Carnobacterium maltaromaticum boosts intestinal vitamin D production to suppress colorectal cancer in female mice.

Carnobacterium maltaromaticum was found to be specifically depleted in female patients with colorectal cancer (CRC). Administration of C. maltaromaticum reduces intestinal tumor formation in two murine CRC models in a female-specific manner. Estrogen increases the attachment and colonization of C. maltaromaticum via increasing the colonic expression of SLC3A2 that binds to DD-CPase of this bacterium. Metabolomic and transcriptomic profiling unveils the increased gut abundance of vitamin D-related metabolites and the mucosal activation of vitamin D receptor (VDR) signaling in C. maltaromaticum-gavaged mice in a gut microbiome- and VDR-dependent manner. In vitro fermentation system confirms the metabolic cross-feeding of C. maltaromaticum with Faecalibacterium prausnitzii to convert C. maltaromaticum-produced 7-dehydrocholesterol into vitamin D for activating the host VDR signaling. Overall, C. maltaromaticum colonizes the gut in an estrogen-dependent manner and acts along with other microbes to augment the intestinal vitamin D production to activate the host VDR for suppressing CRC.

Development of an Accurate and Proactive Immunomodulatory Strategy to Improve Bone Substitute Material-Mediated Osteogenesis and Angiogenesis.

Background: Treatment of large bone defects represents a major clinical problem worldwide. Suitable bone substitute materials are commonly required to achieve successful bone regeneration, and much effort has been spent to optimize their chemical compositions, 3D architecture and mechanical properties. However, material-immune system interactions are increasingly being recognized as a crucial factor influencing regeneration. Here, we envisioned an accurate and proactive immunomodulation strategy via delivery of IL-4 (key regulator of macrophage polarization) to promote bone substitute material-mediated regeneration. Methods: Four different IL-4 doses (0 ng, 10 ng, 50 ng and 100 ng) were delivered into rat large cranial bone defects at day 3 post-operation of decellularized bone matrix (DBM) material implantation, and the osteogenesis, angiogenesis and macrophage polarization were meticulously evaluated. Results: Micro-CT analysis showed that immunomodulation with 10 ng IL-4 significantly outperformed the other groups in terms of new bone formation (1.23-5.05 fold) and vascularization (1.29-6.08 fold), achieving successful defect bridging and good vascularization at 12 weeks. Histological analysis at 7 and 14 days showed that the 10 ng group generated the most preferable M1/M2 macrophage polarization profile, resulting in a pro-healing microenvironment with more IL-10 and less TNF-α secretion, a reduced apoptosis level in tissues around the materials, and enhanced mesenchymal stem cell migration and osteogenic differentiation. Moreover, in vitro studies revealed that M1 macrophages facilitated mesenchymal stem cell migration, while M2 macrophages significantly increased cell survival, proliferation and osteogenic differentiation, explaining the in vivo findings. Conclusions: Accurate immunomodulation via IL4 delivery significantly enhanced DBM-mediated osteogenesis and angiogenesis via the coordinated involvement of M1 and M2 macrophages, revealing the promise of this accurate and proactive immunomodulatory strategy for developing new bone substitute materials.

Expression of E-prostanoid receptors in nasal polyp tissues of smoking and nonsmoking patients with chronic rhinosinusitis.

BACKGROUND: Different inflammatory reactions have been observed in the polyp tissues of nonsmokers and smokers with chronic rhinosinusitis (CRS). E-prostanoid (EP) receptors play a role in the inflammatory processes. Cigarette smoke (CS) exposure regulates EP-receptor expression levels promoting inflammatory mediator release from various inflammatory cells. In this study, we characterize the EP-receptor expression profiles in the polyps of nonsmoking and smoking CRS patients to explore the possible role of CS in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). METHODS: Polyp biopsies were obtained from 28 non-smoking and 21 smoking CRSwNP patients. Histopathological characteristics were observed under a light microscope. The prostaglandin E2 (PGE2), TNF-α, and IL-8 contents in polyp tissues were detected using enzyme-linked immunosorbent assay. Immunostaining was used to locate EP receptors in polyps. Messenger RNA and protein expression of EP receptors were examined using quantitative real-time polymerase chain reaction and Western blot, respectively. RESULTS: More severe inflammatory reactions occurred in polyp tissues of smoking CRSwNP patients. The PGE2, TNF-α, and IL-8 in tissue homogenate levels were significantly higher in smoking CRSwNP patients than those in nonsmoking CRSwNP patients. Moreover, the distribution of each EP receptor subtype was similar in both groups. Compared with the EP-receptor expression in nonsmokers, messenger RNA and protein of EP2 and EP4 receptor were significantly down-expressed in smoking patients, but EP1 and EP3 receptors did not show significant differences. CONCLUSION: CS exposure downregulates the expression levels of EP2 and EP4 receptors and stimulates the production of PGE2 and the proinflammatory cytokine IL-8 and TNF-α in polyp tissues of CRS patients. The down-expressed EP2 and EP4 receptors might be associated with severe inflammatory reactions in smoking CRSwNP patients.

Expression profiles of prostaglandin E2 receptor subtypes in aspirin tolerant adult Chinese with chronic rhinosinusitis.

BACKGROUND: Several studies have indicated that prostaglandin E2 and E-prostanoid (EP) receptors play a role in the pathogenesis of chronic rhinosinusitis (CRS) in white populations. However, until now there was no report about EP receptor expression and its role in the pathophysiology of CRS in Chinese patients. OBJECTIVE: To investigate the expression profiles of EP receptors, including EP1, EP2, EP3, and EP4 receptors in different Chinese patients with CRS with aspirin tolerance. METHODS: Nasal biopsy specimens were obtained from 12 controls, 12 patients with CRS without nasal polyps (CRSsNP), 12 with eosinophilic CRS with nasal polyps (CRSwNP), and 16 with noneosinophilic CRSwNP. Histopathologic characteristics were observed under a light microscope. Immunostaining was used to examine tissue localization of EP receptors. Messenger RNA and protein expression of EP receptors were examined by means of quantitative RT-polymerase chain reaction and Western blot, respectively. RESULTS: Different types of CRS presented different histopathologic hallmarks. EP receptors were expressed mainly on epithelium, glands, and infiltrating inflammatory cells in nasal tissue. In controls, patients with CRSsNP, and those with noneosinophilic CRSwNP, EP4 mRNA levels were higher than EP1, EP2, and EP3 receptors. EP2 was downexpressed, and EP1 was upexpressed in patients with eosinophilic CRSwNP. When comparing EP receptor expression among different groups, Messenger RNA and protein of EP1 receptor were significantly enhanced in eosinophilic CRSwNP, but EP2, EP3, and EP4 receptors did not show significant differences. CONCLUSION: EP receptor expressions present different features in healthy subjects and patients with CRS. The upregulated EP1 receptor in eosinophilic CRSwNP might be associated with excessive infiltrations of eosinophils and other inflammatory cells. The accurate role of the four EP receptors in the pathogenesis of different CRS remains to be further explored.

The Treatment Efficacy of Bone Tissue Engineering Strategy for Repairing Segmental Bone Defects Under Osteoporotic Conditions.

The potential of increasing bone mass and preventing fractures in osteoporosis using stem cell therapy is currently an area of intense focus. However, there are very little data available regarding the postfracture bony defect healing efficacy under osteoporotic conditions. This study aims to investigate whether critical-sized segmental bone defects in a rabbit model of osteoporosis could be repaired using an allogenic stem cell-based tissue engineering (TE) approach and to investigate the potential influence of osteoporosis on the treatment efficacy. Rabbit fetal bone marrow mesenchymal stem cells (BMSCs) were harvested and expanded in vitro. Decalcified bone matrix (DBM) scaffolds were then seeded with allogenic fetal BMSCs and cultivated in osteogenic media to engineer BMSC/DBM constructs. Critical-sized radial defects were created in ovariectomized (OVX) rabbits and the defects were repaired either by insertion of BMSC/DBM constructs or by DBM scaffolds alone. Also, nonovariectomized age-matched (non-OVX) rabbits were served as control. At 3 months post-treatment under the osteoporotic condition (OVX rabbits), the BMSC/DBM constructs inserted within the defect generated significantly more bone tissue when compared to the DBM scaffold as demonstrated by the X-ray, microcomputed tomography, and histological analyses. In addition, when compared to a normal nonosteoporotic condition (age-matched non-OVX rabbits), the defect treatment efficacy was adversely affected by the osteoporotic condition with significantly less bone regeneration. This study demonstrated the potential of allogenic fetal BMSC-based TE strategy for repairing bone defects in an osteoporotic condition. However, the treatment efficacy could be considerably compromised in the OVX animals. Therefore, a more sophisticated strategy that addresses the complicated pathogenic conditions associated with osteoporosis is needed.

Functional characterization of human mast cells cultured from adult peripheral blood.

Mast cells are important effector cells of allergy and techniques for culturing human mast cells have been developed in recent years. In the current investigation, we studied the phenotypic and functional characteristics of mast cells cultured from adult human peripheral blood mononuclear cells. Mature human mast cells were obtained by first culturing mononuclear cells in methylcellulose containing stem cell factor (SCF), IL-3 and IL-6 for six weeks and subsequently in liquid medium containing SCF and IL-6 for another six weeks. These cells expressed numerous basophilic cytoplasmic granules that were predominantly tryptase positive but chymase negative. Following sensitization with human IgE, these cells released histamine and synthesized prostaglandin D2 and cysteinyl-leukotrienes dose-dependently upon activation by anti-IgE and calcium ionophores. Compound 48/80 and substance P were ineffective. When the effects of anti-asthmatic agents on anti-IgE induced mediator release from these cells were compared, only the beta2-adrenoceptor agonists and phosphodiesterase inhibitors produced dose-dependent inhibition but not cromolyn. In total, mast cells cultured from human peripheral blood shared similar morphological, immunocytochemical and functional properties of enzymatically dispersed human lung mast cells. These cultured mast cells can be a convenient substitute for the in vitro studies of human lung mast cell reactions and may be useful for investigating the roles of mast cells in allergic diseases.

CpG oligodeoxynucleotides inhibit tumor growth and reverse the immunosuppression caused by the therapy with 5-fluorouracil in murine hepatoma.

AIM: To investigate the effect of CpG-containing oligodeoxynucleotides (CpG ODN) alone or in combination with the chemotherapeutic agent 5-fluorouracil (5-FU) on tumor growth and whether CpG ODN can reverse the immunosuppression caused by the chemotherapy with 5-FU in murine hepatoma model. METHODS: Hepatoma model was established by subcutaneous inoculation with hepatoma-22 (H(22)) cells into the right flank of BALB/c mice. Mice with tumor were treated by peritumoral injection of CpG ODN alone or in combination with subcutaneous injection of 5-FU. Tumor size was quantified regularly. Serum levels of IL-12 and IFN-gamma in mice were assayed by enzyme-linked immunosorbent assay (ELISA). The lytic capacity of splenic NK cells was tested by lactate dehydrogenase release assay. RESULTS: Peritumoral injection of CpG ODN alone or in combination with subcutaneous injection of 5-FU, and the treatment with 5-FU alone all led to significant inhibition of hepatoma growth. The mean tumor volumes fell by 46.66% in mice injected with CpG ODN, 68.34% in the 5-FU treated mice, and 70.23% in mice treated with the combination of CpG ODN and 5-FU than in controls. There was no significant difference in tumor size between 5-FU-treated mice and mice treated with the combination of 5-FU and CpG ODN (P>0.05). The serum levels of IL-12 and IFN-gamma of mice treated with CpG ODN alone (IL-12: 464.50+/-24.37 pg/mL; IFN-gamma: 134.20+/-25.76 pg/mL) or with the co-administration of CpG ODN and 5-FU (IL-12: 335.83+/-28.74 pg/mL; IFN-gamma: 111.00+/-5.33 pg/mL) were significantly higher than that of controls (IL-12: 237.50+/-45.31 pg/mL; IFN-gamma: 56.75+/-8.22 pg/mL). The production of IL-12 and IFN-gamma was suppressed moderately in 5-FU-treated mice (IL-12: 166.67+/-53.22 pg/mL; 53.33+/-16.98 pg/mL) compared to control mice (P>0.05), whereas the combination of CpG ODN and 5-FU significantly increased the serum levels of IL-12 and IFN-gamma compared to 5-FU alone (P<0.05). The NK cell killing activity in CpG ODN-treated mice (44.04+/-1.38%) or the mice treated with CpG ODN combined with 5-FU (30.67+/-1.28%) was significantly potentiated compared to controls (19.22+/-0.95%, P<0.05). The co-administration of CpG ODN and 5-FU also significantly enhanced the lytic activity of NK cells when compared with the treatment with 5-FU alone (12.03+/-1.42%, P<0.05). CONCLUSION: The present data suggests that CpG ODN used as single therapeutic agent triggers anti-tumor immune response to inhibit the growth of implanted hepatoma and reverses the immunosuppression caused by the chemotherapy with 5-FU.