An increase in hepatic triglyceride (TG) contents usually results in non-alcoholic fatty liver disease (NAFLD) and related metabolic diseases. However, the mechanisms underlying perturbations of hepatic TG homeostasis remain largely unknown. Here, we showed that MicroRNA-124 was up-regulated in the livers of C57BL/6 mice fed a short-term high-fat-diet (HFD). Adenoviral overexpression of miR-124 in C57BL/6 mice led to accumulation of excessive triglycerides and up-regulation of lipogenic genes in the liver. We further identified tribbles homolog 3 (TRB3) as a direct target of miR-124. AKT signaling, which is negatively regulated by TRB3, was enhanced by miR-124 overexpression. Moreover, restoration of TRB3 expression markedly abolished the effect of miR-124 on hepatic TG metabolism. Therefore, our findings revealed that miR-124 played a role in mediating high-fat-diet induced TG accumulation in the liver.

This paper evaluates the impact of the second municipal solid waste (MSW) source separation program on municipal solid waste generation (MSWG) in China. Without considering the spatial interactions between cities, the second MSW source separation program has a nonsignificant adverse effect on the per capita municipal solid waste generation (PMSWG). Relaxing the stable-unit-treatment-value assumption (SUTVA), which holds in most of the previous estimation literature on treatment effects, involving the spatial spillover effect among cities, as well as correcting the endogenous local policy has a significantly negative but not robust impact on the PMSWG. The estimation results of the generalized nesting spatial regression models (GNS) imply that the spatial interaction characteristics among Chinese prefecture-level cities may, if neglected, lead to underestimation of the reduction effects of the second MSW source separation policy on the absolute amount of PMSWG. More importantly, our study indicates that although not all the spatial econometric models support the significant reduction effect of source separation on the absolute amount of PMSWG, the source separation program significantly reduces the relative amount of PMSWG, and this result is robust in all spatial models.

This study attempts to explore the evolution process and driving factors of waste disposal facilities in China by employing a unique dataset that combines municipal-level data on socioeconomic characteristics with establishment-level information on waste disposal facilities over the years 2003–2020. This research reveals a noticeable transformation in the structure of waste disposal facilities in China, with rapid declines in landfill sites and steady increases in incineration plants and composting plants. Meanwhile, the distribution of waste disposal facilities exhibits an apparent spatial imbalance across regions. Specifically, landfill sites are primarily clustered in the central regions; incineration plants are concentrated in eastern areas; and composting plants are scattered and widely distributed. The results of the dynamic spatial Durbin model further indicate that consumption level and land area are the two main driving factors of the increase in the total number of waste disposal facilities and that of three different types of facilities; for each 1% increase in the two factors, the total number of waste disposal facilities will increase by 0.4551 and 0.1329 units respectively. However, waste generation, population density, land price, industrial structure and policy instruments have rather heterogeneous effects on waste disposal facilities and their different types. This study can provide guidelines for optimizing the distribution pattern of waste disposal facilities to mitigate against the unbalanced and inadequate development of waste disposal facilities in China and other developing countries with similar situations.