DLK1 promotes neurogenesis of human and mouse pluripotent stem cell-derived neural progenitors via modulating notch and BMP signalling

A better understanding of the control of stem cell maintenance and differentiation fate choice is fundamental to effectively realising the potential of human pluripotent stem cells in disease modelling, drug screening and cell therapy. Dlk1 is a Notch related transmembrane protein that has been reportedly expressed in several neurogenic regions in the developing brain. In this study, we investigated the ability of Dlk1 in modulating the maintenance and differentiation of human and mouse ESC-derived neural progenitors. We found that DLK1, either employed as an extrinsic factor, or via transgene expression, consistently promoted the generation of neurons in both the mouse and human ESC-derived neural progenitors. DLK1 exerts this function by inducing cell cycle exit of the progenitors, as evidenced by an increase in the number of young neurons retaining BrdU labelling and cells expressing the cycling inhibitor P57Kip2. DLK1 antagonised the cell proliferation activity of Notch ligands Delta 1 and Jagged and inhibited Hes1-mediated Notch signaling as demonstrated by a luciferase reporter assay. Interestingly, we found that DLK1 promotes the neurogenic potential of human neural progenitor cells via suppression of Smad activation when they are challenged with BMP. Together, our data demonstrate for the first time a regulatory role for DLK1 in human and mouse neural progenitor differentiation and establish an interaction between DLK1 and Hes1-mediated Notch signaling in these cells. Furthermore, this study identifies DLK1 as a novel modulator of BMP/Smad signalling

Role of Anterior Intralaminar Nuclei of Thalamus Projections to Dorsomedial Striatum in Incubation of Methamphetamine Craving

Relapse to methamphetamine (Meth) seeking progressively increases after withdrawal from drug self-administration (incubation of Meth craving). We previously demonstrated a role of dorsomedial striatum (DMS) dopamine D1 receptors (D1Rs) in this incubation. Here, we studied the role of afferent glutamatergic projections into the DMS and local D1R-glutamate interaction in this incubation in male rats. We first measured projection-specific activation on day 30 relapse test by using cholera toxin b (retrograde tracer) + Fos (activity marker) double-labeling in projection areas. Next, we determined the effect of pharmacological reversible inactivation of lateral or medial anterior intralaminar nuclei of thalamus (AIT-L or AIT-M) on incubated Meth seeking on withdrawal day 30. We then used an anatomical asymmetrical disconnection procedure to determine whether an interaction between AIT-L -> DMS glutamatergic projections and postsynaptic DMS D1Rs contributes to incubated Meth seeking. We also determined the effect of unilateral inactivation of AIT-L and D1R blockade of DMS on incubated Meth seeking, and the effect of contralateral disconnection of AIT-L -> DMS projections on nonincubated Meth seeking on withdrawal day 1. Incubated Meth seeking was associated with selective activation of AIT -> DMS projections; other glutamatergic projections to DMS were not activated. AIT-L (but not AIT-M) inactivation or anatomical disconnection of AIT-L -> DMS projections decreased incubated Meth seeking. Unilateral inactivation of AIT-L or D1R blockade of the DMS had no effect on incubated Meth craving, and contralateral disconnection of AIT-L -> DMS projections had no effect on nonincubated Meth seeking. Our results identify a novel role of AIT-L and AIT-L -> DMS glutamatergic projections in incubation of drug craving and drug seeking

Upper tract urothelial carcinoma has a luminal-papillary T-cell depleted contexture and activated FGFR3 signaling.

Upper tract urothelial carcinoma (UTUC) is characterized by a distinctly aggressive clinical phenotype. To define the biological features driving this phenotype, we performed an integrated analysis of whole-exome and RNA sequencing of UTUC. Here we report several key insights from our molecular dissection of this disease: 1) Most UTUCs are luminal-papillary; 2) UTUC has a T-cell depleted immune contexture; 3) High FGFR3 expression is enriched in UTUC and correlates with its T-cell depleted immune microenvironment; 4) Sporadic UTUC is characterized by a lower total mutational burden than urothelial carcinoma of the bladder. Our findings lay the foundation for a deeper understanding of UTUC biology and provide a rationale for the development of UTUC-specific treatment strategies

Role of Dorsal Striatum Histone Deacetylase 5 in Incubation of Methamphetamine Craving

BACKGROUND: Methamphetamine (meth) seeking progressively increases after withdrawal (incubation of meth craving). We previously demonstrated an association between histone deacetylase 5 (HDAC5) gene expression in the rat dorsal striatum and incubation of meth craving. Here we used viral constructs to study the causal role of dorsal striatum HDAC5 in this incubation. METHODS: In experiment 1 (overexpression), we injected an adeno-associated virus bilaterally into dorsal striatum to express either green fluorescent protein (control) or a mutant form of HDAC5, which strongly localized to the nucleus. After training rats to self-administer meth (10 days, 9 hours/day), we tested the rats for relapse to meth seeking on withdrawal days 2 and 30. In experiment 2 (knockdown), we injected an adeno-associated virus bilaterally into the dorsal striatum to express a short hairpin RNA either against luciferase (control) or against HDAC5. After training rats to self-administer meth, we tested the rats for relapse on withdrawal days 2 and 30. We also measured gene expression of other HDACs and potential HDAC5 downstream targets. RESULTS: We found that HDAC5 overexpression in dorsal striatum increased meth seeking on withdrawal day 30 but not day 2. In contrast, HDAC5 knockdown in the dorsal striatum decreased meth seeking on withdrawal day 30 but not on day 2; this manipulation also altered other HDACs (Hdac1 and Hdac4) and potential HDAC5 targets (Gnb4 and Suv39h1). CONCLUSIONS: Results demonstrate a novel role of dorsal striatum HDAC5 in incubation of meth craving. These findings also set up future work to identify HDAC5 targets that mediate this incubation