeting lung tissue in mice, and this can be used to study diverse pulmonary diseases.

Beige adipocytes, which consume energy mainly in an uncoupling protein 1 (UCP1)-dependent manner, are risen in white adipose tissue (WAT) depots. Since beige adipocyte development is gaining attention as a potential strategy for conquering obesity, worldwide researchers are making efforts to study its biological aspects. However, assessing UCP1 protein levels in beige adipocytes is challenging because of the high level of lipid contaminants in WAT. This study showed that an acetone precipitation method had advantages over conventional methods for eliminating lipid contaminants, achieving clear Western blot bands for WAT proteins, especially UCP1. Our results suggest that the acetone precipitation cleaning method could be useful for the clear analysis and precise evaluation of WAT proteins.

As concerns about sugar-sweetened beverages are increasing, interest in natural sweeteners with zero calories is also growing. This study explores the health impacts of rebaudioside D and M, emerging sugar substitutes, compared to traditional alternatives and stevioside. In mouse models, we investigated the effects of rebaudioside D and M on obesity, liver health, thermogenic adipocytes, skeletal muscle, and gut microbiota. Results show no weight gain or exacerbation of obesity, no promotion of hepatic steatosis, no impairment of brown adipose tissue function and no changes in skeletal muscle metabolic proteins with either rebaudioside. Importantly, both of these sugar substitutes positively influence gut microbiota without adverse metabolic effects, suggesting their potential as safe sugar alternatives.