Artemisia argyi extracts overcome lapatinib resistance via enhancing TMPRSS2 activation in HER2-positive breast cancer.

Breast cancer stands as the predominant malignancy and primary cause of cancer-related mortality among females globally. Approximately 25% of breast cancers exhibit HER2 overexpression, imparting a more aggressive tumor phenotype and correlating with poor prognoses. Patients with metastatic breast cancer receiving HER2 tyrosine kinase inhibitors (HER2 TKIs), such as Lapatinib, develop acquired resistance within a year, posing a critical challenge in managing this disease. Here, we explore the potential of Artemisia argyi, a Chinese herbal medicine known for its anti-cancer properties, in mitigating HER2 TKI resistance in breast cancer. Analysis of the Cancer Genome Atlas (TCGA) revealed diminished expression of transmembrane serine protease 2 (TMPRSS2), a subfamily of membrane proteolytic enzymes, in breast cancer patients, correlating with unfavorable outcomes. Intriguingly, lapatinib-responsive patients exhibited higher TMPRSS2 expression. Our study unveiled that the compounds from Artemisia argyi, eriodictyol, and umbelliferone could inhibit the growth of lapatinib-resistant HER2-positive breast cancer cells. Mechanistically, they suppressed HER2 kinase activation by enhancing TMPRSS2 activity. Our findings propose TMPRSS2 as a critical determinant in lapatinib sensitivity, and Artemisia argyi emerges as a potential agent to overcome lapatinib via activating TMPRSS2 in HER2-positive breast cancer. This study not only unravels the molecular mechanisms driving cell death in HER2-positive breast cancer cells induced by Artemisia argyi but also lays the groundwork for developing novel inhibitors to enhance therapy outcomes.

The association of TMPRSS6 gene polymorphism with iron status in Egyptian children (a pilot study).

Several studies have shown association of single nucleotide polymorphisms (SNPs) of hepcidin regulatory pathways genes with impaired iron status. The most common is in the TMPRSS6 gene. In Africa, very few studies have been reported. We aimed to investigate the correlation between the common SNPs in the transmembrane protease, serine 6 (TMPRSS6) gene and iron indicators in a sample of Egyptian children for identifying the suitable candidate for iron supplementation.Patients and methods One hundred and sixty children aged 5-13 years were included & classified into iron deficient, iron deficient anemia and normal healthy controls. All were subjected to assessment of serum iron, serum ferritin, total iron binding capacity, complete blood count, reticulocyte count, serum soluble transferrin receptor and serum hepcidin. Molecular study of TMPRSS6 genotyping polymorphisms (rs4820268, rs855791 and rs11704654) were also evaluated.Results There was an association of iron deficiency with AG of rs855791 SNP, (P = 0.01). The minor allele frequency for included children were 0.43, 0.45 & 0.17 for rs4820268, rs855791 & rs11704654 respectively. Genotype GG of rs4820268 expressed the highest hepcidin gene expression fold, the lowest serum ferroportin & iron store compared to AA and AG genotypes (p = 0.05, p = 0.05, p = 0.03 respectively). GG of rs855791 had lower serum ferritin than AA (p = 0.04), lowest iron store & highest serum hepcidin compared to AA and AG genotypes (p = 0.04, p = 0.01 respectively). Children having CC of rs11704654 had lower level of hemoglobin, serum ferritin and serum hepcidin compared with CT genotype (p = 0.01, p = 0.01, p = 0.02) respectively.Conclusion Possible contribution of SNPs (rs855791, rs4820268 and rs11704654) to low iron status.

Anisomeles indica Extracts and Their Constituents Suppress the Protein Expression of ACE2 and TMPRSS2 In Vivo and In Vitro.

Coronavirus disease 2019 (COVID-19), stemming from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a profound global impact. This highly contagious pneumonia remains a significant ongoing threat. Uncertainties persist about the virus's effects on human health, underscoring the need for treatments and prevention. Current research highlights angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) as key targets against SARS-CoV-2. The virus relies on ACE2 to enter cells and TMPRSS2 to activate its spike protein. Inhibiting ACE2 and TMPRSS2 expression can help prevent and treat SARS-CoV-2 infections. Anisomeles indica (L.) Kuntze, a medicinal plant in traditional Chinese medicine, shows various promising pharmacological properties. In this study, ethanolic extracts of A. indica were examined both in vivo (250 and 500 µM) and in vitro (500 µM). Through Western blotting analysis, a significant reduction in the expression levels of ACE2 and TMPRSS2 proteins was observed in HepG2 (human hepatocellular carcinoma) cells and HEK 293T (human embryonic kidney) cell lines without inducing cellular damage. The principal constituents of A. indica, namely, ovatodiolide (5 and 10 µM), anisomlic acid (5 and 10 µM), and apigenin (12.5 and 25 µM), were also found to produce the same effect. Furthermore, immunohistochemical analysis of mouse liver, kidney, and lung tissues demonstrated a decrease in ACE2 and TMPRSS2 protein expression levels. Consequently, this article suggests that A. indica and its constituents have the potential to reduce ACE2 and TMPRSS2 protein expression levels, thus aiding in the prevention of SARS-CoV-2 infections.

Cochlear Implants in Deaf Patients with Novel TMPRSS3 Gene Mutation.

Objective: To investigate the effect of cochlear implants in deaf patients with TMPRSS3 gene pathogenic variations. Methods: Variations of deafness genes were detected in 2 patients with profound hearing loss. Both received unilateral cochlear implantation. Hearing and speech abilities were evaluated and analyzed before and 3 and 6 months after surgery. The analysis included post-surgery evaluation of auditory behavior (Categories of Performance [CAP]) and Speech Intelligibility Rating (SIR). Results: In the 2 patients, 3 pathogenic single nucleotide variations (SNVs) of TMPRSS3 gene and a large deletion in 21q22.3 were detected. The CAP and SIR grades increased with the recovery time. Conclusion: Cochlear implants have a good effect in patients with TMPRSS3 gene mutation deafness. Preoperative gene testing has a certain reference significance for the prognosis in patients with the deafness gene mutation.

Role of Vitamin D, ACE2 and the Proteases as TMPRSS2 and Furin on SARS-CoV-2 Pathogenesis and COVID-19 Severity.

BACKGROUND: COVID-19, the 21st century pandemic disease caused by SARS-CoV-2, has shown a wide clinical spectrum ranging from asymptomatic to deadly serious pneumonia. OBJECTIVE: In our study, the relationship between the pathogenesis and clinical severity of COVID-19 and vitamin D, ACE2, Furin and TMPRSS2 was investigated. METHODS: Serum 25(OH)D, 1,25(OH)2D and ACE2 protein were measured in 85 COVID-19 cases, divided into 5 groups, according to disease severity, from asymptomatic to severe and including a healthy control group. Expression levels of ACE2, VDR, TMPRSS2 and Furin mRNAs in PBMC were also measured. The relationship of the parameters within each group, the severity of the disease and the effect on the patients' fate were investigated. RESULTS: Statistically significant differences were found between the severity of COVID-19 and all study parameters, except for serum 25(OH)D. A strong negative correlation was found between serum ACE2 protein, 1,25(OH)2D, and ACE2 mRNA, and disease severity, length of hospital stay and death/survival rate. Vitamin D deficiency increased the death risk by 5.6-fold (95% CI 0.75-41.47), and the levels of 1,25(OH)2D lower than 1 ng/mL increased the risk of death by 3.8-fold (95% CI 1.07-13.30). CONCLUSION: This study suggests that vitamin D supplementation could be beneficial in the treatment and/or prevention of COVID-19.

Hesperidin identified from Citrus extracts potently inhibits HCV genotype 3a NS3 protease.

BACKGROUND: Hepatitis C virus infection is the main cause of liver ailments across the globe. Several HCV genotypes have been identified in different parts of the world. Effective drugs for combating HCV infections are available but not affordable, particularly to infected individuals from resource-limited countries. Hence, cost-effective drugs need to be developed against important HCV drug targets. As Citrus fruits naturally contain bioactive compounds with antiviral activities, the current study was designed to identify antiviral inhibitors from Citrus fruit extracts against an important drug target, NS3 protease, of HCV genotype 3a which is found predominantly in South Asian countries. METHODS: The full-length NS3 protease alone and the NS3 protease domain in fusion with the cognate NS4A cofactor were expressed in Escherichia coli, and purified by chromatographic techniques. Using the purified protein as a drug target, Citrus extracts were evaluated in a FRET assay, and active ingredients, identified using ESI-MS/MS, were docked to observe the interaction with active site residues of NS3. The best interacting compound was further confirmed through the FRET assay as the inhibitor of NS3 protease. RESULTS: Fusion of the NS3 protease domain to the NS4A cofactor significantly improved the purification yield, and NS3-NS4A was functionally more active than the full-length NS3 alone. The purified protein (NS3-NS4A) was successfully employed in a validated FRET assay to evaluate 14 Citrus fruit extracts, revealing that the mesocarp extract of Citrus paradisi, and whole fruit extracts of C. sinesis, C. aurantinum, and C. reticulata significantly inhibited the protease activity of HCV NS3 protease (IC50 values of 5.79 ± 1.44 µg/mL, 37.19 ± 5.92 µg/mL, 42.62 ± 6.89 µg/mL, and 57.65 ± 3.81 µg/mL, respectively). Subsequent ESI-MSn analysis identified a flavonoid, hesperidin, abundantly present in all the afore-mentioned Citrus extracts. Importantly, docking studies suggested that hesperidin interacts with active site residues, and acts as a potent inhibitor of NS3 protease, exhibiting an IC50 value of 11.34 ± 3.83 µg/mL. CONCLUSIONS: A FRET assay was developed using NS3-NS4A protease, which was successfully utilized for the evaluation of Citrus fruit extracts. Hesperidin, a compound present in the Citrus extracts, was identified as the main flavonoid, which can serve as a cost-effective potent inhibitor of NS3 protease, and could be developed as a drug for antiviral therapy against HCV genotype 3a.

Withanone and Withaferin-A are predicted to interact with transmembrane protease serine 2 (TMPRSS2) and block entry of SARS-CoV-2 into cells.

Coronavirus disease 2019 (COVID-19) initiated in December 2019 in Wuhan, China and became pandemic causing high fatality and disrupted normal life calling world almost to a halt. Causative agent is a novel coronavirus called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2/2019-nCoV). While new line of drug/vaccine development has been initiated world-wide, in the current scenario of high infected numbers, severity of the disease and high morbidity, repurposing of the existing drugs is heavily explored. Here, we used a homology-based structural model of transmembrane protease serine 2 (TMPRSS2), a cell surface receptor, required for entry of virus to the target host cell. Using the strengths of molecular docking and molecular dynamics simulations, we examined the binding potential of Withaferin-A (Wi-A), Withanone (Wi-N) and caffeic acid phenethyl ester to TPMRSS2 in comparison to its known inhibitor, Camostat mesylate. We found that both Wi-A and Wi-N could bind and stably interact at the catalytic site of TMPRSS2. Wi-N showed stronger interactions with TMPRSS2 catalytic residues than Wi-A and was also able to induce changes in its allosteric site. Furthermore, we investigated the effect of Wi-N on TMPRSS2 expression in MCF7 cells and found remarkable downregulation of TMPRSS2 mRNA in treated cells predicting dual action of Wi-N to block SARS-CoV-2 entry into the host cells. Since the natural compounds are easily available/affordable, they may even offer a timely therapeutic/preventive value for the management of SARS-CoV-2 pandemic. We also report that Wi-A/Wi-N content varies in different parts of Ashwagandha and warrants careful attention for their use.Communicated by Ramaswamy H. Sarma.

High-Throughput Fluorescent Assay for Inhibitor Screening of Proteases from RNA Viruses.

Spanish flu, polio epidemics, and the ongoing COVID-19 pandemic are the most profound examples of severe widespread diseases caused by RNA viruses. The coronavirus pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) demands affordable and reliable assays for testing antivirals. To test inhibitors of viral proteases, we have developed an inexpensive high-throughput assay based on fluorescent energy transfer (FRET). We assayed an array of inhibitors for papain-like protease from SARS-CoV-2 and validated it on protease from the tick-borne encephalitis virus to emphasize its versatility. The reaction progress is monitored as loss of FRET signal of the substrate. This robust and reproducible assay can be used for testing the inhibitors in 96- or 384-well plates.

An Updated Review on Betacoronavirus Viral Entry Inhibitors: Learning from Past Discoveries to Advance COVID-19 Drug Discovery.

Even after one year of its first outbreak reported in China, the coronavirus disease 2019 (COVID-19) pandemic is still sweeping the World, causing serious infections and claiming more fatalities. COVID-19 is caused by the novel coronavirus SARS-CoV-2, which belongs to the genus Betacoronavirus (ß-CoVs), which is of greatest clinical importance since it contains many other viruses that cause respiratory disease in humans, including OC43, HKU1, SARS-CoV, and MERS. The spike (S) glycoprotein of ß-CoVs is a key virulence factor in determining disease pathogenesis and host tropism, and it also mediates virus binding to the host's receptors to allow viral entry into host cells, i.e., the first step in virus lifecycle. Viral entry inhibitors are considered promising putative drugs for COVID-19. Herein, we mined the biomedical literature for viral entry inhibitors of other coronaviruses, with special emphasis on ß-CoVs entry inhibitors. We also outlined the structural features of SARS-CoV-2 S protein and how it differs from other ß-CoVs to better understand the structural determinants of S protein binding to its human receptor (ACE2). This review highlighted several promising viral entry inhibitors as potential treatments for COVID-19.

AGTR2, One Possible Novel Key Gene for the Entry of SARS-CoV-2 Into Human Cells.

Recently, it was confirmed that ACE2 is the receptor of SARS-CoV-2, the pathogen causing the recent outbreak of severe pneumonia around the world. It is confused that ACE2 is widely expressed across a variety of organs and is expressed moderately but not highly in lung, which, however, is the major infected organ. Therefore, we hypothesized that there could be some other genes playing key roles in the entry of SARS-CoV-2 into human cells. Here we found that AGTR2 (angiotensin II receptor type 2), a G-protein coupled receptor, has interaction with ACE2 and is highly expressed in lung with a high tissue specificity. More importantly, simulation of 3D structure based protein-protein interaction reveals that AGTR2 shows a higher binding affinity with the Spike protein of SARS-CoV-2 than ACE2 (energy: -8.2 vs. -5.1 [kcal/mol]). A number of compounds, biologics and traditional Chinese medicine that could decrease the expression level of AGTR2 were predicted. Finally, we suggest that AGTR2 could be a putative novel gene for the entry of SARS-CoV-2 into human cells, which could provide different insight for the research of SARS-CoV-2 proteins with their receptors.

Structural Variability, Expression Profile, and Pharmacogenetic Properties of TMPRSS2 Gene as a Potential Target for COVID-19 Therapy.

The human serine protease serine 2 TMPRSS2 is involved in the priming of proteins of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and represents a possible target for COVID-19 therapy. The TMPRSS2 gene may be co-expressed with SARS-CoV-2 cell receptor genes angiotensin-converting enzyme 2 (ACE2) and Basigin (BSG), but only TMPRSS2 demonstrates tissue-specific expression in alveolar cells according to single-cell RNA sequencing data. Our analysis of the structural variability of the TMPRSS2 gene based on genome-wide data from 76 human populations demonstrates that a functionally significant missense mutation in exon 6/7 in the TMPRSS2 gene is found in many human populations at relatively high frequencies, with region-specific distribution patterns. The frequency of the missense mutation encoded by rs12329760, which has previously been found to be associated with prostate cancer, ranged between 10% and 63% and was significantly higher in populations of Asian origin compared with European populations. In addition to single-nucleotide polymorphisms, two copy number variants were detected in the TMPRSS2 gene. A number of microRNAs have been predicted to regulate TMPRSS2 and BSG expression levels, but none of them is enriched in lung or respiratory tract cells. Several well-studied drugs can downregulate the expression of TMPRSS2 in human cells, including acetaminophen (paracetamol) and curcumin. Thus, the interactions of TMPRSS2 with SARS-CoV-2, together with its structural variability, gene-gene interactions, expression regulation profiles, and pharmacogenomic properties, characterize this gene as a potential target for COVID-19 therapy.

GB-2 inhibits ACE2 and TMPRSS2 expression: In vivo and in vitro studies.

After the first case of Coronavirus disease 2019 (COVID-19) was reported in Wuhan, COVID-19 has rapidly spread to almost all parts of world. Angiotensin converting enzyme 2 (ACE2) receptor can bind to spike protein of SARS-CoV-2. Then, the spike protein of SARS-CoV-2 can be cleaved and activated by transmembrane protease, serine 2 (TMPRSS2) of the host cells for SARS-CoV-2 infection. Therefore, ACE2 and TMPRSS2 are potential antiviral targets for treatment of prevention of SARS-CoV-2 infection. In this study, we discovered that 10-250 µg/mL of GB-2, from Tian Shang Sheng Mu of Chiayi Puzi Peitian Temple, can inhibit ACE2 mRNA expression and ACE2 and TMPRSS2 protein expression in HepG2 and 293 T cells without cytotoxicity. GB-2 treatment could decrease ACE2 and TMPRSS2 expression level of lung tissue and kidney tissue without adverse effects, including nephrotoxicity and hepatotoxicity, in animal model. In the compositions of GB-2, we discovered that 50 µg/mL of theaflavin could inhibit protein expression of ACE2 and TMPRSS2. Theaflavin could inhibit the mRNA expression of ACE2. In conclusion, our results suggest that GB-2 and theaflavin could act as potential compounds for ACE2 and TMPRSS2 inhibitors in the further clinical study.

In Silico Identification of Potential Natural Product Inhibitors of Human Proteases Key to SARS-CoV-2 Infection.

Presently, there are no approved drugs or vaccines to treat COVID-19, which has spread to over 200 countries and at the time of writing was responsible for over 650,000 deaths worldwide. Recent studies have shown that two human proteases, TMPRSS2 and cathepsin L, play a key role in host cell entry of SARS-CoV-2. Importantly, inhibitors of these proteases were shown to block SARS-CoV-2 infection. Here, we perform virtual screening of 14,011 phytochemicals produced by Indian medicinal plants to identify natural product inhibitors of TMPRSS2 and cathepsin L. AutoDock Vina was used to perform molecular docking of phytochemicals against TMPRSS2 and cathepsin L. Potential phytochemical inhibitors were filtered by comparing their docked binding energies with those of known inhibitors of TMPRSS2 and cathepsin L. Further, the ligand binding site residues and non-covalent interactions between protein and ligand were used as an additional filter to identify phytochemical inhibitors that either bind to or form interactions with residues important for the specificity of the target proteases. This led to the identification of 96 inhibitors of TMPRSS2 and 9 inhibitors of cathepsin L among phytochemicals of Indian medicinal plants. Further, we have performed molecular dynamics (MD) simulations to analyze the stability of the protein-ligand complexes for the three top inhibitors of TMPRSS2 namely, qingdainone, edgeworoside C and adlumidine, and of cathepsin L namely, ararobinol, (+)-oxoturkiyenine and 3α,17α-cinchophylline. Interestingly, several herbal sources of identified phytochemical inhibitors have antiviral or anti-inflammatory use in traditional medicine. Further in vitro and in vivo testing is needed before clinical trials of the promising phytochemical inhibitors identified here.

Two Novel TMPRSS6 Variants in a Compound Heterozygous Child With Iron Refractory Iron Deficiency Anemia.

We describe a Caucasian family with asymptomatic, nonconsanguineous parents, and a daughter with unexplained microcytic anemia diagnosed on routine hemoglobin screening at her 12-month well child check. After failed response to oral and parental iron supplementation, iron refractory iron deficiency anemia was suspected. The family underwent genetic testing and the proband was found to be a compound heterozygote for 2 previously unreported TMPRSS6 variants.

Post-Weaning Social Isolation Disturbs Gene Expression in Rat Brain Structures.

Post-weaning social isolation of male Wistar rats for 10 weeks led to an increase of their aggressiveness, sensorimotor reactivity, and cognitive deficiency, manifesting in training disorders evaluated by the acoustic startle response (amplitude of the response decreasing). Expression of gene encoding serine protease prolyl endopeptidase (EC 3.4.21.26) in the frontal cortex was higher than in control rats kept in groups, while the level of mRNA of the gene encoding dipeptidyl peptidase IV (EC 3.4.14.5) did not differ from the control in any of the brain structures. The levels of serotonin transporter gene mRNA in the striatum and hypothalamus were higher than in the control. No appreciable changes in the expression of genes encoding tryptophan hydroxylase-2 and monoaminoxidase A and B in the frontal cortex, striatum, amygdala, hypothalamus, and hippocampus were detected. The data indicated the involvement of genes associated with the serotoninergic system in the mechanisms of mental disorders induced by post-weaning social isolation and suggest the gene encoding prolyl endopeptidase as a candidate gene involved in the pathogenesis of these disorders.

The role of TMPRSS6 and HFE variants in iron deficiency anemia in celiac disease.

We investigated the role of HFE C282Y, H63D, and TMPRSS6 A736V variants in the pathogenesis of iron deficiency anemia (IDA) in celiac disease (CD) patients, at diagnosis and after 1 year of gluten-free diet (GFD). Demographic and clinical features were prospectively recorded for all CD patients between 2013 and 2017. C282Y, H63D, and A736V variants were evaluated for CD patients and controls. Finally, 505 consecutive CD patients and 539 age-matched control subjects were enrolled. At diagnosis, 229 CD subjects had IDA (45.3%), with a subgroup of anemic patients (45.4%) presented persistent IDA at follow-up. C282Y allele frequency was significantly increased in CD compared with controls (1.1% vs 0.2%, P = .001), whereas H63D and A736V allele frequencies were similar among patients and controls (P = .92 and .84, respectively). At diagnosis, C282Y variant in anemic CD patients was significantly increased compared to nonanemic group (2% and 0.5%, P = .04). At follow-up, A736V was significantly increased in IDA persistent than in IDA not persistent (57.7% vs 35.2%, P < .0001). CD patients with H63D mutation showed higher Hb, MCV, serum iron, and ferritin levels than subjects without HFE mutations. Decreased hepcidin values were observed in anemic compared to nonanemic subjects at follow-up (1.22 ± 1.14 vs 2.08 ± 2.15, P < .001). This study suggests a protective role of HFE in IDA CD patients and confirms the role of TMPRSS6 in predicting oral iron response modulating hepcidin action on iron absorption. Iron supplementation therapeutic management in CD could depend on TMPRSS6 genotype that could predict persistent IDA despite iron supplementation and GFD.

Short-Term High-Salt Diet Increases Corin Level to Regulate the Salt-Water Balance in Humans and Rodents.

BACKGROUND: Dietary sodium and potassium affect the fluctuation in blood pressure (BP) and renal function. Corin, with its enzymatic activity to convert pro-atrial natriuretic peptide (pro-ANP) to biologically active ANP, regulates BP, cardiac, and renal functions. We investigated whether corin expression responds to a high-salt (HS) diet to regulate salt and water balance. METHODS: Forty-two volunteers followed 3 sequential diets for 7 days each: a low-salt (LS) diet (3.0 g/day NaCl), a HS diet (18.0 g/day NaCl), followed by an HS diet with K+ supplementation (HS + K+) (18.0 g/day NaCl and 4.5 g/day KCl). RESULTS: Corin level was higher with the HS diet than the LS and HS + K+ diets and was positively correlated with systolic BP (SBP) and 24-hour urinary Na+ and microalbumin (U-mALB) excretion. In rodents, serum and renal levels of corin were transiently increased with the HS diet and were decreased if the HS diet was continued for up to 7 days. HS loading increased SBP, 24-hour urinary Na+, U-mALB excretion, and the expression of proprotein convertase subtilisin/kexin-6 (PCSK6), a corin activator. Knockdown of PCSK6 or corin in high salt-treated M1-cortical collecting duct (M1-CCD) cells increased the expression of aquaporin 2 (AQP2) and ß-epithelial Na+ channel (ß-ENaC). CONCLUSIONS: Short-term HS may induce the PCSK6-corin-ANP-AQP2/ß-ENaC pathway in the kidney. Enhanced serum corin level in humans and rodents is positively correlated with HS-induced SBP and 24-hour urinary Na+ and U-mALB excretion, which suggests that corin is involved in the salt-water balance in response to HS intake. CLINICAL TRIALS REGISTRATION: Public Trials Registry Number NCT02915315.

Paeoniflorin suppresses pancreatic cancer cell growth by upregulating HTRA3 expression.

Paeoniflorin (PF) is an active monoterpene glycoside extracted from Paeonia lactiflora Pall. PF has exhibited antitumor effects in various cancer types. However, the effects of PF in pancreatic cancer are largely unexplored. Here, we showed that PF suppressed growth of pancreatic cancer cell lines Capan-1 and MIAPaCa-2 and profoundly sensitized these cells to X-ray irradiation. Through microarray analysis, we identified HTRA3, a tumor-suppressor candidate gene, as the most increased gene upon PF treatment in Capan-1 cells. Ectopic expression of HTRA3 led to reduced cell proliferation and increased expression of apoptotic protein Bax, suggesting a tumor suppressive role of HTRA3 in pancreatic cancer cells. Together, our results provide a set group of genetic proofs and biological proofs that PF inhibited pancreatic cancer growth by upregulating HTRA3.

[Biological diagnosis of iron deficiency in children]. / Diagnostic biologique de la carence martiale chez l'enfant.

Measurement of serum ferritin (SF) is currently the laboratory test recommended for diagnosing iron deficiency. In the absence of an associated disease, a low SF value is an early and highly specific indicator of iron deficiency. The WHO criteria proposed to define depleted storage iron are 12µg/L for children under 5 years and 15µg/L for those over 5 years. A higher threshold of 30µg/L is used in the presence of infection or inflammation. Iron deficiency anemia, with typical low mean corpuscular volume and mean corpuscular hemoglobin, is only present at the end stage of iron deficiency. Other diagnostic tests for iron deficiency including iron parameters (low serum iron, increased total iron-binding capacity, low transferrin saturation) and erythrocyte traits (low mean corpuscular volume, increased zinc protoporphyrin) provide little additional diagnostic value over SF. In children, serum soluble transferrin receptor (sTfR) has been reported to be a sensitive indicator of iron deficiency and is relatively unaffected by inflammation. On the other hand, sTfR is directly related to extent of erythroid activity and not commonly used in clinical practice. In population surveys, approaches based on combinations of markers have been explored to improve the specificity and sensitivity of diagnostic. In addition to Hb value determination, a combination of parameters (among transferrin saturation, zinc protoporphyrin, mean corpuscular volume or serum ferritin) was generally used to assess iron deficiency. More recently sTfR/ ferritin index were evaluated, sTfR in conjunction with SF allowing to better distinguishing iron deficiency from inflammatory anemia. Also, hepcidin measurements appeared an interesting marker for diagnosing iron deficiency and identifying individuals in need of iron supplementation in populations where inflammatory or infectious diseases are frequently encountered. Reticulocyte Hb content (CHr) determination is an early parameter of iron deficiency erythropoiesis. CHr can be measured with several automated hematology analyzers and so, used for individual's iron status assessment. In addition to Hb concentration determination, individual's iron status is commonly assessed in the pediatric clinical practice by the SF measurement accompanied by the determination of C-reactive protein for detection of a simultaneous acute infection and/or inflammation.

A conformational switch high-throughput screening assay and allosteric inhibition of the flavivirus NS2B-NS3 protease.

The flavivirus genome encodes a single polyprotein precursor requiring multiple cleavages by host and viral proteases in order to produce the individual proteins that constitute an infectious virion. Previous studies have revealed that the NS2B cofactor of the viral NS2B-NS3 heterocomplex protease displays a conformational dynamic between active and inactive states. Here, we developed a conformational switch assay based on split luciferase complementation (SLC) to monitor the conformational change of NS2B and to characterize candidate allosteric inhibitors. Binding of an active-site inhibitor to the protease resulted in a conformational change of NS2B and led to significant SLC enhancement. Mutagenesis of key residues at an allosteric site abolished this induced conformational change and SLC enhancement. We also performed a virtual screen of NCI library compounds to identify allosteric inhibitors, followed by in vitro biochemical screening of the resultant candidates. Only three of these compounds, NSC135618, 260594, and 146771, significantly inhibited the protease of Dengue virus 2 (DENV2) in vitro, with IC50 values of 1.8 µM, 11.4 µM, and 4.8 µM, respectively. Among the three compounds, only NSC135618 significantly suppressed the SLC enhancement triggered by binding of active-site inhibitor in a dose-dependent manner, indicating that it inhibits the conformational change of NS2B. Results from virus titer reduction assays revealed that NSC135618 is a broad spectrum flavivirus protease inhibitor, and can significantly reduce titers of DENV2, Zika virus (ZIKV), West Nile virus (WNV), and Yellow fever virus (YFV) on A549 cells in vivo, with EC50 values in low micromolar range. In contrast, the cytotoxicity of NSC135618 is only moderate with CC50 of 48.8 µM on A549 cells. Moreover, NSC135618 inhibited ZIKV in human placental and neural progenitor cells relevant to ZIKV pathogenesis. Results from binding, kinetics, Western blot, mass spectrometry and mutagenesis experiments unambiguously demonstrated an allosteric mechanism for inhibition of the viral protease by NSC135618.