Trihelix transcription factor SlGT31 regulates fruit ripening mediated by ethylene in tomato.

Trihelix proteins are plant-specific transcription factors that are classified as GT factors due to their binding specificity for GT elements, and they play crucial roles in development and stress responses. However, their involvement in fruit ripening and transcriptional regulatory mechanisms remains largely unclear. In this study, we cloned SlGT31, encoding a trihelix protein in tomato (Solanum lycopersicum), and determined that its relative expression was significantly induced by the application of exogenous ethylene whereas it was repressed by the ethylene-inhibitor 1-methylcyclopropene. Suppression of SlGT31 expression resulted in delayed fruit ripening, decreased accumulation of total carotenoids, and reduced ethylene content, together with inhibition of expression of genes related to ethylene and fruit ripening. Conversely, SlGT31-overexpression lines showed opposite results. Yeast one-hybrid and dual-luciferase assays indicated that SlGT31 can bind to the promoters of two key ethylene-biosynthesis genes, ACO1 and ACS4. Taken together, our results indicate that SlGT31 might act as a positive modulator during fruit ripening.

Red emissive boron and nitrogen co-doped "on-off-on" carbon dots for detecting and imaging of mercury(II) and biothiols.

Red emissive B,N co-doped carbon dots (BN-CDs) were hydrothermally synthesized from cresyl violet and boric acid. The BN-CDs exhibited excellent photostability, low cytotoxicity, excitation/emission maxima at 520/616 nm, and a relatively high quantum yield of 18%. The BN-CDs can binded to mercury(II), and this results in quenching of the red-colored fluorescence. However, on subsequent addition of the biothiol (such as cysteine, homocysteine or glutathione), fluorescence recovers. Therefore, the BN-CDs can be used as a multifunctional probe based on "on-off-on" fluorescence response for the detection of Hg(II) and biothiols. The following detection limits were accomplished: (a) Hg(II): 2.8 µM; (b) glutathione: 1.7 µM; (c) cysteine: 2.3 µM; (d) homocysteine: 3.0 µM. The BN-CDs also have been successfully applied for the imaging of Hg(II) and biothiols in HepG2 cells with excellent bio-compatibility. Graphical abstract Red emissive B,N co-doped carbon dots (BN-CDs) were synthesized through hydrothermal treatment of cresyl violet and boric acid. The BN-CDs can be used as a multifunctional probe based on "on-off-on" fluorescence response for detecting mercury(II) and biothiols in aqueous solution and living cells.

A Drug Repositioning Approach Reveals Ergotamine May Be a Potential Drug for the Treatment of Alzheimer's Disease.

Background: Alzheimer's disease (AD) is a neurodegenerative disorder that is the most common form of dementia in the elderly. The drugs currently used to treat AD only have limited effects and are not able to cure the disease. Drug repositioning has increasingly become a promising approach to find potential drugs for diseases like AD. Objective: To screen potential drug candidates for AD based on the relationship between risk genes of AD and drugs. Methods: We collected the risk genes of AD and retrieved the information of known drugs from DrugBank. Then, the AD-related genes and the targets of each drug were mapped to the human protein-protein interaction network (PPIN) to represent AD and the drugs on the network. The network distances between each drug and AD were calculated to screen the drugs proximal to AD-related genes on PPIN, and the screened drug candidates were further analyzed by molecular docking and molecular dynamics simulations. Results: We compiled a list of 714 genes associated with AD. From 5,833 drugs used for human diseases, we identified 1,044 drugs that could be potentially used to treat AD. Then, amyloid-ß (Aß) protein, the key molecule involved in the pathogenesis of AD was selected as the target to further screen drugs that may inhibit Aß aggregation by molecular docking. We found that ergotamine and RAF-265 could bind stably with Aß. In further analysis by molecular dynamics simulations, both drugs exhibited reasonable stability. Conclusions: Our work indicated that ergotamine and RAF-265 may be potential candidates for treating AD.

Dihydroergotamine and Bromocriptine: Potential Drugs for the Treatment of Major Depressive Disorder and Alzheimer's Disease Comorbidity.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease that is characterized by memory loss and cognitive impairment. Evidence shows that depression is a common co-occurrence in AD patients, and major depressive disorder (MDD) is considered a risk factor for AD. The crosstalk between the biological procedures related to the two disorders makes it very difficult to treat the comorbid conditions caused by them. Considering the common pathophysiological mechanisms underlying AD and MDD, antidepressant drugs may have beneficial therapeutic effects against their concurrence. In this study, we aimed to explore the potential drug candidates for the prevention and treatment of the comorbidity of AD and MDD. First, we screened the potential drugs for treating MDD by evaluating the distances of drug targets to MDD-related genes on the human protein-protein interaction network (PPIN) via a network-based algorithm. Then, the drugs were further screened to identify those that may be effective for AD treatment by analyzing their affinities with tau protein and Aß42 peptide via molecular docking. Furthermore, the most stable binding modes were identified via molecular dynamics simulations, and the regulatory effects of drug candidates on genes involved in the pathogenesis of AD and MDD were analyzed. A total of 506 MDD-related genes were retrieved, and 831 drug candidates for MDD treatment were screened via the network-based approach. The results from molecular docking and molecular dynamics simulations indicated dihydroergotamine had the lowest binding affinity with tau protein and bromocriptine could form the most stable binding mode with Aß42 peptide. Further analyses found that both dihydroergotamine and bromocriptine could regulate the expression of genes involved in the pathogenesis of AD and/or MDD in the brain. The exact mechanisms of the two drugs in treating AD and MDD, as well as their comorbidity, are still unclear, and further exploration is needed to evaluate their roles and mechanisms, both in vitro and in vivo. This study revealed that dihydroergotamine and bromocriptine may be the potential drug candidates for the treatment of the comorbidity of AD and MDD, and the therapeutic effects may be achieved by inhibiting the accumulation and aggregation of Aß42 and tau protein and regulating the expression of disease-related genes in the brain.

Antimicrobial drugs for Parkinson's disease: Existing therapeutic strategies and novel drugs exploration.

Parkinson's disease (PD), the second most common neurodegenerative disorder, is characterized by loss of dopaminergic neurons in the substantia nigra, as well as the abnormal accumulation of misfolded α-synuclein. Clinically, PD is featured by typical motor symptoms and some non-motor symptoms. Up to now, although considerable progress has been made in understanding the pathogenesis of PD, there is still no effective therapeutic treatment for the disease. Thus, exploring new therapeutic strategies has been a topic that needs to be addressed urgently. Noteworthy, with the proposal of the microbiota-gut-brain axis theory, antimicrobial drugs have received significant attention due to their effects on regulating the intestinal microbiota. Nowadays, there is growing evidence showing that some antimicrobial drugs may be promising drugs for the treatment of PD. Data from pre-clinical and clinical studies have shown that some antimicrobial drugs may play neuroprotective roles in PD by modulating multiple biochemical and molecular pathways, including reducing α-synuclein aggregation, inhibiting neuroinflammation, regulating mitochondrial structure and function, as well as suppressing oxidative stress. In this paper, we summarized the effects of some antimicrobial drugs on PD treatment from recent pre-clinical and clinical studies. Then, we further discussed the potential of a few antimicrobial drugs for treating PD based on molecular docking and molecular dynamics simulation. Importantly, we highlighted the potential of clorobiocin as the therapeutic strategy for PD owing to its ability to inhibit α-synuclein aggregation. These results will help us to better understand the potential of antimicrobial drugs in treating PD and how antimicrobial drugs may alleviate or reverse the pathological symptoms of PD.

Combination Therapy and Dual-Target Inhibitors Based on LSD1: New Emerging Tools in Cancer Therapy.

Lysine specific demethylase 1 (LSD1), a transcriptional modulator that represses or activates target gene expression, is overexpressed in many cancer and causes imbalance in the expression of normal gene networks. Over two decades, numerous LSD1 inhibitors have been reported, especially some of which have entered clinical trials, including eight irreversible inhibitors (TCP, ORY-1001, GSK-2879552, INCB059872, IMG-7289, ORY-2001, TAK-418, and LH-1802) and two reversible inhibitors (CC-90011 and SP-2577). Most clinical LSD1 inhibitors demonstrated enhanced efficacy in combination with other agents. LSD1 multitarget inhibitors have also been reported, exampled by clinical dual LSD1/histone deacetylases (HDACs) inhibitors 4SC-202 and JBI-802. Herein, we present a comprehensive overview of the combination of LSD1 inhibitors with various antitumor agents, as well as LSD1 multitarget inhibitors. Additionally, the challenges and future research directionsare also discussed, and we hope this review will provide new insight into the development of LSD1-targeted anticancer agents.

Degraders in epigenetic therapy: PROTACs and beyond.

Epigenetics refers to the reversible process through which changes in gene expression occur without changing the nucleotide sequence of DNA. The process is currently gaining prominence as a pivotal objective in the treatment of cancers and other ailments. Numerous drugs that target epigenetic mechanisms have obtained approval from the Food and Drug Administration (FDA) for the therapeutic intervention of diverse diseases; many have drawbacks, such as limited applicability, toxicity, and resistance. Since the discovery of the first proteolysis-targeting chimeras (PROTACs) in 2001, studies on targeted protein degradation (TPD)-encompassing PROTACs, molecular glue (MG), hydrophobic tagging (HyT), degradation TAG (dTAG), Trim-Away, a specific and non-genetic inhibitor of apoptosis protein (IAP)-dependent protein eraser (SNIPER), antibody-PROTACs (Ab-PROTACs), and other lysosome-based strategies-have achieved remarkable progress. In this review, we comprehensively highlight the small-molecule degraders beyond PROTACs that could achieve the degradation of epigenetic proteins (including bromodomain-containing protein-related targets, histone acetylation/deacetylation-related targets, histone methylation/demethylation related targets, and other epigenetic targets) via proteasomal or lysosomal pathways. The present difficulties and forthcoming prospects in this domain are also deliberated upon, which may be valuable for medicinal chemists when developing more potent, selective, and drug-like epigenetic drugs for clinical applications.

A tomato HD-zip I transcription factor, VAHOX1, acts as a negative regulator of fruit ripening.

Homeodomain-leucine zipper (HD-Zip) transcription factors are only present in higher plants and are involved in plant development and stress responses. However, our understanding of their participation in the fruit ripening of economical plants, such as tomato (Solanum lycopersicum), remains largely unclear. Here, we report that VAHOX1, a member of the tomato HD-Zip I subfamily, was expressed in all tissues, was highly expressed in breaker+4 fruits, and could be induced by ethylene. RNAi repression of VAHOX1 (VAHOX1-RNAi) resulted in accelerated fruit ripening, enhanced sensitivity to ethylene, and increased total carotenoid content and ethylene production. Conversely, VAHOX1 overexpression (VAHOX1-OE) in tomato had the opposite effect. RNA-Seq results showed that altering VAHOX1 expression affected the transcript accumulation of a series of genes involved in ethylene biosynthesis and signal transduction and cell wall modification. Additionally, a dual-luciferase reporter assay, histochemical analysis of GUS activity and a yeast one-hybrid (Y1H) assay revealed that VAHOX1 could activate the expression of AP2a. Our findings may expand our knowledge about the physiological functions of HD-Zip transcription factors in tomato and highlight the diversities of transcriptional regulation during the fruit ripening process.

Study on the interaction of Zea mays L. centrin and melittin.

Zea mays L. centrin (Zmcen) is a 20 kDa calcium binding protein also known as caltractin. We used melittin as a simulated target peptide and examined its interaction with Zmcen to understand the structure of Zmcen and the mechanism of interaction with downstream target peptides. The circular dichroism spectrum was used to characterize the typical α-helix structure of Zmcen, and after combining with melittin, the α-helix content of Zmcen changed. Trp residues in melittin were used as fluorescent probes to monitor changes in the conformation of Zmcen upon melittin binding. The Trp residues in melittin gradually shifted from polar environments to nonpolar environments, fluorescence peaks were significantly blueshifted, and the intensity of the fluorescence peak increased. These results showed that Zmcen and melittin combined in a 1 : 1 ratio to form a new complex. The influence of metal ions on binding was also investigated. The combination of Ca2+ and Zmcen helped expose more hydrophobic regions of Zmcen and promoted the binding of Zmcen and melittin. In addition, 2-p-toluidinylnaphthalene-6-sulfonate (TNS) was used as a hydrophobic probe to bind to Zmcen and Zmcen occupied the hydrophobic area on the surface of Zmcen, thereby weakening the binding of Zmcen and melittin. The Biacore experiment was used to calculate the equilibrium constant (K D) for the dissociation of Zmcen and melittin. Melittin mainly binds to C-Zmcen but not to N-Zmcen, indicating that the binding site of melittin on Zmcen was mainly at the C-terminus of Zmcen.

Boron and nitrogen codoped carbon dots as fluorescence sensor for Fe3+ with improved selectivity.

Carbon dots (CDs) are popular as fluorescence sensors, and metal ions are typical analytes. However, CDs used as fluorescent sensors for Fe3+ have some interferences coming from co-existed ions. In this study, we suspect that sp3 boron atom in phenylboronic acid group will be more compatible with Fe3+ to form coordination bonds, thereby increasing the selectivity to Fe3+. Hence, we designed and synthesized boron and nitrogen codoped carbon dots (BN-CDs) for detection of Fe3+ via a hydrothermal method using o-phenylenediamine (OPA) and 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzylchloroformate as precursors. From the results, we found that BN-CDs had superior selectivity to Fe3+ in the presence of the other common interfering metal ions like Cu2+, Fe2+ and Pb2+. Besides, the obtained BN-CDs exhibited good water solubility, favorable photostability, excellent pH stability between pH 2-11, and strong fluorescence intensity with quantum yield up to 31.5 %. These excellent properties of carbon dots validate that our idea is feasible, and can be used for design CDs for Fe3+ detection. Quenching mechanism study showed the fluorescence intensity of BN-CDs could be dramatically quenched by Fe3+ through dynamic and static synergy process. Finally, the as prepared BN-CDs were successfully applied to the determination of Fe3+ in fetal bovine serum and lake water.

Efficacy and Safety of Traditional Chinese Medicine on Nonerosive Reflux Disease: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: Traditional Chinese medicine (TCM) therapy for nonerosive reflux disease (NERD) remains controversial. The aim of this study was to evaluate the efficacy and safety of TCM regimens in NERD treatment. METHODS: Randomized controlled trials (RCTs) of TCM treatment for NERD through September 31, 2017, were systematically identified in PubMed, Wanfang Data, CNKI, VIP, CBM, Ovid, Web of Science, and Cochrane Library databases. Quality assessment was performed by employing the Cochrane Risk of Bias assessment tool. RESULTS: A total of 725 and 719 patients in 14 RCTs were randomly divided into TCM alone and conventional Western medicine groups, respectively. The clinical total effective rate of the TCM group was markedly higher than that of the single proton pump inhibitors (PPIs) or Prokinetics therapy group (RR = 1.19, 95% CI = 1.07-1.31, and P = 0.0008), while it was comparable to that of the combination of PPIs and Prokinetics therapy group (RR = 1.14, 95% CI = 1.00-1.29, and P = 0.05). Compared with Western medicine group, the TCM group showed improved symptom relief through a reduced RDQ score (SMD = -0.91; 95% CI = -1.68--0.15; and P = 0.02). Additionally, TCM clearly decreased the recurrence rate (RR = 0.38, 95% CI = 0.28-0.52, and P < 0.00001). Adverse events, such as constipation, sickness, fever, abdominal distension, and stomach noise, were slight for both the TCM and Western medicine groups and disappeared after the easement of pharmacological intervention; in particular, TCM possessed fewer side effects. CONCLUSION: Compared with PPIs or Prokinetics therapy alone, TCM single therapy can better improve the clinical total effective rate and symptom relief and decrease the recurrence rate and adverse events in the treatment of NERD. Our results suggest that TCM will be a promising alternative therapy for NERD patients in the future.

A Microfluidic Device for Culturing an Encapsulated Ovarian Follicle.

Microfluidic chips have been proved effective in mimicking different organs of human body. Simulating human ovarian follicles by microfluidic device will be useful in exploring the mechanism of folliculogenesis and related diseases. In this paper, a microfluidic chip was designed to culture a single human pre-antral follicle. Ovarian follicles were first encapsulated in 3D calcium alginate hydrogel beads and then cultured on chip and in dish under same conditions. The diameters of cultured ovarian follicles were measured, and the same amount of medium was collected from microfluidic device or dish per two days for measuring the estradiol and androgen concentrations. The results confirmed the successful growth of ovarian follicles on chip with their hormonal trends and diameters increase, which were similar to ovarian follicles cultured in dish. It is concluded that this microfluidic chip can be used to culture a single human ovarian follicle, which provides a useful tool to explore the hormonal changes and their interactions during folliculogenesis.

The Role of Microfluidics for Organ on Chip Simulations.

A multichannel three-dimensional chip of a microfluidic cell culture which enables the simulation of organs is called an "organ on a chip" (OC). With the integration of many other technologies, OCs have been mimicking organs, substituting animal models, and diminishing the time and cost of experiments which is better than the preceding conventional in vitro models, which make them imperative tools for finding functional properties, pathological states, and developmental studies of organs. In this review, recent progress regarding microfluidic devices and their applications in cell cultures is discussed to explain the advantages and limitations of these systems. Microfluidics is not a solution but only an approach to create a controlled environment, however, other supporting technologies are needed, depending upon what is intended to be achieved. Microfluidic platforms can be integrated with additional technologies to enhance the organ on chip simulations. Besides, new directions and areas are mentioned for interested researchers in this field, and future challenges regarding the simulation of OCs are also discussed, which will make microfluidics more accurate and beneficial for biological applications.