The unfolded protein response is required to maintain the integrity of the endoplasmic reticulum, prevent oxidative stress and preserve differentiation in β-cells

Diabetes is an epidemic of worldwide proportions caused by β-cell failure. Nutrient fluctuations and insulin resistance drive β-cells to synthesize insulin beyond their capacity for protein folding and secretion and thereby activate the unfolded protein response (UPR), an adaptive signalling pathway to promote cell survival upon accumulation of unfolded protein in the endoplasmic reticulum (ER). Protein kinase-like endoplasmic reticulum kinase (PERK) signals one component of the UPR through phosphorylation of eukaryotic initiation factor 2 on the α-subunit (eIF2α) to attenuate protein synthesis, thereby reducing the biosynthetic burden. β-Cells uniquely require PERK-mediated phosphorylation of eIF2α to preserve cell function. Unabated protein synthesis in β-cells is sufficient to initiate a cascade of events, including oxidative stress, that are characteristic of β-cell failure observed in type 2 diabetes. In contrast to acute adaptive UPR activation, chronic activation increases expression of the proapoptotic transcription factor CAAT/enhancer-binding protein homologous protein (CHOP). Chop deletion in insulin-resistant mice profoundly increases β-cell mass and prevents β-cell failure to forestall the progression of diabetes. The findings suggest an unprecedented link by which protein synthesis and/or misfolding in the ER causes oxidative stress and should encourage the development of novel strategies to treat diabetes.

Optimization of selected cultivation parameters for Cordyceps guangdongensis

AIMS

To increase the fruit body production of Cordyceps guangdongensis, selected cultivation conditions, especially nutritional parameters were optimized.

METHODS AND RESULTS

Cordyceps guangdongensis was inoculated on potato dextrose agar slants with pH values from 4.5 to 9.0 and cultivated in artificial media with different carbon and nitrogen supplements. Primordium formation in C. guangdongensis was favoured by slightly acidic conditions. Fruit body yields and biological efficiency (BE) recorded were all highest in cultures of C. guangdongensis supplemented with sucrose and KNO3 as carbon and nitrogen supplements, respectively. Highest fruit body yields and BE values were recorded with C : N ratio of 12 : 1. The optimal medium consisted of (g l(-1)) 20.0 sucrose, 4.0 soya bean powder, 5.0 beef extract and 10.0 KNO3. Cultivation experiments using this medium confirmed its reliability; 18.35% of BE was obtained, compared with a calculated maximum BE of 18.65% based on orthogonal test data.

CONCLUSIONS

Cordyceps guangdongensis preferred sucrose and potassium nitrate as best carbon and nitrogen supplements. It produced satisfying yield of fruit body with optimized medium.

SIGNIFICANCE AND IMPACT OF THE STUDY

Optimized artificial cultivation conditions could promote the yield of C. guangdongensis and decreased the cost of production.

One-step route to wurtzite-structured ZnS thin nanorods in pure ethylenediamine or mixed solvent

In the paper, we report one-step synthesis of novel wurtzite-structured ZnS three dimensional architectures assembled from thin nanorods in mixed solvent of ethylenediamine (en) and ethylene glycol, and wurtzite ZnS nanorods in a pure en solvent, both adopting Zn(CH3COO)2 x 2H2O and (NH2)2CS as raw materials. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and selected area electron diffraction were applied to characterize the samples. It was found that the volume ratio of solvents and the concentration of (NH2)2CS played important roles in the formation of wurtzite-structured ZnS nanorods, and the thin wurtzite ZnS nanorods with mean diameter of 6 nm were successfully synthesized. The optical absorption edges of the thin ZnS nanorods were found to be blue-shifted compared with that of the bulk ZnS due to the quantum confinement effect.

A phospholipid-PEG2000 conjugate of a vascular endothelial growth factor receptor 2 (VEGFR2)-targeting heterodimer peptide for contrast-enhanced ultrasound imaging of angiogenesis

The transition of a targeted ultrasound contrast agent from animal imaging to testing in clinical studies requires considerable chemical development. The nature of the construct changes from an agent that is chemically attached to microbubbles to one where the targeting group is coupled to a phospholipid, for direct incorporation to the bubble surface. We provide an efficient method to attach a heterodimeric peptide to a pegylated phospholipid and show that the resulting construct retains nanomolar affinity for its target, vascular endothelial growth factor receptor 2 (VEGFR2), for both the human (kinase insert domain-containing receptor - KDR) and the mouse (fetal liver kinase 1 - Flk-1) receptors. The purified phospholipid-PEG-peptide isolated from TFA-based eluents is not stable with respect to hydrolysis of the fatty ester moieties. This leads to the time-dependent formation of the lysophospholipid and the phosphoglycerylamide derived from the degradation of the product. Purification of the product using neutral eluent systems provides a stable product. Methods to prepare the lysophospholipid (hydrolysis product) are also included. Biacore binding data demonstrated the retention of binding of the lipopeptide to the KDR receptor. The phospholipid-PEG2000-peptide is smoothly incorporated into gas-filled microbubbles and provides imaging of angiogenesis in a rat tumor model.

Resistance to Fusarium head blight and seedling blight in wheat is associated with activation of a cytochrome p450 gene

ABSTRACT One plant genotype displays a resistance phenotype at one development stage but a susceptible reaction to the same pathogen at another stage, which is referred to here as resistance inversion. In wheat, Fusarium head blight (FHB)-resistant cv. Sumai3 showed a Fusarium seedling blight (FSB)-susceptible reaction whereas FHB-susceptible cv. Annong8455 exhibited FSB resistance when challenged with a Fusarium asiaticum strain that produces deoxynivalenol (DON). The resistance to FHB and FSB in wheat was closely associated with expression of a plant cytochrome P450 gene in response to FHB pathogens and mycotoxins. Quantitative real-time polymerase chain reaction analyses showed that expression of nine defense-related genes in spikes and seedlings was induced by the fungal infection, in which a massive accumulation of a plant cytochrome P450 gene, CYP709C1, was clearly associated with the resistance reaction in both seedling and spike. The FHB-resistant Sumai3 accumulated 7-fold more P450 transcripts than did the FHB-susceptible Annong8455, while 84-fold more P450 transcripts were accumulated in the FSB-resistant Annong8455 than the FSB-susceptible Sumai3. A Fusarium strain with a disrupted Tri5 gene, which is not able to produce the first enzyme essential for trichothecene mycotoxin biosynthesis, also induced more P450 transcripts in FHB- and FSB-resistant cultivars. The fungal activation of the P450 gene was more profound in the FSB-resistant reaction than the FHB-resistant reaction relative to their susceptible counterparts. DON triggered a differential expression of the P450 gene with comparable patterns in spikes and seedlings in a resistance-dependent manner. These results may provide a basis for dissecting mechanisms underlying FHB and FSB resistance reactions in wheat and revealing functions of the cytochrome P450 in plant detoxification and defense.

Decision support for teletraining of COPD patients

BACKGROUND

Supervised physical training has been shown to promote rehabilitation of patients affected by chronic obstructive pulmonary disease (COPD). Currently, due to limited resources, not all COPD patients can be trained by an expert supervisor.

OBJECTIVES

The objective of our research is to construct a decision support system (DSS) which observes and controls physical ergometer training sessions of COPD patients.

METHODS

A systematic literature review and expert interviews were carried out to build up the knowledge base for the DSS.

RESULTS

Nine production rules were established and standardized by Drools and Arden Syntax. The developed software autonomously controls training sessions on a bicycle ergometer on the basis of vital signs data. Thus it offers a new way for the rehabilitation of COPD patients.

CONCLUSION

Evaluation with nine healthy subjects in a laboratory environment has confirmed its correct function, but the effects of its use for COPD patients' rehabilitation and their quality of life have to be investigated in a further study.

Roles of the primary cilium component Polaris in synchondrosis development

Primary cilia regulate several developmental processes and mediate hedgehog signaling. To study their roles in cranial base development, we created conditional mouse mutants deficient in Polaris, a critical primary cilium component, in cartilage. Mutant post-natal cranial bases were deformed, and their synchondrosis growth plates were disorganized. Expression of Indian hedgehog, Patched-1, collagen X, and MMP-13 was reduced and accompanied by decreases in endochondral bone. Interestingly, there was excessive intramembranous ossification along the perichondrium, accompanied by excessive Patched-1 expression, suggesting that Ihh distribution was wider and responsible for such excessive response. Indeed, expression of heparan sulfate proteoglycans (HS-PGs), normally involved in restricting hedgehog distribution, was barely detectable in mutant synchondroses. Analyses of the data provides further evidence for the essential roles of primary cilia and hedgehog signaling in cranial base development and chondrocyte maturation, and point to a close interdependence between cilia and HS-PGs to delimit targets of hedgehog action in synchondroses.

TAC (docetaxel, doxorubicin, and cyclophosphamide) adjuvant chemotherapy supported by G-CSF without dose-reduction in node-positive breast cancer

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Background: For node-positive breast cancer, TAC (Docetaxel-Doxorubicin-Cyclophosphamide) chemotherapy is preferred as an adjuvant treatment. However, due to its high toxicity profiles such as severe neutropenia, TAC is a lot beyond enthusiasm. G-CSF support or even prophylaxis has been recommended to help patients recover from nadir, along with some dose-reduction schedule. We tried to evaluate whether TAC with G-CSF support from day 5 can be sustained without dose reduction in women under 69-years old. Methods: After getting IRB approval, between Mar. 2005 and Oct. 2008, 61 node-positive breast cancer patients (33 - 69 years old) had underwent TAC chemotherapy as an adjuvant treatment after curative resection after getting informed consent. Total of 366 cycles (6 cycles per patient, 75–50–500 mg/m2)were completed, G-CSF support was initiated from day 5 to full neutrophil recovery. In case of neutropenia, prophylactic antibiotics (cefoperazone 2 g and tobramycin 200 mg iv) were given. Results: Among 366 cycles, not a single cycle should be delayed to recover from any hematologic shortcomings such as neutropenia, anemia or thrombocytopenia. Interval of three weeks between each cycle could be maintained. No other problem happened for any patient to stop or postpone scheduled chemotherapy. None of antibiotics except prophylaxis with cefoperazone and tobramycin was needed. Conclusions: Maximum tolerable dose of chemotherapeutic agents should be given to patients to get the best oncologic outcome to fight against cancer. It is evident that huge scale prospective clinical trials can answer this question, but we presume that node-positive breast cancer patients between in her fourth and seventh decade can stand TAC chemotherapy with G-CSF support without dose reduction as routine.

No significant financial relationships to disclose.

Weight gain after adjuvant TAC (docetaxel, doxorubicin, and cyclophosphamide) chemotherapy for node-positive breast cancer

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Background: Despite of its proven therapeutic efficacy, TAC (docetaxel, Doxorubicin and cyclophosphamide) regimen as an adjuvant chemotherapy has some serious adverse effects such as fluid retention and neutropenia. Even though dexamethasone is known to be given for three days to the patients having TAC chemotherapy to prevent severe fluid retention, most patients have ironically been complaining of much weight gain more than 15% increase after the use of dexamethasone. We tried to determine abbreviated use of dexamethasone is better to decrease the extent of weight gain after TAC chemotherapy. Methods: Eighty node-positive patients between Jan. 2006 and Oct. 2007 were randomly assigned either into 24-hr (group A: 10 mg dexamethasone the night before TAC, and 10 mg dexamethasone (bid) were given for the day 1) or 72-hr dexamethasone premedication (group B) only after getting informed consent since all the protocols were reviewed by IRB. We compared the incidence of severe weight gain (more than 15%) on completion of six cycles in two groups. No patient was found to have heart or kidney problem before the commencement of chemotherapy. Results: Each group was comprised of 40 patients. All patients underwent 6 cycles. Mean age of each group was 48.5 (A) and 50.3 (B) years. The incidence of severe weight gain was 47.3 % in Group A, and 78.4 % in Group B. There was no difference in the duration of recovering from weight gain in both groups (A: 6.52 months vs. B: 7.02 months). No other hematologic complications seemed different between two groups. Conclusions: Though larger scale prosepctive randomized trials should be required to get the definitive conclusion on this matter, we think that current dexamethasone premedication may aggravate weight gain than to prevent it. If shorter schedule is as much effective as longer one, abbreviated and reduced dexamethasone premedication is more helpful for patients having TAC chemotherapy.

No significant financial relationships to disclose.

Impacts of microRNA-215 on cell proliferation and chemotherapy resistance in colon cancer and osteosarcoma

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Background: Translational control plays a key role in resistance to anti-cancer drug treatment. MicroRNAs regulate gene expression at the post-transcriptional level, mainly by interacting with 3'-UTR of their mRNA targets. Methods: miR-215 was ectopically expressed by transient transfection in both human colon cancer cell lines and osteosarcoma cell lines. The impact of miR-215 on cell proliferation, cell cycle control, chemosensitivity and down stream targets were characterized. The expression of miR-215 in colorectal cancer specimens and normal adjacent tissues was quantified by real time-qRT-PCR analysis. Results: In this study, we discovered that miR-215 down-regulates the expression of both dihydrofolate reductase (DHFR) and thymidylate synthase (TS), two of the most important chemotherapeutic targets, in human osteosarcoma U-2 OS and colon cancer HCT-116 (wt-p53) cell lines. Cells with elevated miR-215 expression are more resistant to DHFR inhibitor methotrexate (MTX) or TS inhibitor Tomudex (TDX) treatment. Ectopically over-expressing miR-215 triggers reduced cell proliferation and increased G2 arrest, at least in part, through the induction of p53 and p21. miR-215 transfected cells with reduced proliferating phenotype were resist to MTX or TDX treatment due to deceased cell cycle in S phase. The expression of endogeneous miR-215 was highly elevated in CD133+/HI CD44+/HI colon cancer stem cells compared to CD133- CD44- colon cancer cells, suggesting that tumor stem cells may be avoiding cellular and DNA damage caused by chemotherapy with a reduced proliferating phenotype mediated by certain miRNAs such as miR-215. The elevated expression of miR-215 in colon cancer stem cells with slow proliferation rate and resistance to chemotherapy further supports the role of miR-215 in cell proliferation and chemotherapy resistance. Conclusions: miR-215 may have a unique potential as a novel therapeutic target and biomarker candidate in cancer.

No significant financial relationships to disclose.

TGFBR1 variants TGFBR1(*)6A and Int7G24A are not associated with an increased familial colorectal cancer risk

Variants of the transforming growth factor-beta receptor type 1 (TGFBR1) gene, TGFBR1*6A and Int7G24A, have been suggested to act as low-penetrance tumour susceptibility alleles with TGFBR1*6A being causally responsible for some cases of familial colorectal cancer (CRC). We performed a case–control study of 262 unrelated familial CRC cases; 83 hereditary non-polyposis colorectal cancer (HNPCC) and 179 non-HNPCC. Patients were genotyped for TGFBR1*6A and Int7G24A and compared with 856 controls. Further, we screened the coding region of TGFBR1 in affected members of a large family with CRC linked to 9q22.32-31.1. TGFBR1*6A allelic frequency was not significantly different in all of the familial cases compared with controls (0.107 and 0.106, respectively; P=0.915). In a subgroup analysis allele frequencies were, however, different between HNPCC and non-HNPCC familial cases (0.157 and 0.084, respectively; P=0.013). TGFBR1*6A genotype did not influence age of onset. Int7G24A allele frequencies were similar in cases and controls. No germ-line mutation was identified in the family with CRC linked to this chromosomal region. Our study provides no substantial support for the hypothesis that the polymorphic variants TGFBR1*6A or Int7G24A contribute to familial CRC risk. We cannot, however, exclude the possibility that TGFBR1 variants have a modifying effect on inherited risk per se.

Correction of congenital severe ptosis by suspension of a frontal muscle flap overlapped with an inferiorly based orbital septum flap

BACKGROUND

This report introduces a new method for correction of congenital severe upper eyelid ptosis.

METHODS

The poor levator-function upper eyelid ptosis of 22 patients was corrected using suspension of the frontal muscle flap overlapped with an inferiorly based orbital septum flap as a motor unit, which substituted for the function of the levator muscle. The frontal muscle flap and orbital septum flap were formed in the frontal part and upper eyelid, respectively. Two flaps were overlapped and sutured to suspend the upper eyelid and to correct the congenital severe upper eyelid ptosis. This technique avoids the need for the linking structure necessary with the standard frontalis sling approach and improves the direction of pull to mimic that of a normal levator more closely than that of frontalis muscle advancement.

RESULTS

The follow-up period ranged from 6 to 20 months (mean, 12 months). A total of 4 patients had bilateral surgery, whereas 18 patients underwent unilateral surgery (26 eyelids). In 22 cases (26 eyes), congenital severe upper eyelid ptosis was treated using suspension of the frontal muscle flap overlapped with an inferiorly based orbital septum flap. After the operation, 17 cases (19 eyes) were followed up and analyzed retrospectively. The average follow-up period was about 12 months (range, 6-20 months). The 17 corrected eyes had a symmetric redundant fold of preseptal skin according to the marginal reflex distance-1 (MRD-1) measurement used to judge efficacy. Two eyes in this series required reoperation for undercorrection. Complications such as ectropion and corneal exposure were avoided.

CONCLUSION

Use of a frontalis muscle lap overlapped with an inferior based orbital septum flap to manage severe congenital upper eyelid ptosis is a useful procedure that results in substantial cosmetic and functional improvement with few complications.

Orexin affects dorsal root ganglion neurons: a mechanism for regulating the spinal nociceptive processing

Orexins (orexin A and B) are initially known to be a hypothalamic peptide critical for feeding and normal wakefulness. In addition, emerging evidence from behavioral tests suggests that orexins are also involved in the regulation of nociceptive processing, suggesting a novel potential therapeutic approach for pain treatment. Both spinal and supraspinal mechanisms appear to contribute to the role of orexin in nociception. In the spinal cord, dorsal root ganglion (DRG) neurons are primary afferent neurons that transmit peripheral stimuli to the pain-processing areas. Morphological results show that both orexin A and orexin-1 receptor are distributed in DRG neurons. Moreover, by using whole-cell patch-clamp recordings and calcium imaging measurements we found that orexin A induced excitability and intracellular calcium concentration elevation in the isolated rat DRG neurons, which was mainly dependent on the activation of spinal orexin-1 receptor. Based on these findings, we propose a hypothesis that the direct effect of orexin A on DRG neurons would represent a possible mechanism for the orexinergic modulation of spinal nociceptive transmission.

Activating transcription factor 3 up-regulated by c-Jun NH(2)-terminal kinase/c-Jun contributes to apoptosis induced by potassium deprivation in cerebellar granule neurons

Cerebellar granule neurons (CGNs) depend on potassium depolarization for survival and undergo apoptosis when deprived of depolarizing concentration of potassium. Activating transcription factor 3 (ATF3), a stress-inducible protein, belongs to the ATF/CREB family of transcription factors family and is involved in cell growth and apoptosis. However, the role of ATF3 in neuronal apoptosis remains unknown. Here, we showed that ATF3 was up-regulated under potassium deprivation in CGNs, and this induction was preceded by a rapid and sustained activation of c-Jun NH(2)-terminal kinase/c-Jun signaling pathway, which plays a fundamental role in neuronal apoptosis. Furthermore, ATF3 up-regulation was abolished by inhibition of JNK or knockdown of c-Jun. Finally, knockdown of ATF3 by RNA interference protected CGNs from potassium deprivation-induced apoptosis. Taken together, our results indicate that ATF3 is a downstream target of JNK/c-Jun pathway and contributes to apoptosis induced by potassium deprivation in rat CGNs.

TGFBR1(*)6A and Int7G24A variants of transforming growth factor-beta receptor 1 in Swedish familial and sporadic breast cancer

Two common variants in transforming growth factor-β receptor 1 (TGFBR1), TGFBR1^*6A and Int7G24A, A allele, have been shown to act as low-penetrance tumour susceptibility alleles in several common cancers, including breast cancer. We evaluated the TGFBR1 9A/6A and Int7G24A variant frequencies in two breast cancer cohorts; a population-based cohort of breast cancer with defined family history (n=459) and in breast cancer patients from a familial cancer clinic (n=340) and in 856 controls from the Stockholm region. The familial patients from both cohorts were further divided into high- and low-risk familial breast cancer based on pedigree analysis. There was no overall association with either variant and breast cancer risk. The TGFBR1^*6A allelic frequency was, however, higher in low-risk familial breast cancer (0.138), compared to controls (0.106; P=0.04). No significant difference was found in the high-risk familial (0.102) or sporadic cases (0.109; P=0.83 and 0.83, respectively). TGFBR1^*6A carrier status was further associated with a high-grade sporadic breast cancer (odds ratio: 2.27; 95% confidence interval: 1.01–5.11; P=0.049). These results indicate that the TGFBR1^*6A variant may be associated with an increased risk of low-risk familial breast cancer and might be a marker for poorly differentiated breast cancer. The Int7G24A variant was not associated with breast cancer risk or clinical presentation of the disease including prognosis in our material.