As a result of a whole-exome sequencing study, we report three mutant alleles in SEC24D, a gene encoding a component of the COPII complex involved in protein export from the ER: the truncating mutation c.613C>T (p.Gln205(∗)) and the missense mutations c.3044C>T (p.Ser1015Phe, located in a cargo-binding pocket) and c.2933A>C (p.Gln978Pro, located in the gelsolin-like domain). Three individuals from two families affected by a similar skeletal phenotype were each compound heterozygous for two of these mutant alleles, with c.3044C>T being embedded in a 14 Mb founder haplotype shared by all three. The affected individuals were a 7-year-old boy with a phenotype most closely resembling Cole-Carpenter syndrome and two fetuses initially suspected to have a severe type of osteogenesis imperfecta. All three displayed a severely disturbed ossification of the skull and multiple fractures with prenatal onset. The 7-year-old boy had short stature and craniofacial malformations including macrocephaly, midface hypoplasia, micrognathia, frontal bossing, and down-slanting palpebral fissures. Electron and immunofluorescence microscopy of skin fibroblasts of this individual revealed that ER export of procollagen was inefficient and that ER tubules were dilated, faithfully reproducing the cellular phenotype of individuals with cranio-lentico-sutural dysplasia (CLSD). CLSD is caused by SEC23A mutations and displays a largely overlapping craniofacial phenotype, but it is not characterized by generalized bone fragility and presented with cataracts in the original family described. The cellular and morphological phenotypes we report are in concordance with the phenotypes described for the Sec24d-deficient fish mutants vbi (medaka) and bulldog (zebrafish).

Mitochondria-associated endoplasmic reticulum membrane (MAM) is a structural link between mitochondria and endoplasmic reticulum (ER). MAM regulates Ca 2+ transport from the ER to mitochondria via an IP3R1-GRP75-VDAC1 complex–dependent mechanism. Excessive MAM formation may cause mitochondrial Ca 2+ overload and mitochondrial dysfunction. However, the exact implication of MAM formation in metabolic syndromes remains debatable. Here, we demonstrate that PDK4 interacts with and stabilizes the IP3R1-GRP75-VDAC1 complex at the MAM interface. Obesity-induced increase in PDK4 activity augments MAM formation and suppresses insulin signaling. Conversely, PDK4 inhibition dampens MAM formation and improves insulin signaling by preventing MAM-induced mitochondrial Ca 2+ accumulation, mitochondrial dysfunction, and ER stress. Furthermore, Pdk4 −/− mice exhibit reduced MAM formation and are protected against diet-induced skeletal muscle insulin resistance. Finally, forced formation and stabilization of MAMs with synthetic ER–mitochondria linker prevented the beneficial effects of PDK4 deficiency on insulin signaling. Overall, our findings demonstrate a critical mediatory role of PDK4 in the development of skeletal muscle insulin resistance via enhancement of MAM formation.

Background: Cordyceps militaris (L.) Fr. (C. militaris) exhibits pharmacological activities, including antitumor properties, through the regulation of the nuclear factor kappa B (NF-κB) signaling. Tumor Necrosis Factor (TNF) and TNF-α modulates cell survival and apoptosis through NF-κB signaling. However, the mechanism underlying its mode of action on the NF-κB pathway is unclear. Methods: Here, we analyzed the effect of C. militaris extract (CME) on the proliferation of ovarian cancer cells by confirming viability, morphological changes, migration assay. Additionally, CME induced apoptosis was determined by apoptosis assay and apoptotic body formation under TEM. The mechanisms of CME were determined through microarray, immunoblotting and immunocytochemistry. Results: CME reduced the viability of cells in a dose-dependent manner and induced morphological changes. We confirmed the decrease in the migration activity of SKOV-3 cells after treatment with CME and the consequent induction of apoptosis. Immunoblotting results showed that the CME-mediated upregulation of tumor necrosis factor receptor 1 (TNFR1) expression induced apoptosis of SKOV-3 cells via the serial activation of caspases. Moreover, CME negatively modulated NF-κB activation via TNFR expression, suggestive of the activation of the extrinsic apoptotic pathway. The binding of TNF-α to TNFR results in the disassociation of IκB from NF-κB and the subsequent translocation of the active NF-κB to the nucleus. CME clearly suppressed NF-κB translocation induced by interleukin (IL-1β) from the cytosol into the nucleus. The decrease in the expression levels of B cell lymphoma (Bcl)-xL and Bcl-2 led to a marked increase in cell apoptosis. Conclusion: These results suggest that C. militaris inhibited ovarian cancer cell proliferation, survival, and migration, possibly through the coordination between TNF-α/TNFR1 signaling and NF-κB activation. Taken together, our findings provide a new insight into a novel treatment strategy for ovarian cancer using C. militaris.

Size- and dose-dependent bioaccumulation of polystyrene nanoplastics influence on the toxicity of gold ion in zebrafish embryos.

BackgroundA fundamental problem in cancer research is identifying the cell type that is capable of sustaining neoplastic growth and its origin from normal tissue cells. Recent investigations of a variety of tumor types have shown that phenotypically identifiable and isolable subfractions of cells possess the tumor-forming ability. In the present paper, using two lineage-related human melanoma cell lines, primary melanoma line IGR39 and its metastatic derivative line IGR37, two main observations are reported. The first one is the first phenotypic evidence to support the origin of melanoma cancer stem cells (CSCs) from mutated tissue-specific stem cells; and the second one is the identification of a more aggressive subpopulation of CSCs in melanoma that are CXCR6+.Methods/FindingsWe defined CXCR6 as a new biomarker for tissue-specific stem cell asymmetric self-renewal. Thus, the relationship between melanoma formation and ABCG2 and CXCR6 expression was investigated. Consistent with their non-metastatic character, unsorted IGR39 cells formed significantly smaller tumors than unsorted IGR37 cells. In addition, ABCG2+ cells produced tumors that had a 2-fold greater mass than tumors produced by unsorted cells or ABCG2- cells. CXCR6+ cells produced more aggressive tumors. CXCR6 identifies a more discrete subpopulation of cultured human melanoma cells with a more aggressive MCSC phenotype than cells selected on the basis of the ABCG2+ phenotype alone.Conclusions/SignificanceThe association of a more aggressive tumor phenotype with asymmetric self-renewal phenotype reveals a previously unrecognized aspect of tumor cell physiology. Namely, the retention of some tissue-specific stem cell attributes, like the ability to asymmetrically self-renew, impacts the natural history of human tumor development. Knowledge of this new aspect of tumor development and progression may provide new targets for cancer prevention and treatment.

We investigated the properties of clonally-expanded mouse hair follicle stem cells (HF-SCs) in culture. The expansion method, suppression of asymmetric cell kinetics (SACK), is non-toxic and reversible, allowing evaluation of the cells' asymmetric production of differentiating progeny cells. A tight association was discovered between non-random sister chromatid segregation, a unique property of distributed stem cells (DSCs), like HF-SCs, and a recently described biomarker, Lgr5. We found that nuclear Lgr5 expression was limited to the HF-SC sister of asymmetric self-renewal divisions that retained non-randomly co-segregated chromosomes, which contain the oldest cellular DNA strands, called immortal DNA strands. This pattern-specific Lgr5 association poses a potential highly specific new biomarker for delineation of DSCs. The expanded HF-SCs also maintained the ability to make differentiated hair follicle cells spontaneously, as well as under conditions that induced cell differentiation. In future human cell studies, this capability would improve skin grafts and hair replacement therapies.

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Bone marrow-derived mononuclear cells (BMNCs) have been shown to effectively treat ischemic cardiovascular diseases. Because diabetic neuropathy (DN) is causally associated with impaired angiogenesis and deficiency of angiogenic and neurotrophic factors in the nerves, we investigated whether DN can be ameliorated by local injection of BMNCs. Severe peripheral neuropathy, characterized by a significant decrease in the motor and sensory nerve conduction velocities (NCVs), developed 12 weeks after the induction of diabetes with streptozotocin in rats. The injection of BMNCs restored motor and sensory NCVs to normal levels and significantly improved vascular density and blood flow in diabetic nerves over 4 weeks. Fluorescent microscopic observation revealed that DiI-labeled BMNCs preferentially engrafted in sciatic nerves. Whole-mount fluorescent imaging and confocal microscopic evaluation demonstrated that many of the BMNCs localized following the course of the vasa nervorum in close proximity to blood vessels without incorporation into vasa nervorum as endothelial cells at a detectable level. Real-time reverse transcription-polymerase chain reaction analysis showed that the levels of angiogenic and neurotrophic factors were significantly increased in the nerves by BMNC injection. Local transplantation of BMNCs improved experimental DN by augmenting angiogenesis and increasing angiogenic and neurotrophic factors in peripheral nerves. These findings suggest that BMNC transplantation may represent a novel therapeutic option for treating DN.