Journal Articles, Multidisciplinary Digital Publishing Institute (MDPI)

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Alantolactone Suppresses Proliferation and the Inflammatory Response in Human HaCaT Keratinocytes and Ameliorates Imiquimod-Induced Skin Lesions in a Psoriasis-Like Mouse Model
Chuo, Wen-Ho; Tung, Yu-Tang; Wu, Chao-Liang; Bracci, Nicole R.; Chang, Yu-Kang; Huang, Hung-Yi; Lin, Chi-Chien (MDPI, 2021-06-25)
Psoriasis is an immune-mediated inflammatory disease that affects 2% to 3% of the world population. Alantolactone, a sesquiterpene lactone, was isolated from Inula helenium and Radix inulae and has several biological effects, including antifungal, anthelmintic, antimicrobial, anti-inflammatory, antitrypanosomal, and anticancer properties. This study aimed to evaluate the antipsoriatic potential of alantolactone in vitro and in vivo and to explore its underlying mechanisms. These results showed that alantolactone significantly attenuated IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) cytokine-induced hyperproliferation in HaCaT keratinocytes. Moreover, M5 cytokines significantly upregulated the mRNA levels of TNF-α, IL-6, IL-1β, and IL-8. However, alantolactone attenuated the upregulation of these inflammatory cytokines. In addition, alantolactone was found to inhibit STAT3 phosphorylation and NF-κB p65 nuclear translocation in HaCaT keratinocytes. Furthermore, alantolactone treatment in mice significantly alleviated the severity of skin lesions (erythema, scaling and epidermal thickness, and inflammatory cell infiltration) and decreased the mRNA expression of inflammatory cytokines (e.g., TNF-α, IL-6, IL-1β, IL-8, IL-17A, and IL-23) in an IMQ-induced-like mouse model. Therefore, our new findings revealed that alantolactone alleviates psoriatic skin lesions by inhibiting inflammation, making it an attractive candidate for future development as an antipsoriatic agent.
Alleviation of Collagen-Induced Arthritis by Crotonoside through Modulation of Dendritic Cell Differentiation and Activation
Lin, Shih-Chao; Lin, Chi-Chien; Li, Shiming; Lin, Wan-Yi; Lehman, Caitlin W.; Bracci, Nicole R.; Tsai, Sen-Wei (MDPI, 2020-11-10)
Crotonoside, a guanosine analog originally isolated from Croton tiglium, is reported to be a potent tyrosine kinase inhibitor with immunosuppressive effects on immune cells. Due to its potential immunotherapeutic effects, we aimed to evaluate the anti-arthritic activity of crotonoside and explore its immunomodulatory properties in alleviating the severity of arthritic symptoms. To this end, we implemented the treatment of crotonoside on collagen-induced arthritic (CIA) DBA/1 mice and investigated its underlying mechanisms towards pathogenic dendritic cells (DCs). Our results suggest that crotonoside treatment remarkably improved clinical arthritic symptoms in this CIA mouse model as indicated by decreased pro-inflammatory cytokine production in the serum and suppressed expression of co-stimulatory molecules, CD40, CD80, and MHC class II, on CD11c⁺ DCs from the CIA mouse spleens. Additionally, crotonoside treatment significantly reduced the infiltration of CD11c⁺ DCs into the synovial tissues. Our in vitro study further demonstrated that bone marrow-derived DCs (BMDCs) exhibited lower yield in numbers and expressed lower levels of CD40, CD80, and MHC-II when incubated with crotonoside. Furthermore, LPS-stimulated mature DCs exhibited limited capability to prime antigen-specific CD4⁺ and T-cell proliferation, cytokine secretions, and co-stimulatory molecule expressions when treated with crotonoside. Our pioneer study highlights the immunotherapeutic role of crotonoside in the alleviation of the CIA via modulation of pathogenic DCs, thus creating possible applications of crotonoside as an immunosuppressive agent that could be utilized and further explored in treating autoimmune disorders in the future.
The Application of a Nanomaterial Optical Fiber Biosensor Assay for Identification of Brucella Nomenspecies
McCutcheon, Kelly; Bandara, Aloka B.; Zuo, Ziwei; Heflin, James R.; Inzana, Thomas J. (MDPI, 2019-05-21)
Bacteria in the genus Brucella are the cause of brucellosis in humans and many domestic and wild animals. A rapid and culture-free detection assay to detect Brucella in clinical samples would be highly valuable. Nanomaterial optical fiber biosensors (NOFS) are capable of recognizing DNA hybridization events or other analyte interactions with high specificity and sensitivity. Therefore, a NOFS assay was developed to detect Brucella DNA from cultures and in tissue samples from infected mice. An ionic self-assembled multilayer (ISAM) film was coupled to a long-period grating optical fiber, and a nucleotide probe complementary to the Brucella IS711 region and modified with biotin was bound to the ISAM by covalent conjugation. When the ISAM/probe duplex was exposed to lysate containing ≥100 killed cells of Brucella, or liver or spleen tissue extracts from Brucella-infected mice, substantial attenuation of light transmission occurred, whereas exposure of the complexed fiber to non-Brucella gram-negative bacteria or control tissue samples resulted in negligible attenuation of light transmission. Oligonucleotide probes specific for B. abortus, B. melitensis, and B. suis could also be used to detect and differentiate these three nomenspecies. In summary, the NOFS biosensor assay detected three nomenspecies of Brucella without the use of polymerase chain reaction within 30 min and could specifically detect low numbers of this bacterium in clinical samples.
ASC-Mediated Inflammation and Pyroptosis Attenuates Brucella abortus Pathogenesis Following the Recognition of gDNA
Tupik, Juselyn D.; Coutermarsh-Ott, Sheryl; Benton, Angela H.; King, Kellie A.; Kiryluk, Hanna D.; Caswell, Clayton C.; Allen, Irving C. (MDPI, 2020-11-30)
Brucella abortus is a zoonotic pathogen that causes brucellosis. Because of Brucella’s unique LPS layer and intracellular localization predominately within macrophages, it can often evade immune detection. However, pattern recognition receptors are capable of sensing Brucella pathogen-associated molecular patterns (PAMPS). For example, NOD-like receptors (NLRs) can form a multi-protein inflammasome complex to attenuate Brucella pathogenesis. The inflammasome activates IL-1β and IL-18 to drive immune cell recruitment. Alternatively, inflammasome activation also initiates inflammatory cell death, termed pyroptosis, which augments bacteria clearance. In this report, we assess canonical and non-canonical inflammasome activation following B. abortus infection. We conducted in vivo studies using Asc^−/− mice and observed decreased mouse survival, immune cell recruitment, and increased bacteria load. We also conducted studies with Caspase-11^−/− mice and did not observe any significant impact on B. abortus pathogenesis. Through mechanistic studies using Asc^−/− macrophages, our data suggests that the protective role of ASC may result from the induction of pyroptosis through a gasdermin D-dependent mechanism in macrophages. Additionally, we show that the recognition of Brucella is facilitated by sensing the PAMP gDNA rather than the less immunogenic LPS. Together, these results refine our understanding of the role that inflammasome activation and pyroptosis plays during brucellosis.
Conserving the Genetic Diversity of Domesticated Livestock
Sponenberg, D. Phillip (MDPI, 2020-07-17)
Domesticated animals live and produce in an environment influenced by both natural and human factors. These agricultural environments are important to maintain for human survival and also for their interactions with natural environments. Effective conservation of domesticated biodiversity can help to assure sustainable agricultural systems that minimize negative influences on natural environments. In addition, livestock biodiversity is a component of total biodiversity and for several species is the only remaining source of diversity because the wild ancestors are now extinct. Conservation of livestock biodiversity depends on cultural and biological approaches. Each of these has differential importance depending on the specific location of the genetic resource as well as the human culture in which it resides. Effective global conservation blends these in different measures to assure positive outcomes that succeed in securing the genetic resource as well as its contribution to human survival and well-being.
Dendritic Cells and Antiphospholipid Syndrome: An Updated Systematic Review
Tang, Kuo-Tung; Chen, Hsin-Hua; Chen, Tzu-Ting; Bracci, Nicole R.; Lin, Chi-Chien (MDPI, 2021-08-09)
Antiphospholipid syndrome (APS) is an autoimmune disease characterized by autoreactive B and T cells against β2-glycoprotein I (B2GPI), with vascular thrombosis or obstetrical complications. Dendritic cells (DCs) are crucial in the generation of autoimmunity. Here, we conducted a comprehensive systematic review on the relationship between DC and APS. We performed a literature search of PubMed as of 26 March 2021. A total of 33 articles were extracted. DCs are pivotal in inducing inflammatory responses and orchestrating adaptive immunity. DCs contribute to the local inflammation regarding vascular thrombosis or obstetrical complications. Both B2GPI and antiphospholipid antibodies (aPL) can promote antigen presentation by DCs and the generation or maintenance of autoimmunity. In addition, plasmacytoid DC activation is enhanced by aPL, thereby augmenting the inflammatory response. In line with these findings, DC modulation appears promising as a future treatment for APS. In conclusion, our review indicated the crucial role of DCs in the pathogenesis of APS. Deeper understanding of the complex relationship would help in developing new treatment strategies.
Detection of Q129H Immune Escape Mutation in Apparently Healthy Hepatitis B Virus Carriers in Southwestern Nigeria
Adesina, Olufisayo Adeyemi; Akanbi, Olusola Aanuoluwapo; Opaleye, Oladele Oluyinka; Japhet, Margaret Oluwatoyin; Wang, Bo; Oluyege, Adekemi Olubukunola; Klink, Patrycja; Bock, C.-Thomas (MDPI, 2021-06-29)
As the global effort to eradicate hepatitis B continues, immune escape mutations (IEMs) and drug resistance mutations (DRMs) affecting its diagnosis, treatment, and prevention are compromising this goal. However, knowledge about the prevalence and circulation of these mutations in Nigeria is scarce. Serum samples (n = 199) from apparently healthy prospective blood donors, pregnant women, and individuals presenting with fever in southwestern Nigeria were analyzed for the presence of IEMs and DRMs by means of nested PCR in the HBV S (HBs) and HBV polymerase (Pol) genes, followed by phylogenetic and mutational analyses. In total, 25.1% (n = 50/199) of samples were positive for HBV, as measured by PCR. In 41 samples (20.6%), both fragments could be amplified, whereas the HBs gene and the Pol gene fragment alone were detected in 0.5% (n = 1/199) and 4% (n = 8/199) of samples, respectively. Sequences were successfully obtained for all 42 HBs gene fragments but for only 31/49 Pol gene fragments (totaling 73 sequences from 44 individuals). All sequences were identified as HBV genotype E. IEMs were present in 18.2% (n = 8/44) of the sequences of HBV-positive individuals with available sequences. IEM Q129H was detected in eight out of the 44 (18.2%) HBV isolates sequenced in this study; however, no DRMs were observed. This study confirms the circulation of HBV IEMs and reports the presence of Q129H IEM for the first time in Nigeria. Intensified research on the dynamics of IEM is necessary in order to enhance the elimination of HBV.
Effect of the Chinese Herbal Medicine SS-1 on a Sjögren’s Syndrome-Like Disease in Mice
Wu, Po-Chang; Lin, Shih-Chao; Panny, Lauren; Chang, Yu-Kang; Lin, Chi-Chien; Tung, Yu-Tang; Chang, Hen-Hong (MDPI, 2021-06-07)
Sjögren’s syndrome (SS) is an inflammatory autoimmune disease primarily affecting the exocrine glands; it has a major impact on patients’ lives. The Chinese herbal formula SS-1 is composed of Gan Lu Yin, Sang Ju Yin, and Xuefu Zhuyu decoction, which exerts anti-inflammatory, immunomodulatory, and antifibrotic effects. Our previous study demonstrated that SS-1 alleviates clinical SS. This study aimed to evaluate the efficacy and mechanism of the Chinese herbal formula SS-1 for salivary gland protein-induced experimental Sjögren’s syndrome (ESS). These results showed that ESS treatment with the Chinese herbal formula SS-1 (1500 mg/kg) significantly alleviated the severity of ESS. We found that SS-1 substantially improved saliva flow rates in SS mice and ameliorated lymphocytic infiltrations in submandibular glands. In addition, salivary gland protein-induced SS in mice treated with SS-1 significantly lowered proinflammatory cytokines (including IFN-γ, IL-6, and IL-17A) in mouse salivary glands and decreased serum anti-M3R autoantibody levels. In addition, we found that CD4+ T cells isolated from SS-1-treated SS mice significantly reduced the percentages of IFN-γ-producing CD4+ T cells (Th1) and IL-17A-producing CD4+ T cells (Th17). Our data show that SS-1 alleviates ESS through anti-inflammatory and immunomodulatory effects, which provides new insight into the clinical treatment of SS.
Epigenetic Contribution and Genomic Imprinting Dlk1-Dio3 miRNAs in Systemic Lupus Erythematosus
Dai, Rujuan; Wang, Zhuang; Ahmed, Sattar Ansar (MDPI, 2021-05-01)
Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease that afflicts multiple organs, especially kidneys and joints. In addition to genetic predisposition, it is now evident that DNA methylation and microRNAs (miRNAs), the two major epigenetic modifications, are critically involved in the pathogenesis of SLE. DNA methylation regulates promoter accessibility and gene expression at the transcriptional level by adding a methyl group to 5′ cytosine within a CpG dinucleotide. Extensive evidence now supports the importance of DNA hypomethylation in SLE etiology. miRNAs are small, non-protein coding RNAs that play a critical role in the regulation of genome expression. Various studies have identified the signature lupus-related miRNAs and their functional contribution to lupus incidence and progression. In this review, the mutual interaction between DNA methylation and miRNAs regulation in SLE is discussed. Some lupus-associated miRNAs regulate DNA methylation status by targeting the DNA methylation enzymes or methylation pathway-related proteins. On the other hand, DNA hyper- and hypo-methylation are linked with dysregulated miRNAs expression in lupus. Further, we specifically discuss the genetic imprinting Dlk1-Dio3 miRNAs that are subjected to DNA methylation regulation and are dysregulated in several autoimmune diseases, including SLE.
Evaluation of the 50% Infectious Dose of Human Norovirus Cin-2 in Gnotobiotic Pigs: A Comparison of Classical and Contemporary Methods for Endpoint Estimation
Ramesh, Ashwin; Parreño, Viviana; Schmidt, Philip J.; Lei, Shaohua; Zhong, Weiming; Jiang, Xi; Emelko, Monica B.; Yuan, Lijuan (MDPI, 2020-08-28)
Human noroviruses (HuNoVs) are the leading causative agents of epidemic and sporadic acute gastroenteritis that affect people of all ages worldwide. However, very few dose–response studies have been carried out to determine the median infectious dose of HuNoVs. In this study, we evaluated the median infectious dose (ID₅₀) and diarrhea dose (DD₅₀) of the GII.4/2003 variant of HuNoV (Cin-2) in the gnotobiotic pig model of HuNoV infection and disease. Using various mathematical approaches (Reed–Muench, Dragstedt–Behrens, Spearman–Karber, exponential, approximate beta-Poisson dose–response models, and area under the curve methods), we estimated the ID₅₀ and DD₅₀ to be between 2400–3400 RNA copies, and 21,000–38,000 RNA copies, respectively. Contemporary dose–response models offer greater flexibility and accuracy in estimating ID₅₀. In contrast to classical methods of endpoint estimation, dose–response modelling allows seamless analyses of data that may include inconsistent dilution factors between doses or numbers of subjects per dose group, or small numbers of subjects. Although this investigation is consistent with state-of-the-art ID₅₀ determinations and offers an advancement in clinical data analysis, it is important to underscore that such analyses remain confounded by pathogen aggregation. Regardless, challenging virus strain ID₅₀ determination is crucial for identifying the true infectiousness of HuNoVs and for the accurate evaluation of protective efficacies in pre-clinical studies of therapeutics, vaccines and other prophylactics using this reliable animal model.
Glyceraldehyde-3-Phosphate Dehydrogenase Increases the Adhesion of Lactobacillus reuteri to Host Mucin to Enhance Probiotic Effects
Deng, Zhaoxi; Dai, Tian; Zhang, Wenming; Zhu, Junli; Luo, Xin M.; Fu, Dongyan; Liu, Jianxin; Wang, Haifeng (MDPI, 2020-12-21)
The ability to adhere to the intestinal mucus layer is an important property of probiotic bacteria. Lactobacillus reuteri strains ZJ615 and ZJ617 show low and high adhesion, respectively, to intestinal epithelial cells. In this study, we quantified bacterial cell wall-associated glyceraldehyde-3-phosphate dehydrogenases (cw-GAPDH) and bacterial cell membrane permeability in both strains using immunoblotting and flow cytometry, respectively. Highly adhesive L. reuteri ZJ617 possessed significantly more cw-GAPDH, higher cell membrane permeability, and significantly higher adhesive ability toward mucin compared with low-adhesive L. reuteri ZJ615. In vitro adhesion studies and analysis of interaction kinetics using the Octet, the system revealed significantly decreased interaction between L. reuteri and mucin when mucin was oxidized when bacterial surface proteins were removed when bacteria were heat-inactivated at 80 °C for 30 min, and when the interaction was blocked with an anti-GAPDH antibody. SWISS-MODEL analysis suggested intensive interactions between mucin glycans (GalNAcα1-O-Ser, GalNAcαSer, and Galβ3GalNAc) and GAPDH. Furthermore, in vivo studies revealed significantly higher numbers of bacteria adhering to the jejunum, ileum, and colon of piglets orally inoculated with L. reuteri ZJ617 compared with those inoculated with L. reuteri ZJ615; this led to a significantly decreased rate of diarrhea in piglets inoculated with L. reuteri ZJ617. In conclusion, there are strong correlations among the abundance of cw-GAPDH in L. reuteri, the ability of the bacterium to adhere to the host, and the health benefits of this probiotic.
The Impact of Protein Acetylation/Deacetylation on Systemic Lupus Erythematosus
Ren, Jingjing; Panther, Eric J.; Liao, Xiaofeng; Grammer, Amrie C.; Lipsky, Peter E.; Reilly, Christopher M. (MDPI, 2018-12-12)
Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease in which the body’s immune system mistakenly attacks healthy cells. Although the exact cause of SLE has not been identified, it is clear that both genetics and environmental factors trigger the disease. Identical twins have a 24% chance of getting lupus disease if the other one is affected. Internal factors such as female gender and sex hormones, the major histocompatibility complex (MHC) locus and other genetic polymorphisms have been shown to affect SLE, as well as external, environmental influences such as sunlight exposure, smoking, vitamin D deficiency, and certain infections. Several studies have reported and proposed multiple associations between the alteration of the epigenome and the pathogenesis of autoimmune disease. Epigenetic factors contributing to SLE include microRNAs, DNA methylation status, and the acetylation/deacetylation of histone proteins. Additionally, the acetylation of non-histone proteins can also influence cellular function. A better understanding of non-genomic factors that regulate SLE will provide insight into the mechanisms that initiate and facilitate disease and also contribute to the development of novel therapeutics that can specifically target pathogenic molecular pathways.
La Crosse Virus Shows Strain-Specific Differences in Pathogenesis
Wilson, Sarah N.; López, Krisangel; Coutermarsh-Ott, Sheryl; Auguste, Dawn I.; Porier, Danielle L.; Armstrong, Philip M.; Andreadis, Theodore G.; Eastwood, Gillian; Auguste, A. Jonathan (MDPI, 2021-03-29)
La Crosse virus (LACV) is the leading cause of pediatric viral encephalitis in North America, and is an important public health pathogen. Historically, studies involving LACV pathogenesis have focused on lineage I strains, but no former work has explored the pathogenesis between or within lineages. Given the absence of LACV disease in endemic regions where a robust entomological risk exists, we hypothesize that some LACV strains are attenuated and demonstrate reduced neuroinvasiveness. Herein, we compared four viral strains representing all three lineages to determine differences in neurovirulence or neuroinvasiveness using three murine models. A representative strain from lineage I was shown to be the most lethal, causing >50% mortality in each of the three mouse studies. However, other strains only presented excessive mortality (>50%) within the suckling mouse neurovirulence model. Neurovirulence was comparable among strains, but viruses differed in their neuroinvasive capacities. Our studies also showed that viruses within lineage III vary in pathogenesis with contemporaneous strains, showing reduced neuroinvasiveness compared to an ancestral strain from the same U.S. state (i.e., Connecticut). These findings demonstrate that LACV strains differ markedly in pathogenesis, and that strain selection is important for assessing vaccine and therapeutic efficacies.
A Natural Botanical Product, Resveratrol, Effectively Suppresses Vesicular Stomatitis Virus Infection In Vitro
Lin, Shih-Chao; Zhang, Xiang; Lehman, Caitlin W.; Pan, Han-Chi; Wen, Ya; Chen, Shiow-Yi (MDPI, 2021-06-17)
Numerous natural phytochemicals such as resveratrol are acknowledged as potent botanical agents in regulating immune responses. However, it is less understood whether such immunomodulatory phytochemicals are appropriate for use as direct treatments in veterinary viral diseases. In the present study, we investigated the efficacy of resveratrol in suppressing vesicular stomatitis virus (VSV) infection. Outbreaks of VSV can cause massive economic loss in poultry and livestock husbandry farming, and VSV treatment is in need of therapeutic development. We utilized a recombinant VSV that expresses green fluorescent protein (GFP) to measure viral replication in cells treated with resveratrol. Our findings revealed that resveratrol treatment affords a protective effect, shown by increased viability and reduced viral replication, as indicated by a reduction in fluorescent signals. Additionally, we found that resveratrol inhibition of VSV infection occurs via suppression of the caspase cascade. Structural analysis also indicated that resveratrol potentially interacts with the active sites of caspase-3 and -7, facilitating antiviral activity. The potential effect of resveratrol on reducing VSV infection in vitro suggests that resveratrol should be further investigated as a potential veterinary therapeutic or prophylactic agent.
Neurotrophic Factors NGF, GDNF and NTN Selectively Modulate HSV1 and HSV2 Lytic Infection and Reactivation in Primary Adult Sensory and Autonomic Neurons
Yanez, Andy A.; Harrell, Telvin; Sriranganathan, Heather J.; Ives, Angela M.; Bertke, Andrea S. (MDPI, 2017-02-07)
Herpes simplex viruses (HSV1 and HSV2) establish latency in peripheral ganglia after ocular or genital infection, and can reactivate to produce different patterns and frequencies of recurrent disease. Previous studies showed that nerve growth factor (NGF) maintains HSV1 latency in embryonic sympathetic and sensory neurons. However, adult sensory neurons are no longer dependent on NGF for survival, some populations cease expression of NGF receptors postnatally, and the viruses preferentially establish latency in different populations of sensory neurons responsive to other neurotrophic factors (NTFs). Thus, NGF may not maintain latency in adult sensory neurons. To identify NTFs important for maintaining HSV1 and HSV2 latency in adult neurons, we investigated acute and latently-infected primary adult sensory trigeminal (TG) and sympathetic superior cervical ganglia (SCG) after NTF removal. NGF and glial cell line-derived neurotrophic factor (GDNF) deprivation induced HSV1 reactivation in adult sympathetic neurons. In adult sensory neurons, however, neurturin (NTN) and GDNF deprivation induced HSV1 and HSV2 reactivation, respectively, while NGF deprivation had no effects. Furthermore, HSV1 and HSV2 preferentially reactivated from neurons expressing GFRα2 and GFRα1, the high affinity receptors for NTN and GDNF, respectively. Thus, NTN and GDNF play a critical role in selective maintenance of HSV1 and HSV2 latency in primary adult sensory neurons.
Noble Metal Organometallic Complexes Display Antiviral Activity against SARS-CoV-2
Chuong, Christina; DuChane, Christine M.; Webb, Emily M.; Rai, Pallavi; Marano, Jeffrey M.; Bernier, Chad M.; Merola, Joseph S.; Weger-Lucarelli, James (MDPI, 2021-05-25)
SARS-CoV-2 emerged in 2019 as a devastating viral pathogen with no available preventative or treatment to control what led to the current global pandemic. The continued spread of the virus and increasing death toll necessitate the development of effective antiviral treatments to combat this virus. To this end, we evaluated a new class of organometallic complexes as potential antivirals. Our findings demonstrate that two pentamethylcyclopentadienyl (Cp*) rhodium piano stool complexes, Cp*Rh(1,3-dicyclohexylimidazol-2-ylidene)Cl₂ (complex 2) and Cp*Rh(dipivaloylmethanato)Cl (complex 4), have direct virucidal activity against SARS-CoV-2. Subsequent in vitro testing suggests that complex 4 is the more stable and effective complex and demonstrates that both 2 and 4 have low toxicity in Vero E6 and Calu-3 cells. The results presented here highlight the potential application of organometallic complexes as antivirals and support further investigation into their activity.
PERK Is Critical for Alphavirus Nonstructural Protein Translation
Dahal, Bibha; Lehman, Caitlin W.; Akhrymuk, Ivan V.; Bracci, Nicole R.; Panny, Lauren; Barrera, Michael D.; Bhalla, Nishank; Jacobs, Jonathan L.; Dinman, Jonathan D.; Kehn-Hall, Kylene (MDPI, 2021-05-12)
Venezuelan equine encephalitis virus (VEEV) is an alphavirus that causes encephalitis. Previous work indicated that VEEV infection induced early growth response 1 (EGR1) expression, leading to cell death via the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) arm of the unfolded protein response (UPR) pathway. Loss of PERK prevented EGR1 induction and decreased VEEV-induced death. The results presented within show that loss of PERK in human primary astrocytes dramatically reduced VEEV and eastern equine encephalitis virus (EEEV) infectious titers by 4–5 log₁₀. Loss of PERK also suppressed VEEV replication in primary human pericytes and human umbilical vein endothelial cells, but it had no impact on VEEV replication in transformed U87MG and 293T cells. A significant reduction in VEEV RNA levels was observed as early as 3 h post-infection, but viral entry assays indicated that the loss of PERK minimally impacted VEEV entry. In contrast, the loss of PERK resulted in a dramatic reduction in viral nonstructural protein translation and negative-strand viral RNA production. The loss of PERK also reduced the production of Rift Valley fever virus and Zika virus infectious titers. These data indicate that PERK is an essential factor for the translation of alphavirus nonstructural proteins and impacts multiple RNA viruses, making it an exciting target for antiviral development.
Phloretin Ameliorates Testosterone-Induced Benign Prostatic Hyperplasia in Rats by Regulating the Inflammatory Response, Oxidative Stress and Apoptosis
Hsu, Chao Yu; Lin, Yi Sheng; Weng, Wei Chun; Panny, Lauren; Chen, Hsiang Lai; Tung, Min Che; Ou, Yen Chuan; Lin, Chi-Chien; Yang, Che Hsueh (MDPI, 2021-07-26)
The inflammatory process is proposed to be one of the factors to benign prostatic enlargement (BPH), and this is the first study examining the anti-inflammatory ability of phloretin in treating rats with testosterone-induced BPH. BPH would be induced by testosterone (10 mg/kg/day testosterone subcutaneously for 28 days), and the other groups of rats were treated with phloretin 50 mg/kg/day or 100 mg/kg/day orally (phr50 or phr100 group) after induction. Prostate weight and prostate weight to body weight ratio were significantly reduced in the Phr100 group. Reduced dihydrotestosterone without interfering with 5α-reductase was observed in the phr100 group. In inflammatory proteins, reduced IL-6, IL-8, IL-17, NF-κB, and COX-2 were seen in the phr100 group. In reactive oxygen species, malondialdehyde was reduced, and superoxide dismutase and glutathione peroxidase were elevated in the phr100 group. In apoptotic assessment, elevated cleaved caspase-3 was observed in rats of the phr100 group. Enhanced pro-apoptotic Bax and reduced anti-apoptotic Bc1-2 could be seen in the phr100 group. In histological stains, markedly decreased glandular hyperplasia and proliferative cell nuclear antigen were observed with reduced expression in the phr100 group. Meanwhile, positive cells of terminal deoxynucleotidyl transferase dUTP nick end labeling were increased in the phr100 group. In conclusion, the treatment of phloretin 100 mg/kg/day could ameliorate testosterone-induced BPH.
Photonic Biosensor Assays to Detect and Distinguish Subspecies of Francisella tularensis
Cooper, Kristie L.; Bandara, Aloka B.; Wang, Yunmiao; Wang, Anbo; Inzana, Thomas J. (MDPI, 2011-03-07)
The application of photonic biosensor assays to diagnose the category-A select agent Francisella tularensis was investigated. Both interferometric and long period fiber grating sensing structures were successfully demonstrated; both these sensors are capable of detecting the optical changes induced by either immunological binding or DNA hybridization. Detection was made possible by the attachment of DNA probes or immunoglobulins (IgG) directly to the fiber surface via layer-by-layer electrostatic self-assembly. An optical fiber biosensor was tested using a standard transmission mode long period fiber grating of length 15 mm and period 260 µm, and coated with the IgG fraction of antiserum to F. tularensis. The IgG was deposited onto the optical fiber surface in a nanostructured film, and the resulting refractive index change was measured using spectroscopic ellipsometry. The presence of F. tularensis was detected from the decrease of peak wavelength caused by binding of specific antigen. Detection and differentiation of F. tularensis subspecies tularensis (type A strain TI0902) and subspecies holarctica (type B strain LVS) was further accomplished using a single-mode multi-cavity fiber Fabry-Perot interferometric sensor. These sensors were prepared by depositing seven polymer bilayers onto the fiber tip followed by attaching one of two DNA probes: (a) a 101-bp probe from the yhhW gene unique to type-A strains, or (b) a 117-bp probe of the lpnA gene, common to both type-A and type-B strains. The yhhW probe was reactive with the type-A, but not the type-B strain. Probe lpnA was reactive with both type-A and type-B strains. Nanogram quantities of the target DNA could be detected, highlighting the sensitivity of this method for DNA detection without the use of PCR. The DNA probe reacted with 100% homologous target DNA, but did not react with sequences containing 2-bp mismatches, indicating the high specificity of the assay. These assays will fill an important void that exists for rapid, culture-free, and field-compatible diagnosis of F. tularensis.
The Pro-Inflammatory Chemokines CXCL9, CXCL10 and CXCL11 Are Upregulated Following SARS-CoV-2 Infection in an AKT-Dependent Manner
Callahan, Victoria; Hawks, Seth A.; Crawford, Matthew A.; Lehman, Caitlin W.; Morrison, Holly A.; Ivester, Hannah M.; Akhrymuk, Ivan V.; Boghdeh, Niloufar; Flor, Rafaela; Finkielstein, Carla V.; Allen, Irving C.; Weger-Lucarelli, James; Duggal, Nisha K.; Hughes, Molly A.; Kehn-Hall, Kylene (MDPI, 2021-06-03)
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible RNA virus that is the causative agent of the Coronavirus disease 2019 (COVID-19) pandemic. Patients with severe COVID-19 may develop acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) and require mechanical ventilation. Key features of SARS-CoV-2 induced pulmonary complications include an overexpression of pro-inflammatory chemokines and cytokines that contribute to a ‘cytokine storm.’ In the current study an inflammatory state in Calu-3 human lung epithelial cells was characterized in which significantly elevated transcripts of the immunostimulatory chemokines CXCL9, CXCL10, and CXCL11 were present. Additionally, an increase in gene expression of the cytokines IL-6, TNFα, and IFN-γ was observed. The transcription of CXCL9, CXCL10, IL-6, and IFN-γ was also induced in the lungs of human transgenic angiotensin converting enzyme 2 (ACE2) mice infected with SARS-CoV-2. To elucidate cell signaling pathways responsible for chemokine upregulation in SARS-CoV-2 infected cells, small molecule inhibitors targeting key signaling kinases were used. The induction of CXCL9, CXCL10, and CXCL11 gene expression in response to SARS-CoV-2 infection was markedly reduced by treatment with the AKT inhibitor GSK690693. Samples from COVID-19 positive individuals also displayed marked increases in CXCL9, CXCL10, and CXCL11 transcripts as well as transcripts in the AKT pathway. The current study elucidates potential pathway specific targets for reducing the induction of chemokines that may be contributing to SARS-CoV-2 pathogenesis via hyperinflammation.

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