Analysis of Neuronal Morphology by Two-Photon Microscopy.

During the development of mammalian brains, pyramidal neurons in the cerebral cortex form highly organized six layers with different functions. These neurons undergo developmental processes such as axon extension, dendrite outgrowth, and synapse formation. A proper integration of the neuronal connectivity through dynamic changes of dendritic branches and spines is required for learning and memory. Disruption of these crucial developmental processes is associated with many neurodevelopmental and neurodegenerative disorders. To investigate the complex dendritic architecture, several useful staining tools and genetic methods to label neurons have been well established. Monitoring the dynamics of dendritic spine in a single neuron is still a challenging task. Here, we provide a methodology that combines in vivo two-photon brain imaging and in utero electroporation, which sparsely labels cortical neurons with fluorescent proteins. This protocol may help elucidate the dynamics of microstructure and neural complexity in living rodents under normal and disease conditions.

Prevalence, proportions of elevated liver enzyme levels, and long-term cardiometabolic mortality of patients with metabolic dysfunction-associated steatotic liver disease.

BACKGROUND AND AIM: This study estimated the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) according to cardiometabolic risk factors. The long-term impacts of MASLD on all-cause and cardiometabolic-specific mortality were evaluated. METHODS: We enrolled 343 816 adults aged ≥30 years who participated in a health screening program from 1997 through 2013. MASLD was identified on the basis of abdominal ultrasonography and metabolic profiles. The participants were further categorized by liver enzyme elevation. Baseline cardiometabolic comorbidities were classified on the basis of self-reported medication use and clinical seromarkers. All-cause and cardiometabolic-specific deaths were determined through computerized data linkage with nationwide death certifications until December 31, 2020. RESULTS: The overall prevalence of MASLD was 36.4%. Among patients with MASLD, 35.9% had abnormal liver enzyme levels. Compared with patients without MASLD, abnormal liver enzymes were positively associated with cardiometabolic comorbidities in patients with MASLD (Pfor trend < 0.001). After follow-up, patients with MASLD had a 9%-29% higher risk of all-cause, cardiovascular-related, or diabetes-related mortality. In the groups with MASLD and elevated and normal liver enzyme levels, the multivariate-adjusted hazard ratios for cardiovascular deaths were 1.14 (1.05-1.25) and 1.10 (1.03-1.17), respectively, and those for diabetes deaths were 1.42 (1.05-1.93) and 1.24 (0.98-1.57), respectively, compared with those in the non-MASLD group (Pfor trend < 0.001). DISCUSSION: Individuals with MASLD and elevated liver enzyme levels exhibited significantly higher risks of all-cause and cardiometabolic deaths and should be monitored and given consultation on cardiometabolic modifications.

Parasympathetic neurons derived from human pluripotent stem cells model human diseases and development.

Autonomic parasympathetic neurons (parasymNs) control unconscious body responses, including "rest-and-digest." ParasymN innervation is important for organ development, and parasymN dysfunction is a hallmark of autonomic neuropathy. However, parasymN function and dysfunction in humans are vastly understudied due to the lack of a model system. Human pluripotent stem cell (hPSC)-derived neurons can fill this void as a versatile platform. Here, we developed a differentiation paradigm detailing the derivation of functional human parasymNs from Schwann cell progenitors. We employ these neurons (1) to assess human autonomic nervous system (ANS) development, (2) to model neuropathy in the genetic disorder familial dysautonomia (FD), (3) to show parasymN dysfunction during SARS-CoV-2 infection, (4) to model the autoimmune disease Sjögren's syndrome (SS), and (5) to show that parasymNs innervate white adipocytes (WATs) during development and promote WAT maturation. Our model system could become instrumental for future disease modeling and drug discovery studies, as well as for human developmental studies.

Long-term Risks of Cirrhosis and Hepatocellular Carcinoma Across Steatotic Liver Disease Subtypes.

INTRODUCTION: The prospective study aimed to investigate the long-term associated risks of cirrhosis and hepatocellular carcinoma (HCC) across various subtypes of steatotic liver disease (SLD). METHODS: We enrolled 332,175 adults who participated in a health screening program between 1997 and 2013. Participants were categorized into various subtypes, including metabolic dysfunction-associated SLD (MASLD), MASLD with excessive alcohol consumption (MetALD), and alcohol-related liver disease (ALD), based on ultrasonography findings, alcohol consumption patterns, and cardiometabolic risk factors. We used computerized data linkage with nationwide registries from 1997 to 2019 to ascertain the incidence of cirrhosis and HCC. RESULTS: After a median follow-up of 16 years, 4,458 cases of cirrhosis and 1,392 cases of HCC occurred in the entire cohort, resulting in an incidence rate of 86.1 and 26.8 per 100,000 person-years, respectively. The ALD group exhibited the highest incidence rate for cirrhosis and HCC, followed by MetALD, MASLD, and non-SLD groups. The multivariate adjusted hazard ratios for HCC were 1.92 (95% confidence interval [CI] 1.51-2.44), 2.91 (95% CI 2.11-4.03), and 2.59 (95% CI 1.93-3.48) for MASLD, MetALD, and ALD, respectively, when compared with non-SLD without cardiometabolic risk factors. The pattern of the associated risk of cirrhosis was similar to that of HCC (all P value <0.001). The associated risk of cirrhosis for ALD increased to 4.74 (95% CI 4.08-5.52) when using non-SLD without cardiometabolic risk factors as a reference. DISCUSSION: This study highlights elevated risks of cirrhosis and HCC across various subtypes of SLD compared with non-SLD, emphasizing the importance of behavioral modifications for early prevention.

Novel lissencephaly-associated NDEL1 variant reveals distinct roles of NDE1 and NDEL1 in nucleokinesis and human cortical malformations.

The development of the cerebral cortex involves a series of dynamic events, including cell proliferation and migration, which rely on the motor protein dynein and its regulators NDE1 and NDEL1. While the loss of function in NDE1 leads to microcephaly-related malformations of cortical development (MCDs), NDEL1 variants have not been detected in MCD patients. Here, we identified two patients with pachygyria, with or without subcortical band heterotopia (SBH), carrying the same de novo somatic mosaic NDEL1 variant, p.Arg105Pro (p.R105P). Through single-cell RNA sequencing and spatial transcriptomic analysis, we observed complementary expression of Nde1/NDE1 and Ndel1/NDEL1 in neural progenitors and post-mitotic neurons, respectively. Ndel1 knockdown by in utero electroporation resulted in impaired neuronal migration, a phenotype that could not be rescued by p.R105P. Remarkably, p.R105P expression alone strongly disrupted neuronal migration, increased the length of the leading process, and impaired nucleus-centrosome coupling, suggesting a failure in nucleokinesis. Mechanistically, p.R105P disrupted NDEL1 binding to the dynein regulator LIS1. This study identifies the first lissencephaly-associated NDEL1 variant and sheds light on the distinct roles of NDE1 and NDEL1 in nucleokinesis and MCD pathogenesis.