Characterization of chlorophyll f synthase heterologously produced in Synechococcus sp. PCC 7002

In diverse terrestrial cyanobacteria, Far-Red Light Photoacclimation (FaRLiP) promotes extensive remodeling of the photosynthetic apparatus, including photosystems (PS)I and PSII and the cores of phycobilisomes, and is accompanied by the concomitant biosynthesis of chlorophyll (Chl) d and Chl f. Chl f synthase, encoded by chlF, is a highly divergent paralog of psbA; heterologous expression of chlF from Chlorogloeopsis fritscii PCC 9212 led to the light-dependent production of Chl f in Synechococcus sp. PCC 7002 (Ho et al., Science 353, aaf9178 (2016)). In the studies reported here, expression of the chlF gene from Fischerella thermalis PCC 7521 in the heterologous system led to enhanced synthesis of Chl f. N-terminally [His]₁₀-tagged ChlF⁷⁵²¹ was purified and identified by immunoblotting and tryptic-peptide mass fingerprinting. As predicted from its sequence similarity to PsbA, ChlF bound Chl a and pheophytin a at a ratio of ~ 3-4:1, bound β-carotene and zeaxanthin, and was inhibited in vivo by 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Cross-linking studies and the absence of copurifying proteins indicated that ChlF forms homodimers. Flash photolysis of ChlF produced a Chl a triplet that decayed with a lifetime (1/e) of ~ 817 µs and that could be attributed to intersystem crossing by EPR spectroscopy at 90 K. When the chlF⁷⁵²¹ gene was expressed in a strain in which the psbD1 and psbD2 genes had been deleted, significantly more Chl f was produced, and Chl f levels could be further enhanced by specific growth-light conditions. Chl f synthesized in Synechococcus sp. PCC 7002 was inserted into trimeric PSI complexes.

Anti-epidermal growth factor receptor (EGFR) monoclonal antibody combined with cisplatin and 5-fluorouracil in patients with metastatic nasopharyngeal carcinoma after radical radiotherapy: a multicentre, open-label, phase II clinical trial

BACKGROUND

We conducted a single-arm phase II trial to evaluate the efficacy and adverse effects (AEs) of an anti-epidermal growth factor receptor monoclonal antibody, nimotuzumab, combined with cisplatin and 5-fluorouracil (PF) as first-line treatment in recurrent metastatic nasopharyngeal carcinoma after radical radiotherapy.

METHODS

Patients who met the eligibility criteria were recruited from ten institutions (ClinicalTrials.gov; NCT01616849). A Simon optimal two-stage design was used to calculate the sample size. All patients received weekly nimotuzumab (200 mg) added to cisplatin (100 mg/m2 D1) and 5-fluorouracil (4 g/m2 continuous infusion D1-4) every 3-weekly for a maximum of six cycles. Primary end point was objective response rate (ORR). Secondary end points included disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and AEs.

RESULTS

A total of 35 patients were enrolled (13 in stage 1 and 22 in stage 2). Overall ORR and DCR were 71.4% (25/35) and 85.7% (30/35), respectively. Median PFS and OS were 7.0 (95% CI 5.8-8.2) months and 16.3 (95% CI 11.4-21.3) months, respectively. Unplanned exploratory analyses suggest that patients who received ≥2400 mg nimotuzumab and ≥4 cycles of PF had superior ORR, PFS and OS than those who did not (88.9% versus 12.5%, P < 0.001; 7.4 versus 2.7 months, P = 0.081; 17.0 versus 8.0 months, P = 0.202). Favourable subgroups included patients with lung metastasis [HROS 0.324 (95% CI 0.146-0.717), P = 0.008] and disease-free interval of >12 months [HROS 0.307 (95% CI 0.131-0.724), P = 0.004], but no difference was observed for metastatic burden. The only major grade 3/4 AE was leukopenia (62.9%).

CONCLUSION

Combination nimotuzumab-PF chemotherapy demonstrates potential efficacy, and is well tolerated as first-line chemotherapy regimen in recurrent metastatic nasopharyngeal carcinoma.

Association of VDR and OPG gene polymorphism with osteoporosis risk in Chinese postmenopausal women

AIMS

The underlying mechanisms of vitamin D receptor (VDR) and osteoprotegerin (OPG) genetic variation associated with bone mineral density and osteoporosis remain uncertain. This study aimed to investigate the association of VDR and OPG gene polymorphism as well as gene-gene interaction and their haplotype combination with the risk of osteoporosis.

METHODS

Polymerase chain reaction restriction fragment length polymorphism was carried out for single nucleotide polymorphism (SNP) detection. Generalized multifactor dimension reduction (GMDR) is used to identify the interaction. SHEsis software evaluated the haplotype and logistic regression was performed to assess the association between the SNPs within the VDR and OPG genes and osteoporosis.

RESULTS

The risk of osteoporosis in the VDR-rs2228570 polymorphism T-allele carriers was significantly higher than that in CC (CT/TT versus CC) individuals (adjusted odds ratio [OR] [95% confidence interval (CI)] = 1.76 [1.33-2.22]). The risk of osteoporosis was also higher in the G-allele carrier of the OPG-rs3102735 polymorphism than in individuals with the AA genotype (AG/GG vs. AA) (adjusted OR [95% CI] = 1.65 [1.27-2.14]). However, after adjusting for sex, age, and waist circumference covariates, no significant association of VDR-rs17879735 and OPG-rs2073618 with the osteoporosis risk was revealed. The GMDR method identified that gene-gene interactions were significant, but not for gene/AO interaction. Haplotypes were analyzed with SHEsis software. We did not detect a high-risk haplotype combination associated with osteoporosis.

CONCLUSIONS

Both VDR-rs2228570-T and OPG-rs3102735-G and their interactions are related to the increased risk of osteoporosis.

Etiology and Pathogenesis of Hemifacial Microsomia

Hemifacial microsomia (HFM) is a common congenital malformation of the craniofacial region. There are 3 possible pathogenic models of HFM—vascular abnormality and hemorrhage in the craniofacial region, damage to Meckel’s cartilage, and the abnormal development of cranial neural crest cells—and the most plausible hypothesis is the vascular abnormality and hemorrhage model. These 3 models are interrelated, and none of them is completely concordant with all the variable manifestations of HFM. External environmental factors (e.g., thalidomide, triazene, retinoic acid, and vasoactive medications), maternal intrinsic factors (e.g., maternal diabetes), and genetic factors (e.g., the recently reported mutations in OTX2, PLCD3, and MYT1) may lead to HFM through ≥1 of these pathogenic processes. Whole genome sequencing to identify additional pathogenic variants, biological functional studies to understand the exact molecular mechanisms, and additional animal model and clinical studies with large stratified samples to elucidate the pathogenesis of HFM will be necessary. Small-molecule drugs, as well as CRISPR/CAS9-based genetic interventions, for the prevention and treatment of HFM may also be a future research hotspot.

Oestrogen-related receptor reduces vitellogenin expression by crosstalk with the ecdysone receptor pathway in female silkworm, Bombyx mori

Oestrogen-related receptor (ERR) is involved in oestrogen receptor (ER) signalling pathways owing to its similarity to ER in terms of domain structure and co-activator and response elements. Although insects lack ER, they harbour an ERR gene that is thought to modulate metabolism and energy conversion via an unknown mechanism. The present study investigated the function of ERR in insects using female silkworm (Bombyx mori, Bm). We found that the expression of B. mori vitellogenin (BmVg) and B. mori ERR (BmERR) in the fat bodies of female silkworms at different stages of development exhibited alternating patterns, and RNA interference of BmERR in females induced BmVg transcription, resulting in an increase in egg weight relative to the control. Furthermore, BmERR was found to be involved in regulating the transcription of BmVg through an oestrogen-related receptor response element (ERRE) in the promoter of the BmVg gene, as demonstrated by electrophoretic mobility shift assay, cell transfection assay and chromatin immunoprecipitation. In summary, our results indicate that BmERR bound to the ERRE motif in the BmVg promoter reducing the expression of BmVg in the fat body of the female silkworm. To our surprise, the ERRE also showed the ability to bind the ecdysone receptor (BmEcR) and ultraspiracle complex. Thus, we surmise that ERR participates in steroid hormone signalling by engaging in crosstalk with the ER pathway in vertebrates and with the EcR pathway in insects.

Validation of a revised Mandarin Chinese language version of the Postoperative Quality of Recovery Scale

The aim of the study was to validate a revised Mandarin version of the Postoperative Quality of Recovery Scale (PostopQRS) and to apply the revised version in a Chinese population. In a prospective design, bilingual volunteers completed the scale at baseline, day one, day seven, and day 14 in both languages, with the order of language and parallel forms randomised. In addition, lung cancer patients undergoing open or video-assisted thoracoscopic surgery (VATS) completed the Mandarin version prior to surgery, day one, day three, day seven, day 14, one month, and three months postoperatively. Sixty-eight volunteers participated in the validation part of the study and in the clinical application, 93 lung cancer patients were included. The scores in the Mandarin version were equal to the English version in all domains at all timepoints including the word generation task, when the Mandarin morpheme was included in any part of the Mandarin word. However, Mandarin scores were lower in the word generation task if the morpheme was only included in the first part of the word. In addition, the Mandarin version was able to identify lower rates of overall recovery (<i>P</i> <0.01), nociceptive (<i>P</i> <0.01), emotive (<i>P</i> <0.01), and activities of daily living recovery (<i>P</i>=0.02) after open surgery compared to after VATS. The revised Mandarin version is equivalent to the English version for the cognitive domain, if morpheme substitution for the word generation task is allowed as any part of the word, and it is able to discriminate quality of recovery in Chinese patients.

Stabilization of warfarin-binding pocket of VKORC1 and VKORL1 by a peripheral region determines their different sensitivity to warfarin inhibition

Essentials VKORL1 and VKORC1 have a similar overall structure and warfarin-binding pocket. A peripheral region stabilizing this pocket controls warfarin sensitivity of the VKOR paralogs. A human single nucleotide polymorphism in this region renders VKORL1 sensitive to warfarin. A group of warfarin-resistant mutations in VKORC1 acts by disrupting peripheral interactions.

SUMMARY

Background The human genome encodes two paralogs of vitamin-K-epoxide reductase, VKORC1 and VKORL1, that support blood coagulation and other vitamin-K-dependent processes. Warfarin inhibits both enzymes, but VKORL1 is relatively resistant to warfarin. Objectives To understand the difference between VKORL1 and VKORC1, and the cause of warfarin-resistant (WR) mutations in VKORC1. Methods We performed systematic mutagenesis and analyzed warfarin responses with a cell-based activity assay. Mass spectrometry analyses were used to detect cellular redox state. Results VKORC1 and VKORL1 adopt a similar intracellular redox state with four-transmembrane-helix topology. Most WR mutations identified in VKORC1 also confer resistance in VKORL1, indicating that warfarin inhibits these paralogs at a common binding site. A group of WR mutations, distant from the warfarin-binding site, show significantly less resistance in VKORL1 than in VKORC1, implying that their different warfarin responses are determined by peripheral interactions. Remarkably, we identify a critical peripheral region in which single mutations, Glu37Lys or His46Tyr, drastically increase the warfarin sensitivity of VKORL1. In the background of these warfarin-sensitive VKORL1 mutants, WR mutations showing relative less resistance in wild-type VKORL1 become much more resistant, suggesting a structural conversion to resemble VKORC1. At this peripheral region, we also identified a human single nucleotide polymorphism that confers warfarin sensitivity of VKORL1. Conclusions Peripheral regions of VKORC1 and VKORL1 primarily maintain the stability of their common warfarin-binding pocket, and differences of such interactions determine their relative sensitivity to warfarin inhibition. This new model also explains most WR mutations located at the peripheral regions of VKORC1.

A microRNA-1 gene, tci-miR-1-3p, is involved in cyflumetofen resistance by targeting a glutathione S-transferase gene, TCGSTM4, in Tetranychus cinnabarinus

microRNA-1 (miR-1) is a well-studied conservative microRNA (miRNA) involved in immune responses in mammals and insects. However, little is known about its role in pesticide resistance in arthropods. In this study, we found that a microRNA belong to miR-1 family (tci-miR-1-3p) was significantly down-regulated in a cyflumetofen-resistant strain (CYR) of Tetranychus cinnabarinus compared with its homologous susceptible strain (SS), indicating an involvement of miR-1 in cyflumetofen resistance in mites. One glutathione S-transferase (GST) gene (TCGSTM4, a mu class GST gene), a candidate target gene of tci-miR-1-3p, was found to be significantly down-regulated when tci-miR-1-3p was over-expressed. The specific interaction between tci-miR-1-3p and the target sequence in the 3' untranslated region of TCGSTM4 was confirmed. A decrease or increase in tci-miR-1-3p abundance through feeding miRNA inhibitors or mimics significantly increased or decreased TCGSTM4 expressions at the mRNA and protein levels, respectively. In addition, an over-expression of tci-miR-1-3p resulted in a decrease in the tolerance of T. cinnabarinus to cyflumetofen in both SS and CYR strains, and vice versa. After decreasing TCGSTM4 transcription via RNA interference, T. cinnabarinus became more sensitive to cyflumetofen in both resistant and susceptible mites, and the change in mortality was greater in CYR than that in SS. Moreover, the recombinant TCGSTM4 could significantly decompose cyflumetofen, indicating that TCGSTM4 is a functional gene responsible for cyflumetofen resistance in mites.

Appropriate cyclic tensile strain promotes biological changes of cranial base synchondrosis chondrocytes

OBJECTIVES

This study was designed to clarify biological changes of cranial base synchondrosis chondrocytes (CBSCs) upon cyclic tensile strain (CTS) loading which simulated orthopaedic mechanical protraction on cranial base synchondroses (CBS).

MATERIAL AND METHODS

A two-step digestion method was used to isolate CBSCs obtained from 1-week-old Sprague Dawley rats. Immunohistochemical staining of type II collagen and Sox9 was conducted to identify chondrocytes. A CTS of 1 Hz and 10% elongation was applied to the second passage of CBSCs by FX-5000™ Tension System for 24 hours. The control group kept static at the same time. The expression levels of extracellular matrix (Acan, Col1a1, Col2a1 and Col10a1) and key regulatory factors (Sox9, Ihh and PTHrP) were detected by quantitative real-time RT-PCR.

RESULTS

Positive staining of type II collagen and Sox9 was detected in the isolated CBSCs. The relative expression level of Acan, Col2a1, Col10a1, Sox9 and Ihh in the CTS-loading group was 1.85-fold, 2.19-fold, 1.53-fold, 6.62-fold, and 1.39-fold, respectively, as much as that in the control group, which had statistical significance (P<.05). There was no statistical difference (P>.05) in the expression of Col1a1 and PTHrP.

CONCLUSIONS

A CTS of 1 Hz and 10% elongation for 24 hours had positive effects on chondrocyte proliferation, phenotype maintenance and cartilage matrix synthesis.

Presence of a [3Fe-4S] cluster in a PsaC variant as a functional component of the photosystem I electron transfer chain in Synechococcus sp. PCC 7002

A site-directed C14G mutation was introduced into the stromal PsaC subunit of Synechococcus sp. strain PCC 7002 in vivo in order to introduce an exchangeable coordination site into the terminal F_B [4Fe-4S] cluster of Photosystem I (PSI). Using an engineered PSI-less strain (psaAB deletion), psaC was deleted and replaced with recombinant versions controlled by a strong promoter, and the psaAB deletion was complemented. Modified PSI accumulated at lower levels in this strain and supported slower photoautotrophic growth than wild type. As-isolated PSI complexes containing PsaC_C14G showed resonances with g values of 2.038 and 2.007 characteristic of a [3Fe-4S]¹⁺ cluster. When the PSI complexes were illuminated at 15 K, these resonances partially disappeared and two new sets of resonances appeared. The majority set had g values of 2.05, 1.95, and 1.85, characteristic of F_A^-, and the minority set had g values of 2.11, 1.90, and 1.88 from F_B' in the modified site. The S = 1/2 spin state of the latter implied the presence of a thiolate as the terminal ligand. The [3Fe-4S] clusters could be partially reconstituted with iron, producing a larger population of [4Fe-4S] clusters. Rates of flavodoxin reduction were identical in PSI complexes isolated from wild type and the PsaC_C14G variant strain; this implied equivalent capacity for forward electron transfer in PSI complexes that contained [3Fe-4S] and [4Fe-4S] clusters. The development of this cyanobacterial strain is a first step toward translation of in vitro PSI-based biosolar molecular wire systems in vivo and provides new insights into the formation of Fe/S clusters.

[Effect of treatment of infant parotid hemangioma with no response to oral propranolol]

Hemangioma is the most common vascular tumor in infantile period, and propranolol is the first choice, but there are still a few patients with poor curative effect. Seven cases of infant parotid hemangioma with no response to oral propranolol were treated with transcatheter arterial sclerosing embolization combined with cortisol and satisfactory results achievod. The treatment and efficacy are disccused in this paper.

Light regulation of pigment and photosystem biosynthesis in cyanobacteria

Most cyanobacteria are obligate oxygenic photoautotrophs, and thus their growth and survival is highly dependent on effective utilization of incident light. Cyanobacteria have evolved a diverse set of phytochromes and cyanobacteriochromes (CBCRs) that allow cells to respond to light in the range from ∼300nm to ∼750nm. Together with associated response regulators, these photosensory proteins control many aspects of cyanobacterial physiology and metabolism. These include far-red light photoacclimation (FaRLiP), complementary chromatic acclimation (CCA), low-light photoacclimation (LoLiP), photosystem content and stoichiometry (long-term adaptation), short-term acclimation (state transitions), circadian rhythm, phototaxis, photomorphogenesis/development, and cellular aggregation. This minireview highlights some discoveries concerning phytochromes and CBCRs as well as two acclimation processes that improve light harvesting and energy conversion under specific irradiance conditions: FaRLiP and CCA.

Identification of a novel HLA-A allele, HLA-A*02:505, by sequence-based typing in a patient with tuberculosis

The novel allele HLA-A*02:505 was identified in a tuberculosis patient by human leukocyte antigen sequence-based typing.

Description of the novel HLA-A allele, HLA-A*11:229, identified by sequence-based typing in a Chinese individual

HLA-A*11:229 differs from HLA-A*11:01:01:01 by 1 nucleotide exchange at position 556 (G > A) with an amino exchange.