TRDMT1 exhibited protective effects against LPS-induced inflammation in rats through TLR4-NF-κB/MAPK-TNF-α pathway

Establishment and evaluation of an improved rat model of open abdomen

INTRODUCTION

This study aimed to establish an animal model of open abdomen (OA) through temporary abdominal closure via different techniques.

METHODS

Adult male Sprague-Dawley rats were randomly divided into three groups: group A (OA with polypropylene mesh alone); group B (OA with polypropylene mesh combined with a patch); and group C (OA with polypropylene mesh and a sutured patch). Vital signs, pathophysiological changes, and survival rates were closely monitored in the rats for 7 days after surgery. Abdominal X-rays and histopathological examinations were performed to assess abdominal organ changes and wound healing.

RESULTS

The results showed no significant difference in mortality rates among the three groups (p > 0.05). However, rats in group B exhibited superior overall condition, cleaner wounds, and a higher rate of wound healing compared to the other groups (p < 0.05). Abdominal X-rays indicated that varying degrees of distal intestinal obstruction in all groups. Histopathological examinations revealed fibrous hyperplasia, inflammatory cell infiltration, neovascularization, and collagen deposition in all groups. Group B demonstrated enhanced granulation tissue generation, neovascularization, and collagen deposition compared to the other groups (p < 0.05).

CONCLUSIONS

Polypropylene mesh combined with patches is the most suitable method for establishing an animal model of OA. This model successfully replicated the pathological and physiological changes in postoperative patients with OA, specifically the progress of abdominal skin wound healing. It provides a practical and reliable animal model for OA research.

Hydrangea paniculata coumarins alleviate adriamycin-induced renal lipotoxicity through activating AMPK and inhibiting C/EBPβ

ETHNOPHARMACOLOGICAL RELEVANCE

Throughout Chinese history, Hydrangea paniculata Siebold has been utilized as a traditional medicinal herb to treat a variety of ailments associated to inflammation. In a number of immune-mediated kidney disorders, total coumarins extracted from Hydrangea paniculata (HP) have demonstrated a renal protective effect.

AIM OF THE STUDY

To investigate renal beneficial effect of HP on experimental Adriamycin nephropathy (AN), and further clarify whether reversing lipid metabolism abnormalities by HP contributes to its renoprotective effect and find out the underlying critical pathways.

MATERIALS AND METHODS

After establishment of rat AN model, HP was orally administrated for 6 weeks. Biochemical indicators related to kidney injury were determined. mRNAs sequencing using kidney tissues were performed to clarify the underlying mechanism. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, western blot, molecular docking, and drug affinity responsive target stability (DARTS) assay was carried out to further explore and confirm pivotal molecular pathways and possible target by which HP and 7-hydroxylcoumarin (7-HC) played their renal protection effect via modulating lipid metabolism.

RESULTS

HP could significantly improve renal function, and restore renal tubular abnormal lipid metabolism and interstitial fibrosis in AN. In vitro study demonstrated that HP and its main metabolite 7-HC could reduce ADR-induced intracellular lipid deposition and fibrosis characteristics in renal tubular cells. Mechanically, HP and 7-HC can activate AMP-activated protein kinase (AMPK) via direct interaction, which contributes to its lipid metabolism modulation effect. Moreover, HP and 7-HC can inhibit fibrosis by inhibiting CCAAT/enhancer binding protein beta (C/EBPβ) expression in renal tubular cells. Normalization of lipid metabolism by HP and 7-HC further provided protection of mitochondrial structure integrity and inhibited the nuclear factor kappa-B (NF-κB) pathway. Long-term toxicity using beagle dogs proved the safety of HP after one-month administration.

CONCLUSION

Coumarin derivates from HP alleviate adriamycin-induced lipotoxicity and fibrosis in kidney through activating AMPK and inhibiting C/EBPβ.

Biological function molecular pathways and druggability of DNMT2/TRDMT1

5-methylcytosine (m5C) is among the most common epigenetic modification in DNA and RNA molecules, and plays an important role in the animal development and disease pathogenesis. Interestingly, unlike other m5C DNA methyltransferases (DNMTs), DNMT2/TRDMT1 has the double-substrate specificity and adopts a DNMT-similar catalytic mechanism to methylate RNA. Moreover, it is widely involved in a variety of physiological regulatory processes, such as the gene expression, precise protein synthesis, immune response, and disease occurrence. Thus, comprehending the epigenetic mechanism and function of DNMT2/TRDMT1 will probably provide new strategies to treat some refractory diseases. Here, we discuss recent studies on the spatiotemporal expression pattern and post-translational modifications of DNMT2/TRDMT1, and summarize the research advances in substrate characteristics, catalytic recognition mechanism, DNMT2/TRDMT1-related genes or proteins, pharmacological application, and inhibitor development. This review will shed light on the pharmacological design by targeting DNMT2/TRDMT1 to treat parasitic, viral and oncologic diseases.

Jiaohong pills attenuate neuroinflammation and amyloid-β protein-induced cognitive deficits by modulating the mitogen-activated protein kinase/nuclear factor kappa-B pathway

BACKGROUND

Jiaohong pills (JHP) consist of Pericarpium Zanthoxyli (PZ) and Radix Rehmanniae, two herbs that have been extensively investigated over many years due to their potential protective effects against cognitive decline and memory impairment. However, the precise mechanisms underlying the beneficial effects remain elusive. Here, research studies were conducted to investigate and validate the therapeutic effects of JHP on Alzheimer's disease.

METHODS

BV-2 cell inflammation was induced by lipopolysaccharide. AD mice were administered amyloid-β (Aβ). Behavioral experiments were used to evaluate learning and memory ability. The levels of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-10 (IL-10) were detected using enzyme-linked immunosorbent assay (ELISA). The protein expressions of inducible nitric oxide synthase (iNOS) and the phosphorylation level of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) were detected using Western blot. Nissl staining was used to detect neuronal degeneration.

RESULTS

The results demonstrated that an alcoholic extract of PZ significantly decreased the levels of NO, IL-1β, TNF-α, and iNOS; increased the expression level of IL-10; and significantly decreased the phosphorylation levels of MAPK and NF-κB. These inhibitory effects were further confirmed in the AD mouse model. Meanwhile, JHP improved learning and memory function in AD mice, reduced neuronal damage, and enriched the Nissl bodies in the hippocampus. Moreover, IL-1β and TNF-α in the cortex were significantly downregulated after JHP administration, whereas IL-10 showed increased expression.

CONCLUSIONS

It was found that JHP reduced neuroinflammatory response in AD mice by targeting the MAPK/NF-κB signaling pathway.

In-depth analyses of lncRNA and circRNA expression in the hippocampus of LPS-induced AD mice by Byu d Mar 25

Byu d Mar 25 (BM25) has been verified to have neuroprotective effects in Alzheimer's disease (AD) mice. However, the molecular mechanism remains unclear. We aimed to investigate the expression profiling of lncRNAs and circRNAs by microarray analysis. Six hippocampus from LPS-mediated AD mice model treated with (normal saline (NS) (n = 3) and AD mice model treated with BM25 (n = 3) were selected. Microarray analysis was performed to detect the expression profiles of lncRNAs and circRNAs in hippocampus. Differentially expressed (DE) lncRNAs, mRNAs and circRNAs were identified through scatter plot and volcano plot filtering with a threshold of fold-change ≥2 and P  ≤ 0.05. Co-expression network is analyzed by Circos software. Cis - and Trans - regulation were analyzed using RIsearch-2.0 and FEELNC softwares. LncRNA-transcription factors (TFs) and LncRNA-Target-TFs network were analyzed by Clusterprofiler software. The prediction of miRNAs bind to circRNAs were performed with miRNAbase. A total of 113 DElncRNAs, 117 DEmRNAs, and 4 DEcircRNAs were detected. The pathway analysis showed the mRNAs that correlated with lncRNAs were involved in apoptosis, inflammatory mediator regulation of TRP channels, NF-kappa B and PI3K-Akt signaling pathway. The lncRNA-TFs network analysis suggested the lncRNAs were mostly regulated by Ncoa1, Phf5a, Klf6, Lmx1b, and Pax3. Additionally, lncRNA-target-TFs network analysis indicated the GATA6, Junb, Smad1, Twist1, and Mafb mostly regulate the same lncRNAs: XR_001783430.1 and NR_051982.1. Furthermore, 480 miRNAs were predicted binding to 4 identified circRNAs. The BM25 may affect AD by regulating the expression of lncRNAs and circRNAs, which could regulate the expressions of mRNAs or miRNAs by LncRNA-Target-TFs network.

Restricted tRNA methylation by intermolecular disulfide bonds in DNMT2/TRDMT1

Reportedly, DNMT2/TRDMT1 mainly methylates tRNAs at C38 and prevents them from the cleavage under stress. It also plays an essential role in the survival and physiological homeostasis of organisms. Nevertheless, DNMT2/TRDMT1 exhibits much weaker tRNA methylation activity in vitro than other tRNA methyltransferases, TrmD and Trm5. Here, we explored the restricted tRNA methylation mechanism by DNMT2/TRDMT1. In the current study, the optimized buffer C at 37 °C was the best condition for DNMT2/TRDMT1 activation. Of note, Dithiothreitol (DTT) was an indispensable component for this enzyme catalysis. Moreover, reductants took similar effects on the conformation change and oligomeric formation of DNMT2/TRDMT1. Ultimately, LC-MS/MS result revealed that C292-C292 and C292-C287 were predominant intermolecular disulfide bonds in recombinant DNMT2/TRDMT1. Notably, DNMT2/TRDMT1 existed primarily as dimers via intermolecular disulfide bonds C79-C24, C292-C292, and C222-C24 in HEK293T cells. GSSG stress enhanced tRNA methylation level in the early stage of stress, whereas the DNMT2/TRDMT1 activity might be unfavorable along with this enzyme accumulation in the nucleus. Excitingly, GSH stress downregulated the DNMT2/TRDMT1 expression and promoted tRNA methylation in cells, probably through breaking intermolecular disulfide bonds in this enzyme. Thus, our findings demonstrated restricted tRNA methylation by disulfide bonds in DNMT2/TRDMT1, and will provide important implications for redox stress related-diseases.

TRDMT1-mediated RNA C-5 methylation as a novel target in anticancer therapy

Affected landscape of RNA modifications is frequently observed in different cancer cells that can be associated with the development of cancer cell phenotypic traits such as sustained proliferation, migration and invasion, apoptosis resistance and metabolic reprograming. DNMT2/TRDMT1 5-methylcytosine methyltransferase, initially classified as DNA methyltransferase, can methylate both tRNA and mRNA promoting tRNA stability and proper protein synthesis, and orchestrating DNA damage response (DDR) and DNA stability, respectively. TRDMT1 is associated with cancer progression as its levels can be elevated and its mutations can be observed in a number of cancer types. TRDMT1 gene knockout (KO) can sensitize cancer cells of different origin to radiotherapy and chemotherapy. In the present review paper, based on literature data, the physiological and pathophysiological roles of TRDMT1 in different biological systems are described with the emphasis on human normal and cancer cells. Potential TRDMT1 substrates, inhibitors and regulatory mechanisms of catalytic activity and cellular localization are also presented and evaluated. TRDMT1 as a novel promising target in anticancer therapy is proposed and discussed.

Review of research progress on the role of the effective components of traditional Chinese medicine in sepsis with multiple organ dysfunction

The concept of sepsis has recently evolved from one of a 'systemic inflammatory response syndrome caused by infection' to a 'severe, potentially fatal organic dysfunction caused by an inadequate or imbalanced host response to infection'. Organ dysfunction is closely related to sepsis. Multiple organ dysfunction syndrome (MODS) is the most serious outcome of sepsis, often leading to a poor prognosis. However, specific drugs for sepsis and MODS caused by sepsis remain undetermined, and the fatality rate is relatively high. Under the guidance of modern medicine, traditional Chinese medicine (TCM) has gained a wealth of experience in the prevention and treatment of sepsis and plays a key role via the effects of its numerous components, pathways and targets. This study used 'Sepsis', 'Organ dysfunction' and 'Traditional Chinese medicine' as strategies for searching the databases of Chinese National Knowledge Infrastructure, Wanfang, PubMed and The Web of Science. This paper presents an overview of the current status of TCM component formulations for preventing and treating sepsis with MODS to provide a theoretical basis for clinical treatment and drug development.

Integrated metabolomics and network pharmacology revealing the mechanism of arsenic-induced hepatotoxicity in mice

Endemic arsenic (As) poisoning is a severe biogeochemical disease that endangers human health. Epidemiological investigations and animal experiments have confirmed the damaging effects of As on the liver, but there is an urgent need to investigate the underlying mechanisms. This study adopted a metabolomic approach using UHPLC-QE/MS to identify the different metabolites and metabolic mechanisms associated with As-induced hepatotoxicity in mice. A network pharmacology approach was applied to predict the potential target of As-induced hepatotoxicity. The predicted targets of differential metabolites were subjected to a deep matching for elucidating the integration mechanisms. The results demonstrate that the levels of ALT and AST in plasma significantly increased in mice after As exposure. In addition, the liver tissue showed disorganized liver lobules, lax cytoplasm and inflammatory cell infiltration. Metabolomic analysis revealed that As exposure caused disturbance to 40 and 75 potential differential metabolites in plasma and liver, respectively. Further investigation led to discovering five vital metabolic pathways, including phenylalanine, tyrosine, and tryptophan biosynthesis and nicotinate and nicotinamide metabolism pathways. These pathways may responded to As-induced hepatotoxicity primarily through lipid metabolism, apoptosis, and deoxyribonucleic acid damage. The network pharmacology suggested that As could induce hepatotoxicity in mice by acting on targets including Hsp90aa1, Akt2, Egfr, and Tnf, which regulate PI3K Akt, HIF-1, MAPK, and TNF signaling pathways. Finally, the integrated metabolomics and network pharmacology revealed eight key targets associated with As-induced hepatoxicity, namely DNMT1, MAOB, PARP1, MAOA, EPHX2, ANPEP, XDH, and ADA. The results also suggest that nicotinic acid and nicotinamide metabolisms may be involved in As-induced hepatotoxicity. This research identified the metabolites, targets, and mechanisms of As-induced hepatotoxicity, offering meaningful insights and establishing the groundwork for developing antidotes for widespread As poisoning.

Zataria multiflora and its constituent, carvacrol, counteract sepsis-induced aortic and cardiac toxicity in rat: Involvement of nitric oxide and oxidative stress

BACKGROUND

Zataria multiflora and carvacrol showed various pharmacological properties including anti-inflammatory and anti-oxidant effects. However, up to now no studies have explored its potential benefits in ameliorating sepsis-induced aortic and cardiac injury. Thus, this study aimed to investigate the effects of Z. multiflora and carvacrol on nitric oxide (NO) and oxidative stress indicators in lipopolysaccharide (LPS)-induced aortic and cardiac injury.

METHODS

Adult male Wistar rats were assigned to: Control, lipopolysaccharide (LPS) (1 mg/kg, intraperitoneal (i.p.)), and Z. multiflora hydro-ethanolic extract (ZME, 50-200 mg/kg, oral)- and carvacrol (25-100 mg/kg, oral)-treated groups. LPS was injected daily for 14 days. Treatment with ZME and carvacrol started 3 days before LPS administration and treatment continued during LPS administration. At the end of the study, the levels of malondialdehyde (MDA), NO, thiols, and antioxidant enzymes were evaluated.

RESULTS

Our findings showed a significant reduction in the levels of superoxide dismutase (SOD), catalase (CAT), and thiols in the LPS group, which were restored by ZME and carvacrol. Furthermore, ZME and carvacrol decreased MDA and NO in cardiac and aortic tissues of LPS-injected rats.

CONCLUSIONS

The results suggest protective effects of ZME and carvacrol on LPS-induced cardiovascular injury via improved redox hemostasis and attenuated NO production. However, additional studies are needed to elucidate the effects of ZME and its constituents on inflammatory responses mediated by LPS.

Mechanisms of human DNA methylation, alteration of methylation patterns in physiological processes and oncology

DNA methylation is one of the epigenetic modifications of the genome, the essence of which is the attachment of a methyl group to nitrogenous bases. In the eukaryote genome, cytosine is methylated in the vast majority of cases. About 98% of cytosines are methylated as part of CpG dinucleotides. They, in turn, form CpG islands, which are clusters of these dinucleotides. Islands located in the regulatory elements of genes are in particular interest. They are assumed to play an important role in the regulation of gene expression in humans. Besides that, cytosine methylation serves the functions of genomic imprinting, transposon suppression, epigenetic memory maintenance, X- chromosome inactivation, and embryonic development. Of particular interest are the enzymatic processes of methylation and demethylation. The methylation process always depends on the work of enzymatic complexes and is very precisely regulated. The methylation process largely depends on the functioning of three groups of enzymes: writers, readers and erasers. Writers include proteins of the DNMT family, readers are proteins containing the MBD, BTB/POZ or SET- and RING-associated domains and erasers are proteins of the TET family. Whereas demethylation can be performed not only by enzymatic complexes, but also passively during DNA replication. Hence, the maintenance of DNA methylation is important. Changes in methylation patterns are observed during embryonic development, aging, and cancers. In both aging and cancer, massive hypomethylation of the genome with local hypermethylation is observed. In this review, we will review the current understanding of the mechanisms of DNA methylation and demethylation in humans, the structure and distribution of CpG islands, the role of methylation in the regulation of gene expression, embryogenesis, aging, and cancer development.

Inhibitory Effects of Bacillus Coagulans TL3 on the Ileal Oxidative Stress and Inflammation Induced by Lipopolysaccharide in Rats

This study aimed to explore the effect and mechanism of Bacillus coagulans TL3 (B. coagulans TL3) on ileal inflammatory injury induced by lipopolysaccharide (LPS). Animal models were established wherein male Wistar rats were randomly divided into four groups: a control group, an LPS group, a high-concentration B. coagulans (HBC) group, and a low-concentration B. coagulans (LBC) group. The results showed that the biochemical indices changed, significant pathological changes were found, the number of apoptotic cells increased in the ileal tissue of the LPS group rats; the protein expressions of NFκB, MYD88, TLR4, TNF-α, Il-6, IL-1β, Claudin-1, Occludin, and ZO-1 in the LPS group were significantly decreased. The biochemical indices, pathological changes, and protein expressions in rats subjected to intragastric administration with high or low concentrations of B. coagulans TL3, were significantly reversed compared with the LPS group. These results indicated that TL3 strain could protect rats against ileal oxidative stress and inflammation induced by LPS and the protective mechanism was related to inhibition of the toll-like receptor 4 (TLR4) / myeloid differentiation factor-88 (MyD88) signaling pathway.

Non-targeting siRNA-mediated responses are associated with apoptosis in chemotherapy-induced senescent skin cancer cells

It is widely accepted that siRNA transfection can promote some off-target effects in the genome; however, little is known about how the cells can respond to the presence of non-viral dsRNA. In the present study, non-targeting control siRNA (NTC-siRNA) was used to evaluate its effects on the activity of pathogen and host-derived nucleic acid-associated signaling pathways such as cGAS-STING, RIG-I, MDA5 and NF-κB in A431 skin cancer cells and BJ fibroblasts. NTC-siRNA treatment promoted cytotoxicity in cancer cells. Furthermore, NTC-siRNA-treated doxorubicin-induced senescent cancer cells were more prone to apoptotic cell death compared to untreated doxorubicin-induced senescent cancer cells. NTC-siRNA stimulated the levels of NF-κB, APOBECs, ALY, LRP8 and phosphorylated STING that suggested the involvement of selected components of nucleic acid sensing pathways in NTC-siRNA-mediated cell death response in skin cancer cells. NTC-siRNA-mediated apoptosis in cancer cells was not associated with IFN-β-based pro-inflammatory response and TRDMT1-based adaptive response. In contrast, in NTC-siRNA-treated fibroblasts, an increase in the levels of RIG-I and IFN-β was not accompanied by affected cell viability. We propose that the use of NTC-siRNA in genetic engineering may provoke a number of unexpected effects that should be carefully monitored. In our experimental settings, NTC-siRNA promoted the elimination of doxorubicin-induced senescent cancer cells that may have implications in skin cancer therapies.

Synergistic effect of arginine and Lactobacillus plantarum against potassium dichromate induced-acute liver and kidney injury in rats: Role of iNOS and TLR4/NF-κB signaling pathways

Objectives

Our study was conducted to evaluate the synergistic effect of arginine (ARG) and Lactobacillus plantarum against potassium dichromate (K2Cr2O7) induced-acute hepatic and kidney injury.

Materials and Methods

Fifty male Wistar rats were divided into five groups. The control group received distilled water. The potassium dichromate group (PDC) received a single dose of PDC (20 mg/kg; SC). The arginine group (ARG) and Lactobacillus plantarum group received either daily doses of ARG (100 mg/kg, PO) or L. plantarum (10⁹ CFU/ml, PO) for 14 days. The combination group (ARG+L. plantarum) received daily doses of ARG (100 mg/kg) with L. plantarum (10⁹ CFU/ml), orally for 14 days, before induction of acute liver and kidney injury. Forty eight hours after the last dose of PDC, serum biochemical indices, oxidative stress biomarkers, pro-inflammatory cytokines, histopathological and immunohistochemical analysis were evaluated.

Results

Combining ARG with L. plantarum restored the levels of serum hepatic & kidney enzymes, hepatic & renal oxidative stress biomarkers, and TLR 4/ NF-κB signaling pathway. Furthermore, they succeeded in decreasing the expression of iNOS and ameliorate the hepatic and renal markers of apoptosis: Caspase-3, Bax, and Bcl2.

Conclusion

This study depicts that combining ARG with L. plantarum exerted a new bacteriotherapy against hepatic and renal injury caused by PDC.