Laboratory of Virology and Infectious Disease, Rockefeller University, New York, NY, USA; Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA; The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, USA.
Infection Biology Program and Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
J Hepatol. 2023 Jan;78(1):45-56. doi: 10.1016/j.jhep.2022.08.022. Epub 2022 Aug 30.
BACKGROUND & AIMS: A number of genetic polymorphisms have been associated with susceptibility to or protection against non-alcoholic fatty liver disease (NAFLD), but the underlying mechanisms remain unknown. Here, we focused on the rs738409 C>G single nucleotide polymorphism (SNP), which produces the I148M variant of patatin-like phospholipase domain-containing protein 3 (PNPLA3) and is strongly associated with NAFLD.
To enable mechanistic dissection, we developed a human pluripotent stem cell (hPSC)-derived multicellular liver culture by incorporating hPSC-derived hepatocytes, hepatic stellate cells, and macrophages. We first applied this liver culture to model NAFLD by utilising a lipotoxic milieu reflecting the circulating levels of disease risk factors in affected individuals. We then created an isogenic pair of liver cultures differing only at rs738049 and compared NAFLD phenotype development.
Our hPSC-derived liver culture recapitulated many key characteristics of NAFLD development and progression including lipid accumulation and oxidative stress, inflammatory response, and stellate cell activation. Under the lipotoxic conditions, the I148M variant caused the enhanced development of NAFLD phenotypes. These differences were associated with elevated IL-6/signal transducer and activator of transcription 3 (STAT3) activity in liver cultures, consistent with transcriptomic data of liver biopsies from individuals carrying the rs738409 SNP. Dampening IL-6/STAT3 activity alleviated the I148M-mediated susceptibility to NAFLD, whereas boosting it in wild-type liver cultures enhanced NAFLD development. Finally, we attributed this elevated IL-6/STAT3 activity in liver cultures carrying the rs738409 SNP to increased NF-κB activity.
Our study thus reveals a potential causal link between elevated IL-6/STAT3 activity and 148M-mediated susceptibility to NAFLD.
An increasing number of genetic variants manifest in non-alcoholic fatty liver disease (NAFLD) development and progression; however, the underlying mechanisms remain elusive. To study these variants in human-relevant systems, we developed an induced pluripotent stem cell-derived multicellular liver culture and focused on a common genetic variant (i.e. rs738409 in PNPLA3). Our findings not only provide mechanistic insight, but also a potential therapeutic strategy for NAFLD driven by this genetic variant in PNPLA3. Our liver culture is therefore a useful platform for exploring genetic variants in NAFLD development.
许多遗传多态性与非酒精性脂肪性肝病（NAFLD）的易感性或保护作用有关，但潜在机制尚不清楚。在这里，我们重点研究 rs738409 C>G 单核苷酸多态性（SNP），该 SNP 产生 patatin-like 磷脂酶结构域包含蛋白 3（PNPLA3）的 I148M 变体，与 NAFLD 强烈相关。
为了实现机制剖析，我们通过纳入人多能干细胞（hPSC）衍生的肝细胞、肝星状细胞和巨噬细胞，开发了一种多细胞肝培养物。我们首先利用反映受影响个体中疾病风险因素循环水平的脂毒性环境，利用该肝培养物来模拟 NAFLD。然后，我们创建了一对仅在 rs738049 处存在差异的肝培养物，并比较了 NAFLD 表型的发展。
我们的 hPSC 衍生的肝培养物再现了 NAFLD 发展和进展的许多关键特征，包括脂质积累和氧化应激、炎症反应和星状细胞激活。在脂毒性条件下，I148M 变体导致 NAFLD 表型的发展增强。这些差异与携带 rs738409 SNP 的个体肝活检的转录组数据一致，与携带 rs738409 SNP 的个体肝活检的转录组数据一致，与携带 rs738409 SNP 的个体肝活检的转录组数据一致。IL-6/STAT3 活性升高。抑制 IL-6/STAT3 活性可减轻 I148M 介导的 NAFLD 易感性，而在野生型肝培养物中增强 IL-6/STAT3 活性可增强 NAFLD 发展。最后，我们将携带 rs738409 SNP 的肝培养物中升高的 IL-6/STAT3 活性归因于 NF-κB 活性的增加。
因此，我们的研究揭示了升高的 IL-6/STAT3 活性与 148M 介导的 NAFLD 易感性之间的潜在因果关系。
越来越多的遗传变异与非酒精性脂肪性肝病（NAFLD）的发展和进展有关；然而，潜在的机制仍不清楚。为了在人类相关系统中研究这些变体，我们开发了一种诱导多能干细胞衍生的多细胞肝培养物，并重点研究了一种常见的遗传变体（即 PNPLA3 中的 rs738409）。我们的发现不仅提供了机制上的见解，而且为 PNPLA3 中由这种遗传变体驱动的 NAFLD 提供了一种潜在的治疗策略。因此，我们的肝培养物是探索 NAFLD 发展中遗传变体的有用平台。
