Increased expression of CXCL2 in ACPA-positive rheumatoid arthritis and its role in osteoclastogenesis

Anti-citrullinated protein/peptide antibodies (ACPA) play important roles in the pathogenesis of rheumatoid arthritis (RA). ACPA-positive (ACPA⁺ ) and ACPA-negative (ACPA^- ) RA were suggested to be different disease subsets, with distinct differences in genetic variation and clinical outcomes. The aims of the present study were to compare gene expression profiles in ACPA⁺ and ACPA^- RA, and to identify novel candidate gene signatures that might serve as therapeutic targets. Comprehensive transcriptome analysis of peripheral blood mononuclear cells (PBMCs) from ACPA⁺ and ACPA^- RA patients and healthy controls was performed via RNA sequencing. A validation cohort was used to further investigate differentially expressed genes via polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Spearman's correlation test was used to evaluate the correlation of differentially expressed genes and the clinical and laboratory data of the patients. The role of differentially expressed genes in osteoclastogenesis was further investigated. Expression of C-X-C motif chemokine ligand 2 (CXCL2) was significantly increased in ACPA⁺ RA than in ACPA^- RA, which was validated in PBMCs and serum. CXCL2 promoted the migration of CD14⁺ monocytes and increased osteoclastogenesis in RA patients. RAW264.7 macrophages were used to investigate specific mechanisms, and the results suggested that CXCL2 stimulated osteoclastogenesis via extracellular receptor kinase (ERK) mitogen-activated protein kinase (MAPK) and nuclear factor kappa B pathways. In conclusion, CXCL2 was highly expressed in ACPA⁺ RA than in ACPA^- RA. CXCL2 promoted osteoclastogenesis and was related to bone erosion in RA, which suggests that the blockade of CXCL2 might be a novel strategy for the treatment of RA.

[Study on the expression of non-coding microRNA-376b-3p in serum exosomes of patients with malignant glioma and the mechanism of anti-angiogenesis]

Objective: To screen the different microRNAs in the serum exosomes of patients with malignant glioma, to explore the effect of non-coding microRNA-376b-3p (miR-376b-3p) on the proliferation, invasion and tumor vasculogenic mimicry of glioma cells, and to verify its targeting effect on HOXD10. Methods: HiSeq/MiSeq high-throughput sequencing was used to screen the different microRNA expression profiles, target genes and action pathways in the serum exosomes of patients with malignant glioma. Samples were used to evaluate the expression of candidate microRNAs in serum exosomes of high-grade gliomas. The effects of miR-376b-3p on the proliferation, invasion and angiogenesis of glioma cells were detected by MTT assay, Transwell migration assay and Matrigel vasculogenic mimicry assay. The mRNA and protein expression of HOXD10 were detected to evaluate the regulatory effect of miR-376b-3p on it. Results: There were 144 different expression microRNAs in the serum exosomes between malignant glioma and the normal control. Focal adhesion and tumor protein polysaccharides were involved in the regulation of glioma enriched by KEGG(Kyoto Encyclopedia of Genes and Genomes). MiR-376b-3p was down regulated in malignant glioma, and AUC of malignant glioma was 0.85 (P<0.01). MTT test showed that the proliferation ability of miR-376b-3p inhibitor group was higher than that of the control group, and that of miR-376b-3p mimic group was lower than that of the control group. Transwell migration test showed that the number of transmembrane cells in miR-376b-3p inhibitor group was higher than that in NC inhibitor group, and the number of transmembrane cells in miR-376b-3p mimic group was lower than that in NC mimic group. The number of tubes of vasculogenic mimicry in miR-376b-3p mimic group was lower than that in NC mimic group. MiR-376b-3p inhibitor decreased the expression level of HOXD10 mRNA and protein, and miR-376b-3p mimic increased the expression level of HOXD10 mRNA and protein. Conclusions: MiR-376b-3p is down-regulated in the serum exosomes of malignant glioma patients. The up-regulated miR-376b-3p can reduce the proliferation and invasion of glioma cells, inhibit the formation of vasculogenic mimicry, and increase the expression of HOXD10, which is expected to inhibit the formation of two forms of angiogenesis at the same time. MiR-376b-3p may be a new therapeutic target of anti-angiogenesis for malignant glioma.

Polymorphisms rs763110 in FASL is linked to hepatitis C virus infection among high-risk populations

BACKGROUND

The Fas cell surface death receptor (FAS) and Fas ligand (FASL) can participate in the apoptosis of immune cells and target cells infected with a virus through the FAS-FASL signalling pathway. The decoy receptor 3 (DCR3) can competitively inhibit the binding of FAS to FASL. Our aim is to investigate the effect of single nucleotide polymorphisms (SNPs) in FAS, FASL and DCR3 on hepatitis C virus (HCV) infection.

METHODS

Four SNPs (rs763110 in FASL, rs1324551 and rs2234767 in FAS and rs2257440 in DCR3) were genotyped in 1495 controls free of HCV, 522 individuals with spontaneous HCV clearance and 732 patients with hepatitis C virus infection. The RegulomeDB database and RNAfold web servers were used to explore potential biological functions of SNPs.

RESULTS

FASL rs763110 was associated with susceptibility to HCV infection, and not to CHC. The odds ratio (95% confidence interval) of HCV infection in high-risk populations carrying FASL rs763110-TT was 1.82 (1.36-2.51, P < 0.001) compared to that of CC genotypes and 1.93 (1.43-2.60, P < 0.001) higher than that of CC + CT genotypes. Based on computer simulation, FASL rs763110-T may affect the transcription of mRNA by affecting the binding of a transcription factor, leading to structural changes in mRNA.

CONCLUSION

The genetic variant in FASL is linked with HCV infection, but not to spontaneous HCV clearance.

Molecular cloning, characterization and expression analysis of LoTPS2 and LoTPS4 involved in floral scent formation in oriental hybrid Lilium variety 'Siberia'

Lilies are a commercially significant cut flower worldwide due not only to their elegant shape but also to their appealing scent. Among Lilium varieties, Lilium 'Siberia' is a cultivar that is prominent and highly favored by consumers due to its snowy white color and strong floral scent. Here, two terpene synthase genes (LoTPS2 and LoTPS4) that are responsible for floral scent production in Lilium 'Siberia' were cloned and functionally characterized. Recombinant LoTPS2 specifically catalyzed the formation of (E, E)-α-farnesene from FPP. Recombinant LoTPS4 is a multiproduct enzyme that produces D-limonene and β-myrcene as major volatile compounds and β-phellandrene, (+)-4-carene and 3-carene as minor products from GPP. Furthermore, LoTPS4 generates trans-α-bergamotene as a major product and di-epi-α-cedrene, α-cubebene and (E)-β-farnesene as minor compounds from FPP. Subcellular localization analysis using GFP fusion constructs revealed that LoTPS2 was localized in the cytosol, whereas LoTPS4 was localized in plastids. Real-time PCR analysis showed that LoTPS2 was highly expressed in the petals and sepals of the flower, while LoTPS4 was highly expressed in the filament of the flower. Moreover, mechanical wounding of flowers revealed that LoTPS2 showed a strong response to wounding via a rapid increase in its mRNA transcript level. Our results will assist scientists in exploring the molecular mechanisms of terpene biosynthesis in this species and will provide new insight into the biotechnological modification of the floral bouquet in Lilium.

Older Adults' Perspective towards Participation in a Multicomponent Frailty Prevention Program: A Qualitative Study

OBJECTIVES

This study aimed to explore pre-frail and frail older Chinese people's perspectives on a multi-component, group-based frailty prevention program in Hong Kong, along with their views regarding factors determining participation and sustainability of such program.

DESIGN

Seven focus groups were conducted.

SETTING

Community elderly centres.

PARTICIPANTS

A total of 38 community-dwelling older people aged 54 - 84 (mean age, 64.9 years; female, 58%; married, 68%; retired, 97%) screened with pre-frailty or frailty completing a 12-week multi-component (involving physical, cognitive, and social activities), group-based frailty prevention program were interviewed.

MEASUREMENTS

Thematic analysis was conducted.

RESULTS

Using thematic analysis, perceived health benefits, peer support and social networking were identified as key motivators concerning intention to participate in the frailty prevention program; whereas perceived health benefits, socializing, sense of connectedness, expert guidance and sense of dignity were identified as key motivators concerning program adherence.

CONCLUSION

Majority of participants provided positive feedbacks about the multi-component intervention program in regards to their physical health, psychological well-being and social life. These findings highlighted several important factors for consideration in future design of frailty interventions regarding the needs of pre-frail and frail older adults, which could help to motivate and sustain their participation in community-based frailty prevention programs.

Directional massless Dirac fermions in a layered van der Waals material with one-dimensional long-range order

One or a few layers of van der Waals (vdW) materials are promising for applications in nanoscale electronics. Established properties include high mobility in graphene, a large direct gap in monolayer MoS₂, the quantum spin Hall effect in monolayer WTe₂ and so on. These exciting properties arise from electron quantum confinement in the two-dimensional limit. Here, we use angle-resolved photoemission spectroscopy to reveal directional massless Dirac fermions due to one-dimensional confinement of carriers in the layered vdW material NbSi_0.45Te₂. The one-dimensional directional massless Dirac fermions are protected by non-symmorphic symmetry, and emerge from a stripe-like structural modulation with long-range translational symmetry only along the stripe direction as we show using scanning tunnelling microscopy. Our work not only provides a playground for investigating further the properties of directional massless Dirac fermions, but also introduces a unique component with one-dimensional long-range order for engineering nano-electronic devices based on heterostructures of vdW materials.

How Much Money Is Enough? Poverty and Health in Older People

OBJECTIVES

We examined the relationship between absolute income, adequacy of disposable income, and self-rated health among participants aged 60 years and over.

DESIGN

Cross sectional study.

SETTING

Community living older people in Hong Kong.

PARTICIPANTS

Older people aged 60 years and over in five districts in Hong Kong.

MEASUREMENTS

Data from a cross sectional survey of age friendly characteristics across five districts of Hong Kong carried out using stratified random sampling across a broad range of socioeconomic attributes.

RESULTS

Self-rated health showed a gradient for both absolute and adequacy of disposable income. The OR for the association between having just enough, or insufficient disposable income and poor health was higher: 2.0 and 3.6 respectively, and higher than that for absolute income (OR 1.8), and remained significant after adjustment for absolute income. No association between absolute income and self-rated health was observed among women. These findings suggest that adequacy of disposable income provide a stronger association with self-rated health compared with absolute income among older people aged 60 years and over, particularly for women. The absolute income corresponding to what is considered adequate disposable income lies between HK$4000-10000.

CONCLUSION

Adequacy of disposable income may be a better indicator than absolute income for older people in examining the relationship with health outcomes, particularly for older women.

Prognostic value of the pretreatment albumin:globulin ratio combined with adult comorbidity evaluation 27 and TMN staging in patients with squamous cell carcinoma of the maxillary sinus

The albumin:globulin (A:G) ratio, adult comorbidity evaluation 27 (ACE-27), and TMN staging have been shown to be strong predictive indicators of the survival of patients with many types of tumours. We have investigated the prognostic value of pretreatment based on the A:G ratio combined with TMN staging and ACE-27 in patients with squamous cell carcinoma (SCC) of the maxillary sinus. We studied 196 patients, and the prognostic value was explored by univariate and multivariate Cox's hazards analysis. Multivariate analyses suggested that pretreatment A:G ratio was independently associated with overall survival (hazard ratio (HR) 1.542, 95% CI 1.219 to 1.991, p=0.002); disease-specific survival, (HR 1.499, 95% CI 1.197 to 1.842, p=0.001); and disease-free survival (HR 1.452, 95% CI 1.207 to 1.834, p<0.001). Additional prognostic factors shown in the survival analyses included ACE-27, pathological T stage, and pathological N stage. Pretreatment A:G ratio combined with ACE-27 and TMN staging were powerful prognostic indicators of outcome in patients with SCC of the maxillary sinus, which has potentially important ramifications for stratification of the disease in the future.

[Diagnostic value of gadobenate dimeglumine enhanced MRI in hepatic fibrosis of rats]

Objective: To evaluate the value of Gd-BOPTA enhanced MRI in the staging of liver fibrosis. Method: Fifty male SD rats (6-week-old, 180-220 g) were divided into the modeling group (n=42) and the control group (n=8). The model of liver fibrosis in the modeling group was established by carbon tetrachloride (animal license No. SYXK (Su) 2017-0043). From week 2 to week 10, rats in the modeling group (n=4) and control group (n=1) were randomly selected to scan 1 h(RER1), 2 h(RER2) and 3 h(RER3) after injection of Gd-BOPTA, respectively, to measure the relative enhancement rate (RER) of liver parenchyma. The shape of intrahepatic bile duct and the degree of enhancement at each time point were observed. Results: Forty-two rats (34 rats in the modeling group and 8 rats in the control group) completed the experiment. RER1, RER2 and RER3 of the control group were 1.44±0.37, 1.22±0.37 and 0.84±0.28 respectively. RER1, RER2 and RER3 of the modeling group were respectively: S1 (n=6): 1.49±0.48, 1.29±0.39, 0.91±0.38;S2 (n=9): 1.48±0.44, 1.34±0.37, 1.04±0.40;S3 (n=11): 1.49±0.43, 1.37±0.39, 1.21±0.30; S4 (n=8): 1.49±0.44, 1.40±0.37, 1.24±0.40. There was no significant difference in RER1 and RER2 values between the control group and the liver fibrosis group (F=0.022, P=0.999; F=0.301, P=0.875). There were significant differences between the control group and RER3 values of hepatic fibrosis stage S3 and S4 (t=2.249, P=0.031; t=2.274, P=0.029), there was no significant difference between the remaining groups (all P>0.05).In the control group, the intrahepatic bile duct was obviously strengthened within 1 hour after enhancement, and walked naturally. The intrahepatic bile duct was slightly enhanced 1h after the enhancement of S3-S4 stage of hepatic fibrosis, and the intrahepatic bile duct was significantly enhanced 2-3 hours later, with distorted alignment. Conclusion: Delayed 3 hours liver parenchymal RER and intrahepatic bile duct distortion delay enhancement after Gd-BOPTA enhancement contribute to the S3-S4 diagnosis of liver fibrosis.

[The clinical study of Chinese version of voice activities and participation profile in patients with voice disorder]

Objective:To explore the applicability of the Chinese version of voice activity and participation profile in patients with voice disorder. Method:This study enrolled patients with voice disorder and their healthy family members in the outpatient, from 2017 July to 2019 April. They were divided into voice disorder group and without voice disorder group, and the questionnaire was filled out. Result:These scores of 28 items and five dimensions in the voice disorder group were higher than those in the group without voice disorder, and the differences were statistically significant（P<0.05）. In the voice disorder group, the score of items affecting work was the highest（4.26）, and the score of low self-esteem caused by voice disorder was the lowest（1.98）. Conclusion:Voice disorder could negatively affect the voice related quality of life. The Chinese version of voice activity and participation profile is suitable for evaluating voice related quality of life.

A Hedychium coronarium short chain alcohol dehydrogenase is a player in allo-ocimene biosynthesis

An enzyme is crucial for the formation of Hedychium coronarium scent and defense responses, which may be responsible for the biosynthesis of allo-ocimene in H. coronarium. Hedychium coronarium can emit a strong scent as its main scent constituents are monoterpenes and their derivatives. Among these derivatives, allo-ocimene is not only a very important volatile substance in flower aroma, but is also crucial to plant defense. However, the molecular mechanism of allo-ocimene biosynthesis has not been characterized in plants. In this study, a new alcohol dehydrogenase gene, HcADH, was cloned. The amino acid sequences encoded by HcADH contained the most conserved motifs of short chain alcohol dehydrogenase/reductases (SDRs), which included NAD⁺ binding domain, TGxxx[AG]xG and active site YxxxK. Real-time PCR analyses showed that the HcADH was highly expressed in the outer labellum but was almost undetectable in vegetative organs. The change in its expression level in petals was positively correlated with the emission pattern of allo-ocimene during flower development. HcADH expression coincides also the release level of allo-ocimene among different Hedychium species. Although HcADH is not expressed in the leaves, HcADH expression and allo-ocimene release in leaves can be induced by mechanical wounding or methyl jasmonate (MeJA) treatment. In addition, the expression of HcADH induced by mechanical wounding can be prevented by acetylsalicylic acid, a jasmonic acid biosynthesis inhibitor, suggesting that jasmonic acid might participate in the transmission of wounding signals. Using the Barley stripe mosaic virus (BSMV)-VIGS method, it was found that BSMV:HcADH₃₃₅ inoculation was able to down-regulate HcADH expression, decreasing only the release of allo-ocimene in flowers while the content of other volatile substances did not decrese. In vitro characterization showed that recombinant HcADH can catalyze geraniol into citral, and citral is an intermediate of allo-ocimene biosynthesis. HcADH may be responsible for the biosynthesis of allo-ocimene in H. coronarium, which is crucial for the formation of H. coronarium scent and defense function.

[Research advances in the relationship between nonalcoholic fatty fiver disease and sarcopenia]

Nonalcoholic fatty liver disease (NAFLD) is one of the common causes for chronic liver diseases, which progress gradually from nonalcoholic type simple fatty liver disease to hepatitis, cirrhosis and even liver failure and hepatocellular carcinoma. Sarcopenia is a progressive disease characterized by reduced skeletal muscle mass and function in association to metabolic dysfunctions. Recent studies have shown that the occurrence and development of NAFLD and sarcopenia are related, and there is a common base for the pathogenesis between the two, which may promote each other for mutual risk factors. This article reviews the current research progress of this field in order to clinically further understand the pathogenesis and intrinsic links between the two to look for appropriate interventions.

Genome-Wide Analysis and Characterization of the Aux/IAA Family Genes Related to Floral Scent Formation in Hedychium coronarium

Auxin plays a key role in different plant growth and development processes, including flower opening and development. The perception and signaling of auxin depend on the cooperative action of various components, among which auxin/indole-3-acetic acid (Aux/IAA) proteins play an imperative role. In a recent study, the entire Aux/IAA gene family was identified and comprehensively analyzed in Hedychium coronarium, a scented species used as an ornamental plant for cut flowers. Phylogenetic analysis showed that the Aux/IAA gene family in H. coronarium is slightly contracted compared to Arabidopsis, with low levels of non-canonical proteins. Sequence analysis of promoters showed numerous cis-regulatory elements related to various phytohormones. HcIAA genes showed distinct expression patterns in different tissues and flower developmental stages, and some HcIAA genes showed significant responses to auxin and ethylene, indicating that Aux/IAAs may play an important role in linking hormone signaling pathways. Based on the expression profiles, HcIAA2, HcIAA4, HcIAA6 and HcIAA12, were selected as candidate genes and HcIAA2 and HcIAA4 were screened for further characterization. Downregulation of HcIAA2 and HcIAA4 by virus-induced gene silencing in H. coronarium flowers modified the total volatile compound content, suggesting that HcIAA2 and HcIAA4 play important roles in H. coronarium floral scent formation. The results presented here will provide insights into the putative roles of HcIAA genes and will assist the elucidation of their precise roles during floral scent formation.

Effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts

In the development of dental fluorosis, oxidative stress is considered as the key mechanism. Endoplasmic reticulum (ER) stress can induce oxidative stress and activate the important antioxidative factor nuclear factor erythroid 2-related factor 2 (Nrf2) in a PKR-like ER kinase (PERK)-dependent manner, but combining ER stress and oxidative stress, the role of PERK-Nrf2 signaling pathway involved in fluoride-regulated ameloblasts is not fully defined. Here, we studied the effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts. We found that low-dose and continuous fluoride exposure increased binding immunoglobulin protein expression and activated PERK-activating transcription factor 4 signaling pathway. Meanwhile, the expression of Nrf2 and its target genes (glutamylcysteine synthetase and glutathione S-transferase-P1) enhanced following ER stress. Tunicamycin increased the expression of PERK, leading to Nrf2 nuclear import, and tauroursodeoxycholate suppressed Nrf2 activation through PERK during ER stress, indicating that PERK activation is required for Nrf2 nuclear entry. Furthermore, tert-butylhydroquinone triggered the overexpression of Nrf2 to reduce ER stress, but luteolin inhibited Nrf2 nuclear localization to elevate ER stress. In summary, this study proved that fluoride under certain dose can induce ER stress and promote Nrf2 nuclear import via PERK activation and suggested that antioxidation mechanism mediated by PERK-Nrf2 can alleviate fluoride-induced ER stress effectively.

Tracking ultrafast hot-electron diffusion in space and time by ultrafast thermomodulation microscopy

The ultrafast response of metals to light is governed by intriguing nonequilibrium dynamics involving the interplay of excited electrons and phonons. The coupling between them leads to nonlinear diffusion behavior on ultrashort time scales. Here, we use scanning ultrafast thermomodulation microscopy to image the spatiotemporal hot-electron diffusion in thin gold films. By tracking local transient reflectivity with 20-nm spatial precision and 0.25-ps temporal resolution, we reveal two distinct diffusion regimes: an initial rapid diffusion during the first few picoseconds, followed by about 100-fold slower diffusion at longer times. We find a slower initial diffusion than previously predicted for purely electronic diffusion. We develop a comprehensive three-dimensional model based on a two-temperature model and evaluation of the thermo-optical response, taking into account the delaying effect of electron-phonon coupling. Our simulations describe well the observed diffusion dynamics and let us identify the two diffusion regimes as hot-electron and phonon-limited thermal diffusion, respectively.

The E3 ubiquitin ligase Cbl-b inhibits tumor growth in multidrug-resistant gastric and breast cancer cells

Most receptor tyrosine kinases (RTKs) contribute to tumor growth, and their ubiquitination and degradation is related to the inhibition of tumor growth. Our previous study showed that the ubiquitin ligase Cbl-b was expressed at low levels in multidrug-resistant (MDR) gastric cancer cells compared with their parental cells. However, whether enhancement of Cbl-b expression in MDR cancer cells could prevent tumor proliferation via ubiquitination and degradation of RTK remains unclear. In the present study, Cbl-b overexpression reduced cell proliferation in MDR gastric and breast cancer cells, and effectively inhibited tumor growth in vivo. Additionally, Cbl-b overexpression reduced the total protein level of insulin-like growth factor 1 (IGF-1R), an important member of the RTK family. Moreover, Cbl-b overexpression promoted interaction of Cbl-b with IGF-1R, and induced ubiquitination and degradation of IGF-1R and inactivation of the IGF-1R pathway. These results suggest that the ubiquitin ligase Cbl-b inhibited tumor growth via ubiquitination and degradation of IGF-1R in MDR gastric and breast cancer cells.

Effect of microRNA-409 on the pathogenesis of polycystic ovary syndrome

OBJECTIVE

To explore the expression level of microRNA-409 in PCOS (polycystic ovary syndrome) rats, as well as its potential effects on fertility of PCOS rats and phenotypes of offspring rats.

MATERIALS AND METHODS

PCOS model in rats was established by Letasazole administration. Follicular development of rats was evaluated by the percentages of the cystic follicle (FC) and corpus luteum (CL) of all follicles. The enzyme-linked immunosorbent assay (ELISA) was conducted to detect serum levels of hormones in rats, including LH, LH/FSH, T, INS, FSH, and E2. Subsequently, PCOS rats received a subcapsular injection of microRNA-409 mimics. The expression level of microRNA-409 in ovary was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Serum levels of LH, LH/FSH, T, INS, FSH, and E2 in PCOS rats with microRNA-409 overexpression were accessed by enzyme-linked immunosorbent assay (ELISA) as well. PCOS rats were mated with male rats for recording pregnancy rate. At 6-week-old of offspring, they were sacrificed for detecting microRNA-409 level, percentages of FC and CL, as well as serum levels of hormones.

RESULTS

PCOS rats showed irregular estrous cycle and they were mainly in the anestrum. Rats in the control group were in a regular estrous cycle. A higher percentage of FC and a lower percentage of CL were seen in PCOS rats compared with those of controls. ELISA data revealed higher serum levels of LH, LH/FSH, and T in PCOS rats compared with those of controls. However, levels of FSH and E2 were lower in PCOS rats. Although INS level increased in PCOS rats, we did not observe a significant difference in INS level between PCOS rats and control rats. MicroRNA-409 was lowly expressed in ovaries of PCOS rats than those of controls. After injection of microRNA-409 mimics into rat ovary, microRNA-409 expression remarkably upregulated than those PCOS rats without injection. Rats in PCOS+microRNA-409 mimics group showed the largest body weight compared with those in the PCOS group and control group. PCOS rats showed a lower pregnancy rate than those of controls, which was markedly increased after administration of microRNA-409 mimics. Rats in PCOS+microRNA-409 mimics group presented lower levels of LH, LH/FSH, T, and INS, but higher levels of FSH and E2 than those in PCOS group.

CONCLUSIONS

MicroRNA-409 is lowly expressed in the ovary of PCOS rats. Overexpression of microRNA-409 could improve hormone levels and pregnancy rate in PCOS rats, as well as affect clinical phenotypes of their offspring.

Functional characterization and expression analysis of two terpene synthases involved in floral scent formation in Lilium 'Siberia'

Floral scent formation in Lilium 'Siberia' is mainly due to monoterpene presence in the floral profile. LoTPS1 and LoTPS3 are responsible for the formation of (±)-linalool and β-ocimene in Lilium 'Siberia'. Lilium 'Siberia' is a perennial herbaceous plant belonging to Liliaceae family, cultivated both as a cut flower and garden plant. The snowy white flower emits a pleasant aroma which is mainly caused by monoterpenes present in the floral volatile profile. Previously terpene synthase (TPS) genes have been isolated and characterized from various plant species but less have been identified from Liliaceae family. Here, two terpene synthase genes (LoTPS1 and LoTPS3), which are highly expressed in sepals and petals of Lilium 'Siberia' flower were functionally characterized recombinant LoTPS1 specifically catalyzes the formation of (Z)-β-ocimene and (±)-linalool as its main volatile compounds from geranyl pyrophosphate (GPP), whereas LoTPS3 is a promiscuous monoterpene synthase which utilizes both GPP and farnesyl pyrophosphate (FPP) as a substrate to generate (±)-linalool and cis-nerolidol, respectively. Transcript levels of both genes were prominent in flowering parts, especially in sepals and petals which are the main source of floral scent production. The gas chromatography-mass spectrometry (GC-MS) and quantitative real-time PCR analysis revealed that the compounds were emitted throughout the day, prominently during the daytime and lower levels at night following a strong circadian rhythm in their emission pattern. Regarding mechanical wounding, both genes showed considerable involvement in floral defense by inducing the emission of (Z)-β-ocimene and (±)-linalool, elevating the transcript accumulation of LoTPS1 and LoTPS3. Furthermore, the subcellular localization experiment revealed that LoTPS1 was localized in plastids, whilst LoTPS3 in mitochondria. Our findings on these two TPSs characterized from Lilium 'Siberia' provide new insights into molecular mechanisms of terpene biosynthesis in this species and also provide an opportunity for biotechnological modification of floral scent profile of Lilium.