Chemokines play pivotal roles in the recruitment of various immune cells to diverse tissues in both physiological and pathological conditions. CXCL17 is an orphan chemokine preliminarily found to be involved in tumor angiogenesis. However, its protein nature, as well as its endogenous bioactivity, has not been well clarified. Using real-time PCR, immunohistochemical staining, and Western blotting, we found that CXCL17 is highly expressed in both a constitutive and inducible manner in the rat gastric mucosa, where it undergoes endoproteolysis during protein maturation. The mature CXCL17 exhibited strong chemoattractant abilities targeting monocytes and macrophages, potentially through ERK1/2 and p38 but not JNK signaling. CXCL17 also induced the production of proangiogenic factors such as vascular endothelial growth factor A from treated monocytes. Furthermore, in contrast to other CXC chemokines that accelerate inflammatory responses, CXCL17 showed novel anti-inflammatory effects on LPS-activated macrophages. Therefore, our data suggest that CXCL17 in the gastric lamina propria may play an important role in tissue repair and anti-inflammation, both of which help to maintain the integrity of the gastric mucosa.
Neuromedin U (NMU) activates two G protein-coupled receptors, NMUR1 and NMUR2; this signaling not only controls many physiological responses but also promotes tumorigenesis in diverse tissues. We recently identified a novel truncated NMUR2 derived by alternative splicing, namely NMUR2S, from human ovarian cancer cDNA. Sequence analysis, cell surface ELISA and immunocytochemical staining using 293T cells indicated that NMUR2S can be expressed well on the cell surface as a six-transmembrane protein. Receptor pull-down and fluorescent resonance energy transfer assays demonstrated that NMUR1, NMUR2 and this newly discovered NMUR2S can not only form homomeric complexes but also heteromeric complexes with each other. Although not activated by NMU itself, functional assay in combination with receptor quantification and radio-ligand binding in 293T cells indicated that NMUR2S does not alter the translocation and stability of NMUR1 or NMUR2, but rather effectively dampens their signaling by blocking their NMU binding capability through receptor heterodimerization. We further demonstrated that NMU signaling is significantly up-regulated in human ovarian cancers, whereas expression of NMUR2S can block endogenous NMU signaling and further lead to suppression of proliferation in SKOV-3 ovarian cancer cells. In contrast, in monocytic THP-1 cells that express comparable levels of NMUR1 and NMUR2S, depletion of NMUR2S restored both the signaling and effect of NMU. Thus, these results not only reveal the presence of previously uncharacterized heteromeric relationships among NMU receptors but also provide NMUR2S as a potential therapeutic target for the future treatment of NMU signaling-mediated cancers.
Bone morphogenetic proteins (BMPs) are known to play an indispensable role in preventing the precocious luteinization of granulosa cells within growing ovarian follicles. In this study, we found that the transcripts of BMP8 genes are enriched in the ovaries of humans and rodents. When analyzing transcriptomic datasets obtained from human mature granulosa cells, we further found that the BMP8 transcripts not only show the highest abundance among the searchable BMP-related ligands but also decrease significantly in women of advanced age or women with polycystic ovarian syndrome. The correlation between the BMP8 levels in granulosa cells and the decline in ovarian function in these subjects suggests that BMP8 protein may be involved in the regulation of granulosa cell function(s). Using a rat model, we demonstrated that human BMP8A protein activates the SMAD1/5/8 and the SMAD2/3 pathways simultaneously in both immature and mature granulosa cells. Furthermore, the expression of potential type I and type II receptors used by BMP8 in rat granulosa cells was characterized. We found that BMP8A treatment can significantly inhibit gonadotropin-induced progesterone production and steroidogenesis-related gene expression in granulosa cells. Pathway dissection using receptor inhibitors further revealed that such inhibitory effects occur specifically through the BMP8-activated SMAD1/5/8, but not SMAD2/3, pathway. Taken together, considering its abundance and possible functions in granulosa cells, we suggest that BMP8 may act as a novel luteinization inhibitor in growing follicles.
Leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) promotes the Wnt signaling through interaction with R-spondins or norrin. Using PCR amplification from rat ovarian cDNAs, we identified a naturally occurring Lgr4 splice variant encoding only the ectodomain of Lgr4, which was named Lgr4-ED. Lgr4-ED can be detected as a secreted protein in the extracts from rodent and bovine postnatal gonads, suggesting conservation of Lgr4-ED in mammals. Recombinant Lgr4-ED purified from the conditioned media of transfected 293T cells was found to dose-dependently inhibit the LGR4-mediated Wnt signaling induced by RSPO2 or norrin, suggesting that it is capable of ligand absorption and could have a potential role as an antagonist. Intraperitoneal injection of purified recombinant Lgr4-ED into newborn mice was found to significantly decrease the testicular expression of estrogen receptor alpha and aquaporin 1, which is similar to the phenotype found in Lgr4-null mice. Administration of recombinant Lgr4-ED to superovulated female rats can also decrease the expression of estrogen receptor alpha, aquaporin 1, LH receptor and other key steroidogenic genes as well as bring about the suppression of progesterone production. Thus, these findings suggest that endogenously expressed Lgr4-ED may act as an antagonist molecule and help to fine-tune the R-spondin/norrin-mediated Lgr4-Wnt signaling during gonadal development.
Abstract Background TGF-β superfamily signaling is indispensable for bone homeostasis. However, the global expression profiles of all the genes that make up this signaling module in bone and bone-related diseases have not yet been well characterized. Methods Transcriptomic datasets from human bone marrows, bone marrow-derived mesenchymal stem cells (MSCs) and MSCs of primary osteoporotic patients were used for expression profile analyses. Protein treatments, gene quantification, reporter assay and signaling dissection in MSC lines were used to clarify the interactive regulations and feedback mechanisms between TGF-β superfamily ligands and antagonists. Ingenuity Pathway Analysis was used for network construction. Results We identified TGFB1 in the ligand group that carries out SMAD2/3 signaling and BMP8A , BMP8B and BMP2 in the ligand group that conducts SMAD1/5/8 signaling have relatively high expression levels in normal bone marrows and MSCs. Among 16 antagonist genes, the dominantly expressed TGF-β superfamily ligands induced only NOG , GREM1 and GREM2 via different SMAD pathways in MSCs. These induced antagonist proteins further showed distinct antagonisms to the treated ligands and thus would make up complicated negative feedback networks in bone. We further identified TGF-β superfamily signaling is enriched in MSCs of primary osteoporosis. Enhanced expression of the genes mediating TGF-β-mediated SMAD3 signaling and the genes encoding TGF-β superfamily antagonists served as significant features to osteoporosis. Conclusion Our data for the first time unveiled the transcription landscape of all the genes that make up TGF-β superfamily signaling module in bone. The feedback mechanisms and regulatory network prediction of antagonists provided novel hints to treat osteoporosis.
Abstract Background The development of donor‐specific antibodies ( DSA ) to human leukocyte antigens ( HLA ) has been associated with acute rejection and allograft failure after heart transplantation. Not all DSA , however, can fix complement. Methods To determine the association between complement‐fixing DSA and heart transplant outcomes, we retrospectively analyzed results obtained using the C1q solid‐phase assay that specifically detects complement‐fixing DSA in parallel with the standard IgG assay in 121 adult heart transplant recipients. Results The 52 recipients who developed post‐transplant DSA had a higher incidence of acute cellular rejection (58% vs 19%, P < .001) and antibody‐mediated rejection (29% vs 7%, P < .001) than the 69 recipients without DSA . The 24 recipients with C1q+ DSA had more antibody‐mediated rejection than the 28 recipients with C1q− DSA (46% vs 14%, P = .012), but there was no difference in the incidence of acute cellular rejection between these two groups. Patients with post‐transplant DSA had higher mortality than patients with no DSA (29% vs 13%, P = .031), mainly due to increased incidence of acute rejection. No differences in survival were found between recipients with C1q+ DSA and C1q− DSA . Conclusions Routine monitoring of DSA post‐transplant, and their characterization using the C1q assay, may provide prognostic information for acute rejection after heart transplantation.
Objective: To summarize the clinical features, treatment outcome and prognostic factors of childhood anaplastic large cell lymphoma (ALCL). Methods: Clinical data of 60 newly diagnosed and biopsy-proven ALCL pediatric patients (≤18 years of age) at Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine from January 2010 to December 2018 were collected. All patients were treated with the Chinese Children Cancer Group-B cell-non-Hodgkin Lymphoma 2010 (CCCG-BNHL-2010) regimen. Overall survival (OS), event free survival (EFS) and progression free survival (PFS) rates were calculated by the Kaplan-Meier method. Univariate analysis was performed with Log-Rank test to find factors of poor prognosis. Results: Among 60 ALCL patients included in the current study, 39 were males and 21 females, the age of onset was 7.9 (1.2-16.7) years. Among all cases, 43 (72%) had B syndrome (any of the following: fever, drenching, weight loss). Forty-nine (82%) cases had lactate dehydrogenase (LDH) levels<2 times upper limit of normal (ULN) and 11 (18%) cases had LDH levels 2-<4 times ULN. The distribution of stages was stage Ⅰ,Ⅱ,Ⅲ, and Ⅳ in 2% (1/60), 5% (3/60), 92% (55/60), and 2% (1/60) of patients, respectively. Of 58 cases who had results of anaplastic lymphoma kinase (ALK) immunohistochemical staining, 53 (91%, 53/58) cases were positive. Visceral involvement was observed in 12 patients (20%). The 4-year OS and EFS rates were (88±4)% and (76±6)% for the entire group, respectively. Univariate analysis for gender, B symptoms, LDH level, ALK expression, clinical stage and visceral involvement showed that only LDH level correlated with an inferior OS rate (χ²=6.571, P=0.010) while not correlated with EFS rate. No independent risk factor for disease progression or recurrence was found by Logistic regression. Up to the last follow-up, 44 cases were continuously at complete remission state, and their follow-up time was 50 (13-119) months. Of 13 (23%) cases experienced disease progression or relapse, 3 cases abandoned treatment, 2 cases progressed to death, 8 cases received second line or salvage treatment (6 survived at last follow-up). For post progression or relapse cases, the 2-year OS and PFS rates were (60±16)% and (16±14)%, respectively. The treatment related death occurred in 3 cases (5%) and all of them were due to severe infection during the chemotherapy. Conclusions: The efficacy of CCCG-BNHL-2010 regimen in the treatment of children with ALCL was good. However, the safety needs to be improved as the treatment-related mortality in the present study was slightly higher. Efficient second line or salvage treatment can achieve cure in pediatric patients post progression or recurrence. LDH ≥2 times ULN was associated with worse prognosis.