Structural and Release Properties of Combined Curcumin Controlled-Release Tablets Formulated with Chitosan/Sodium Alginate/HPMC.

Controlled-release tablets offer several benefits, such as controlled release, odor masking, ease of use, stability, extended shelf life, and reduced production costs. This study developed combined curcumin controlled-release tablets (CCCTs) to increase the bioavailability of curcumin with hydroxypropyl methylcellulose (HPMC), chitosan, and sodium alginate. The hardness of the CCCTs was 5.63-1.98 kgf, friability was 0.00-1.22%, and disintegration time was 0.00-401.25 min. Differential scanning calorimetry and Fourier-transform infrared spectroscopy indicated a high compatibility between the excipients and curcumin. CCCTs with chitosan formed a gel structure, impeded disintegration, and reduced the release rate to 72.5% in simulated gastric fluid. In simulated intestinal fluid, CCCT with the HPMC-sodium alginate group formed a polyelectrolyte membrane hydrogel to prolong release from 6 to 12 h. This study developed various CCCT formulations that can be delivered through the gastric or intestinal tracts, using chitosan and HPMC-sodium alginate as excipients, respectively. CCCT can be used as a reference strategy for controlled-release curcumin delivery in the functional and healthcare supplement development.

Identification of the metaphyseal skeletal stem cell building trabecular bone.

Skeletal stem cells (SSCs) that are capable of self-renewal and multipotent differentiation contribute to bone development and homeostasis. Several populations of SSCs at different skeletal sites have been reported. Here, we identify a metaphyseal SSC (mpSSC) population whose transcriptional landscape is distinct from other bone mesenchymal stromal cells (BMSCs). These mpSSCs are marked by Sstr2 or Pdgfrb+Kitl-, located just underneath the growth plate, and exclusively derived from hypertrophic chondrocytes (HCs). These HC-derived mpSSCs have properties of self-renewal and multipotency in vitro and in vivo, producing most HC offspring postnatally. HC-specific deletion of Hgs, a component of the endosomal sorting complex required for transport, impairs the HC-to-mpSSC conversion and compromises trabecular bone formation. Thus, mpSSC is the major source of BMSCs and osteoblasts in bone marrow, supporting the postnatal trabecular bone formation.

PeHVA22 gene family in passion fruit (Passiflora edulis): initial characterization and expression profiling diversity.

Passion fruit, an economically valuable fruit crop, is highly vulnerable to adverse climate conditions. The HVA22 genes, recognized as abscisic acid (ABA) and stress-inducible, play vital roles in stress response and growth regulation in diverse eukaryotic organisms. Here, six HVA22 genes were firstly identified in passion fruit genome and all predicted to be localized within the endoplasmic reticulum. Phylogenetic analyses showed that all PeHVA22s were divided into four subgroups. The gene structural features of PeHVA22 genes clustered in the same subgroup were relatively conserved, while the gene structure characteristics of PeHVA22s from different subgroups varied significantly. PeHVA22A and PeHVA22C closely clustered with barley HVA22 in Group II, were also induced by ABA and drought stress treatment, suggesting conserved roles similar to barley HVA22. Meanwhile, most PeHVA22s exhibited induced expression post-drought treatment but were suppressed under salt, low and high-temperature conditions, indicating a unique role in drought response. Additionally, PeHVA22s displayed tissue-specific expression patterns across diverse tissues, except for PeHVA22B which maybe a pseudogene. Notably, PeHVA22C, PeHVA22E, and PeHVA22F predominantly expressed in fruit, indicating their involvement in fruit development. Almost all PeHVA22s showed variable expression at different developmental stages of stamens or ovules, implying their roles in passion fruit's sexual reproduction. The intricate roles of PeHVA22s may result from diverse regulatory factors including transcription factors and CREs related to plant growth and development, hormone and stress responsiveness. These observations highlighted that PeHVA22s might play conserved roles in ABA response and drought stress tolerance, and also be participated in the regulation of passion fruit growth and floral development.

Transforming Growth Factor-ß Signaling Regulates Tooth Root Dentinogenesis by Cooperation With Wnt Signaling.

Proper differentiation of odontoblasts is crucial for the development of tooth roots. Previous studies have reported the osteogenic/odontogenic potential of pre-odontoblasts during root odontoblast differentiation. However, the underlying molecular pathway that orchestrates these processes remains largely unclear. In this study, ablation of transforming growth factor-ß receptor type 2 (Tgfbr2) in root pre-odontoblasts resulted in abnormal formation of root osteodentin, which was associated with ectopic osteogenic differentiation of root odontoblasts. Disrupting TGF-ß signaling caused upregulation of Wnt signaling characterized by increased Wnt6, Wnt10a, Tcf-1, and Axin2 expression. Interestingly, inhibiting Wnt signaling by deleting Wntless (wls) in Osteocalcin (Ocn)-Cre; Tgfbr2 fl/fl ; Wls fl/fl mice or overexpressing the Wnt antagonist Dkk1 in Ocn-Cre; Tgfbr2 fl/fl ; ROSA26 Dkk1 mice decreased ectopic osteogenic differentiation and arrested odontoblast differentiation. Our results suggest that TGF-ß signaling acts with Wnt signaling to regulate root odontogenic differentiation.

Sustained Akt signaling in articular chondrocytes causes osteoarthritis via oxidative stress-induced senescence in mice.

Osteoarthritis (OA) is an age-related disorder that is strongly associated with chondrocyte senescence. The causal link between disruptive PTEN/Akt signaling and chondrocyte senescence and the underlying mechanism are unclear. In this study, we found activated Akt signaling in human OA cartilage as well as in a mouse OA model with surgical destabilization of the medial meniscus. Genetic mouse models mimicking sustained Akt signaling in articular chondrocytes via PTEN deficiency driven by either Col2a1-Cre or Col2a1-Cre ERT2 developed OA, whereas restriction of Akt signaling reversed the OA phenotypes in PTEN-deficient mice. Mechanistically, prolonged activation of Akt signaling caused an accumulation of reactive oxygen species and triggered chondrocyte senescence as well as a senescence-associated secretory phenotype, whereas chronic administration of the antioxidant N-acetylcysteine suppressed chondrocyte senescence and mitigated OA progression in PTEN-deficient mice. Therefore, inhibition of Akt signaling by PTEN is required for the maintenance of articular cartilage. Disrupted Akt signaling in articular chondrocytes triggers oxidative stress-induced chondrocyte senescence and causes OA.

Odontoblast ß-catenin signaling regulates fenestration of mouse Hertwig's epithelial root sheath.

The interaction between Hertwig's epithelial root sheath (HERS) and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnb1 (encoding ß-catenin) deletion mice, and demonstrated that odontoblast ß-catenin signaling regulates odontoblast proliferation and differentiation. However, the role of odontoblast ß-catenin signaling in regulation of HERS behavior has not been fully investigated. Here, using the same odontoblast- specific Ctnnb1 deletion mice, we found that ablation of ß-catenin signaling in odontoblasts led to aberrant HERS formation. Mechanistically, odontoblast-specific Ctnnb1 deletion resulted in elevated bone morphogenetic protein 7 (Bmp7) expression and reduced expression of noggin and follistatin, both of which encode extracellular inhibitors of BMPs. Furthermore, the levels of phosphorylated Smad1/5/8 were increased in HERS cells. In vitro tissue culture confirmed that BMP7 treatment disrupted the HERS structure. Taken together, we demonstrated that odontoblast ß-catenin signaling may act through regulation of BMP signaling to maintain the integrity of HERS cells.

Mesenchymal TGF-ß signaling orchestrates dental epithelial stem cell homeostasis through Wnt signaling.

In mouse, continuous growth of the postnatal incisor is coordinated by two populations of multipotent progenitor cells, the dental papilla mesenchymal cells and dental epithelial stem cells, residing at the proximal end of the incisor, yet the molecular mechanism underlying the cooperation between mesenchymal and epithelial cells is largely unknown. Here, transforming growth factor-ß (TGF-ß) type II receptor (Tgfbr2) was specifically deleted within the postnatal dental papilla mesenchyme. The Tgfbr2-deficient mice displayed malformed incisors with wavy mineralized structures at the labial side as a result of increased differentiation of dental epithelial stem cells. We found that mesenchymal Tgfbr2 disruption led to upregulated expression of Wnt5a and downregulated expression of Fgf3/10 in the mesenchyme, both of which synergistically enhanced Lrp5/6-ß-catenin signaling in the cervical loop epithelium. In accord with these findings, mesenchyme-specific depletion of the Wnt transporter gene Wls abolished the aberrant mineralized structures caused by Tgfbr2 deletion. Thus, mesenchymal TGF-ß signaling provides a unifying mechanism for the homeostasis of dental epithelial stem cells via a Wnt signaling-mediated mesenchymal-epithelial cell interaction.

High resolution melting analysis for the detection of SLC25A13 gene mutations in Taiwan.

BACKGROUND: Citrin, encoded by SLC25A13 gene, is a mitochondrial solute transporter with a crucial role in urea, nucleotide and protein synthesis. SLC25A13 mutations cause two phenotypes, adult-onset type II citrullinemia and neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). This study aimed to develop a high resolution melting (HRM) analysis for SLC25A13 mutation scanning and determine the carrier rate in Taiwan. METHODS: DNAs from healthy subjects (n=479), and patients with hepatocellular carcinoma (HCC, n=100) and NICCD (n=5) were scanned in exons 6, 9, 11, 16, and 17 and parts of introns of SLC25A13 using HRM analysis. All mutations detected by HRM analysis were further confirmed by TaqMan method and/or direct sequencing. RESULTS: In healthy subjects, seventeen carriers with mutants c.851_854del (n=10), c.1638_1660dup, c.615+5G>A (n=4), and two novel mutants, c.475C>T and c.1658G>A, were detected. The frequency of carriers was about 1/28. In patients with HCC, there were only 2 carriers with c.851_854del mutant. Patients with NICCD (n=5) diagnosed during 2007 and 2008, harbored compound heterozygous mutations c.851_854del/c.1177+1G>A, c.851_854del/c.1638_1660dup (n=2), c.851_854del/c.615+5G>A, and c.1638_1660dup/c.615+5G>A. CONCLUSIONS: HRM analysis is a simple, rapid and robust method for detecting SLC25A13 mutations in clinical laboratories. SLC25A13 mutations may not be a major contributor to the pathogenesis of HCC in Taiwan.