Noncanonical registers and base pairs in human 5' splice-site selection.

Accurate recognition of splice sites is essential for pre-messenger RNA splicing. Mammalian 5' splice sites are mainly recognized by canonical base-pairing to the 5' end of U1 small nuclear RNA, yet we described multiple noncanonical base-pairing registers by shifting base-pair positions or allowing one-nucleotide bulges. By systematic mutational and suppressor U1 analyses, we prove three registers involving asymmetric loops and show that two-nucleotide bulges but not longer can form in this context. Importantly, we established that a noncanonical uridine-pseudouridine interaction in the 5' splice site/U1 helix contributes to the recognition of certain 5' splice sites. Thermal melting experiments support the formation of noncanonical registers and uridine-pseudouridine interactions. Overall, we experimentally validated or discarded the majority of predicted noncanonical registers, to derive a list of 5' splice sites using such alternative mechanisms that is much different from the original. This study allows not only the mechanistic understanding of the recognition of a wide diversity of mammalian 5' splice sites, but also the future development of better splice-site scoring methods that reliably predict the effects of disease-causing mutations at these sequences.

Characterization of the Regulation of CD46 RNA Alternative Splicing.

Here we present a detailed analysis of the alternative splicing regulation of human CD46, which generates different isoforms with distinct functions. CD46 is a ubiquitous membrane protein that protects host cells from complement and plays other roles in immunity, autophagy, and cell adhesion. CD46 deficiency causes an autoimmune disorder, and this protein is also involved in pathogen infection and cancer. Before this study, the mechanisms of CD46 alternative splicing remained unexplored even though dysregulation of this process has been associated with autoimmune diseases. We proved that the 5' splice sites of CD46 cassette exons 7 and 8 encoding extracellular domains are defined by noncanonical mechanisms of base pairing to U1 small nuclear RNA. Next we characterized the regulation of CD46 cassette exon 13, whose inclusion or skipping generates different cytoplasmic tails with distinct functions. Using splicing minigenes, we identified multiple exonic and intronic splicing enhancers and silencers that regulate exon 13 inclusion via trans-acting splicing factors like PTBP1 and TIAL1. Interestingly, a common splicing activator such as SRSF1 appears to repress CD46 exon 13 inclusion. We also report that expression of CD46 mRNA isoforms is further regulated by non-sense-mediated mRNA decay and transcription speed. Finally, we successfully manipulated CD46 exon 13 inclusion using antisense oligonucleotides, opening up opportunities for functional studies of the isoforms as well as for therapeutics for autoimmune diseases. This study provides insight into CD46 alternative splicing regulation with implications for its function in the immune system and for genetic disease.

Identification of novel carbonic anhydrase II receptor-targeting drugs for treating myocardial infarction through the mechanism of Xue-Fu-Zhu-Yu decoction.

Myocardial infarction (MI) is a significant threat to human health and life. Xue-Fu-Zhu-Yu Decoction (XFZYD), a renowned traditional Chinese medicine prescription for treating myocardial infarction, is known to play a significant role in the management of MI. However, its mechanism of action remains unclear. Through network pharmacology analysis of compound-target interactions, we have identified Carbonic Anhydrase II (CA2) as a critical target for XFZYD in the treatment of MI. Subsequently, we will embark on a target-based drug design approach with a focus on CA2 as the key target: Pharmacophore modeling: Two pharmacophore models were developed and validated to screen for small molecules with CA2 inhibitory features. Virtual screening: Based on two pharmacophore models, small molecules with the property of binding to the CA2 target were screened from a virtual screening library. Molecular docking: Molecular docking was employed to identify small molecules with stable binding affinity to CA2. ADMET prediction: ADMET models were utilized to screen for small molecules with favorable pharmacological properties. Molecular dynamics: Molecular dynamics simulations were further conducted to analyze the binding modes of the selected small molecules with CA2, ultimately resulting in the identification of Ligand 3 and Ligand 5 as small molecule inhibitors targeting CA2. Finally, the mechanisms underlying the anti-MI effects were discussed. The primary objective of this article is to uncover the mechanism by which XFZYD acts on MI and utilize it for drug development. These findings provide novel avenues for the development of anti-MI drugs.Communicated by Ramaswamy H. Sarma.

[Clinical manifestations and gene mutations of a Chinese family with MYH9-related syndrome].

OBJECTIVE: To explore the method for early diagnosis and pathogenesis of MYH9-related syndrome through analysis of the clinical manifestation and gene mutation of a Chinese family with MYH9-related syndrome. METHODS: Peripheral blood samples were collected from a three-generation Chinese family with MYH9-related syndrome (11 individuals, including 3 patients) and 100 healthy individuals. Polymerase chain reaction (PCR) amplification and direct sequencing of DNA were performed to analyze mutations of MYH9 gene. RESULTS: Thrombocytopenia, increased volume of platelet, and granulocyte inclusion bodies were found in the patients with MYH9-related syndrome via a peripheral blood test. A missense mutation of a base pair (G-A) in exon 30 was revealed by PCR amplification and direct sequencing of MYH9 of the proband. That lead to Asp-Asn substitution at position 1424 (D1424N mutation). The mutation was the same as in other patients with MYH9-related syndrome. It was not found in healthy people from the Chinese family or in the other 100 healthy individuals. CONCLUSIONS: Patients with MYH9-related syndrome show diverse symptoms. Mutation of MYH9 gene may be the molecular mechanism of MYH9-related syndrome, and D1424N mutation of MYH9 has not been reported in Chinese people. Early diagnosis of MYH9-related syndrome can be carried out by investigating family history and making early examinations.

Overexpression of long noncoding RNA MCM3AP-AS1 promotes osteogenic differentiation of dental pulp stem cells via miR-143-3p/IGFBP5 axis.

MCM3AP-AS1 regulates the cartilage repair in osteoarthritis, but how it regulates osteogenic differentiation of dental pulp stem cells (DPSCs) remains to be determined. DPSCs were isolated and induced for osteogenic differentiation. MCM3AP-AS1 expression was increased along with the osteogenic differentiation of DPSCs, whose expression was positive correlated with those of OCN, alkaline phosphatase (ALP) and RUNX2. On contrary, miR-143-3p expression was decreased along with the osteogenic differentiation and was negatively correlated with those of OCN, ALP and RUNX2. Dual-luciferase reporter gene assay showed that miR-143-3p can be negatively regulated by MCM3AP-AS1 and can regulate IGFBP5. MCM3AP-AS1 overexpression increased the expression levels of osteogenesis-specific genes, ALP activity and mineralized nodules during DPSC osteogenic differentiation, while IGFBP5 knockdown or miR-143-3p overexpression counteracted the effect of MCM3AP-AS1 overexpression in DPSCs. Therefore, this study demonstrated the role of MCM3AP-AS1/miR-143-3p/IGFBP5 axis in regulating DPSC osteogenic differentiation.

Surgical treatment of sagittal fracture of mandibular condyle using long-screw osteosynthesis.

PURPOSE: The retrospective study evaluated long-screw (bicortical screw) osteosynthesis used in the surgical treatment of sagittal fracture of the mandibular condyle and compared it with titanium plates and removal of the condylar fragment. PATIENTS AND METHODS: Ninety-five patients with sagittal fracture of the mandibular condyle received open surgical treatment from 1997 to 2008. Among these patients, the condylar fragments were fixed with long screws in 56 cases (group A), were fixed with titanium plates in 12 cases (group B), and were completely removed in 24 cases (group C). Follow-up was carried out clinically and radiologically. The clinical features included limitation of mandibular mobility, occlusion disturbance, lateral deviation on mouth opening, joint pain, clicking, facial asymmetry, and patient's subjective evaluation. The radiologic parameters consisted of degree of bony resorption, bony change, change of osteosynthesis material, and shortening of mandibular ramus height. RESULTS: Anatomic reduction and functional restoration were obtained and no severe complication was detected in group A. However, 3 of 14 patients had severe osteoarthrosis and 2 of 14 patients had ankylosis in group B. In group C 3 of 24 patients had mandibular retrusion, 4 of 24 patients had front teeth open bite, 4 of 24 patients had severe osteoarthrosis, and 1 of 24 patients had ankylosis. CONCLUSION: The long-screw fixation group had a more favorable prognosis than the titanium plate group and the group in which removal of the condylar fragment was performed. The long-screw fixation technique might be suitable for use in the surgical treatment of sagittal fractures of the mandibular condyle.

In vitro photothermal study of gold nanoshells functionalized with small targeting peptides to liver cancer cells.

Gold nanoshells functionalized with a small peptide as a targeting agent were designed and synthesized for photothermal therapy of hepatocarcinoma. The nanoshells exhibited high absorption in the near-infrared (NIR) range, 800-1,100 nm, and were functionalized with 12-amino acid sequence peptides for targeting liver cancer cells. The nanoshells were characterized by Dynamic Light Scattering (DLS), Transmission Electron Microscope (TEM) and IR spectra. The functionalized gold nanoshells showed good targeting ability to liver cancer cells BEL-7404 and BEL-7402 while not to the normal healthy liver cell HL-7702, and also had a low cytotoxic activity. The fluorescence images showed that the gold nanoshells caused death to the liver cancer cells efficiently after being treated with a NIR light in vitro. These simple, stable, low cytotoxic, cancer-cell targeting gold nanoshells present a great promise as delivery agents for the selective photothermal treatment of liver cancer cells.

Association between polymorphism of MMP-1 promoter and the susceptibility to anterior disc displacement and temporomandibular joint osteoarthritis.

OBJECTIVE: To investigate the correlation of the polymorphism of MMP-1 promoter (-1607 1G/2G) with the susceptibility to anterior disc displacement (ADD) and temporomandibular joint osteoarthritis (TMJ OA). METHODS: A total of 185 healthy individuals (group A), 141 unilateral ADDWR patients (group B), and 321 unilateral ADDWOR patients (group C) were included in the investigation. Group C included 115 patients without TMJ OA (named group C-1) and 206 with TMJ OA (named group C-2). The genotyping of this single nucleotide polymorphism was evaluated by high resolution melting assay. Pairwise comparison between the distributions of genotypes and alleles in these groups was conducted with a multivariate logistic regression model adjusted on the basis of possible covariates. RESULTS: A significant difference in the 2G2G genotype frequency was found among the different groups on the basis of three sets of comparisons (P(C-A)<0.0005; P(C1-B)=0.049; P(C2-B)=0.018). The susceptibility of 2G2G genotype carriers to ADDWOR with or without TMJ OA was considerably higher than that of other genotypes carriers (OR(C-A)=2.455; OR(C1-B)=1.849; OR(C2-B)=1.912). A significant difference in 1G2G genotype frequency was also observed on the basis of two sets of comparisons (P(C-A)<0.0005; P(C2-B)=0.041). The susceptibility of 1G2G genotype carriers to ADDWOR with or without TMJ OA was also considerably higher than that of other genotype carriers (OR(C-A)=2.641; OR(C2-B)=1.896). CONCLUSION: The -1607 1G/2G polymorphism of MMP-1 promoter may be related to the susceptibility to ADDWOR with or without TMJ OA.

Alteration of the tongue manifestation reflects clinical outcomes of peptic ulcer disease.

OBJECTIVES: This study investigated whether the tongue inspection technique in Traditional Chinese Medicine (TCM) can be used as a noninvasive auxiliary diagnostic tool to differentiate the subtypes of peptic ulcer disease (PUD) and as an indicator of therapeutic efficacy. SUBJECTS AND METHODS: A total of 198 outpatients from the China Medical University Hospital were recruited. The control group comprised 50 healthy adults. The remaining 148 patients were diagnosed with gastric ulcer, duodenal ulcer, or Helicobacter pylori (Hp) infection using upper gastrointestinal (GI) endoscopy, biopsy, and Campylobacter-like organism test. Tongue appearance was evaluated by a physician experienced in clinical Chinese medicine. Images of the tongue were immediately recorded using a high-resolution digital camera system. RESULTS: The affected group of 148 patients received an 8-week course of ulcer therapy. Of these, 108 patients infected with Hp were subjected to triple therapy in the first week. Forty-nine of these 108 cases infected with Hp completed secondary examination of upper GI endoscopy and tongue inspection. Forty-one of 49 cases (83.7%) were fully cured of Hp infection. These results showed that the color of the tongue body did not change in the cured patients; however, tongue fur was markedly thinner with a color change to white (p<0.05), while sublingual veins with engorgement (p<0.05) and blood stasis (p<0.01) improved after the ulcer healed and Hp was eradicated. CONCLUSIONS: TCM tongue inspection can be potentially used as a noninvasive auxiliary diagnostic method and as an indicator for clinical outcomes for patients with PUD.

Surface-modified gold nanoshells for enhanced cellular uptake.

Gold nanoshells have shown a great potential for use as agents in a wide variety of biomedical applications, and some of which require the delivery of large numbers of gold nanoshells onto or into the cells. Here, we develop a ready method to enhance the cellular uptake of gold nanoshells by modifying with meso-2,3-dimercaptosuccinic acid (DMSA). The quantifiable technique of inductively coupled plasma atomic emissions spectroscopy (ICP-AES) and transmission electron microscopy (TEM) were used to investigate the cellular uptake of unmodified and DMSA-modified gold nanoshells. Three cell lines (RAW 264.7, A549, and BEL-7402) were involved and the results indicated that the cellular uptake of the DMSA-modified gold nanoshells was obviously enhanced versus the unmodified gold nanoshells. The reason possibly lies in the nonspecific adsorption of serum protein on the DMSA-modified gold nanoshells (DMSA-GNs), which consequently enhanced the cellular uptake. As a continued effort, in vitro experiments with endocytic inhibitors suggested the DMSA-GNs internalized into cells via receptor-mediated endocytosis (RME) pathway. This study has provided a valuable insight into the effects of surface modification on cellular uptake of nanoparticles.

Fabrication of nanomicelle with enhanced solubility and stability of camptothecin based on alpha,beta-poly[(N-carboxybutyl)-L-aspartamide]-camptothecin conjugate.

This research is aimed to develop a nanomicelle delivery system in order to enhance the solubility and stability of camptothecin (CPT) in aqueous media. In this case, alpha,beta-poly[(N-carboxybutyl)-L-aspartamide] (PBAsp)-CPT was conjugated by the esterification between PBAsp and 20-OH of CPT, and hence used to fabricate nanomicelles with a particle size between the pore size of blood capillary in normal tissue and that in tumor tissue. It was worthy of note that the drug-loaded system of PBAsp-CPT nanomicelle improved the solubility and stability of CPT in aqueous media. However, with an increase of the CPT loading in PBAsp-CPT, the solubility sharply decreased. Meanwhile, the sizes of PBAsp-CPT nanomicelles showed a tendency of increase. Moreover, the drug release of PBAsp-CPT nanomicelles displayed a linear sustaining profile, and hence resulted in the essential decrease of cytotoxicity to L929 cell line. The assembled nanomicelles based on the PBAsp-CPT conjugates showed a great potential as polymer prodrug of tumor therapy, and the controlled nano-scale might achieve the passive tumor targeting.

Fabrication of polymer-platinum(II) complex nanomicelle from mPEG-g-alpha,beta-poly [(N-amino acidyl)-DL-aspartamide] and cis-dichlorodiammine platinum(II) and its cytotoxicity.

The aim of research is to develop and optimize delivery system for cis-dichlorodiammine platinum(II) (CDDP) based on polymer-metal complex nanomicelles with controllable particle size in order to achieve the passive tumor targeting. In particular, graft copolymers, mPEG-g-alpha,beta-poly [(N-amino acidyl)-DL-aspartamide] (mPEG-g-PAAsp) were synthesized by the ring-opening reaction of polysuccinimide with mPEG-NH(2) (M(w): 2000 and 5000 Da), and then with l-aspartic acid and l-glutamic acid, respectively. mPEG-g-PAAsp-CDDP complex nanomicelles were fabricated from mPEG-g-PAAsp and CDDP. The formation of mPEG-g-PAAsp-CDDP nanomicelles was confirmed by fluorescence spectrophotoscopy, electrical conductivity and particle size measurements. It was found that all the nanomicelles showed spherical shapes with clear core-shell structures and narrow size distributions. Their sizes ranged from 80 to 160 nm, suggesting of their passive targeting potential to tumor tissue. With the increase of the molecular weight of mPEG, the sizes of mPEG-g-PAAsp-CDDP micelles showed a tendency to increase. mPEG-g-PAAsp-CDDP nanomicelles showed linear gradual drug release profiles in 40 h, suggestion of their sustained drug release behaviors. Compared with CDDP, mPEG-g-PAAsp-CDDP micelles showed essential decreased cytotoxicity to Bel-7402 cell line.

Preparation and characterization of amino-functionalized magnetic nanogels via photopolymerization for MRI applications.

To design peptide-targeted iron oxide as magnetic resonance imaging (MRI) contrast agents, amino-functionalized magnetic nanogels were prepared by using N-(2-aminoethyl) methacrylamide hydrochloride (AEM x HCl) as monomer via new photochemical approach. Their chemical structure and composition were characterized by Fourier transform infrared spectra (FTIR) and thermogravimetric analyses (TGA). The core-shell structure of magnetic nanogels was confirmed by high-resolution transmission electron microscopy (HRTEM). The good storage stability, high magnetic content (88.7%), high saturation magnetizations and superparamagnetic behavior suggested their great potentials as MRI contrast agents, which were confirmed by their measurements of r(2) and coronal image of the crossing of mouse kidney.