The predominantly deep-sea hexactinellid sponges are known for their ability to construct remarkably complex skeletons from amorphous hydrated silica. The skeletal system of one such species of sponge, Euplectella aspergillum, consists of a square-grid-like architecture overlaid with a double set of diagonal bracings, creating a chequerboard-like pattern of open and closed cells. Here, using a combination of finite element simulations and mechanical tests on 3D-printed specimens of different lattice geometries, we show that the sponge's diagonal reinforcement strategy achieves the highest buckling resistance for a given amount of material. Furthermore, using an evolutionary optimization algorithm, we show that our sponge-inspired lattice geometry approaches the optimum material distribution for the design space considered. Our results demonstrate that lessons learned from the study of sponge skeletal systems can be exploited for the realization of square lattice geometries that are geometrically optimized to avoid global structural buckling, with implications for improved material use in modern infrastructural applications.Commercial carbazole has been widely used to synthesize organic functional materials that have led to recent breakthroughs in ultralong organic phosphorescence1, thermally activated delayed fluorescence2,3, organic luminescent radicals4 and organic semiconductor lasers5. However, the impact of low-concentration isomeric impurities present within commercial batches on the properties of the synthesized molecules requires further analysis. Here, we have synthesized highly pure carbazole and observed that its fluorescence is blueshifted by 54 nm with respect to commercial samples and its room-temperature ultralong phosphorescence almost disappears6. We discover that such differences are due to the presence of a carbazole isomeric impurity in commercial carbazole sources, with concentrations less then 0.5 mol%. Ten representative carbazole derivatives synthesized from the highly pure carbazole failed to show the ultralong phosphorescence reported in the literature1,7-15. However, the phosphorescence was recovered by adding 0.1 mol% isomers, which act as charge traps. Investigating the role of the isomers may therefore provide alternative insights into the mechanisms behind ultralong organic phosphorescence1,6-18.The maintenance of human skeletal stem cells (hSSCs) and their progeny in bone defects is a major challenge. Here, we report on a transplantable bandage containing a three-dimensional Wnt-induced osteogenic tissue model (WIOTM). This bandage facilitates the long-term viability of hSSCs (8 weeks) and their progeny, and enables bone repair in an in vivo mouse model of critical-sized calvarial defects. The newly forming bone is structurally comparable to mature cortical bone and consists of human and murine cells. Furthermore, we show that the mechanism of WIOTM formation is governed by Wnt-mediated asymmetric cell division of hSSCs. Covalently immobilizing Wnts onto synthetic materials can polarize single dividing hSSCs, orient the spindle and simultaneously generate a Wnt-proximal hSSC and a differentiation-prone Wnt-distal cell. Our results provide insight into the regulation of human osteogenesis and represent a promising approach to deliver human osteogenic constructs that can survive in vivo and contribute to bone repair.Copy number variants (CNVs), defined as genome sequences of ≥50 bp that differ in copy number from that in a reference genome, are a common form of structural variation. Germline CNVs account for some of the missing heritability that single nucleotide polymorphisms could not account for. Recent technological advances have had a huge impact on CNV research. Microarray technology enables relatively low-cost, high-throughput, genome-wide measurements, and short-read sequencing technology enables the detection of short CNVs that cannot be detected by microarrays. As a result, large-scale genetic studies have been able to identify a variety of common and rare germline CNVs and their associations with diseases. Rare germline CNVs have been reported to be associated with neuropsychiatric disorders. In this review, we focused on germline CNVs and briefly described their functional characteristics, formation mechanisms, detection methods, related databases, and the latest findings. Finally, we introduced recent large-scale genetic studies to assess associations of CNVs with diseases, especially psychiatric disorders, and discussed the use of CNV-based animal models to investigate the molecular and cellular mechanisms underlying these disorders. The development and implementation of improved detection methods, such as long-read single-molecule sequencing, are expected to provide additional insight into the molecular basis of psychiatric disorders and other complex diseases, thus facilitating basic and clinical research on CNVs.Intestinal stem cells at the bottom of crypts fuel the rapid renewal of the different cell types that constitute a multitasking tissue. The intestinal epithelium facilitates selective uptake of nutrients while acting as a barrier for hostile luminal contents. Recent discoveries have revealed that the lineage plasticity of committed cells - combined with redundant sources of niche signals - enables the epithelium to efficiently repair tissue damage. New approaches such as single-cell transcriptomics and the use of organoid models have led to the identification of the signals that guide fate specification of stem cell progeny into the six intestinal cell lineages. https://www.selleckchem.com/products/hs148.html These cell types display context-dependent functionality and can adapt to different requirements over their lifetime, as dictated by their microenvironment. These new insights into stem cell regulation and fate specification could aid the development of therapies that exploit the regenerative capacity and functionality of the gut.Hedgehog plays an important role in a wide range of physiological and pathological conditions. Paracrine activation of Hedgehog pathway in stromal cells increases the expression of VEGF, which promotes neovascularization in colorectal cancer and ultimately the growth of colorectal cancer. Berberine (BBR) has anticancer activity. In this study we investigated whether BBR inhibited the growth of colon cancer through suppressing the paracrine sonic hedgehog (SHH) signaling in vitro and in vivo. We showed that BBR (1-10 μM) dose-dependently inhibited the secretion and expression of SHH protein in HT-29 and SW480 cells. BBR did not influence the transcription of SHH, but promoted the degradation of SHH mRNA, thus decreased the SHH mRNA expression in the colorectal cancer cells. In nude **** bearing HT-29 xenograft, oral administration of BBR (100 mg · kg-1 · d-1) or a positive control drug GDC-0449 (100 mg · kg-1 · d-1) for 4 weeks markedly suppressed the growth of HT-29 tumor with BBR exhibiting a better antitumor efficacy.
The predominantly deep-sea hexactinellid sponges are known for their ability to construct remarkably complex skeletons from amorphous hydrated silica. The skeletal system of one such species of sponge, Euplectella aspergillum, consists of a square-grid-like architecture overlaid with a double set of diagonal bracings, creating a chequerboard-like pattern of open and closed cells. Here, using a combination of finite element simulations and mechanical tests on 3D-printed specimens of different lattice geometries, we show that the sponge's diagonal reinforcement strategy achieves the highest buckling resistance for a given amount of material. Furthermore, using an evolutionary optimization algorithm, we show that our sponge-inspired lattice geometry approaches the optimum material distribution for the design space considered. Our results demonstrate that lessons learned from the study of sponge skeletal systems can be exploited for the realization of square lattice geometries that are geometrically optimized to avoid global structural buckling, with implications for improved material use in modern infrastructural applications.Commercial carbazole has been widely used to synthesize organic functional materials that have led to recent breakthroughs in ultralong organic phosphorescence1, thermally activated delayed fluorescence2,3, organic luminescent radicals4 and organic semiconductor lasers5. However, the impact of low-concentration isomeric impurities present within commercial batches on the properties of the synthesized molecules requires further analysis. Here, we have synthesized highly pure carbazole and observed that its fluorescence is blueshifted by 54 nm with respect to commercial samples and its room-temperature ultralong phosphorescence almost disappears6. We discover that such differences are due to the presence of a carbazole isomeric impurity in commercial carbazole sources, with concentrations less then 0.5 mol%. Ten representative carbazole derivatives synthesized from the highly pure carbazole failed to show the ultralong phosphorescence reported in the literature1,7-15. However, the phosphorescence was recovered by adding 0.1 mol% isomers, which act as charge traps. Investigating the role of the isomers may therefore provide alternative insights into the mechanisms behind ultralong organic phosphorescence1,6-18.The maintenance of human skeletal stem cells (hSSCs) and their progeny in bone defects is a major challenge. Here, we report on a transplantable bandage containing a three-dimensional Wnt-induced osteogenic tissue model (WIOTM). This bandage facilitates the long-term viability of hSSCs (8 weeks) and their progeny, and enables bone repair in an in vivo mouse model of critical-sized calvarial defects. The newly forming bone is structurally comparable to mature cortical bone and consists of human and murine cells. Furthermore, we show that the mechanism of WIOTM formation is governed by Wnt-mediated asymmetric cell division of hSSCs. Covalently immobilizing Wnts onto synthetic materials can polarize single dividing hSSCs, orient the spindle and simultaneously generate a Wnt-proximal hSSC and a differentiation-prone Wnt-distal cell. Our results provide insight into the regulation of human osteogenesis and represent a promising approach to deliver human osteogenic constructs that can survive in vivo and contribute to bone repair.Copy number variants (CNVs), defined as genome sequences of ≥50 bp that differ in copy number from that in a reference genome, are a common form of structural variation. Germline CNVs account for some of the missing heritability that single nucleotide polymorphisms could not account for. Recent technological advances have had a huge impact on CNV research. Microarray technology enables relatively low-cost, high-throughput, genome-wide measurements, and short-read sequencing technology enables the detection of short CNVs that cannot be detected by microarrays. As a result, large-scale genetic studies have been able to identify a variety of common and rare germline CNVs and their associations with diseases. Rare germline CNVs have been reported to be associated with neuropsychiatric disorders. In this review, we focused on germline CNVs and briefly described their functional characteristics, formation mechanisms, detection methods, related databases, and the latest findings. Finally, we introduced recent large-scale genetic studies to assess associations of CNVs with diseases, especially psychiatric disorders, and discussed the use of CNV-based animal models to investigate the molecular and cellular mechanisms underlying these disorders. The development and implementation of improved detection methods, such as long-read single-molecule sequencing, are expected to provide additional insight into the molecular basis of psychiatric disorders and other complex diseases, thus facilitating basic and clinical research on CNVs.Intestinal stem cells at the bottom of crypts fuel the rapid renewal of the different cell types that constitute a multitasking tissue. The intestinal epithelium facilitates selective uptake of nutrients while acting as a barrier for hostile luminal contents. Recent discoveries have revealed that the lineage plasticity of committed cells - combined with redundant sources of niche signals - enables the epithelium to efficiently repair tissue damage. New approaches such as single-cell transcriptomics and the use of organoid models have led to the identification of the signals that guide fate specification of stem cell progeny into the six intestinal cell lineages. https://www.selleckchem.com/products/hs148.html These cell types display context-dependent functionality and can adapt to different requirements over their lifetime, as dictated by their microenvironment. These new insights into stem cell regulation and fate specification could aid the development of therapies that exploit the regenerative capacity and functionality of the gut.Hedgehog plays an important role in a wide range of physiological and pathological conditions. Paracrine activation of Hedgehog pathway in stromal cells increases the expression of VEGF, which promotes neovascularization in colorectal cancer and ultimately the growth of colorectal cancer. Berberine (BBR) has anticancer activity. In this study we investigated whether BBR inhibited the growth of colon cancer through suppressing the paracrine sonic hedgehog (SHH) signaling in vitro and in vivo. We showed that BBR (1-10 μM) dose-dependently inhibited the secretion and expression of SHH protein in HT-29 and SW480 cells. BBR did not influence the transcription of SHH, but promoted the degradation of SHH mRNA, thus decreased the SHH mRNA expression in the colorectal cancer cells. In nude mice bearing HT-29 xenograft, oral administration of BBR (100 mg · kg-1 · d-1) or a positive control drug GDC-0449 (100 mg · kg-1 · d-1) for 4 weeks markedly suppressed the growth of HT-29 tumor with BBR exhibiting a better antitumor efficacy.
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