Neural organoids provide a powerful tool for investigating neural development, modeling neural diseases, screening drugs, and developing cell-based therapies. Somatic cells have previously been reprogrammed by transcription factors (TFs) into sensory ganglion (SG) neurons but not SG organoids. We identify a combination of triple TFs Ascl1, Brn3b/3a, and Isl1 (ABI) as an efficient means to reprogram mouse and human fibroblasts into self-organized and networked induced SG (iSG) organoids. The iSG neurons exhibit molecular features, subtype diversity, electrophysiological and calcium response properties, and innervation patterns characteristic of peripheral sensory neurons. Moreover, we have defined retinal ganglion cell (RGC)–specific identifiers to demonstrate the ability for ABI to reprogram induced RGCs (iRGCs) from fibroblasts. Unlike iSG neurons, iRGCs maintain a scattering distribution pattern characteristic of endogenous RGCs. iSG organoids may serve as a model to decipher the pathogenesis of sensorineural diseases and screen effective drugs and a source for cell replacement therapy.

During development, neural progenitors change their competence states over time to sequentially generate different types of neurons and glia. Several cascades of temporal transcription factors (tTFs) have been discovered inDrosophilato control the temporal identity of neuroblasts, but the temporal regulation mechanism is poorly understood in vertebrates. Mammalian retinal progenitor cells (RPCs) give rise to several types of neuronal and glial cells following a sequential yet overlapping temporal order. Here, by temporal cluster analysis, RNA-sequencing analysis, and loss-of-function and gain-of-function studies, we show that the Fox domain TF Foxn4 functions as a tTF during retinogenesis to confer RPCs with the competence to generate the mid/late-early cell types: amacrine, horizontal, cone, and rod cells, while suppressing the competence of generating the immediate-early cell type: retinal ganglion cells (RGCs). In early embryonic retinas,Foxn4inactivation causes down-regulation of photoreceptor marker genes and decreased photoreceptor generation but increased RGC production, whereas its overexpression has the opposite effect. Just as inDrosophila, Foxn4 appears to positively regulate its downstream tTF Casz1 while negatively regulating its upstream tTF Ikzf1. Moreover, retina-specific ablation ofFoxn4reveals that it may be indirectly involved in the synaptogenesis, establishment of laminar structure, visual signal transmission, and long-term maintenance of the retina. Together, our data provide evidence that Foxn4 acts as a tTF to bias RPCs toward the mid/late-early cell fates and identify a missing member of the tTF cascade that controls RPC temporal identities to ensure the generation of proper neuronal diversity in the retina.

To identify the factors associated with serum total bilirubin (STB) and determine whether STB is independently associated with diabetic retinopathy (DR) or diabetic kidney disease (DKD), 1,665 Chinese patients with type 2 diabetes (T2DM) (248 outpatients newly diagnosed with T2DM [NDM] and 1,417 inpatients previously diagnosed with T2DM [PDM]) were studied. Clinical and biochemical information was collected, and a single nucleotide polymorphism (rs6704078) of the UGT1A1 gene was genotyped in 1,059 individuals. Multiple linear regression showed that STB was associated with haemoglobin concentration, platelet count, and serum triglyceride concentration in NDM and PDM patients, and with serum albumin, duration of diabetes, and smoking in PDM patients. In patients with PDM, multiple logistic regression revealed that serum albumin was associated with DR (odds ratio [OR] = 0.92, 95% confidence interval [CI]: 0.87–0.96, p = 0.001) and DKD (OR = 0.93, 95% CI: 0.88–0.98, p = 0.005) after adjustment for STB, STB-related factors, and risk factors for DR and DKD. In addition, patients with the T allele of rs6704078 had higher STB (13.2 [10.4–17.9] μmol/L versus 11.8 (9.4–14.8) μmol/L; p < 0.001) and similar risks of DR or DKD to those without the T allele. Thus, serum albumin, but not STB, is associated with DR and DKD.

Purpose: Mutations in hepatocyte nuclear factor 1α (HNF1α) are the cause of maturityonset diabetes of the young type 3 (MODY3) and involved in the development of hepatocellular adenoma and abnormal lipid metabolism. Previously, we have found that the serum microRNA (miR)-122 levels in MODY3 patients were lower than those in type 2 diabetes mellitus and healthy controls. This study aimed to investigate the mechanism of decreased miR-122 levels in patients with MODY3 and whether low levels of miR-122 mediate tumorigenesis and abnormal lipid metabolism associated with HNF1α deficiency in human hepatocytes. Methods: The expression of miR-122 was examined by real-time PCR. Dual-luciferase reporter assay was performed to confirm the transcriptional regulation of miR-122 by HNF1α. HepG2 cells were transfected with siRNA or miRNA mimic to downregulate or upregulate the expression of HNF1α or miR-122, respectively. CCK-8 and colony formation assay were used to determine cell proliferation. Lipid accumulation was examined by Oil Red O staining and intracellular triglyceride and cholesterol quantification assays. Results: HNF1α regulated the expression of miR-122 by directly binding to its promoter. Knockdown of HNF1α in HepG2 cells reduced the expression of miR-122, increased proliferation and promoted intracellular cholesterol accumulation. Overexpression of miR-122 partially rescued the phenotypes associated with HNF1α deficiency in human hepatocytes. Mechanistically, HNF1α modulated cholesterol homeostasis via miR-122-dependent activation of sterol regulatory element-binding protein-2 (SREBP-2) and regulation of proprotein convertase subtilisin/kexin type 9 (PCSK9). Moreover, circulating miR-122 levels were associated with serum cholesterol levels. Conclusion: Loss of HNF1α function led to hepatocyte proliferation and abnormal cholesterol metabolism by downregulating miR-122. Our findings revealed a novel mechanism that low levels of miR-122 mediate tumorigenesis and abnormal lipid metabolism associated with MODY3. MiR-122 may be a potential therapeutic target for the treatment of MODY3.

miR-122, the expression of which is regulated by several transcription factors, such as HNF1A, was recently reported to be associated with type 2 diabetes (T2DM) and hepatocellular carcinoma. HNF1A variants can cause diabetes and might be involved in the development of primary liver neoplasm. Differences in miR-122 expression among different types of diabetes have not been studied. This study aimed to investigate differences in serum miR-122 levels in Chinese patients with different forms of diabetes, including T2DM, type 1 diabetes (T1DM), HNF1A variant-induced diabetes (HNF1A-DM), glucokinase variant-induced diabetes (GCK-DM), and mitochondrial A3243G mutation-induced diabetes (MDM). In total, 12 HNF1A-DM patients, 24 gender-, age-, and body mass index-matched (1 : 2) T2DM patients and 24 healthy subjects were included in this study. In addition, 30 monogenic diabetes (11 GCK-DM and 19 MDM) and 17 T1DM patients were included. Fasted blood biochemistry and miR-122 were measured. The results showed that the HNF1A-DM patients had lower miR-122 levels [0.046 (0.023, 0.121)] than T2DM patients [0.165 (0.036, 0.939), P = 0.02] and healthy controls [0.249 (0.049, 1.234), P = 0.019]. The area under the curve of the receiver operating characteristic curve for miR-122 to discriminate HNF1A-DM and T2DM was 0.687 (95% CI: 0.52–0.86, P = 0.07). There was no difference in serum miR-122 among HNF1A-DM, GCK-DM, MDM, and T1DM patients. Lower serum miR-122 is a unique feature of HNF1A-DM patients and might partially explain the increased risk for liver neoplasm and abnormal lipid metabolism in HNF1A-DM patients.