Objective:To observe the projections from tyrosine hydroxylase(TH)positive neurons in locus coerule-us(LC)to tachykinin-1(TAC1)neurons in paraventricular nucleus of the thalamus(PVT),and morphologically determine whether they are involved in transmission and modulation of nociceptive information.Methods:TAC1-ires-Cre mice were hybridized with Rosa26:CAG-LSL-tdTomato(Ai9)mice.And spared nerve injury(SNI)induced neu-ropathic pain model was established with TAC1-ires-Cre::Ai9 mice to observe the colocalization of TAC1 and Fos and the close appositions between TAC1/FOS double-labeled neurons and TH positive axonal terminals.The distribution of the TH positive neurons and FG retrogradely labeled neurons were observed in the LC after Fluorogold(FG)was injec-ted into the PVT.Finally,the coexistences of TH positive neurons and RV labeled neurons in the LC were observed after injection of RV-mediated retrograde tracing system.Results:TAC1 positive neurons were shown with red fluores-cence in TAC1-ires-Cre::Ai9 mice.TAC1/FOS double-labeled neurons were found in the PVT of the SNI model.Some TAC1/FOS double labeled neurons made close appositions with TH positive axonal terminals.FG retrogradely labeled neurons were observed in the LC after FG injected into the PVT,and some of the FG labeled neurons coexisted with TH positive neurons.Using RV retrograde transsynaptic tracing virus,the results showed that presynaptic neurons of TAC1 positive neurons in the PVT were found in the LC,and most of the presynaptic neurons were TH positive neu-rons.Conclusion:TH positive neurons in the LC project to TAC1 positive neurons of the PVT,forming LCTH+-PVTTAC1+neural circuit,which were activated by nociceptive information.It demonstrates that this pathway plays a role in pain transmission or regulation.

Modulating Tankyrases (TNKS), interactions with USP25 to promote TNKS degradation, rather than inhibiting their enzymatic activities, is emerging as an alternative/specific approach to inhibit the Wnt/β-catenin pathway. Here, we identified UAT-B, a novel neoantimycin analog isolated from Streptomyces conglobatus, as a small-molecule inhibitor of TNKS-USP25 protein-protein interaction (PPI) to overcome multi-drug resistance in colorectal cancer (CRC). The disruption of TNKS-USP25 complex formation by UAT-B led to a significant decrease in TNKS levels, triggering cell apoptosis through modulation of the Wnt/β-catenin pathway. Importantly, UAT-B successfully inhibited the CRC cells growth that harbored high TNKS levels, as demonstrated in various in vitro and in vivo studies utilizing cell line-based and patient-derived xenografts, as well as APC^min/+ spontaneous CRC models. Collectively, these findings suggest that targeting the TNKS-USP25 PPI using a small-molecule inhibitor represents a compelling therapeutic strategy for CRC treatment, and UAT-B emerges as a promising candidate for further preclinical and clinical investigations.