12/05/2024


Gallbladder carcinoma has a high degree of malignancy. No effective treatment exists for patients with advanced tumors. The second mitochondria-derived activator of caspases (Smac) is the antagonist of the inhibitors of apoptosis protein. Smac mimetics are a class of effective tumor-targeted drugs undergoing clinical trials. However, studies on the effect of Smac mimetics on gallbladder cancer are unavailable. In this study, Smac mimetics can promote tumor necrosis factor-α (TNF-α) to inhibit the proliferation of gallbladder cancer cells and activate the apoptotic pathway, thereby promoting the ubiquitination of Lys48 on Receptor interacting protein kinase-1 (RIPK1) and leading to proteasomal degradation that causes damage to RIPK1 protein integrity. The formation of complex I (RIPK1, tumor necrosis factor 1-associated death domain protein, and TNF receptor-associated factor 2) is inhibited. Then, nonubiquitinated RIPK1 binds with the Fas-associated death domain and caspase-8 to form complex II and promotes the death receptor pathway of apoptosis. Animal experiments further verify that TNF-α combined with Smac mimetics can inhibit the growth of transplanted tumors and induce the apoptosis of transplanted tumor cells. This research provides a new direction for the targeted therapy of gallbladder cancer. Fibrin is an essential constituent of the coagulation cascade, and the formation of hemostatic fibrin clots is central to wound healing. Fibrin clots are over time degraded into fibrin degradation products as the injured tissue is replaced by granulation tissue. Our goal was to study the role of the fibrin degradation product fragment E (FnE) in fibroblast activation and migration. We present evidence that FnE is a chemoattractant for fibroblasts and that FnE can potentiate TGF-β-induced myofibroblast formation. FnE forms a stable complex with αVβ3 integrin, and the integrin β3 subunit is required both for FnE-induced fibroblast migration and for potentiation of TGF-β-induced myofibroblast formation. Finally, subcutaneous infusion of FnE in mice results in a fibrotic response in the hypodermis. These results support a model where FnE released from clots in wounded tissue promote wound healing and fibrosis by both recruitment and activation of fibroblasts. Fibrin fragment E could thus represent a therapeutic target for treatment of pathological fibrosis. Mechanisms controlling the recycling of G protein-coupled receptors (GPCRs) remain largely unclear. We report that GGA3 (Golgi-associated, γ adaptin ear containing, ADP-ribosylation factor-binding protein 3) regulates the recycling and signaling of the PGD2 receptor DP1 through a new mechanism. An endogenous interaction between DP1 and GGA3 was detected by co-immunoprecipitation in HeLa cells. The interaction was promoted by DP1 agonist stimulation, which was supported by increased DP1-GGA3 colocalization in confocal microscopy. Pulldown assays showed that GGA3 interacts with the intracellular loop 2 and C-terminus of DP1, whereas the receptor interacts with the VHS domain of GGA3. The Arf-binding deficient GGA3 N194A mutant had the same effect as wild-type GGA3 on DP1 trafficking, suggesting a new mechanism for GGA3 in recycling. Depletion of Rab4 inhibited the GGA3 effect on DP1 recycling, revealing a Rab4-dependent mechanism. Interestingly, depletion of L-PGDS (L-type prostaglandin synthase, the enzyme that produces the agonist for DP1) impaired the ability of GGA3 to mediate DP1 recycling, while GGA3 knockdown prevented L-PGDS from promoting DP1 recycling, indicating that both proteins function interdependently. A novel interaction was observed between co-immunoprecipitated endogenous L-PGDS and GGA3 proteins in HeLa cells, and in vitro using purified recombinant proteins. Redistribution of L-PGDS towards GGA3- and Rab4-positive vesicles was induced by DP1 activation. Silencing of GGA3 inhibited ERK1/2 activation following DP1 stimulation. Altogether, our data reveal a novel function for GGA3, in a newly described association with L-PGDS, in the recycling and signaling of a GPCR, namely DP1. KMN-159 is the lead compound from a series of novel difluorolactam prostanoid EP4 receptor agonists aimed at inducing local bone formation while avoiding the inherent side effects of systemic EP4 activation. KMN-159 is a potent, selective small molecule possessing pharmacokinetic properties amenable to local administration. Unfractionated rat bone marrow cells (BMCs) were treated once at plating with escalating doses of KMN-159 (1 pM to 10 μM). The resulting elevated alkaline phosphatase (ALP) levels measured 9 days post-dose are consistent with increased osteoblastic differentiation and exposure to KMN-159 at low nanomolar concentrations for as little as 30 min was sufficient to induce complete osteoblast differentiation of the BMCs from both sexes and regardless of age. ALP induction was blocked by an EP4 receptor antagonist but not by EP1 or EP2 receptor antagonists and was not induced by EP2 or EP3 receptor agonists. Addition of BMCs to plates coated with KMN-159 24 days earlier resulted in ALP activation, highlighting the chemical stability of the compound. The expression of phenotype markers such as ALP, type I collagen, and osteocalcin was significantly elevated throughout the osteoblastic differentiation timecourse initiated by KMN-159 stimulation. An increased number of tartrate-resistant acid phosphatase-positive cells was observed KMN-159 or PGE2 treated BMCs but only in the presence of exogenous receptor activator of nuclear factor kappa-Β ligand (RANKL). No change in the number of adipocytes was observed. KMN-159 also increased bone healing in a rat calvarial defect model with a healing rate equivalent to recombinant human bone morphogenetic protein-2. Our studies show that KMN-159 is able to stimulate osteoblastic differentiation with a very short time of exposure, supporting its potential as a therapeutic candidate for augmenting bone mass. Light-harvesting chlorophyll a/b-binding (Lhc) proteins comprise a plant-specific superfamily involved in photosynthesis and stress responses. Despite their importance, little is known in papaya (Carica papaya), an economically important tree fruit crop as well as a species close to the model plant arabidopsis (Arabidopsis thaliana). This study reports a first genome-wide analysis of Lhc superfamily genes in papaya, and a total of 28 members that represent four defined families or 26 orthologous groups were identified from the papaya genome. The superfamily number is comparable to 28 or 27 reported in castor (Ricinus communis) and jatropha (Jatropha curcas), respectively, two Euphorbiaceous plants also without any recent whole-genome duplication (WGD), but relatively less than 35, 34, 32, 32, 37, 30 or 32 present in cassava (Manihot esculenta), arabidopsis, A. lyrata, A. halleri, Capsella rubella, C. https://www.selleckchem.com/products/pixantrone-maleate.html grandiflora, and Eutrema salsugineum, respectively, representative species having experienced one or two recent WGDs.