Arctigenin from Forsythia viridissima Fruit Inhibits the Replication of Human Coronavirus.

Coronavirus can cause various diseases, from mild symptoms to the recent severe COVID-19. The coronavirus RNA genome is frequently mutated due to its RNA nature, resulting in many pathogenic and drug-resistant variants. Therefore, many medicines should be prepared to respond to the various coronavirus variants. In this report, we demonstrated that Forsythia viridissima fruit ethanol extract (FVFE) effectively reduces coronavirus replication. We attempted to identify the active compounds and found that actigenin from FVFE effectively reduces human coronavirus replication. Arctigenin treatment can reduce coronavirus protein expression and coronavirus-induced cytotoxicity. These results collectively suggest that arctigenin is a potent natural compound that prevents coronavirus replication.

Upregulation of EMR1 (ADGRE1) by Tumor-Associated Macrophages Promotes Colon Cancer Progression by Activating the JAK2/STAT1,3 Signaling Pathway in Tumor Cells.

Previously, we reported that epidermal growth factor-like module-containing mucin-like hormone receptor-like 1 (EMR1/ADGRE1) is abnormally expressed in colon cancer (CC) and is a risk factor for lymph node metastasis (LNM) and poor recurrence-free survival in patients with abundant tumor-associated macrophages (TAMs). However, the signaling pathways associated with EMR1 expression in CC progression remain unclear. In this study, we aimed to explore the role of EMR1 and its signaling interactions with macrophages in CC progression. Spatial transcriptomics of pT3 microsatellite unstable CC tissues revealed heightened Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling in EMR1-HL CC with LNM compared to EMR1-N CC without LNM. Through in vitro coculture of CC cells with macrophages, EMR1 expression by CC cells was found to be induced by TAMs, ultimately interacting with upregulated JAK/STAT signaling, increasing cell proliferation, migration, and motility, and reducing apoptosis. JAK2/STAT3 inhibition decreased the levels of EMR1, JAK2, STAT1, and STAT3, significantly impeded the proliferation, migration, and mobility of cells, and increased the apoptosis of EMR1+ CC cells compared to their EMR1KO counterparts. Overall, TAMs-induced EMR1 upregulation in CC cells may promote LNM and CC progression via JAK2/STAT1,3 signaling upregulation. This study provides further insights into the molecular mechanisms involving macrophages and intracellular EMR1 expression in CC progression, suggesting its clinical significance and offering potential interventions to enhance patient outcomes.

Systemic Immune Modulation Induced by Ephedrine in Obese-Diabetes (db/db) Mice.

Immune-modulatory effects in obese-diabetes (db/db) mice were observed to understand the possible mechanism(s) of ephedrine-induced unfavorable responses. The ephedrine doses were selected based on the FDA report (NTP Tech Rep Ser NO 307; CAS# 134-72-5), which showed the non-toxic dose for B6C3F1 mice. In db/db mice, higher doses (6 and 12 mg/mouse) of ephedrine significantly harmed the liver and lung morphology, including fatty liver with multiple blood vessel engorgement, alveolar wall thickening, and inflammatory response in the lung. The immune micro-environment of db/db mice was an inflammatory state with suppressed adaptive cellular immunity. After the administration of ephedrine, significant deterioration of NK activity was observed with lowered gene transcription of klrk1 encoding NKG2D, and of ccl8, a NK cell targeting chemokine. Suppressed cellular immunity in db/db mice was lowered ever further by single ephedrine treatment, as was evidenced by mitogen-induced T or B cell proliferations. These observations demonstrate that at the non-toxic doses in normal B6C3F1 mice, ephedrine clearly suppressed systemic immunity of db/db mice. The data suggest that the immune micro-environment of obese individuals is fragile and susceptible to ephedrine-related pathologic response, and this may be a prelude to the induction of obesity-related secondary immunological disorders.

EGCG, a green tea polyphenol, inhibits human coronavirus replication in vitro.

COVID-19 pandemic results in record high deaths in many countries. Although a vaccine for SARS-CoV-2 is now available, effective antiviral drugs to treat coronavirus diseases are not available yet. Recently, EGCG, a green tea polyphenol, was reported to inhibit SARS-CoV-2 3CL-protease, however the effect of EGCG on coronavirus replication is unknown. In this report, human coronavirus HCoV-OC43 (beta coronavirus) and HCoV-229E (alpha coronavirus) were used to examine the effect of EGCG on coronavirus. EGCG treatment decreases 3CL-protease activity of HCoV-OC43 and HCoV-229E. Moreover, EGCG treatment decreased HCoV-OC43-induced cytotoxicity. Finally, we found that EGCG treatment decreased the levels of coronavirus RNA and protein in infected cell media. These results indicate that EGCG inhibits coronavirus replication.

6-Azauridine Induces Autophagy-Mediated Cell Death via a p53- and AMPK-Dependent Pathway.

6-Azauridine (6-AZA), a pyrimidine nucleoside analogue, is known to exhibit both antitumor and antiviral activities. Although 6-AZA was discovered more than 60 years ago, the cellular effects of this compound are yet to be elucidated. Here, we report that 6-AZA regulates autophagy-mediated cell death in various human cancer cells, where 6-AZA treatment activates autophagic flux through the activation of lysosomal function. Furthermore, 6-AZA exhibited cytotoxicity in all cancer cells studied, although the mechanisms of action were diverse. In H460 cells, 6-AZA treatment induced apoptosis, and the extent of the latter could be reduced by treatment with chloroquine (CQ), a lysosomal inhibitor. However, 6-AZA treatment resulted in cell cycle arrest in H1299 cells, which could not be reversed by CQ. The cytotoxicity associated with 6-AZA treatment could be linearly correlated to the degree of autophagy-mediated cell death. In addition, we demonstrated that the cytotoxic effect of 6-AZA was dependent on AMPK and p53. These results collectively indicate that autophagy-mediated cell death triggered by 6-AZA contributes to its antitumor effect.

LNX1 contributes to tumor growth by down-regulating p53 stability.

The well-known tumor suppressor p53 inhibits the formation of various cancers by inducing cell cycle arrest and apoptosis. Although p53 mutations are commonly found in many cancers, p53 is functionally inactivated in tumor cells that retain wild-type p53. Here, we show that the ligand of numb protein X1 (LNX1) inhibited p53-dependent transcription by decreasing the half-life of p53. We generated LNX1 knockout (KO) cells in p53 wild-type cancer cells (A549, HCT116, and MCF7) using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 gene-editing system. LNX1 KO activated p53-dependent transcription by increasing the stability of p53. Moreover, lentivirus-mediated overexpression of LNX1 decreased p53 protein levels and inhibited p53-dependent transcription. LNX1 interacted with p53 and mouse double minute 2 (MDM2) and increased the ubiquitination of p53 in an MDM2-dependent manner. Finally, we demonstrated that LNX1 was required for efficient tumor growth both in cell culture and in a mouse tumor xenograft model. These results collectively indicated that LNX1 contributed to tumor growth by inhibiting p53-dependent signaling in p53 wild-type cancer cells.-Park, R., Kim, H., Jang, M., Jo, D., Park, Y.-I., Namkoong, S., Lee, J. I., Jang, I.-S., Park, J. LNX1 contributes to tumor growth by down-regulating p53 stability.

Compound C inhibits the replication of feline coronavirus.

Feline Coronavirus (FCoV) is a viral pathogen of cats and a highly contagious virus. Cats in a cattery can be infected by up to 100%, and even household cats are infected by 20-60%. Some strains of FCoV are known to induce a fatal disease in cats named Feline Infectious Peritonitis (FIP). However, no effective treatments are available. We demonstrated that compound C (dorsomorphin) can potentially inhibit feline coronavirus replication. Compound C treatment decreased the FCoV-induced plaque formation and cytopathic effect in FCoV-infected cells. Compound C treatment also significantly reduced the amount of viral RNA and viral protein in the cells in a dose-dependent manner. Our findings suggest that compound C is potentially useful for feline coronavirus-related diseases.

AMPK inhibitor, compound C, inhibits coronavirus replication in vitro.

The coronavirus disease (COVID-19) pandemic has resulted in more than six million deaths by October 2022. Vaccines and antivirals for severe acute respiratory syndrome coronavirus 2 are now available; however, more effective antiviral drugs are required for effective treatment. Here, we report that a potent AMP-activated protein kinase (AMPK) inhibitor, compound C/dorsomorphin, inhibits the replication of the human coronavirus OC43 strain (HCoV-OC43). We examined HCoV-OC43 replication in control and AMPK-knockout (KO) cells and found that the virus replication decreased in AMPK-KO cells. Next, we examined the effect of the AMPK inhibitor, compound C on coronavirus replication. Compound C treatment efficiently inhibited the replication and decreased the coronavirus-induced cytotoxicity, further inhibiting autophagy. In addition, treatment with compound C in combination with chloroquine synergistically inhibited coronavirus replication. These results suggest that compound C can be considered as a potential drug candidate for COVID-19.

Coronavirus enzyme inhibitors-experimentally proven natural compounds from plants.

Coronavirus disease (COVID-19) can cause critical conditions that require efficient therapeutics. Several medicines are derived from plants, and researchers are seeking natural compounds to ameliorate the symptoms of COVID-19. Viral enzymes are popular targets of antiviral medicines; the genome of coronaviruses encodes several enzymes, including RNA-dependent RNA polymerase and viral proteases. Various screening systems have been developed to identify potential inhibitors. In this review, we describe the natural compounds that have been shown to exert inhibitory effects on coronavirus enzymes. Although computer-aided molecular structural studies have predicted several antiviral compound candidates, the current review focuses on experimentally proven natural compounds.

CTRP1 Knockout Attenuates Tumor Progression in A549 and HCT116 Cancer Cells.

C1q and TNF-related 1 (C1QTNF1/CTRP1) is an adiponectin-associated protein belonging to the C1q/TNF-related protein family. Recent studies have shown that the C1q and TNF-related protein (CTRP) family is involved in cancer progression; however, the specific role of CTRP1 in tumor progression has not yet been elucidated. To examine the role of CTRP1 in tumor progression, we generated CTRP1 knockout A549 and HCT116 cell lines, which reduced the expression levels of nuclear factor (NF)-κB-dependent and metastasis-promoting transcripts. We demonstrated that CTRP1 knockout inhibited the cell proliferation and invasion and tumor growth. Finally, database analysis showed that CTRP1 expression was upregulated in metastatic cancers and elevated levels of CTRP1 were associated with poor prognosis. These results suggest that CTRP1 expression contributes to NF-κB signaling and promotes tumor progression.

An ESIPT-based fluorescent turn-on probe with isothiocyanate for detecting hydrogen sulfide in environmental and biological systems.

A probe with an isothiocyanate group was synthesized and evaluated for its H2S sensing ability. Upon addition of H2S, the probe exhibited ratiometric properties during absorption with a red-shift. The probe exhibited fluorescent off-on responses towards H2S via the ESIPT process, due to the conversion of isocyanate into amine. UV-vis, fluorescence, and 1H NMR spectroscopic analyses were performed to investigate the sensing mechanism. The probe has a large Stokes shift, short response time, and low detection limit. It can be used to estimate H2S levels within the range of 0-36 nM. The practical applicability of the probe was demonstrated using water samples and living cells.

Therapeutic Potential of EGCG, a Green Tea Polyphenol, for Treatment of Coronavirus Diseases.

Epigallocatechin gallate (EGCG) is a major catechin found in green tea, and there is mounting evidence that EGCG is potentially useful for the treatment of coronavirus diseases, including coronavirus disease 2019 (COVID-19). Coronaviruses encode polyproteins that are cleaved by 3CL protease (the main protease) for maturation. Therefore, 3CL protease is regarded as the main target of antivirals against coronaviruses. EGCG is a major constituent of brewed green tea, and several studies have reported that EGCG inhibits the enzymatic activity of the coronavirus 3CL protease. Moreover, EGCG has been reported to regulate other potential targets, such as RNA-dependent RNA polymerase and the viral spike protein. Finally, recent studies have demonstrated that EGCG treatment interferes with the replication of coronavirus. In addition, the bioavailability of EGCG and future research prospects are discussed.

Epigallocatechin Gallate (EGCG), a Green Tea Polyphenol, Reduces Coronavirus Replication in a Mouse Model.

The COVID-19 pandemic has resulted in a huge number of deaths from 2020 to 2021; however, effective antiviral drugs against SARS-CoV-2 are currently under development. Recent studies have demonstrated that green tea polyphenols, particularly EGCG, inhibit coronavirus enzymes as well as coronavirus replication in vitro. Herein, we examined the inhibitory effect of green tea polyphenols on coronavirus replication in a mouse model. We used epigallocatechin gallate (EGCG) and green tea polyphenols containing more than 60% catechin (GTP60) and human coronavirus OC43 (HCoV-OC43) as a surrogate for SARS-CoV-2. Scanning electron microscopy analysis results showed that HCoV-OC43 infection resulted in virion particle production in infected cells. EGCG and GTP60 treatment reduced coronavirus protein and virus production in the cells. Finally, EGCG- and GTP60-fed mice exhibited reduced levels of coronavirus RNA in mouse lungs. These results demonstrate that green tea polyphenol treatment is effective in decreasing the level of coronavirus in vivo.

Elevated Levels of CTRP1 in Obesity Contribute to Tumor Progression in a p53-Dependent Manner.

Mounting evidence supports the relationship between obesity and cancer. However, the molecular mechanisms linking obesity with cancer remain largely uninvestigated. In this study, we demonstrate that the expression of C1q/TNF-related protein 1 (CTRP1), an adiponectin paralogue, contributes to tumor growth by regulating the tumor suppressor p53. In our study, obese mice on a high-fat diet showed higher serum CTRP1 levels. Through in vitro experiments, we showed that the secreted form of CTRP1 in the culture medium decreased p53 expression and p53-dependent transcription in the cells. Moreover, CTRP1 treatment enhanced colony formation and cell migration. These results collectively suggest that elevated levels of CTRP1 in obesity significantly contribute to tumor progression.

LNX1 Contributes to Cell Cycle Progression and Cisplatin Resistance.

The ligand of numb-protein X1 (LNX1) acts as a proto-oncogene by inhibiting p53 stability; however, the regulation of LNX1 expression has not been investigated. In this study, we screened chemicals to identify factors that potentially regulate LNX1 expression. We found that LNX1 expression levels were decreased by DNA damage, including that by cisplatin. Upon treatment with lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA), LNX1 expression levels increased. In addition, cell-cycle progression increased upon LNX1 expression; the levels of S and G2/M populations were correlated with LNX1 expression. Moreover, in CRISPR-Cas9-mediated LNX1 knockout cells, we observed a delay in cell-cycle progression and a downregulation of genes encoding the cell-cycle markers cyclin D1 and cyclin E1. Finally, the upregulation of LNX1-activated cell-cycle progression and increased resistance to cisplatin-mediated cell death. Taken together, these results suggest that LNX1 contributes to cell-cycle progression and cisplatin resistance.

Tea Polyphenols EGCG and Theaflavin Inhibit the Activity of SARS-CoV-2 3CL-Protease In Vitro.

COVID-19, a global pandemic, has caused over 750,000 deaths worldwide as of August 2020. A vaccine or remedy for SARS-CoV-2, the virus responsible for COVID-19, is necessary to slow down the spread and lethality of COVID-19. However, there is currently no effective treatment available against SARS-CoV-2. In this report, we demonstrated that EGCG and theaflavin, the main active ingredients of green tea and black tea, respectively, are potentially effective to inhibit SARS-CoV-2 activity. Coronaviruses require the 3CL-protease for the cleavage of its polyprotein to make individual proteins functional. EGCG and theaflavin showed inhibitory activity against the SARS-CoV-2 3CL-protease in a dose-dependent manner, and the half inhibitory concentration (IC50) was 7.58 µg/ml for EGCG and 8.44 µg/ml for theaflavin. In addition, we did not observe any cytotoxicity for either EGCG or theaflavin at the concentrations tested up to 40 µg/ml in HEK293T cells. These results suggest that upon further study, EGCG and theaflavin can be potentially useful to treat COVID-19.

The Flower Extract of Abelmoschus manihot (Linn.) Increases Cyclin D1 Expression and Activates Cell Proliferation.

Abelmoschus manihot (Linn.) is a medicinal herbal plant that is commonly used to treat chronic kidney disease and hepatitis. However, its effect on cell proliferation has not been clearly revealed. In this report, we sought to determine the effect of the flower extract of A. manihot (FA) on cell proliferation. Based on our findings, FA increased the proliferation of human diploid fibroblast (HDF) and HEK293 cells. Through cell cycle analysis, FA was found to increase the number of HDF cells in the S phase and G2/M phase. FA also increased the expression of cyclin D1 and enhanced the migration of HDF cells. By administering FA to HDF cells with ≥30 passages, a decrease in the number of senescence-associated ß galactosidase-positive cells was observed, thereby indicating that FA can ameliorate cellular senescence. Collectively, our findings indicate that FA increases cyclin D1 expression and regulates cell proliferation.

CRISPR-Cas9 mediated CD133 knockout inhibits colon cancer invasion through reduced epithelial-mesenchymal transition.

We previously reported that CD133, as a putative cancer stem cell marker, plays an important role in cell proliferation and invasion in colon cancer. To understand the role of CD133 expression in colon cancer, we evaluated the inhibitory effect of CD133 in colon cancer cells. In this study, we generated CD133knockout colon cancer cells (LoVo) using the CRISPR-Cas9 gene editing system. CD133+ colon cancer cells (LoVo) were infected with the lentiviral vector carrying CD133 gRNA and purified cell by culturing single cell colonies. CD133knockout cells was validated by western blot and flow cytometry analysis. In functional study, we observed a significant reduction in cell proliferation and colony formation in CRISPR-Cas9 mediated CD133 knockout cells in compare with control (P < 0.001). We also found the anticancer effect of stattic was dependent on CD133 expression in colon cancer cells. Although CD133knockout cells could not completely block the tumorigenic property, they showed remarkable inhibitory effects on the ability of cell migration and invasion (P < 0.001). In addition, we examined the epithelial mesenchymal transition (EMT)-related protein expression by western blot. The result clearly showed a loss of vimentin expression in CD133knockout cells. Therefore, CRISPR-Cas9 mediated CD133knockout can be an effective treatment modality for CD133+ colon cancer through reducing the characteristics of cancer stem cells.

Conessine Treatment Reduces Dexamethasone-Induced Muscle Atrophy by Regulating MuRF1 and Atrogin-1 Expression.

Conessine, a steroidal alkaloid, is a potent histamine H3 antagonist with antimalarial activity. We recently reported that conessine treatment interferes with H2O2-induced cell death by regulating autophagy. However, the cellular signaling pathways involved in conessine treatment are not fully understood. Here, we report that conessine reduces muscle atrophy by interfering with the expression of atrophy-related ubiquitin ligases MuRF-1 and atrogin-1. Promoter reporter assay revealed that conessine treatment inhibits FoxO3a-dependent transcription, NF-κB-dependent transcription, and p53-dependent transcription. We also showed by quantitative RT-PCR and western blot assays that conessine treatment reduced dexamethasone-induced expression of MuRF1 and atrogin-1. Finally, we demonstrated that conessine treatment reduced dexamethasone-induced muscle atrophy using differentiated C2C12 cells. These results collectively suggest that conessine is potentially useful in the treatment of muscle atrophy.

AMP-activated protein kinase regulates the expression of human telomerase reverse transcriptase.

The expression of hTERT in tumor cells contributes to oncogenic transformation by promoting immortalization. For this reason, hTERT is one of the major targets for cancer therapy, and an efficient method to downregulate hTERT expression is required for treatment of hTERT-positive cancer. In this report, we demonstrated that inhibition of AMP-activated protein kinase (AMPK) downregulates the expression of hTERT. We screened cell signaling pathways in AMPK α1 knockout cells and found that AMPKα1 is required for activity of the hTERT promoter. AMPKα1 knockout cells showed decreased expression of hTERT mRNA and protein. We also demonstrated that compound C, a reversible AMPK inhibitor, suppressed the expression of hTERT. However, AMPK activators, including AICAR and metformin, did not increase the level of hTERT protein. Finally, we showed that tumor cells stably expressing hTERT are resistant to compound C treatment. These results indicate that AMPK activity is required for tumor progression.