The impact of molecular profile on the lymphatic spread pattern in stage III colon cancer

The anatomical spread of lymph node (LN) metastasis is of practical importance in the surgical management of colon cancer (CC). We examined the effect of KRAS, BRAF, and microsatellite instability (MSI) on LN count and anatomical spread pattern in stage III CC. We determined KRAS, BRAF, and MSI status from stage III CC patients. Biomarker status was correlated with LN count and anatomical spread pattern, which was classified as sequential or skipped. Relapse-free survival (RFS) was estimated using Kaplan-Meier method, and correlations were assessed using log-rank and Cox regression analyses. We analyzed 369 stage III CC patients. The proportion of KRAS mutant (mt), BRAF mt, and MSI-high (H) were 44.2% (163/344), 6.8% (25/344), and 6.8% (25/344), respectively. The mean number of metastatic LN was higher in microsatellite-stable (MSS) compared with MSI patients (3.5 vs. 2.7, P = .0406), although no differences were observed in accordance with KRAS or BRAF status. Interestingly, patients with BRAF mt and MSI-H were less likely to harbor skipped metastatic LN (9.3% vs 20% and 4% vs 10.5% compared with BRAF wild-type (wt) and MSS, respectively), but KRAS status did not predict anatomical spread pattern. Patients with KRAS wt and MSI-H showed superior RFS compared with KRAS mt and MSS patients, respectively, whereas BRAF status did not affect RFS. Differences exist in the anatomical pattern of invaded LN in accordance with the molecular status of stage III CC. Patients with MSI-H CC have less invaded and skipped LN, suggesting that a tailored surgical approach is possible

Mesenchymal Stem Cell-Mediated Functional Tooth Regeneration in Swine

Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla). Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs) to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance

cAMP/PKA Regulates Osteogenesis, Adipogenesis and Ratio of RANKL/OPG mRNA Expression in Mesenchymal Stem Cells by Suppressing Leptin

BACKGROUND: Mesenchymal stem cells (MSCs) are a pluripotent cell type that can differentiate into adipocytes, osteoblasts and other cells. The reciprocal relationship between adipogenesis and osteogenesis was previously demonstrated; however, the mechanisms remain largely unknown. METHODS AND FINDINGS: We report that activation of PKA by 3-isobutyl-1 methyl xanthine (IBMX) and forskolin enhances adipogenesis, the gene expression of PPARgamma2 and LPL, and downregulates the gene expression of Runx2 and osteopontin, markers of osteogenesis. PKA activation also decreases the ratio of Receptor Activator of the NF-kappaB Ligand to Osteoprotegerin (RANKL/OPG) gene expression - the key factors of osteoclastogenesis. All these effects are mediated by the cAMP/PKA/CREB pathway by suppressing leptin, and may contribute to PKA stimulators-induced in vivo bone loss in developing zebrafish. CONCLUSIONS: Using MSCs, the center of a newly proposed bone metabolic unit, we identified cAMP/PKA signaling, one of the many signaling pathways that regulate bone homeostasis via controlling cyto-differentiation of MSCs and altering RANKL/OPG gene expression

Candida albicans Isolates from the Gut of Critically Ill Patients Respond to Phosphate Limitation by Expressing Filaments and a Lethal Phenotype

Candida albicans is an opportunistic pathogen that proliferates in the intestinal tract of critically ill patients where it continues to be a major cause of infectious-related mortality. The precise cues that shift intestinal C. albicans from its ubiquitous indolent colonizing yeast form to an invasive and lethal filamentous form remain unknown. We have previously shown that severe phosphate depletion develops in the intestinal tract during extreme physiologic stress and plays a major role in shifting intestinal Pseudomonas aeruginosa to express a lethal phenotype via conserved phosphosensory-phosphoregulatory systems. Here we studied whether phosphate dependent virulence expression could be similarly demonstrated for C. albicans. C. albicans isolates from the stool of critically ill patients and laboratory prototype strains (SC5314, BWP17, SN152) were evaluated for morphotype transformation and lethality against C. elegans and mice during exposure to phosphate limitation. Isolates ICU1 and ICU12 were able to filament and kill C. elegans in a phosphate dependent manner. In a mouse model of intestinal phosphate depletion (30% hepatectomy), direct intestinal inoculation of C. albicans caused mortality that was prevented by oral phosphate supplementation. Prototype strains displayed limited responses to phosphate limitation; however, the pho4Δ mutant displayed extensive filamentation during low phosphate conditions compared to its isogenic parent strain SN152, suggesting that mutation in the transcriptional factor Pho4p may sensitize C. albicans to phosphate limitation. Extensive filamentation was also observed in strain ICU12 suggesting that this strain is also sensitized to phosphate limitation. Analysis of the sequence of PHO4 in strain ICU12, its transcriptional response to phosphate limitation, and phosphatase assays confirmed that ICU12 demonstrates a profound response to phosphate limitation. The emergence of strains of C. albicans with marked responsiveness to phosphate limitation may represent a fitness adaptation to the complex and nutrient scarce environment typical of the gut of a critically ill patient

BRCA1 Regulates Follistatin Function in Ovarian Cancer and Human Ovarian Surface Epithelial Cells

Follistatin (FST), a folliculogenesis regulating protein, is found in relatively high concentrations in female ovarian tissues. FST acts as an antagonist to Activin, which is often elevated in human ovarian carcinoma, and thus may serve as a potential target for therapeutic intervention against ovarian cancer. The breast cancer susceptibility gene 1 (BRCA1) is a known tumor suppressor gene in human breast cancer; however its role in ovarian cancer is not well understood. We performed microarray analysis on human ovarian carcinoma cell line SKOV3 that stably overexpress wild-type BRCA1 and compared with the corresponding empty vector-transfected clones. We found that stable expression of BRCA1 not only stimulates FST secretion but also simultaneously inhibits Activin expression. To determine the physiological importance of this phenomenon, we further investigated the effect of cellular BRCA1 on the FST secretion in immortalized ovarian surface epithelial (IOSE) cells derived from either normal human ovaries or ovaries of an ovarian cancer patient carrying a mutation in BRCA1 gene. Knock-down of BRCA1 in normal IOSE cells demonstrates down-regulation of FST secretion along with the simultaneous up-regulation of Activin expression. Furthermore, knock-down of FST in IOSE cell lines as well as SKOV3 cell line showed significantly reduced cell proliferation and decreased cell migration when compared with the respective controls. Thus, these findings suggest a novel function for BRCA1 as a regulator of FST expression and function in human ovarian cells

Epithelial Cells Derived from Swine Bone Marrow Express Stem Cell Markers and Support Influenza Virus Replication In Vitro

The bone marrow contains heterogeneous population of cells that are involved in the regeneration and repair of diseased organs, including the lungs. In this study, we isolated and characterized progenitor epithelial cells from the bone marrow of 4- to 5-week old germ-free pigs. Microscopically, the cultured cells showed epithelial-like morphology. Phenotypically, these cells expressed the stem cell markers octamer-binding transcription factor (Oct4) and stage-specific embryonic antigen-1 (SSEA-1), the alveolar stem cell marker Clara cell secretory protein (Ccsp), and the epithelial cell markers pan-cytokeratin (Pan-K), cytokeratin-18 (K-18), and occludin. When cultured in epithelial cell growth medium, the progenitor epithelial cells expressed type I and type II pneumocyte markers. Next, we examined the susceptibility of these cells to influenza virus. Progenitor epithelial cells expressed sialic acid receptors utilized by avian and mammalian influenza viruses and were targets for influenza virus replication. Additionally, differentiated type II but not type I pneumocytes supported the replication of influenza virus. Our data indicate that we have identified a unique population of progenitor epithelial cells in the bone marrow that might have airway reconstitution potential and may be a useful model for cell-based therapies for infectious and non-infectious lung diseases

Dental pulp tissue engineering

Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research

Human BDNF/TrkB variants impair hippocampal synaptogenesis and associate with neurobehavioural abnormalities

Abstract: Brain-derived neurotrophic factor (BDNF) signals through its high affinity receptor Tropomyosin receptor kinase-B (TrkB) to regulate neuronal development, synapse formation and plasticity. In rodents, genetic disruption of Bdnf and TrkB leads to weight gain and a spectrum of neurobehavioural phenotypes. Here, we functionally characterised a de novo missense variant in BDNF and seven rare variants in TrkB identified in a large cohort of people with severe, childhood-onset obesity. In cells, the E183K BDNF variant resulted in impaired processing and secretion of the mature peptide. Multiple variants in the kinase domain and one variant in the extracellular domain of TrkB led to a loss of function through multiple signalling pathways, impaired neurite outgrowth and dominantly inhibited glutamatergic synaptogenesis in hippocampal neurons. BDNF/TrkB variant carriers exhibited learning difficulties, impaired memory, hyperactivity, stereotyped and sometimes, maladaptive behaviours. In conclusion, human loss of function BDNF/TrkB variants that impair hippocampal synaptogenesis may contribute to a spectrum of neurobehavioural disorders