Application of molecular dynamics-based pharmacophore and machine learning approaches to identify novel Mcl1 inhibitors through drug repurposing and mechanics research.

Myeloid cell leukemia 1 (Mcl1), a critical protein that regulates apoptosis, has been considered as a promising target for antitumor drugs. The conventional pharmacophore screening approach has limitations in conformation sampling and data mining. Here, we offered an innovative solution to identify Mcl1 inhibitors with molecular dynamics-refined pharmacophore and machine learning methods. Considering the safety and druggability of FDA-approved drugs, virtual screening of the database was performed to discover Mcl1 inhibitors, and the hit was subsequently validated via TR-FRET, cytotoxicity, and flow cytometry assays. To reveal the binding characteristics shared by the hit and a typical Mcl1 selective inhibitor, we employed quantum mechanics and molecular mechanics (QM/MM) calculations, umbrella sampling, and metadynamics in this work. The combined studies suggested that fluvastatin had promising cell inhibitory potency and was suitable for further investigation. We believe that this research will shed light on the discovery of novel Mcl1 inhibitors that can be used as a supplemental treatment against leukemia and provide a possible method to improve the accuracy of drug repurposing with limited computational resources while balancing the costs of experimentation well.

Uncovering the selectivity mechanism of phosphodiesterase 7A/8A inhibitors through computational studies.

The expression of phosphodiesterase 7A (PDE7A) and phosphodiesterase 8A (PDE8) genes is integral to human signaling pathways, and the inhibition of PDE7A has been associated with the onset of various diseases, including effects on the immune system and nervous system. The development of PDE7 selective inhibitors can promote research on immune and nervous system diseases, such as multiple sclerosis, chronic inflammation, and autoimmune responses. PDE8A is expressed alongside PDE8B, and its inhibitory mechanism is still unclear. Studying the mechanisms of selective inhibitors against different PDE subtypes is crucial to prevent potential side effects, such as nausea and cardiac toxicity, and the sequence similarity of the two protein subtypes was 55.9%. Therefore, it is necessary to investigate the differences of both subtypes' ligand binding sites. Selective inhibitors of two proteins were chosen to summarize the reason for their selectivity through molecular docking, molecular dynamics simulation, alanine scanning mutagenesis, and MM-GBSA calculation. We found that Phe384PDE7A, Leu401PDE7A, Gln413PDE7A, Tyr419PDE7A, and Phe416PDE7A in the active site positively contribute to the selectivity towards PDE7A. Additionally, Asn729PDE8A, Phe767PDE8A, Gln778PDE8A, and Phe781PDE8A positively contribute to the selectivity towards PDE8A.

Transferrin receptor 1 promotes hepatocellular carcinoma progression and metastasis by activating the mTOR signaling pathway.

BACKGROUND: Aberrant iron metabolism is commonly observed in multiple tumor types, including hepatocellular carcinoma (HCC). However, as the key regulator of iron metabolism involved in iron absorption, the role of transferrin receptor (TFRC) in HCC remains elusive. METHODS: The mRNA and protein expression of TFRC were evaluated in paired HCC and adjacent non-tumor specimens. The correlation between TFRC level and clinicopathological features or prognostic significance was also analyzed. The role of TFRC on biological functions was finally studied in vitro and in vivo. RESULTS: The TFRC level was remarkably upregulated in HCC tissues compared to paired peritumor tissues. Overexpressed TFRC positively correlated with serum alpha-fetoprotein, carcinoembryonic antigen, and poor tumor differentiation. Multivariate analysis demonstrated that upregulated TFRC was an independent predictive marker for poorer overall survival and disease-free survival in HCC patients. Loss of TFRC markedly impaired cell proliferation and migration in vitro and notably suppressed HCC growth and metastasis in vivo, while overexpression of TFRC performed an opposite effect. Mechanistically, the mTOR signaling pathway was downregulated with TFRC knockdown, and the mTOR agonist MHY1485 completely reversed the biological inhibition in HCC cells caused by TFRC knockdown. Furthermore, exogenous ferric citrate (FAC) or iron chelator reversed the changed biological functions and signaling pathway expression of HCC cells caused by TFRC knockdown or overexpression, respectively. CONCLUSIONS: Our study indicates that TFRC exerts an oncogenic role in HCC and may become a promising therapeutic target to restrain HCC progression.

Synergistic Photochemo Effects Based on Light-Activatable Dual Prodrug Nanoparticles for Effective Cancer Therapy.

Ferroptosis is identified as a novel type of cell death with distinct properties involved in physical conditions and various diseases, including cancers. It is considered that ferroptosis provides a promising therapeutic strategy for optimizing oncotherapy. Although erastin is an effective ferroptosis trigger, the potential of its clinical application is largely restricted by its poor water solubility and concomitant limitations. To address this issue, an innovative nanoplatform (PE@PTGA) that integrated protoporphyrin IX (PpIX) and erastin coated with amphiphilic polymers (PTGA) to evoke ferroptosis and apoptosis is constructed and exemplified using an orthotopic hepatocellular carcinoma (HCC) xenograft mouse model as a paradigm. The self-assembled nanoparticles can enter HCC cells and release PpIX and erastin. With light stimulation, PpIX exerts hyperthermia and reactive oxygen species to inhibit the proliferation of HCC cells. Besides, the accumulated reactive oxygen species (ROS) can further promote erastin-induced ferroptosis in HCC cells. In vitro and in vivo studies reveal that PE@PTGA synergistically inhibits tumor development by stimulating both ferroptosis- and apoptosis-related pathways. Moreover, PE@PTGA has low toxicity and satisfactory biocompatibility, suggesting its promising clinical benefit in cancer treatments.

[Effect of Astragali Radix-Curcumae Rhizoma compatibility combined with 5-fluorouracil on Th17/Treg balance and tumor-related mRNA and protein expression in orthotopic xenograft model mice of CT26.WT colorectal carcinoma].

Astragali Radix-Curcumae Rhizoma(AR-CR) is a combination commonly used in the clinical treatment of tumors. Based on the T helper 17(Th17)/regulatory T cell(Treg) balance, the present study explored the possible mechanism of AR-CR combined with 5-fluorouracil(5-FU) on the tumor growth of orthotopic xenograft model mice of colorectal carcinoma. Ninety male BALB/c mice were randomly divided into nine groups, i.e., a blank group, a model group, a 5-FU group, high-, medium-, and low-dose AR-CR(2∶1) groups, and high-, medium-, and low-dose AR-CR+5-FU groups, with 10 mice in each group. The orthotopic xenograft model of CT26.WT colorectal carcinoma was induced in mice except those in the blank group. Twenty-four hours after the ope-ration, mice in the blank group and the model group received normal saline by gavage(10 mL·kg~(-1), once per day), and those in the 5-FU group received 5-FU by intraperitoneal injection(25 mg·kg~(-1), once every other day). Mice in the AR-CR groups received AR and CR decoctions by gavage(12, 6, and 3 g·kg~(-1), once a day) and those in the combination groups received AR and CR decoctions and 5-FU(doses and administration methods were the same as above). After intervention for three weeks, all mice were sacrificed and tumor tissues were collected. The tumor mass was weighed and the average tumor weight was calculated. The changing trend of Th17/Treg(%) in the CD4~+T lymphocytes of the spleen tissues of the mice in each group was detected. The mRNA expression in the blood and protein expression in the tumor tissues of transforming growth factor-ß(TGF-ß), tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ), Smad4, N-cadherin, matrix metalloproteinase-7(MMP-7) were detected. The experimental results revealed that compared with the model group, the groups with drug intervention showed reduced tumor mass(P<0.01), decreased CD4~+IL-17~+ in the spleen tissues to varying degrees(P<0.001), and increased proportion of CD4~+Foxp3~+(P<0.001 or P<0.05), indicating that Th17/Treg maintained dynamic balance, and the effect of the combination groups was predominant. Additionally, the mRNA expression in the blood and protein expression in the tumor tissues of TGF-ß, TNF-α, IFN-γ, Smad4, N-cadherin, and MMP-7 declined to varying degrees in a dose-dependent manner(P<0.01 or P<0.001). The AR-CR combined with 5-FU can inhibit the tumor growth of orthotopic xenograft model mice of CT26.WT colorectal carcinoma. The mechanism may be related to maintenance of Th17/Treg dynamic balance in the body and down-regulation of TGF-ß, TNF-α, IFN-γ, Smad4, N-cadherin, and MMP-7 expression.

Role of caspase-8 in stem cell transplantation alleviates rat cerebral cortex apoptosis after cardiopulmonary resuscitation / 中华危重病急救医学

Objective:To explore the effects and the possible mechanism of bone marrow mesenchymal stem cell (BMMSC) transplantation on apoptosis in rats cerebral cortex after cardiac arrest/cardiopulmonary resuscitation (CA/CPR).Methods:The BMMSC of 2 Sprague-Dawley (SD) rats aged 4-5weeks was extracted, and the 3rd passage was used in experimental study. Eighteen Sprague-Dawley (SD) rats were divided into sham group, model group (CA/CPR group) and intervention group (BMMSC group) according to random number table method, with 6 rats in each group. CPR was performed 6 minutes after asphyxia induced CA. In sham group, CA was not induced except performing general surgical procedure. At 1 hour after return of spontaneous circulation (ROSC), 0.5 mL phosphate buffered saline (PBS) was injected through tail vein in CA/CPR group. 2×10 9/L green fluorescence protein (GFP)-labeled BMMSC was injected through tail vein 1 hour after ROSC in BMMSC group. Neurological deficit score (NDS) were assessed in every group at 72 hours after CPR. Serum S100 calcium binding protein B (S100B) levels were assayed by enzyme linked immunosorbent assay (ELISA). Distribution of BMMSC in brain was observed under a fluorescent microscope. Apoptosis rate in cerebral cortex was assayed by TdT-mediated dUTP nick-end labeling (TUNEL). Western blotting was performed to measure the expression levels of active aspartic acid specific cysteine proteinase (caspase-8 and caspase-9) in cerebral cortex. Results:At 3 days after CPR, compared with sham group, the apoptosis of cerebral cortex cells was increased and brain damage was obvious, NDS score was decreased significantly (56.6±5.5 vs. 80.0±0.0, P < 0.05), and serum S100B was increased markedly (ng/L: 45.1±4.7 vs. 19.1±1.4, P < 0.05), apoptosis rate of cerebral cortex cells increased significantly [(52.9±11.8)% vs. (10.1±1.5)%, P < 0.05], the level of active caspase-8 expression in cerebral cortex was significantly higher (caspase-8/GAPDH: 0.689±0.047 vs. 0.330±0.108, P < 0.05), and there was no significant difference in active caspase-9 protein expression (caspase-9/GAPDH: 0.428±0.014 vs. 0.426±0.021, P > 0.05) in CA/CPR group. After BMMSC transplantation, GFP-labeled BMMSC were primarily detected in cerebral cortex, compared with CA/CPR group, the apoptosis of cerebral cortex cells and brain injury were significantly improved in BMMSC group, NDS score increased significantly (70.6±2.1 vs. 56.6±5.5, P < 0.05), serum S100B levels in BMMSC group were lower (ng/L: 32.0±3.2 vs. 45.1±4.7, P < 0.05), apoptosis rate of cerebral cortex cells decreased significantly [(31.1±3.4)% vs. (52.9±11.8)%, P < 0.05], and the active caspase-8 expression in cerebral cortex in BMMSC group was significantly decreased (caspase-8/GAPDH: 0.427±0.067 vs. 0.689±0.047, P < 0.05). The active caspase-9 expression in cerebral cortex in BMMSC group and CA/CPR group were not significantly different (caspase-9/GAPDH: 0.431±0.022 vs. 0.428±0.014, P > 0.05). Conclusion:BMMSC transplantation can alleviate rat brain damage after CA/CPR possibly by inhibiting the death receptor mediated apoptotic pathway to inhibit the apoptosis of brain cells.

Characterization of the complete chloroplast genome of Alsophila spinulosa, an endangered species endemic to China.

Tree fern Alsophila spinulosa is an endangered relic plant in the world. It is currently on the International Union for Conservation of Nature (IUCN) red list of threatened species. In this study, we first assembled the complete chloroplast (cp) genome of A. spinulosa by Illumina paired-end reads data. The whole genome was 156,661 bp, consisting of a pair of inverted repeats of 24,364 bp, large single copy region and a small single copy region (70,352 and 21,624 bp in length, respectively). The cp genome contained 133 genes, including 92 protein-coding genes, 33 trRNA genes, and eight rRNA genes. The overall GC content of the whole genome was 40.4%. A neighbour-joining phylogenetic analysis demonstrated a close relationship between A. spinulosa and Cystoathyrium chinense Ching.

Predictive value of p16INK4a, Ki-67 and ProExC immuno-qualitative features in LSIL progression into HSIL.

The current nested case-control study was conducted to explore the prognostic value of cyclin-dependent kinase inhibitor 2A (p16INK4a), marker of proliferation Ki-67 (Ki-67) and immunohistochemical cocktail containing antibodies directed against topoisomerase IIα (TOP2A) and minichromosome maintenance 2 (MCM2) proteins (ProExC) immuno-qualitative features to predict low-grade squamous intraepithelial lesion (LSIL) progression. A total of 92 LSIL patients were followed-up for 2 years, where those with high-grade squamous intraepithelial lesion (HSIL) or persistent LSIL were designated as the case group and those who spontaneously regressed were designated as the control group. The infection status of human papillomavirus (HPV) was evaluated using flow-through hybridization and gene chip, whilst the expression of p16INK4a, Ki-67 and ProExC were tested in LSIL patient biopsies by immunohistochemistry. All data were collected at the beginning of the follow-up and patient outcomes were diagnosed by histopathological examination. To analyze the risk factors for LSIL progression, sensitivity, specificity, positive-negative predictive value (PPV-NPV), positive-negative likelihood ratio (PLR-NLR), Youden's index (YI) and multinomial logistic regression analysis was performed. The expression rates of p16INK4a, Ki-67, and ProExC were found to be higher in the progression group compared with those in the persistence and regression groups. Only p16INK4a expression significantly associated with high-risk HPV infection. With respect to predicting HSIL, p16INK4a staining was the most sensitive but Ki-67 staining was found to be the most specific. YI was the highest (42.1%) for p16INK4a expression in the present study, followed by ProExC (39.5%) and Ki-67 (28.3%). However, the expression of ProExC was found to be an independent risk factor for LSIL progression into HSIL. In conclusion, whilst immunohistochemical staining for p16INK4a, Ki-67, and ProExC can be used to predict HSIL progression, only ProExC expression can be applied an independent risk factor for LSIL progression.

The complete chloroplast genome sequence of Camellia granthamiana.

Camellia granthamiana is a rare and endangered plant peculiar to China, and a total of 5 plants have been found at present. Based on the next generation sequencing, the whole chloroplast (Cp) genome of (Camellia granthamiana Sealy) of Camellia oleifera was constructed.In this study, the complete chloroplast (cp) genome of Camellia granthamiana was assembled based on next generation sequencing.The cp genome was 157,001 bp in length, including a large single copy (LSC) region of 70,387 bp, a small single copy (SSC) region of 18,296 bp and a pair of inverted repeats (IRs) of 52,082 bp. The genome contained 135 genes, including 90 protein-coding genes, 37 tRNA genes and 8 ribosomal RNA genes. The majority of these gene species occurred as a single copy.

Characterization of the complete chloroplast genome of Ginkgo biloba L. (Ginkgoaceae), an endangered species endemic to China.

Ginkgo biloba L. is the oldest relict plant among the gymnosperms, left after the quaternary glacial movement. There are few living G. biloba and few old trees over a hundred years old. It is currently on the International Union for Conservation of Nature (IUCN) red list of threatened species. In this study, we first assembled the complete chloroplast (cp) genome of G. biloba L. by Illumina paired-end reads data. The whole genome was 156,988 bp, consisting of a pair of inverted repeats of 34,056 bp, large and small single copy regions of 56,819 and 22,763 bp in length, respectively. The cp genome contained 131 genes, including 84 protein-coding genes, 31 trRNA genes and 5 rRNA genes. The overall GC content of the whole genome was 39.6%. A neighbour-joining phylogenetic analysis demonstrated a close relationship between G. biloba L. and Cycas revoluta.

Characterization of the complete chloroplast genome of Davidia involucrata Baill. (Nysssaceae), an endangered species endemic to China.

Davidia involucrata Baill. is a kind of tertiary paleotropical plant floristic relic species unique to China. This rare plant is disappearing due to poor adaptability and serious poaching. We first assembled the complete chloroplast (cp) genome of Davidia involucrata Baill. by Illumina paired-end reads data. The whole genome was 169,085 bp, consisting of a pair of inverted repeats of 169,379 bp, large single copy region and a small single copy region (96,712 and 67,667 bp in length, respectively). The cp genome contained 90 genes, including 64 protein-coding genes, 22 trRNA genes and 4 rRNA genes. The overall GC content of the whole genome was 38.04%. A neighbor-joining phylogenetic analysis demonstrated a close relationship between Davidia involucrata Baill. and Nyssa yunnanensis.

Application of modular cementless femoral stems in complex revision hip arthroplasty / 中国骨伤

<p><b>OBJECTIVE</b>To investigate and clarify the key surgical techniques and evaluate clinical effectiveness of modular cementless femoral stems(LINK MP modular stem) in complex revision hip arthroplasty.</p><p><b>METHODS</b>From January 2002 to December 2013, 470 patients in Chinese PLA General Hospital received revision hip arthroplasties using MP stems. Among them, 246 patients were followed for an average of 5.7 years (ranged, 0.5 to 11 years). There were 148 males and 98 females, with an average age of 62.5 years old (ranged from 26 to 83 years old). The most common reason for revision was aseptic loosening of femoral stems (107 cases, 43.5%), followed by prosthetic joint infection (104 cases, 42.3%). Other reasons included unexplained hip or thigh pain, periprosthetic femoral fracture, prosthesis wear and dislocation. According to Paprosky classification of femoral deficiency, there were 171 cases of type IIIA (69.5%), 14 cases of type I, 39 cases of type II, and 22 cases of type IIIB. The average preoperative Harris hip score (HHS) was 37.4 ± 7.5. In addition, radiographic presentation, degree of patients' subjective satisfaction, and clinical effectiveness were assessed as well.</p><p><b>RESULTS</b>The average Harris score was im- proved to 87.8 ± 4.2 after operation,with significant statistical difference when compared to preoperative score (t = 92.13,P = 0.00). Analysis of patients' subjective satisfaction for leg length discrepancy, stability and overall degree of satisfaction showed that the number of patients with great satisfaction were 27, 60, 61 respectively. The most common complication was the periprosthetic fracture (intraoperatively 21 cases and postoperatively 8 cases). Other complications included infection (7 cases), dislocation (5 cases), numbness possibly caused by incomplete sciatic nerve injury (6 cases) and thigh swelling (3 cases). The X-ray taken at the final follow-up revealed that prosthesis subsidence occurred in 4 cases, 2 of which needed a second revision.</p><p><b>CONCLUSION</b>The application of modular cementless femoral stems (LINK MP modular stem) in complex revision hip arthroplasty (especially in cases with the serious defect of proximal femoral bone) shows good results at both the short-term and long-term follow-up, especially in the revision for prosthetic infection with the high success rate. In order to avoid complications and improve clinical outcomes,the surgeons should carefully select proper surgery candidates,perform the procedure with care, and master the key surgical techniques.</p>

[Drosophila spen protein: generation of ployclonal antibodies, functional analysis and tissue-specific expression].

The spen family of proteins participates in various biological processes. It is involved in neuronal cell fate, survival and axon guidance, and cell cycle regulation. Recent studies showed the Drosophila spen gene was required for Wnt-dependent signaling in the eye, wing and leg. However, the genetic role and biological function in Drosophila remain largely unclear. A Drosophila C-terminal fragment of spen was cloned and expresed in E. coli. The purified 6×His-spen protein was injected into SD rat to generate polyclonal antibodies. Subcellular localization and tissue-specific expression of spen protein were analysed by immunostaining and histoimmunochemistry. The results indicated that spen protein was localized in the nucleus and expressed at high levels in brain, fat body, hemocyte, gut and salivary gland. To assay the function of mutant hemocytes in vivo, wild-type and spen mutant larvae were infected with fluorescent microspheres. Wild-type hemocytes showed a strong fluorescence signal from the phagocytosed microspheres; however, spen mutant had a weak fluorescence signal, indicating that the mutant hemocytes were defective in the uptake of the microspheres.

Growth and wood/bark properties of Abies faxoniana seedlings as affected by elevated CO2.

Growth and wood and bark properties of Abies faxoniana seedlings after one year's exposure to elevated CO2 concentration (ambient + 350 (+/- 25) micromol/mol) under two planting densities (28 or 84 plants/m(2)) were investigated in closed-top chambers. Tree height, stem diameter and cross-sectional area, and total biomass were enhanced under elevated CO2 concentration, and reduced under high planting density. Most traits of stem bark were improved under elevated CO2 concentration and reduced under high planting density. Stem wood production was significantly increased in volume under elevated CO2 concentration under both densities, and the stem wood density decreased under elevated CO2 concentration and increased under high planting density. These results suggest that the response of stem wood and bark to elevated CO2 concentration is density dependent. This may be of great importance in a future CO2 enriched world in natural forests where plant density varies considerably. The results also show that the bark/wood ratio in diameter, stem cross-sectional area and dry weight are not proportionally affected by elevated CO2 concentration under the two contrasting planting densities. This indicates that the response magnitude of stem bark and stem wood to elevated CO2 concentration are different but their response directions are the same.