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.
Side Population (SP) cells, a subset of Hoechst-low cells, are enriched with stem cells. Originally, SP cells were isolated from bone marrow but recently have been found in various solid tumors and ...cancer cell lines that are clonogenic in vitro and tumorigenic in vivo. In this study, SP cells from lymph node metastatic head and neck squamous cell carcinoma (HNSCC) cell lines were examined using flow cytometry and Hoechst 3342 efflux assay. We found that highly metastatic HNSCC cell lines M3a2 and M4e contained more SP cells compared to the low metastatic parental HNSCC cell line 686LN. SP cells in HNSCC were highly invasive in vitro and tumorigenic in vivo compared to non-SP cells. Furthermore, SP cells highly expressed ABCG2 and were chemoresistant to Bortezomib and etoposide. Importantly, we found that SP cells in HNSCC had abnormal activation of Wnt/beta-catenin signaling as compared to non-SP cells. Together, these findings indicate that SP cells might be a major driving force of head and neck tumor formation and metastasis. The Wnt/beta-catenin signaling pathway may be an important target for eliminating cancer stem cells in HNSCC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Human colorectal cancer stem cells (CSCs) are tumour initiating cells that can self-renew and are highly tumorigenic and chemoresistant. While genetic mutations associated with human colorectal ...cancer development are well-known, little is known about how and whether epigenetic factors specifically contribute to the functional properties of human colorectal CSCs. Here we report that the KDM3 family of histone demethylases plays an important role in tumorigenic potential and survival of human colorectal CSCs by epigenetically activating Wnt target gene transcription. The depletion of KDM3 inhibits tumorigenic growth and chemoresistance of human colorectal CSCs. Mechanistically, KDM3 not only directly erases repressive H3K9me2 marks, but also helps to recruit histone methyltransferase MLL1 to promote H3K4 methylation, thereby promoting Wnt target gene transcription. Our results suggest that KDM3 is a critical epigenetic factor in Wnt signalling that orchestrates chromatin changes and transcription in human colorectal CSCs, identifying potential therapeutic targets for effective elimination of CSCs.
The Yes-associated protein (YAP) transcription coactivator is a key regulator of organ size and a candidate human oncogene. YAP is inhibited by the Hippo pathway kinase cascade, at least in part via ...phosphorylation of Ser 127, which results in YAP 14-3-3 binding and cytoplasmic retention. Here we report that YAP is phosphorylated by Lats on all of the five consensus HXRXXS motifs. Phosphorylation of Ser 381 in one of them primes YAP for subsequent phosphorylation by CK1delta/epsilon in a phosphodegron. The phosphorylated phosphodegron then recruits the SCF(beta-TRCP) E3 ubiquitin ligase, which catalyzes YAP ubiquitination, ultimately leading to YAP degradation. The phosphodegron-mediated degradation and the Ser 127 phosphorylation-dependent translocation coordinately suppress YAP oncogenic activity. Our study identified CK1delta/epsilon as new regulators of YAP and uncovered an intricate mechanism of YAP regulation by the Hippo pathway via both S127 phosphorylation-mediated spatial regulation (nuclear-cytoplasmic shuttling) and the phosphodegron-mediated temporal regulation (degradation).
Periodontal (gum) disease is one of the main global oral health burdens and severe periodontal disease (periodontitis) is a leading cause of tooth loss in adults globally. It also increases the risk ...of cardiovascular disease and diabetes mellitus. Porphyromonas gingivalis lipopolysaccharide (LPS) is a key virulent attribute that significantly contributes to periodontal pathogenesis. Baicalin is a flavonoid from Scutellaria radix, an herb commonly used in traditional Chinese medicine for treating inflammatory diseases. The present study examined the modulatory effect of baicalin on P. gingivalis LPS-induced expression of IL-6 and IL-8 in human oral keratinocytes (HOKs). Cells were pre-treated with baicalin (0-80 µM) for 24 h, and subsequently treated with P. gingivalis LPS at 10 µg/ml with or without baicalin for 3 h. IL-6 and IL-8 transcripts and proteins were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The expression of nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) proteins was analyzed by western blot. A panel of genes related to toll-like receptor (TLR) signaling was examined by PCR array. We found that baicalin significantly downregulated P. gingivalis LPS-stimulated expression of IL-6 and IL-8, and inhibited P. gingivalis LPS-activated NF-κB, p38 MAPK and JNK. Furthermore, baicalin markedly downregulated P. gingivalis LPS-induced expression of genes associated with TLR signaling. In conclusion, the present study shows that baicalin may significantly downregulate P. gingivalis LPS-upregulated expression of IL-6 and IL-8 in HOKs via negative regulation of TLR signaling.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract The aim of this study was to examine the expression of programmed death‐ligand 1 (PD‐L1) and of T cell immunoglobulin and mucin domain‐containing protein (TIM3) in oral epithelial dysplasia ...and head and neck squamous cell carcinoma (HNSCC). Mouse HNSCC was induced with 4‐nitroquinoline‐1 oxide (4NQO). Oral epithelial dysplastic lesions, carcinoma in situ and HNSCC lesions were stained with anti‐PD‐L1 and TIM3 antibodies. The expression of PD‐L1 and TIM3 in tumor cells and immune cells was semiquantitatively measured and compared. In parallel, human dysplasia and HNSCC were stained with anti‐PD‐L1 and anti‐TIM3. The expression pattern of PD‐L1 + and TIM3 + cells was further compared. In human and mouse samples both PD‐L1 and TIM3 were found to be expressed in neoplastic and immune cells in HNSCC, but not in dysplasia. There was no significant difference in PD‐L1 and TIM3 expression between metastatic and nonmetastatic HNSCC. We conclude that the 4NQO‐induced mouse HNSCC model may be an excellent preclinical model for immune checkpoint therapy.
A direct transformation of secondary amides into α‐branched ketones with enamines as soft alkylation reagents was developed. In this reaction, enamines serve as surrogates of alkyl carbanions, rather ...than the conventional enolates equivalents in the Stork's reactions, which allowed for the easy introduction of alkyl groups with electrophilic functional groups. In the presence of 4 Å molecular sieves, the method can be extended to the one‐pot coupling of secondary amides with aldehydes to yield ketones.
Aberrant lineage specification of skeletal stem cells (SSCs) contributes to reduced bone mass and increased marrow adipose tissue (MAT) in osteoporosis and skeletal aging. Although master regulators ...of osteoblastic and adipogenic lineages have been identified, little is known about factors that are associated with MAT accumulation and osteoporotic bone loss. Here, we identify peroxisome-proliferator-activated receptor γ coactivator 1-α (PGC-1α) as a critical switch of cell fate decisions whose expression decreases with aging in human and mouse SSCs. Loss of PGC-1α promoted adipogenic differentiation of murine SSCs at the expense of osteoblastic differentiation. Deletion of PGC-1α in SSCs impaired bone formation and indirectly promoted bone resorption while enhancing MAT accumulation. Conversely, induction of PGC-1α attenuated osteoporotic bone loss and MAT accumulation. Mechanistically, PGC-1α maintains bone and fat balance by inducing TAZ. Our results suggest that PGC-1α is a potentially important therapeutic target in the treatment of osteoporosis and skeletal aging.
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•Loss of PGC-1α in SSCs is associated with osteoporosis and skeletal aging•Loss of PGC-1α promotes adipogenesis of SSCs at the expense of osteogenesis•PGC-1α induction prevents MAT accumulation and bone loss in osteoporosis•PGC-1α controls bone-fat balance by inducing TAZ
Yu et al. show that the metabolic regulator PGC-1α regulates bone-fat balance in osteoporosis. Loss of PGC-1α in SSCs impaired bone formation and promoted MAT accumulation. Mechanistically, PGC-1α directly controlled SSC fate decision by inducing TAZ expression. Induction of PGC-1α could attenuate bone loss and MAT accumulation in osteoporosis.
The YAP transcription coactivator has been implicated as an oncogene and is amplified in human cancers. Recent studies have established that YAP is phosphorylated and inhibited by the Hippo tumor ...suppressor pathway. Here we demonstrate that the TEAD family transcription factors are essential in mediating YAP-dependent gene expression. TEAD is also required for YAP-induced cell growth, oncogenic transformation, and epithelial-mesenchymal transition. CTGF is identified as a direct YAP target gene important for cell growth. Moreover, the functional relationship between YAP and TEAD is conserved in Drosophila Yki (the YAP homolog) and Scalloped (the TEAD homolog). Our study reveals TEAD as a new component in the Hippo pathway playing essential roles in mediating biological functions of YAP.
Yes-associated protein (YAP) and its homolog transcriptional coactivator with PDZ-binding motif (TAZ) are key effectors of the Hippo pathway to control cell growth and organ size, of which ...dysregulation yields to tumorigenesis or hypertrophy. Upon activation, YAP/TAZ translocate into the nucleus and bind to TEAD transcription factors to promote transcriptional programs for proliferation or cell specification. Immediate early genes, represented by AP-1 complex, are rapidly induced and control later-phase transcriptional program to play key roles in tumorigenesis and organ maintenance. Here, we report that YAP/TAZ directly promote
transcription that in turn contributes to the biological function of YAP/TAZ. YAP/TAZ bind to the promoter region of
to stimulate its transcription. Deletion of YAP/TAZ blocks the induction of immediate early genes in response to mitogenic stimuli.
induction contributes to expression of YAP/TAZ downstream target genes. Genetic deletion or chemical inhibition of AP-1 suppresses growth of YAP-driven cancer cells, such as
-deficient cancer cells as well as Gα
mutated uveal melanoma. Furthermore, AP-1 inhibition almost completely abrogates the hepatomegaly induced by YAP overexpression. Our findings reveal a feed-forward interplay between immediate early transcription of AP-1 and Hippo pathway function.
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