GABA is the primary inhibitory neurotransmitter in the nervous system. GABA A receptors (GABA A Rs) are pentameric ionotropic channels. Subunit composition of the receptors is associated with the affinity of GABA binding and its downstream inhibitory actions. Fluctuations in subunit expression levels with increasing age have been demonstrated in animal and human studies. However, our knowledge regarding the age-related hippocampal GABA A R expression changes is limited and based on rat studies. This study is the first analysis of the aging-related changes of the GABA A R subunit expression in the CA1, CA2/3, and dentate gyrus regions of the mouse hippocampus. Using Western blotting and immunohistochemistry we found that the GABAergic system is robust, with no significant age-related differences in GABA A R α1, α2, α3, α5, β3, and γ2 subunit expression level differences found between the young (6 months) and old (21 months) age groups in any of the hippocampal regions examined. However, we detected a localized decrease of α2 subunit expression around the soma, proximal dendrites, and in the axon initial segment of pyramidal cells in the CA1 and CA3 regions that is accompanied by a pronounced upregulation of the α2 subunit immunoreactivity in the neuropil of aged mice. In summary, GABA A Rs are well preserved in the mouse hippocampus during normal aging although GABA A Rs in the hippocampus are severely affected in age-related neurological disorders, including Alzheimer’s disease.

Gene expression profiling provides a detailed molecular snapshot of cellular phenotypes that can be used to compare different biological conditions. Nanopore sequencing technology can generate high-resolution transcriptomic data in real-time and at low cost, which heralds new opportunities for molecular medicine. In this study, we demonstrate the clinical utility of real-time transcriptomic profiling by processing RNA sequencing data from childhood acute lymphoblastic leukemia (ALL) patients on-the-fly with a trained neural network classifier. This strategy successfully distinguished 11/12 representative ALL molecular subtypes and one non-leukemia control in as little as 5 minutes of sequencing on a MinION sequencer or in less than 1 hour on disposable, low cost Flongle flow cells. Our findings suggest that real-time transcriptomics constitutes a drastically efficient solution for the molecular diagnosis of ALL and other diseases, where conventional clinical workflows require days if not weeks to achieve similar results.

A series of well-regulated cellular and molecular events result in the compartmentalization of the anterior foregut into the esophagus and trachea. Disruption of the compartmentalization process leads to esophageal atresia/tracheoesophageal fistula (EA/TEF). The cause of EA/TEF remains largely unknown. Therefore, to mimic the early development of the esophagus and trachea, we differentiated iPSCs from EA/TEF patients and iPSCs and embryonic stem cells from healthy individuals into mature 3-dimensional esophageal organoids. CXCR4, SOX17, and GATA4 expression was similar in both patient and healthy endodermal cells. Key transcription factor SOX2 was significantly lower in patient-derived anterior foregut. We also observed an abnormal expression of NKX2.1 in the patient-derived mature esophageal organoids. At the anterior foregut stage, RNA sequencing revealed critical genes GSTM1 and RAB37 to be significantly lower in patient-derived anterior foregut. We therefore hypothesize that a transient dysregulation of SOX2 and the abnormal expression of NKX2.1 in patient-derived cells could be responsible for the abnormal foregut compartmentalization.

A series of well-regulated cellular and molecular events result in the compartmentalization of the anterior foregut into the esophagus and trachea. Disruption of the compartmentalization process leads to esophageal atresia/tracheoesophageal fistula (EA/TEF). Therefore, the objective is to differentiate pluripotent stem cells (PSCs), namely, embryonic stem cells and iPSCs from healthy individuals and iPSCs from EA/TEF type C patients, into mature 3-dimensional esophageal organoids expressing Involucrin, Keratin-4, -13, and p63. CXCR4, SOX17, and GATA4 expression was similar in both patient and healthy endodermal cells. Key transcription factor SOX2 was significantly lower in patient-derived anterior foregut. RNA sequencing revealed critical genes GSTM1 and RAB37 to be significantly lower in patient-derived anterior foregut. Furthermore, we observed an abnormal expression of NKX2.1 in the patient-derived mature esophageal organoids. We therefore hypothesize that a transient dysregulation of SOX2 and the abnormal expression of NKX2.1 in patient-derived cells could be responsible for the abnormal foregut compartmentalization.