Probes for INS

Cannabinoid CB2 receptors (CB2R) are importantly involved in drug reward and addiction. However, the cellular mechanisms underlying CB2R action remain unclear. We have previously reported that cocaine self-administration upregulates CB2R expression in midbrain dopamine (DA) neurons. In the present study, we investigated whether cocaine or heroin also alters CB2R expression in striatal medium-spiny neurons that express dopamine D1 or D2 receptors (D1-MSNs, D2-MSNs) and microglia. Due to the concern of CB2R antibody specificity, we developed three mouse CB2-specific probes to detect CB2R mRNA using quantitative RT-PCR and RNAscope in situ hybridization (ISH) assays. We found that a single injection of cocaine failed to alter, while repeated cocaine injections or self-administration dose-dependently upregulated CB2R gene expression in both brain (cortex and striatum) and periphery (spleen). In contrast, repeated administration of heroin produced a dose-dependent reduction in striatal CB2 mRNA expression. RNAscope ISH assays detected CB2R mRNA in striatal D1- and D2-MSNs, not in microglia. We then used transgenic CX3CR1eGFP/+ microglia reporter mice and D1- or D2-Cre-RiboTag mice to purify striatal microglia or ribosome-associated mRNAs from CX3CR1eGFP/+, D1-MSNs, or D2-MSNs, respectively. We found that CB2R upregulation occurred mainly in D1-MSNs, not in D2-MSNs or microglia, in the nucleus accumbens rather than the dorsal striatum. These findings indicate that repeated cocaine exposure may upregulate CB2R expression in both brain and spleen, with regional and cell type-specific profiles. In the striatum, CB2R upregulation occurs mainly in D1-MSNs in the nucleus accumbens. Given the important role of D1-MSNs in brain reward function, the present findings provide new insight into mechanisms by which brain CB2Rs modulate cocaine action.

In rodent models of type 2 diabetes (T2D), central administration of fibroblast growth factor 1 (FGF1) normalizes elevated blood glucose levels in a manner that is sustained for weeks or months. Increased activity of NPY/AgRP neurons in the hypothalamic arcuate nucleus (ARC) is implicated in the pathogenesis of hyperglycemia in these animals, and the ARC is a key brain area for the antidiabetic action of FGF1. We therefore sought to determine whether FGF1 inhibits NPY/AgRP neurons, and if so whether this inhibitory effect is sufficiently durable to offer a feasible explanation for sustained diabetes remission induced by central administration of FGF1. Here we show that FGF1 inhibits ARC NPY/AgRP neuron activity, both after icv injection in vivo and when applied ex vivo in a slice preparation, and that the underlying mechanism involves increased input from presynaptic GABAergic neurons. Following central administration, the inhibitory effect of FGF1 on NPY/AgRP neurons is also highly durable, lasting for at least two weeks. To our knowledge, no precedent for such a prolonged inhibitory effect exists. Future studies are warranted to determine whether NPY/AgRP neuron inhibition contributes to the sustained antidiabetic action elicited by icv FGF1 injection in rodent models of T2D.  .

Anaplastic thyroid carcinoma (ATC) are highly aggressive malignant tumors with poor overall prognosis despite multimodal therapy. As ATC are extremely rare, no randomized controlled study has been published for metastatic disease. Thyrosine kinase inhibitors, especially lenvatinib and immune checkpoint inhibitors such as pembrolizumab, are emerging drugs for ATC. Few studies have reported the efficacity of pembrolizumab and lenvatinib association, resulting in its frequent off-label use. In this review, we discuss rationale efficacy and safety evidence for the association of lenvatinib and pembrolizumab in ATC. First, we discuss preclinical rationale for pembrolizumab monotherapy, lenvatinib monotherapy and synergistic action of pembrolizumab and lenvatinib in the metastatic setting. We also discuss clinical evidence for immunotherapy and pembrolizumab in ATC through the analysis of studies evaluating immunotherapy, lenvatinib and pembrolizumab lenvatinib association in ATC. In addition, we discuss the safety of this association and potential predictive biomarkers of efficiency.

Treatment options for poorly differentiated (PDTC) and anaplastic (ATC) thyroid carcinoma are unsatisfactory and prognosis is generally poor. Lenvatinib (LEN), a multi-tyrosine kinase inhibitor targeting fibroblast growth factor receptors (FGFR) 1-4 is approved for advanced radioiodine refractory thyroid carcinoma, but response to single agent is poor in ATC. Recent reports of combining LEN with PD-1 inhibitor pembrolizumab (PEM) are promising.Primary ATC (n=93) and PDTC (n=47) tissue samples diagnosed 1997-2019 at five German tertiary care centers were assessed for PD-L1 expression by immunohistochemistry using Tumor Proportion Score (TPS). FGFR 1-4 mRNA was quantified in 31 ATC and 14 PDTC with RNAscope in-situ hybridization. Normal thyroid tissue (NT) and papillary thyroid carcinoma (PTC) served as controls. Disease specific survival (DSS) was the primary outcome variable.PD-L1 TPS≥50% was observed in 42% of ATC and 26% of PDTC specimens. Mean PD-L1 expression was significantly higher in ATC (TPS 30%) than in PDTC (5%; p<0.01) and NT (0%, p<0.001). 53% of PDTC samples had PD-L1 expression ≤5%. FGFR mRNA expression was generally low in all samples but combined FGFR1-4 expression was significantly higher in PDTC and ATC compared to NT (each p<0.001). No impact of PD-L1 and FGFR 1-4 expression was observed on DSS.High tumoral expression of PD-L1 in a large proportion of ATCs and a subgroup of PDTCs provides a rationale for immune checkpoint inhibition. FGFR expression is low thyroid tumor cells. The clinically observed synergism of PEM with LEN may be caused by immune modulation.