Phosphorothioate Modification of mRNA Accelerates the Rate of Translation Initiation to Provide More Efficient Protein Synthesis.

Messenger RNAs (mRNAs) with phosphorothioate modification (PS-mRNA) to the phosphate site of A, G, C, and U with all 16 possible combinations were prepared, and the translation reaction was evaluated using an E. coli cell-free translation system. Protein synthesis from PS-mRNA increased in 12 of 15 patterns when compared with that of unmodified mRNA. The protein yield increased 22-fold when the phosphorothioate modification at A/C sites was introduced into the region from the 5'-end to the initiation codon. Single-turnover analysis of PS-mRNA translation showed that phosphorothioate modification increases the number of translating ribosomes, thus suggesting that the rate of translation initiation (rate of ribosome complex formation) is positively affected by the modification. The method provides a new strategy for improving translation by using non-natural mRNA.

Clock genes influence gene expression in growth plate and endochondral ossification in mice.

We have previously shown transient promotion by parathyroid hormone of Period-1 (Per1) expression in cultured chondrocytes. Here we show the modulation by clock genes of chondrogenic differentiation through gene transactivation of the master regulator of chondrogenesis Indian hedgehog (IHH) in chondrocytes of the growth plate. Several clock genes were expressed with oscillatory rhythmicity in cultured chondrocytes and rib growth plate in mice, whereas chondrogenesis was markedly inhibited in stable transfectants of Per1 in chondrocytic ATDC5 cells and in rib growth plate chondrocytes from mice deficient of brain and muscle aryl hydrocarbon receptor nuclear translocator-like (BMAL1). Ihh promoter activity was regulated by different clock gene products, with clear circadian rhythmicity in expression profiles of Ihh in the growth plate. In BMAL1-null mice, a predominant decrease was seen in Ihh expression in the growth plate with a smaller body size than in wild-type mice. BMAL1 deficit led to disruption of the rhythmic expression profiles of both Per1 and Ihh in the growth plate. A clear rhythmicity was seen with Ihh expression in ATDC5 cells exposed to dexamethasone. In young mice defective of BMAL1 exclusively in chondrocytes, similar abnormalities were found in bone growth and Ihh expression. These results suggest that endochondral ossification is under the regulation of particular clock gene products expressed in chondrocytes during postnatal skeletogenesis through a mechanism relevant to the rhythmic Ihh expression.

Histone deacetylase induces accelerated maturation in Xenopus laevis oocytes.

In oocyte maturation in Xenopus laevis, nuclear material induces rapid maturation and is required for entry into meiosis II. Nuclear material contains a large number of RNAs and proteins, including histone deacetylase (HDAC); however, it is not known which materials induce accelerated maturation. The HDAC activity modifies transcription rate and is required for normal meiosis; however, its function in oocyte maturation is still unclear. We investigated the function of HDAC activity, which is localized in the nuclear material, in the regulation of the speed of oocyte maturation. Inhibition of HDAC activity with trichostatin A (TSA) induced hyperacetylation of histone H3 and prolonged oocyte maturation. In contrast, increase in HDAC activity with an injection of FLAG-tagged maternal histone deacetylase (HDACm-FLAG) mRNA induced deacetylation of histone H3 and reduced the duration of oocyte maturation. Cdc2 kinase, Cdc25C or mitogen-activated protein kinase (MAPK), which are key regulators of the meiosis, were activated coincidently with maturation progression. In oocytes, the mRNA level of Cdc25C, an activator of Cdc2, was increased by HDACm-FLAG mRNA-injection; in contrast, the mRNA level of Cdc2 inhibitor Wee1 was increased by TSA treatment. These results suggest that HDAC activity is involved in the control of maturation speed through the regulation of mRNA levels of cell cycle regulators. Thus, HDACm is a candidate for the nuclear material component that induces rapid maturation in Xenopus oocytes.

Functional expression of beta2 adrenergic receptors responsible for protection against oxidative stress through promotion of glutathione synthesis after Nrf2 upregulation in undifferentiated mesenchymal C3H10T1/2 stem cells.

Adrenaline is believed to play a dual role as a neurotransmitter in the central nervous system and an adrenomedullary hormone in the peripheral tissues. In contrast to accumulating evidence for the involvement in endochondral ossification, osteoblastogenesis, and osteoclastogenesis, little attention has been paid to the role of adrenergic signals in the mechanisms underlying proliferation and differentiation of mesenchymal stem cells with self-renewal capacity and multi-potentiality to differentiate into osteoblast, chondrocyte, adipocyte, and myocyte lineages. Expression of mRNA was seen for different adrenergic receptor (AdR) subtypes, including beta(2)AdR, in the mesenchymal stem cell line C3H10T1/2 cells and mouse bone marrow mesenchymal stem cells before differentiation. Exposure to adrenaline not only increased cAMP formation, phosphorylation of cAMP responsive element (CRE) binding protein (CREB) on serine133 and CRE reporter activity in a manner sensitive to propranolol, but also rendered C3H10T1/2 cells resistant to the cytotoxicity of hydrogen peroxide, but not of either 2,4-dinitirophenol or tunicamycin. Adrenaline induced a rapid but transient increase in mRNA expression of the antioxidative gene nuclear factor E2 p45-related factor-2 (Nrf2) along with an increase in the cystine/glutamate antiporter subunit xCT mRNA expression. Hydrogen peroxide was less cytotoxic in cells overexpressing Nrf2, moreover, while adrenaline significantly increased xCT promoter activity with an increase in endogenous glutathione levels. These results suggest that adrenaline may selectively protect mesenchymal C3H10T1/2 cells from oxidative stress through a mechanism related to the promoted biosynthesis of glutathione in association with transient Nrf2 expression after activation of beta(2)AdR.

Influence of dosing schedules on toxicity and antitumour effects of combined cisplatin and docetaxel treatment in mice.

OBJECTIVES: The combination of cisplatin and docetaxel shows a better cure rate against non-small-cell lung cancer than other drug combinations in clinical studies; however, severe myelosuppression and nephrotoxicity are dose-limiting factors. The purpose of this study was to establish a suitable dosing schedule to reduce adverse effects and improve the antitumour effects. METHODS: Cisplatin and docetaxel were administered i.p. to male ICR mice simultaneously, or sequentially with either cisplatin or docetaxel first followed by the second drug 12 h later (docetaxel-cisplatin and cisplatin-docetaxel groups). Antitumour effects of these schedules were also tested in C57BL/6N mice bearing Lewis lung carcinomas. KEY FINDINGS: The simultaneous docetaxel/cisplatin group showed the lowest survival rate and the highest blood urea nitrogen (BUN) concentration. Cisplatin concentrations in the plasma and kidney were higher in the simultaneous dosing group than the sequential dosing groups. Antitumour effect was the greatest in the docetaxel-cisplatin group. CONCLUSIONS: The docetaxel-cisplatin regimen inhibited tumour growth the best and reduced mortality and nephrotoxicity.

Preparation of Circular RNA In Vitro.

This chapter describes a simple and straightforward way to obtain single-stranded circular RNA sequences in vitro. Linear RNA that is phosphorylated at the 5' end is first prepared by a chemical or enzymatic method, then circularized using ligase. The function of the prepared circular RNA molecule, such as an ability to induce translation, can then be investigated.

Bone Resorption Is Regulated by Circadian Clock in Osteoblasts.

We have previously shown that endochondral ossification is finely regulated by the Clock system expressed in chondrocytes during postnatal skeletogenesis. Here we show a sophisticated modulation of bone resorption and bone mass by the Clock system through its expression in bone-forming osteoblasts. Brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 (Bmal1) and Period1 (Per1) were expressed with oscillatory rhythmicity in the bone in vivo, and circadian rhythm was also observed in cultured osteoblasts of Per1::luciferase transgenic mice. Global deletion of murine Bmal1, a core component of the Clock system, led to a low bone mass, associated with increased bone resorption. This phenotype was recapitulated by the deletion of Bmal1 in osteoblasts alone. Co-culture experiments revealed that Bmal1-deficient osteoblasts have a higher ability to support osteoclastogenesis. Moreover, 1α,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ]-induced receptor activator of nuclear factor κB ligand (Rankl) expression was more strongly enhanced in both Bmal1-deficient bone and cultured osteoblasts, whereas overexpression of Bmal1/Clock conversely inhibited it in osteoblasts. These results suggest that bone resorption and bone mass are regulated at a sophisticated level by osteoblastic Clock system through a mechanism relevant to the modulation of 1,25(OH)2 D3 -induced Rankl expression in osteoblasts. © 2017 American Society for Bone and Mineral Research.

NS-018, a selective JAK2 inhibitor, preferentially inhibits CFU-GM colony formation by bone marrow mononuclear cells from high-risk myelodysplastic syndrome patients.

JAK2/STAT signaling promotes survival and expansion of myelodysplastic syndrome (MDS) clones, but little is known about the potential of JAK2/STAT as a therapeutic target in MDS. We investigated the effect of NS-018, a novel antagonist for JAK2, on the colony-forming ability of bone marrow mononuclear cells (BMMNCs) from high-risk MDS patients. NS-018 decreased colony-forming unit-granulocyte/macrophage (CFU-GM) colony numbers from MDS-derived BMMNCs in a dose-dependent manner, and this effect was significantly more potent than against normal BMMNCs. In addition, NS-018 suppressed the phosphorylation of STAT3 in colony-forming cells from MDS patients. Collectively, NS-018 could be a new therapeutic option for high-risk MDS.

Predominant promotion by tacrolimus of chondrogenic differentiation to proliferating chondrocytes.

Tacrolimus (FK506) has been used as a therapeutic drug beneficial for the treatment of rheumatoid arthritis in humans. In this study, we investigated the effects of FK506 on cellular differentiation in cultured chondrogenic cells. Culture with FK506 led to a significant and concentration-dependent increase in Alcian blue staining for matrix proteoglycan at 0.1 to 1,000 ng/ml, but not in alkaline phosphatase (ALP) activity, in ATDC5 cells, a mouse pre-chondrogenic cell line, cultured for 7 to 28 days, while the non-steroidal anti-inflammatory drug indomethacin significantly decreased Alcian blue staining in a concentration-dependent manner, without altering ALP activity. FK506 significantly increased the expression of mRNA for both type II and type X collagen, but not for osteopontin, in ATDC5 cells. Similar promotion was seen in chondrogenic differentiation in both mouse metatarsals and chondrocytes cultured with FK506. However, FK506 failed to significantly affect transcriptional activity of the reporter construct for either sry-type HMG box 9 (Sox9) or runt-related transcription factor-2 (Runx2), which are both transcription factors responsible for chondrocytic maturation as a master regulator. These results suggest that FK506 may predominantly promote cellular differentiation into proliferating chondrocytes through a mechanism not relevant to the transactivation by either Sox9 or Runx2 in chondrogenic cells.

Interference by adrenaline with chondrogenic differentiation through suppression of gene transactivation mediated by Sox9 family members.

In contrast to osteoblasts, little attention has been paid to the functional expression of adrenergic signaling machineries in chondrocytes. Expression of mRNA was for the first time demonstrated for different adrenergic receptor (AdR) subtypes in chondrogenic ATDC5 cells and mouse metatarsals isolated before vascularization in culture, but not for other molecules related to adrenergic signaling. In neonatal mouse tibial sections, beta(2)AdR and alpha(2a)AdR mRNA expression was found in chondrocytes at different developmental stages by in situ hybridization. Exposure to adrenaline significantly suppressed expression of several maturation markers through the cAMP/protein kinase A pathway activated by beta(2)AdR without affecting cellular proliferation in both cultured ATDC5 cells and metatarsals. Adrenaline also significantly inhibited gene transactivation by sry-type HMG box 9 (Sox9) family members essential for chondrogenic differentiation in a manner prevented by the general betaAdR antagonist propranolol, with a concomitant significant decrease in the levels of Sox6 mRNA and corresponding protein, in ATDC5 cells and primary cultured mouse costal chondrocytes. Systemic administration of propranolol significantly promoted the increased expression of mRNA for collagen I and collagen X, but not for collagen II, in callus of fractured femur in mice. These results suggest that adrenaline may interfere with chondrogenic differentiation through downregulation of Sox6 expression for subsequent suppression of gene transactivation mediated by Sox9 family members after activation of beta(2)AdR expressed by chondrocytes.

Pre-administration of docetaxel protects against adriamycin-induced cardiotoxicity.

BACKGROUND: We have revealed in a pre-clinical study that the combination of adriamycin (ADR) and docetaxel (DOC) in which ADR was administered 12 h after DOC injection not only significantly reduced leukopenia and toxic death but also significantly increased the antitumor effect compared with the dosing schedule without an interval between each injection used commonly in clinical practice. The purpose of this study was to clarify in mice whether the toxic death caused by ADR was reduced by administering ADR after DOC injection when the doses and dosing-interval of ADR and DOC were changed. METHODS: ADR alone or a combination of ADR and DOC (ADR/DOC group in which both drugs were administered simultaneously or DOC-ADR group in which ADR was administered after DOC injection) was administered every 7 days in mice. RESULTS: When dosing intervals (0-24 h) were changed, there were no differences in survival rate among the 6, 12, and 24-h interval groups, although these groups showed significantly higher survival rate compared with the ADR/DOC group. When the dose of ADR (2.5-15 mg/kg) was changed, the survival rate was higher in all the DOC-ADR groups than the ADR alone groups. When the dose of DOC (3.125-12.5 mg/kg) was changed, DOC caused a dose-dependent reduction in toxic death. Although there was no striking difference in adverse effects between the ADR alone and DOC-ADR groups, the DOC-ADR group showed markedly attenuated increases in CPK-MB activity compared with the ADR alone group. CONCLUSIONS: We conclude that pre-administration of DOC may protect against ADR-induced toxic death and cardiotoxicity.

Gengivectomia para o restabelecimento do arco côncavo regular: relato de caso / Gingivectomy for restoring the regular concave arch: Case report

O objetivo deste trabalho é descrever um tratamento cirúrgico periodontal na região de incisivos superiores, com a finalidade de restabelecer a estética periodontal após tratamento ortodôntico. A gengivectomia associada à plastia gengival viabilizou a estética periodontal do caso clínico apresentado, solucionando a desproporção periodontal.

The aim of this paper is to describe the surgical periodontal treatment in the maxillary incisors area for restoring periodontal esthetics after orthodontic treatment. Gengivectomy associated to gingivoplasty allowed the periodontal esthetic rehabilitation in the clinical case reported, solving the periodontal disproportion.