Constructing artificial gap junctions to mediate intercellular signal and mass transport.

Natural gap junctions are a type of channel protein responsible for intercellular signalling and mass communication. However, the scope of applications for these proteins is limited as they cannot be prepared at a large scale and are unable to spontaneously insert into cell membranes in vitro. The construction of artificial gap junctions may provide an alternative strategy for preparing analogues of the natural proteins and bottom-up building blocks necessary for the synthesis of artificial cells. Here we show the construction of artificial gap junction channels from unimolecular tubular molecules consisting of alternately arranged positively and negatively charged pillar[5]arene motifs. These molecules feature a hydrophobic-hydrophilic-hydrophobic triblock structure that allows them to efficiently insert into two adjacent plasma membranes and stretch across the gap between the two membranes to form gap junctions. Similar to natural gap junction channels, the synthetic channels could mediate intercellular signal coupling and reactive oxygen species transmission, leading to cellular activity.

Forrestiacids E-K: Further [4 + 2]-Type Triterpene-Diterpene Hybrids as Potential ACL Inhibitors from the Vulnerable Conifer Pseudotsuga forrestii.

Seven [4 + 2]-type triterpene-diterpene hybrids derived from a rearranged or a normal lanostane unit (dienophile) and an abietane moiety (diene), forrestiacids E-K (1-7, respectively), were further isolated and characterized from Pseudotsuga forrestii (a vulnerable conifer endemic to China). The intriguing molecules were revealed with the guidance of an LC-MS/MS-based molecular ion networking strategy combined with conventional phytochemical procedures. Their chemical structures with absolute configurations were established by spectroscopic data, chemical transformation, electronic circular dichroism calculations, and single-crystal X-ray diffraction analysis. They all contain a rare bicyclo[2.2.2]octene motif. Both forrestiacids J (6) and K (7) represent the first examples of this unique class of [4 + 2]-type hybrids that arose from a normal lanostane-type dienophile. Some isolates remarkably inhibited ATP-citrate lyase (ACL), with IC50 values ranging from 1.8 to 11 µM. Docking studies corroborated the findings by highlighting the interactions between the bioactive compounds and the ACL enzyme (binding affinities: -9.9 to -10.7 kcal/mol). The above findings reveal the important role of protecting plant species diversity in support of chemical diversity and potential sources of new therapeutics.

Clinical Implications of Necroptosis Genes Expression for Cancer Immunity and Prognosis: A Pan-Cancer Analysis.

Background: Necroptosis, a form of programmed cell death, is increasingly being investigated for its controversial role in tumorigenesis and progression. Necroptosis suppresses tumor formation and tumor development by killing tumor cells; however, the necrotic cells also promote tumor formation and tumor development via the immunosuppressive effect of necroptosis and inflammatory response caused by cytokine release. Thus, the exact mechanism of necroptosis in pan-cancer remains unknown. Methods: The data of 11,057 cancer samples were downloaded from the TCGA database, along with clinical information, tumor mutation burden, and microsatellite instability information of the corresponding patients. We used the TCGA data in a pan-cancer analysis to identify differences in mRNA level as well as single nucleotide variants, copy number variants, methylation profiles, and genomic signatures of miRNA-mRNA interactions. Two drug datasets (from GDSC, CTRP) were used to evaluate drug sensitivity and resistance against necroptosis genes. Results: Necroptosis genes were aberrantly expressed in various cancers. The frequency of necroptosis gene mutations was highest in lung squamous cell carcinoma. Furthermore, the correlation between necroptosis gene expression in the tumor microenvironment and immune cell infiltration varied for different cancers. High necroptosis gene expression was found to correlate with NK, Tfh, Th1, CD8_T, and DC cells. These can therefore be used as biomarkers to predict prognosis. By matching gene targets with drugs, we identified potential candidate drugs. Conclusion: Our study showed the genomic alterations and clinical features of necroptosis genes in 33 cancers. This may help clarify the link between necroptosis and tumorigenesis. Our findings may also provide new approaches for the clinical treatment of cancer.

Liriogerphines A-D, a Class of Sesquiterpene-Alkaloid Hybrids from the Rare Chinese Tulip Tree Plant.

Liriogerphines A-D (1-4, respectively), an unprecedented class of hybrids of germacranolide-type sesquiterpenoids and aporphine-type alkaloids, were isolated from the rare medicinal plant Liriodendron chinense. Their structures were elucidated by comprehensive spectroscopic analyses combined with electronic circular dichroism calculations and X-ray crystallographic data. Biosynthetically, an aza-Michael addition reaction is proposed to be involved in the assemblies of this class of hybrids. Compound 4 exhibited cytotoxicity against leukemia cells via inducing apoptosis and inhibiting Bcl-2 expression.

Beshanzoides A-D, unprecedented cycloheptanone-containing polyketides from Penicillium commune P-4-1, an endophytic fungus of the endangered conifer Abies beshanzuensis.

A number of previously undescribed (1-7) and structurally related known (8-17) isobenzofuran-type polyketides were obtained from the fermentation of Penicillium commune P-4-1, an endophytic fungus isolated from the fresh trunk bark of the critically endangered conifer Abies beshanzuensis. Beshanzoides A-D (1-4, resp.) feature a cycloheptanone-containing isobenzofuran ring system hitherto unknown, which might be biosynthesized via two steps of aldol reactions starting from a common co-occurring isobenzofuran-type polyketide as the precursor. The new structures were elucidated by spectroscopic methods, electronic circular dichroism data, and single crystal X-ray diffraction analyses. Beshanzoide E (5) showed antimicrobial activity (MIC: 16 µg mL-1) against Staphylococcus aureus, whereas (±)-strobide A (10) inhibited (MIC: 16 µg mL-1) Candida albicans. Cyclopaldic acid (12) and 3-O-methyl-cyclopaldic acid (13) exhibited inhibitory effects against acetyl-CoA carboxylase 1 (ACC1) with IC50 values of 0.96 and 11.77 µM, respectively. Compound 12 also inhibited (IC50: 7.56 µM) ATP-citrate lyase (ACL).

Design of a microfluidic chip consisting of micropillars and its use for the enrichment of nasopharyngeal cancer cells.

The aim of the present study was to discuss the design of a microfluidic chip consisting of columns, and its use for the enrichment of nasopharyngeal cancer (NPC) cells. A microfluidic chip experiment was simulated using FLUENT software. Within the microfluidic chip, aptamers were bound to the reaction chamber (consisting of columns) using a biotin-avidin system. Cell suspension was introduced into the reaction chamber to capture NPC cells. NPC cells were subsequently eluted, and the capture rate of the cells was calculated. The modified aptamer-bound microfluidic chip was able to capture NPC cells with a capture rate of ~90%. The modified aptamer-bound microfluidic chip has a wide range of potential applications for the diagnosis of NPC.

Structural Modifications of Diarylpyrimidine-quinolone Hybrids as Potent HIV-1 NNRTIs with an Improved Drug Resistance Profile.

Earlier we reported the identification of diarylpyrimidine-quinolone hybrids as a new class of HIV-1 NNRTIs. A few of these hybrids displayed moderate inhibitory activity against wt HIV-1 replication at submicromolar level, however, all of them lacked inhibitory activity against the double mutant virus (K103N/Y181C), which is the most prevalent NNRTI resistant-associated double mutant observed in the clinic. In the present study, we designed and synthesized a new series of diarylpyrimidine-quinolone hybrids featuring a halogen group at C-6' position of quinolone ring. The biological results indicated that most of these hybrids could inhibit wt HIV-1 replication at nanomolar level ranging from 0.088 to 0.0096 µM. The most promising hybrid 5c displayed a significant EC50 value of 0.0096 µM against HIV-1 IIIB and of 0.98 µM against K103N/Y181C. Further docking studies revealed that these hybrids could be well located in the hydrophobic NNIBP of HIV-1 RT despite the bulky and polar properties of a quinolone 3-carboxylic acid scaffold in the molecules. These promising results suggested a high potential to further develop these hybrids as next-generation NNRTIs with improved antiviral efficacy and resistance profile.

Antibacterial mechanism and activities of black pepper chloroform extract.

Black pepper extracts reportedly inhibit food spoilage and food pathogenic bacteria. This study explored the antimicrobial activity of black pepper chloroform extract (BPCE) against Escherichia coli and Staphylococcus aureus. The antibacterial mechanism of BPCE was elucidated by analyzing the cell morphology, respiratory metabolism, pyruvic acid content, and ATP levels of the target bacteria. Scanning electron micrographs showed that the bacterial cells were destroyed and that plasmolysis was induced. BPCE inhibited the tricarboxylic acid pathway of the bacteria. The extract significantly increased pyruvic acid concentration in bacterial solutions and reduced ATP level in bacterial cells. BPCE destroyed the permeability of the cell membrane, which consequently caused metabolic dysfunction, inhibited energy synthesis, and triggered cell death.

Pyrimidine sulfonylacetanilides with improved potency against key mutant viruses of HIV-1 by specific targeting of a highly conserved residue.

Based on molecular simulation, the etravirine-VRX-480773 hybrids previously disclosed by our group were optimized to yield novel pyrimidine sulfonylacetanilides 8 with improved activity against a panel of seven clinically relevant single and double mutant strains of HIV-1. The improvement in potency in this in vitro model of HIV RNA replication partly validates the mechanism by which this class of allosteric pyrimidine derivatives inhibits the reverse transcriptase (RT), and represents a remarkable step forward in the development of anti-HIV drugs.

Anti-HIV diarylpyrimidine-quinolone hybrids and their mode of action.

A molecular hybridization approach is a powerful tool in the design of new molecules with improved affinity and efficacy. In this context, a series of diarylpyrimidine-quinolone hybrids were synthesized and evaluated against both wt HIV-1 and mutant viral strains. The most active hybrid 5a displayed an EC50 value of 0.28±0.07µM against HIV-1 IIIB. A couple of enzyme-based assays clearly pinpoint a RT-targeted mechanism of action. Docking studies revealed that these hybrids could be well located in the NNIBP of HIV-1 RT despite the bulky and polar properties of a quinolone 3-carboxylic acid moiety in the molecules.

Synthesis and biological evaluation of DAPY-DPEs hybrids as non-nucleoside inhibitors of HIV-1 reverse transcriptase.

A series of new DAPY-DPEs hybrids, combined the important pharmacophores of DAPYs and DPEs, has been synthesized and biologically evaluated for their anti-HIV activities against wild-type HIV-1 strain IIIB, double RT mutant (K103N+Y181C) strain RES056 and HIV-2 strain ROD in MT-4 cell cultures. Many promising candidates with potent inhibitory activity (wild-type) within the EC50 range from 0.16 to 0.013 µM were obtained. In particular, 3c, 3p, 3r and 3s displayed low nM level EC50 values (35, 13, 50 and 17 nM, respectively) and high selectivity (9342, 25131, 2890 and 11338, respectively), which were much more potent than NVP (EC50=0.31 µM, SI=48), 3TC (EC50=2.24 µM, SI>39), DDI (EC50=23.20 µM, SI>9) and DLV (EC50=0.65 µM, SI>67), and comparable to AZT (EC50=0.0071 µM, SI>13144) and EFV (EC50=0.0062 µM, SI>1014). The HIV-1 reverse transcriptase inhibitory assay confirmed that these DAPY-DPEs hybrids targeted HIV-1 RT. Molecular simulation was performed to investigate the potential binding mode of the newly synthesized compounds. And reasonable explanation for the activity results was discussed with docking method.

Optimization of extraction conditions of areca seed polyphenols and evaluation of their antioxidant activities.

Polyphenols are functional compounds in plants, which possess many bioactivities beneficial for humans. The aim of this study was to establish a highly efficient method for extracting polyphenol compounds from areca seeds and further to identify polyphenols and antioxidant properties of the seeds. A quadratic general rotary unitized design was used to determine the optimal extraction process. The polyphenols were identified using LC-TOF-MS. By comparison with ascorbic acid (Vc), the antioxidant activities of the ethanol extracts were evaluated using three complementary in vitro assays: inhibition of the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity, hydroxyl radical-scavenging activity, and reducing ability. The two major polyphenols obtained were epicatechin and syringic acid. The ethanol extracts of areca seeds showed significantly greater antioxidant activity (p < 0.05) than Vc using the DPPH and reducing power assay, but lower ability (p < 0.05) using the hydroxyl radical assay. The results indicate that the areca seed is an excellent food material with potential antioxidant properties.

Synthesis and biological evaluation of CHX-DAPYs as HIV-1 non-nucleoside reverse transcriptase inhibitors.

A series of new diarylpyrimidines (DAPYs) characterized by a halogen atom on the methylene linker between wing I and the central pyrimidine ring was synthesized and evaluated for their anti-HIV activity in MT-4 cell cultures. The two most promising compounds 7f and 7g showed excellent activity against wild-type HIV-1 with low nanomolar EC50 values of 0.005 and 0.009 µM, respectively, which were comparable to or more potent than all the reference drugs zidovudine (AZT), lamivudine (3TC), nevirapine (NEV), efavirenz (EFV), delaviridine (DLV) and etravirine (ETV). In particular, 7g also displayed strong activity against the double mutant strain 103N + 181C with an EC50 value of 8.2 µM. The preliminary structure-activity relationship (SAR) and molecular docking analysis of this new series of CHX-DAPYs were also investigated.

Structural modifications of CH(OH)-DAPYs as new HIV-1 non-nucleoside reverse transcriptase inhibitors.

A series of CR2(OH)-diarylpyrimidine derivatives (CR2(OH)-DAPYs) featuring a hydrophobic group at CH(OH) linker between wing I and the central pyrimidine were synthesized and evaluated for their anti-HIV activity in MT-4 cell cultures. All the target compounds except for compound 3k displayed inhibitory activity against HIV-1 wild-type with EC50 values ranging from 7.21±1.99 to 0.067±0.006 µM. Among them, compound 3d showed the most potent anti-HIV-1 activity (EC50=0.067±0.006 µM, SI>592), which was approximately 2-fold more potent than the reference drugs nevirapine (NVP) and delaviridine (DLV) in the same assay. In addition, the binding modes with HIV-1 RT and the preliminary SAR studies of these new derivatives were also investigated.

[Study on hypoglycemic effect and mechanism of total flavonoids of Propolis in STZ diabetic rats].

OBJECTIVE: To study hypoglycemic effect and mechanism of the total flavonoids of Propolis (TFP) in the STZ diabetic rats. METHODS: The model of type 2 diabetic rats was induced by high-fat diet feeding for 4 weeks combined with intraperitoneal injection of streptozotocin (STZ). Then the rats without above-mentioned treatment were selected as the normal control group,the diabetic rats were randomly divided into four groups by blood glucose, the model control group, high doses (240 mg/kg), medium doses (120 mg/kg) and low doses (60 mg/kg) TFP groups. The TFP preparation was intragastric administration given to rats in TFP groups. The model control rats were treated intragastric administration with 0.5% sodium carboxymethyl cellulose (CMC-Na) for 4 weeks. The rats were fed with high fat diet during treatment. 12 hours after the last administration, glucose (GLU), total cholesterol (TC), triglyceride (TG), high density lipoprotein( HDL-C), low density lipoprotein LDL-C), glycated hemoglobin (GHb), serum insulin INS), C-peptide (C-P), superoxide dismutase( SOD), malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor-alpha (TNF-alpha), free fatty acid (FFA), nitric oxide (NO), and hepatic glycogen were determined. RESULTS: Compared with the normal group, the levels of GLU, TC, TG, HDL-C, FFA, TNF-alpha, NO, MDA and GHb in serum were increased significantly in the model control group (P < 0.05-P < 0.001), the levels of HDL-C, INS, C-P, SOD and GSH in serum and hepatic glycogen in hepatic tissue were decreased significantly (P < 0.01 or P < 0.001). The levels of all above indexes of high and medium doses groups were improved significantly compared with the model control group (P < 0.05-P < 0.01). CONCLUSION: TFP can significantly decrease the level of blood glucose,improve the glucose and lipid metabolism and inhibit insulin resistance in STZ diabetic rats.

Towards new C6-rigid S-DABO HIV-1 reverse transcriptase inhibitors: synthesis, biological investigation and molecular modeling studies.

A series of C6-rigid S-DABO analogs characterized by a substituted benzoyl group at C6 position of the pyrimidine ring has been synthesized and biological evaluation as NNRTIs against wild-type HIV-1 strain IIIB, double RT mutant (K103N+Y181C) strain RES056 as well as HIV-2 strain ROD in MT-4 cell cultures. Most of the compounds exhibited moderate antiviral activities. Among them, compound 7q displayed the highest anti-HIV-1 activity with an EC50 value of 0.26µM and a selectivity index (SI) of 541. The preliminary structure-activity relationship (SAR) of these new S-DABOs was investigated, the target RT was confirmed and docking study was performed.

[Comparative study on effect and safty of treating on calcaneus fractures with manipulative reduction with percutaneous K-wire fixation].

OBJECTIVE: To explore the clinical effects and safty of manipulative reduction with percutaneous poking K-wire fixation for the treatment of the calcaneus fractures and analyze the indication of the minimal invasion. METHODS: From December 2008 to December 2011,135 closed calcaneal fractures cases were divided randomly into poking group and plate group, treated respectively by percutaneous poking reduction and operative reduction. In poking group, there were 69 cases (82 feet) including 60 males and 9 females, with an average age of (43.29+/-10.46) years ranging from 18 to 64 years; 30 cases of left, 26 cases of right and 13 cases of double; 54 feet of Essex-Lopresti classification tongue form, 28 feet of joint compression; 33 feet of Sanders type II ,49 of type III. In plate group, there were 66 cases (75 feet) including 58 males and 8 females,with an average age of (46.00+/-2.42) years ranging from 21 to 63 years; 31 cases of left, 26 cases of right and 9 cases of double; 48 feet of Essex-Lopresti classification tongue form, 27 feet of joint compression; 28 feet of Sanders type II, 47 of type III. According to Kerr scoring standard,clinical effects and complications were evaluated combining with Sanders and Essex-Lopresti classification. RESULTS: All 135 cases were followed up after 24 weeks. Fractures were recoveried in 8 to 12 weeks (means 10.2 weeks). In poking group, there were 2 cases of infection, 5 cases of wire movement; in plate group,18 cases of wound local skin necrosis, 5 cases of calf intestines nerve injured; there were statistical significant (P<0.05). Postoperative evaluation of Sanders type II after 24 weeks, the proportion of excellent results was above 70%,and there were no significant differences on effects of tongue form and compressing form of calcaneus fractures with percutaneous poking and operative redution (P>0.05). In the caes of Sanders type III, there were no significant differences on effects of tongue form fractures with percutaneous poking and operative reduction (P>0.05). There were significant differences on effects and complications of compressing form fractures (P<0.01), operative reduction better than percutaneous poking. Pain, walking,Kerr scoring of tongue form fractures of Sanders II , III with poking reduction were better than compression fractures. In compression fractures of Sanders Ill, plate internal fixation was better than poking redution in working and walking function, there were significant difference (P<0.05). CONCLUSION: For tongue form or compressing form of Sanders type II and tongue form of Sanders type III, manipulative reduction with percutaneous poking K-wire fixation has advantages of minimal invasion, minimized complications. Compressing form of Sanders type III fracture should be treated with operative redution.

[Case-control study on bone setting manipulation for the treatment of over degree II supination-eversion fractures of ankle joint].

OBJECTIVE: To explore therapeutic effects of bone setting manipulation for the treatment of over degree II supination-eversion fractures of ankle,and analyze manipulative reduction mechanism. METHODS: From 2005 to 2008, 95 patients with over degree II supination-eversion fractures of ankle were treated respectively by manipulation and operation. There were 43 cases [11 males and 32 females with an average age of (44.95 +/- 12.65) years] in manipulation group, and 2 cases were degree II, 11 cases were degree III, and 30 cases were degree IV. There were 52 cases [21 males and 31 females with an average age of (39.96 +/- 13.28) years] in operative group,and 6 cases were degree II, 18 cases were degree III, and 28 cases were degree IV. Bone setting manipulation and hard splint external fixation were applied to manipulative group. Operative reduction internal fixation was performed in operative group. X-ray was used to evaluate reduction of fracture before and after treatment, 2 months after treatment. Ankle joint function was evaluated according to Olerud-Molander scoring system after 6 months treatment. RESULTS: All patients were followed up with good reduction. Three cases occurred wound complication in operative group, but not in manipulative group. In manipulation group, 19 cases got excellent results, 20 cases good and 4 cases fair; while in operative group, 30 cases got excellent results, 20 cases good and 2 cases poor. There were no significant differences in fracture reduction and ankle joint function recovery between two groups (P > 0.05). Efficacy of operative treatment was better than that of manipulative treatment at degree IV fracture (P < 0.05). CONCLUSION: Bone setting manipulation is a good method for treating supination-eversion ankle joint fractures, which has advantages of simple and safe operation, reliable efficacy. For ankle join fracture at degree IV, manipulative reduction should be adopted earlier, and operative treatment also necessary

NMR studies on chiral intermediates in the total synthesis of (+)-biotin from D-mannose.

The chemical structure and stereochemistry of 12 intermediates in the total synthesis of (+)-biotin starting from D-mannose as chiral pool were completely assigned using one- and two-dimensional NMR experiments, including 1D selective NOE, DEPT, COSY, HSQC and HMBC.

[Relationship between the expression of P-glycoprotein, glutathione S-transferase-pi and thymidylate synthase proteins and adenosine triphosphate tumor chemosensitivity assay in cervical cancer].

OBJECTIVE: To explore the feasibility of the adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA) in human cervical cancer chemosensitivity testing and to analyze the relationship between the three drug resistance-associated proteins: P-glycoprotein (P-gp); glutathione S-transferase-pi (GST-pi); thymidylate synthase (TS) and ATP-TCA. METHODS: ATP-TCA was used to detect the sensitivity of 35 specimens of fresh cervical cancer to six cytotoxic drugs as follows: paclitaxel (TAX), cisplatin (DDP), bleomycin (BLM), gemcitabine (GEM), 5-fluorouracil (5-FU), irinotecan (CPT-11). Consecutive sections from 35 cases of cervical cancer were assessed immunohistochemically for expression of P-gp, GST-pi and TS proteins. RESULTS: (1) Thirty-two of 35 assays were completed successfully, with an evaluability rate of ATP-TCA at 91% (32/35). There was a marked heterogeneity of chemosensitivity in cervical cancer. The ex vivo sensitive rate of TAX was 88% (28/32), of 5-FU 72% (23/32), of GEM 62% (20/32), of DDP 19% (6/32), of BLM 16% (5/32), and of CPT-11 12% (4/32). (2) The expression of GST-pi and TS protein in cervical cancer was 66% (21/32) and 44% (14/32), which was associated with the resistance to DDP and 5-FU ex vivo (P=0.011, P=0.022), respectively; but the expression of P-gp protein was not associated with any resistance to TAX, 5-FU, GEM, DDP, BLM or CPT-11 ex vivo (P>0.05). CONCLUSIONS: ATP-TCA could be used to individualize chemotherapy by selecting agents for particular patients of cervical cancer. The expression of GST-pi and TS protein might be useful biomarkers to predict the resistance to DDP and 5-FU in patients with cervical cancer.