-
Chinese Journal of Integrative Medicine Jun 2024To investigate the protective effects of stir-fried Semen Armeniacae Amarum (SAA) against aristolochic acid I (AAI)-induced nephrotoxicity and DNA adducts and elucidate...
OBJECTIVE
To investigate the protective effects of stir-fried Semen Armeniacae Amarum (SAA) against aristolochic acid I (AAI)-induced nephrotoxicity and DNA adducts and elucidate the underlying mechanism involved for ensuring the safe use of Asari Radix et Rhizoma.
METHODS
In vitro, HEK293T cells overexpressing Flag-tagged multidrug resistance-associated protein 3 (MRP3) were constructed by Lentiviral transduction, and inhibitory effect of top 10 common pairs of medicinal herbs with Asari Radix et Rhizoma in clinic on MRP3 activity was verified using a self-constructed fluorescence screening system. The mRNA, protein expressions, and enzyme activity levels of NAD(P)H quinone dehydrogenase 1 (NQO1) and cytochrome P450 1A2 (CYP1A2) were measured in differentiated HepaRG cells. Hepatocyte toxicity after inhibition of AAI metabolite transport was detected using cell counting kit-8 assay. In vivo, C57BL/6 mice were randomly divided into 5 groups according to a random number table, including: control (1% sodium bicarbonate), AAI (10 mg/kg), stir-fried SAA (1.75 g/kg) and AAI + stir-fried SAA (1.75 and 8.75 g/kg) groups, 6 mice in each group. After 7 days of continuous gavage administration, liver and kidney damages were assessed, and the protein expressions and enzyme activity of liver metabolic enzymes NQO1 and CYP1A2 were determined simultaneously.
RESULTS
In vivo, combination of 1.75 g/kg SAA and 10 mg/kg AAI suppressed AAI-induced nephrotoxicity and reduced dA-ALI formation by 26.7%, and these detoxification effects in a dose-dependent manner (P<0.01). Mechanistically, SAA inhibited MRP3 transport in vitro, downregulated NQO1 expression in vivo, increased CYP1A2 expression and enzymatic activity in vitro and in vivo, respectively (P<0.05 or P<0.01). Notably, SAA also reduced AAI-induced hepatotoxicity throughout the detoxification process, as indicated by a 41.3% reduction in the number of liver adducts (P<0.01).
CONCLUSIONS
Stir-fried SAA is a novel drug candidate for the suppression of AAI-induced liver and kidney damages. The protective mechanism may be closely related to the regulation of transporters and metabolic enzymes.
PubMed: 38850483
DOI: 10.1007/s11655-024-3809-2 -
Chemico-biological Interactions Jun 2024It is established that organophosphorus pesticide (OPP) toxicity results from modification of amino acids in active sites of target proteins. OPPs can also modify...
It is established that organophosphorus pesticide (OPP) toxicity results from modification of amino acids in active sites of target proteins. OPPs can also modify unrelated target proteins such as histones and such covalent histone modifications can alter DNA-binding properties and lead to aberrant gene expression. In the present study, we report on non-enzymatic covalent modifications of calf thymus histones adducted to selected OPPs and organophosphate flame retardants (OPFRs) in vitro using a bottom-up proteomics method approach. Histones were not found to form detectable adducts with the two tested OPFRs but were avidly modified by a few of the seven OPPs that were tested in vitro. Dimethyl phosphate (or diethyl phosphate) adducts were identified on Tyr, Lys and Ser residues. Most of the dialkyl phosphate adducts were identified on Tyr residues. Methyl and ethyl modified histones were also detected. Eleven amino residues in histones showed non-enzymatic covalent methylation by exposure of dichlorvos and malathion. Our bottom-up proteomics approach showing histone-OPP adduct formation warrants future studies on the underlying mechanism of chronic illness from exposure to OPPs.
PubMed: 38844256
DOI: 10.1016/j.cbi.2024.111095 -
Cancer Prevention Research... Jun 2024
PubMed: 38831722
DOI: 10.1158/1940-6207.CAPR-24-0164 -
Georgian Medical News Mar 2024Changing the vision, understanding, interpretation and analysis of certain data or scientific dilemmas is what is able to change the status quo and revitalize a mission,...
(NDMA) METFORMIN AND (NTTP) SITAGLIPTIN INDUCED CUTANEOUS MELANOMAS: LINKS TO NITROSOGENESIS, NITROSO-PHOTOCARCINOGENESIS, ONCOPHARMACOGENESIS AND THE METABOLIC REPROGRAMMING.
Changing the vision, understanding, interpretation and analysis of certain data or scientific dilemmas is what is able to change the status quo and revitalize a mission, an impulse or important thoughts, thus creating the conditions for it to increase immensely the chances of bringing it to success. Or, following Albert Einstein's postulate: ˝We cannot solve our problems with the same thinking we used when we created them˝, we should think: ˝Where does the road to success start? How do we solve or neutralize a problem? ˝ And the answer is: ˝ By taking a consistent and systematic approach, analyzing each component! And we eliminate every possibility of negative influence.˝ These thoughts apply with full force to cancer rates in general, but also to melanoma rates in particular: the murderous tempo of globalization and modernization in medicine has not yet led to the desired decrease in these rates; on the contrary, they are rising headlong and remain largely unpredictable and difficult to regulate. The conclusion is that a solution should be sought by refracting light through another prism: that of Nitrosogenesis and Pharmaco-Oncogenesis. A step-by-step and systematic approach to solving a problem requires patience, determination, and perseverance. As this perseverance is needed mainly to overcome the general ignorance, neglect, disinterest, uneducation and uncertainty of others, rather than doubt in one's own thesis, analysis, and the need for an active approach. Careful analysis of concepts such as ˝Drug Mediated Nitrosogenesis˝ and ˝Onco-pharmacogenesis/Pharmaco-oncogenesis˝ of skin cancer would certainly contribute to the elucidation of skin carcinogenesis in the context of polymedication of the contamination and polymorbidity worldwide. The FDA has already in 2019 taken this much needed first step of universal awareness and its ˝arm˝ has been taken seriously and responsibly solely by dermatologists and dermatosurgeons. It was this guild and only this guild that launched its independent, never-ending observations, logically grounded (hypo)theses, remaining to date confirmatory, unshakable, and enigmatic regarding the unit: intake of potentially contaminated medication and subsequent development of melanomas. It is this and only this branch of the medical guild that has also become the guarantor of safety and objectivity in science, and thus of safety in the fight for survival of a huge number of skin cancer patients. Contaminated oral antidiabetic drugs in the face of Metformin and Sitagliptin do not make an exception in this respect. Similarly to cutaneous melanomas occurring (and published in the scientific literature) after combined intake (or monomedication) of/ between ranitidine, valsartan, olmesartan, candesartan, telmisartan, irbesartan, losartan, enalapril, lisinopril, perindopril, hydrochlorothiazide, nifedipine, amlodipine, propafenone, bisoprolol, nebivolol, melitracen and a number of others, we inform about another rare but not unexpected clinical observation: occurrence of cutaneous melanomas after taking another class of drugs- oral antidiabetic ones. Or after the intake of nitrosamine-contaminated antidiabetic drugs. And whether this contamination is "real or potential" is left to regulators and manufacturers to decide. We accept it as `real-potential' or `potentially-real' because of the fact that neither the regulators nor the manufacturers know what it is or whether it is there or how it arose. The data shared in patients one and two in the presented scientific work are confirmatory in relation to the potential pathogenetic action of nitrosamine contaminated drugs such as 1) bisoprolol/ nebivolol/ candesartan/ hydrochlorothiazide and amlodipine, as well as 2) furosemide in the direction of cutaneous melanoma. Patient 3 in fact also represents the first formally described patient with subsequent melanoma development worldwide, having developed it following intake of potentially/actually nitrosamine-contaminated metformin and metformin/sitagliptin (both drugs are themed in the FDA's Potentially Contaminated Drug Bulletin: 1) metformin, multiple times between 2020-21, due to its contamination with NDMA and 2) sitagliptin, as of September 2022, due to its contamination with NTTP). It should not be seen as surprising to anyone that the intake of relatively similar carcinogens/nitrosamines or NDSRIs, but as an unofficial component of heterogeneous drugs, produces a relatively monomorphic clinical picture- that of cutaneous melanoma. Or to put it metaphorically: ˝The wolf changes its hair, but not its mood˝. A carcinogen remains a carcinogen, regardless of whether it is ingested in a lemonade, a tablet, a sandwich, or a bonbon. Similarly to the intake of nitrosamines in food. Future studies should address the important tasks/dilemmas to elucidate 1) the phototoxic/photocarcinogenic effect of unmetabolized nitrosamines identified in drug formulations; 2) the phototoxic/photocarcinogenic effect of DNA adducts generated after their metabolization, and 3) the availability of specific DNA adducts in lesional/tumor tissue and blood of patients after ingestion of nitroso-containing drug formulations. This level of evidence is likely to lead to a reconsideration of the arguments for the introduction of permanent elimination regimes for nitrosamines in medicines. Metabolic reprogramming (and its relationship to UVB radiation) due to the availability of nitrosamines in cigarette smoke is also currently a proven reality. Based on the available clinicopathological correlations, we believe that nitrosamines in drugs have a similar effect and are part of the key pathway activating skin carcinogenesis under the influence of solar radiation. Intake of contaminated medication is associated with skin cancer generation and progression. It is up to regulators and manufacturers to justify the merits and benefits of the self-imposed presence of carcinogens in drugs or the benefits of such drugs. Apart from the "cancer-generating benefit", of course, which is already widely known. And let us not forget that: "A lie stops being a lie and becomes a truth the moment it is officially refuted".
Topics: Humans; Melanoma; Skin Neoplasms; Metformin; Sitagliptin Phosphate; Carcinogenesis; Melanoma, Cutaneous Malignant; Hypoglycemic Agents; Metabolic Reprogramming
PubMed: 38807407
DOI: No ID Found -
Environment International Jun 2024Extracellular vesicles (EVs) mediate the intercellular crosstalk by transferring functional cargoes. Recently, we have discovered that BaP/BPDE exposure suppresses...
BaP/BPDE suppresses human trophoblast cell migration/invasion and induces unexplained miscarriage by up-regulating a novel lnc-HZ11 in extracellular vesicles: An intercellular study.
Extracellular vesicles (EVs) mediate the intercellular crosstalk by transferring functional cargoes. Recently, we have discovered that BaP/BPDE exposure suppresses trophoblast cell migration/invasion and induces miscarriage, which are also regulate by lncRNAs at intracelluar levels. However, the EVs-mediated intercellular regulatory mechanisms are completely unexplored. Specifically, whether EVs might transfer BPDE-induced toxic lncRNA to fresh recipient trophoblast cells and suppress their migration/invasion to further induce miscarriage is completely unknown. In this study, we find that BPDE exposure up-regulates a novel lnc-HZ11, which suppresses EGR1/NF-κB/CXCL12 pathway and migration/invasion of trophoblast cells. Intercellular studies show that EV-HZ11 (lnc-HZ11 in EVs), which is highly expressed in BPDE-exposed donor cells, suppresses EGR1/NF-κB/CXCL12 pathway and migration/invasion in recipient cells by transferring lnc-HZ11 through EVs. Analysis of villous tissues collected from UM (unexplained miscarriage) patients and HC (healthy control) group shows that the levels of BPDE-DNA adducts, lnc-HZ11 or EV-lnc-HZ11, and EGR1/NF-κB/CXCL12 pathway are all associated with miscarriage. Mouse assays show that BaP exposure up-regulates the levels of lnc-Hz11 or EV-Hz11, suppresses Egr1/Nf-κb/Cxcl12 pathway, and eventually induces miscarriage. Knockdown of lnc-Hz11 by injecting EV-AS-Hz11 could effectively alleviate miscarriage in BaP-exposed mice. Furthermore, EV-HZ11 in serum samples could well predict the risk of miscarriage. Collectively, this study not only discovers EVs-HZ11-mediated intercellular mechanisms that BaP/BPDE suppresses trophoblast cell migration/invasion and induces miscarriage but also provides new approach for treatment against unexplained miscarriage through EV-HZ11.
Topics: Extracellular Vesicles; Trophoblasts; Cell Movement; Humans; Female; RNA, Long Noncoding; Mice; Up-Regulation; Abortion, Spontaneous; Animals; Pregnancy; Early Growth Response Protein 1; NF-kappa B
PubMed: 38788414
DOI: 10.1016/j.envint.2024.108750 -
Journal of Neuroimmunology Jul 2024SUMO (small ubiquitin like modifier) conjugated proteins have emerged as an important post translational modifier of cellular function. SUMOylation modulates several... (Review)
Review
SUMO (small ubiquitin like modifier) conjugated proteins have emerged as an important post translational modifier of cellular function. SUMOylation modulates several cellular processes involved in transcriptional regulation of genes, protein-protein interactions and DNA damage and repair. Since abnormalities in SUMOylation has been observed in neoplastic and neurodegenerative disorders, the SUMO pathway has become an attractive site for targeting of new therapies to regulate SUMOylation and reduce disease burden. Conjugation of SUMO to their respective substrates is orchestrated by an enzymatic cascade involving three main enzymes, E1, activation enzyme, E2, conjugating enzyme and E3, a protein ligase. Each of these enzymes are therefore potential "druggable" sites for future therapeutics. SUMOylation is a well-known mechanism by which the innate immune response is regulated in response to viral infections and in the adaptive immune response to tumor immunity. We have shown that small molecules which inhibit the SUMO activation pathway are also capable of inhibiting autoimmune response. TAK981 which forms adducts with SUMO and anacardic acid which inhibits the E1 enzyme of the SUMO pathway were effective in preventing the development of experimental allergic encephalitis (EAE), a mouse model of multiple sclerosis. Anacardic acid and TAK981 inhibited activation of TH17 cells and reduced clinical and pathological injury in IL-17 mediated myelin oligodendrocyte glycoprotein (MOG) induced EAE. Ginkgolic acid, another known inhibitor of SUMO pathway, was also shown to be effective in reducing the severity of inflammatory arthropathies which is also IL-17 mediated. In addition, the increase in the transcription of myelin genes with TAK981 and anacardic acid improved remyelination in experimental models of demyelination. In the present review paper, we examine the mechanism of action of inhibitors of the SUMO pathway on regulating the immune response and the possibility of the use of these agents as therapeutics for MS.
Topics: Animals; Humans; Multiple Sclerosis; Sumoylation; Encephalomyelitis, Autoimmune, Experimental
PubMed: 38788318
DOI: 10.1016/j.jneuroim.2024.578371 -
The Journal of Biological Chemistry May 2024Aristolochic acids I and II (AA-I/II) are carcinogenic principles of Aristolochia plants, which have been employed in traditional medicinal practices and discovered as...
Aristolochic acids I and II (AA-I/II) are carcinogenic principles of Aristolochia plants, which have been employed in traditional medicinal practices and discovered as food contaminants. While the deleterious effects of AAs are broadly acknowledged, there is a dearth of information to define the mechanisms underlying their carcinogenicity. Following bioactivation in the liver, N-hydroxyaristolactam and N-sulfonyloxyaristolactam metabolites are transported via circulation and elicit carcinogenic effects by reacting with cellular DNA. In this study, we apply DNA adduct analysis, X-ray crystallography, isothermal titration calorimetry, and fluorescence quenching to investigate the role of human serum albumin (HSA) in modulating AA carcinogenicity. We find that HSA extends the half-life and reactivity of N-sulfonyloxyaristolactam-I with DNA, thereby protecting activated AAs from heterolysis. Applying novel pooled plasma HSA crystallization methods, we report high-resolution structures of myristic acid-enriched HSA (HSA) and its AA complexes (HSA/AA-I and HSA/AA-II) at 1.9 Å resolution. While AA-I is located within HSA subdomain IB, AA-II occupies subdomains IIA and IB. ITC binding profiles reveal two distinct AA sites in both complexes with association constants of 1.5 and 0.5 · 10 M for HSA/AA-I versus 8.4 and 9.0 · 10 M for HSA/AA-II. Fluorescence quenching of the HSA Trp suggests variable impacts of fatty acids on ligand binding affinities. Collectively, our structural and thermodynamic characterizations yield significant insights into AA binding, transport, toxicity, and potential allostery, critical determinants for elucidating the mechanistic roles of HSA in modulating AA carcinogenicity.
PubMed: 38782206
DOI: 10.1016/j.jbc.2024.107358 -
Chemical Research in Toxicology Jun 2024Emerging evidence showing urothelial cancer in herbalists is linked to aristolochic acid (AA) exposure; however, the exposure pathway remains unclear. Here, we show that...
Emerging evidence showing urothelial cancer in herbalists is linked to aristolochic acid (AA) exposure; however, the exposure pathway remains unclear. Here, we show that dermal contact and inhalation of fine powders of AA-containing herbs are significant occupational AA exposure pathways for herbalists. We initiated the study by quantifying the amount of AA in the AA-containing powder deposited on gloves and face masks worn by the operators of an AA-containing herb grinding machine. Then, we measured the kinetics of dermal absorption and dissolution of AA from fine powders of AA-containing herbs into artificial sweat and surrogate lung fluid. Lastly, we quantified the mutagenic AA-DNA adduct levels formed in the kidneys of mice exposed to AA-containing fine powders through dermal contact. Our findings highlight an urgent occupational risk that should demand implementation of safety standards for herbalists exposed to AA-containing fine powders.
Topics: Aristolochic Acids; Occupational Exposure; Powders; Animals; Humans; Mice; DNA Adducts; Inhalation Exposure; Urothelium; Traditional Medicine Practitioners
PubMed: 38780306
DOI: 10.1021/acs.chemrestox.4c00157 -
NAR Molecular Medicine Apr 2024Increased risk for the development of hepatocellular carcinoma (HCC) is driven by a number of etiological factors including hepatitis viral infection and dietary...
Increased risk for the development of hepatocellular carcinoma (HCC) is driven by a number of etiological factors including hepatitis viral infection and dietary exposures to foods contaminated with aflatoxin-producing molds. Intracellular metabolic activation of aflatoxin B (AFB) to a reactive epoxide generates highly mutagenic AFB-Fapy-dG adducts. Previously, we demonstrated that repair of AFB-Fapy-dG adducts can be initiated by the DNA glycosylase NEIL1 and that male mice were significantly more susceptible to AFB-induced HCC relative to wild-type mice. To investigate the mechanisms underlying this enhanced carcinogenesis, WT and mice were challenged with a single, 4 mg/kg dose of AFB and frequencies and spectra of mutations were analyzed in liver DNAs 2.5 months post-injection using duplex sequencing. The analyses of DNAs from AFB-challenged mice revealed highly elevated mutation frequencies in the nuclear genomes of both males and females, but not the mitochondrial genomes. In both WT and mice, mutation spectra were highly similar to the AFB-specific COSMIC signature SBS24. Relative to wild-type, the NEIL1 deficiency increased AFB-induced mutagenesis with concomitant elevated HCCs in male mice. Our data establish a critical role of NEIL1 in limiting AFB-induced mutagenesis and ultimately carcinogenesis.
PubMed: 38779538
DOI: 10.1093/narmme/ugae006 -
Journal of Neuro-oncology May 2024Glioblastoma (GBM) stands out as the most prevalent and aggressive intracranial tumor, notorious for its poor prognosis. The current standard-of-care for GBM patients...
PURPOSE
Glioblastoma (GBM) stands out as the most prevalent and aggressive intracranial tumor, notorious for its poor prognosis. The current standard-of-care for GBM patients involves surgical resection followed by radiotherapy, combined with concurrent and adjuvant chemotherapy using Temozolomide (TMZ). The effectiveness of TMZ primarily relies on the activity of O-methylguanine DNA methyltransferase (MGMT), which removes alkyl adducts from the O position of guanine at the DNA level, thereby counteracting the toxic effects of TMZ.
METHOD
In this study, we employed fusions of catalytically-inactive Cas9 (dCas9) to DNA methyltransferases (dCas9-DNMT3A) to selectively downregulation MGMT transcription by inducing methylation at MGMT promoter and K-M enhancer.
RESULT
Our findings demonstrate a significant reduction in MGMT expression, leading to intensified TMZ sensitivity in the HEK293T cell line.
CONCLUSION
This study serves as a proof of concept for the utilization of CRISPR-based gene suppression to overcome TMZ resistance and enhance the lethal effect of TMZ in glioblastoma tumor cells.
PubMed: 38762829
DOI: 10.1007/s11060-024-04708-0