Dihydromyricetin alleviates inflammatory bowel disease associated intestinal fibrosis by inducing autophagy through the PI3K/AKT/mTOR signaling pathway.

Intestinal fibrosis is a common complication of inflammatory bowel disease and is characterized by tissue stiffening and luminal narrowing. Dihydromyricetin (DHM) can alleviate liver fibrosis and renal interstitial fibrosis by inducing autophagy. However, whether DHM can alleviate intestinal fibrosis remains unclear. This study is aimed at evaluating the role and mechanism of action of DHM in inflammatory bowel disease-associated intestinal fibrosis. Mice were administered dextran sulfate sodium (DSS) in drinking water to induce inflammatory bowel disease-associated intestinal fibrosis. HE staining, qPCR, and Western blotting were used to analyze colon inflammation. Masson's trichrome staining, qPCR, Western blotting, and immunofluorescence staining were used to evaluate the severity of fibrosis. Transmission electron microscopy and Western blotting were used to assess the activation of autophagosomes. The human colonic fibroblast line CCD-18Co was cultured in the presence of TGF-ß1 to develop a fibrotic phenotype. Immunofluorescence staining, Western blotting, and qPCR were used to assess the alteration of fibrosis markers and used to investigate whether DHM-induced autophagy was involved in the inactivation of CCD-18Co cells. Additionally, the role of the PI3K/AKT/mTOR pathway was investigated. DHM alleviated intestinal inflammation and inhibited the progression of intestinal fibrosis. Additionally, DHM induced the activation of autophagy, thereby alleviating intestinal fibrosis, and downregulated the PI3K/AKT/mTOR signaling pathway in vitro. Overall, this study demonstrated that DHM can inhibit the progression of intestinal fibrosis and activation of colonic fibroblasts by inducing autophagy through the PI3K/AKT/mTOR signaling pathway, thereby playing a preventive and therapeutic role in intestinal fibrosis.

Exploration of mRNA nanoparticles based on DOTAP through optimization of the helper lipids.

Lipid nanoparticles (LNPs) are one of the most efficient carriers for RNA packaging and delivery, and vaccines based on mRNA-LNPs have received substantial attention since the outbreak of the COVID-19 pandemic. LNPs based on 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) have been widely used in preclinical and clinical settings. A novel non-viral gene delivery system called LNP3 was previously developed, which was composed of DOTAP, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and cholesterol. One of the helper lipids in this carrier was DOPE, which belongs to phospholipids. Given that substituting DOPE with non-phospholipids as helper lipids can increase the delivery efficiency of some LNPs, this study aimed to examine whether non-phospholipids can be formulated with DOTAP as helper lipids. It was found that monoglycerides with C14:0, C16:0, C18:0, C18:1, and C18:2 mediated mRNA transfection, and the transfection efficiency varied between C18:0, C18:1, and C18:2. Furthermore, substituting of the glycerol with other moieties such as the cholesterol or the ethanolamine similarly mediated mRNA transfection. The introduction of cholesterol can further improve the transfection capacity of some DOTAP-based LNPs. One of the best-performing formulations, LNP3-MO, was used to mediate luciferase-mRNA expression in vivo, and the luminescence signal was found to be mainly enriched in the lung and spleen. In addition, the level of SARS-CoV-2 spike antibody in the serum increased after three doses of LNP3-MO mediated SARS-CoV-2 spike mRNA. Altogether, this study demonstrates that non-phospholipids are promising helper lipids that can be formulated with DOTAP to facilitate efficient delivery of mRNAs in vitro and in vivo with organ-specific targeting.

High-dose amoxicillin-proton pump inhibitor dual therapy as first-line treatment for Helicobacter pylori infection in Northwest China: A prospective, randomised controlled trial.

AIMS: We aimed to assess the eradication efficacy and factors that influencing it of high-dose dual therapy (HDDT) in Gansu region, Northwest China. METHODS: A total of 216 treatment-naive patients with Helicobacter pylori infection were randomly assigned to two groups for the 14-day eradication treatment: the HDDT group (amoxicillin 750 mg q.i.d. and esomeprazole 40 mg t.i.d.) and the amoxicillin and clarithromycin-containing bismuth quadruple therapy group (ACBQT: esomeprazole 20 mg, bismuth potassium citrate 2 g, amoxicillin 1 g, and clarithromycin 500 mg; b.i.d.). The eradication rates, adverse effects and patient compliance of these two groups were compared. Eradication efficacy was determined by 13 C urea breath test (13 C UBT) 4-8 weeks after finishing treatment. Antibiotic resistance was determined by the Epsilometer testing (E-test) method. RESULTS: The eradication rates for the HDDT and ACBQT groups were 71.0% and 74.7% (P = .552) by per-protocol analysis, and 65.7% and 68.5% (P = .664) by intention-to-treat analysis. The overall adverse event rates in the HDDT and ACBQT groups were 2.0% and 43.4% (P < .001), respectively. The resistance rates to amoxicillin, clarithromycin, tetracycline, levofloxacin and metronidazole were 15.2%, 42.0%, 5.4%, 35.7% and 83.0%, respectively. Amoxicillin resistance and delta over baseline (DOB) of 13 C UBT ≥ 20 before treatment significantly reduced the eradication rate in 112 participants with H. pylori cultured. CONCLUSION: The HDDT as first-line treatment for H. pylori was unsatisfactory in Gansu. Amoxicillin resistance and DOB of 13 C UBT ≥ 20 before treatment were significantly correlated with H. pylori eradication failure.

[A Prognostic Nomogram Based on Response to Bortezomib and BTK Expression for Treatment-Experienced Multiple Myeloma Patients].

OBJECTIVE: To establish a prognostic nomogram based on response to bortezomib and BTK expression for treatment-experienced multiple myeloma patients. METHODS: The Oncomine database was utilized to determine BTK expression, sex, age, albumin, Mayo index, response to bortezomib treatment, follow-up time and survival status in multiple myeloma(MM) patients. Cut-off point for BTK expression was calculated using R software. Univariate and multivariate analyses by Cox proportional hazards regression were then performed. Significant prognostic factors were combined to build a nomogram. The discrimination ability and predictive accuracy of the nomogram were evaluated using the index of concordance (C-index) and calibration curves. RESULTS: Multivariate analysis showed that response to bortezomib, BTK expression and sex were independent risk factors for prognosis. The C-index value of the nomogram made according to the independent risk factors was 0.729 (95%CI, 0.642-0.8164). The calibration curves showed good consistency between predicted and actual survivals for 1-year and 2-year overall survival. CONCLUSION: The proposed nomogram is accurate in predicting the prognosis of patients with MM.

Optimization of Lipid Nanoformulations for Effective mRNA Delivery.

Introduction: Since the coronavirus disease 2019 (COVID-19) pandemic, the value of mRNA vaccine has been widely recognized worldwide. Messenger RNA (mRNA) therapy platform provides a promising alternative to DNA delivery in non-viral gene therapy. Lipid nanoparticles (LNPs), as effective mRNA delivery carriers, have been highly valued by the pharmaceutical industry, and many LNPs have entered clinical trials. Methods: We developed an ideal lipid nanoformulation, named LNP3, composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and cholesterol, and observed its release efficiency, sustained release, organ specific targeting and thermal stability. Results: In vitro studies showed that the transfection efficiency of LNP3 was higher than that of LNPs composed of DOTAP-DOPE and DOTAP-cholesterol. The positive to negative charge ratio of LNPs is a determinant of mRNA transfer efficiency in different cell lines. We noted that the buffer affected the packaging of mRNA LNPs and identified sodium potassium magnesium calcium and glucose solution (SPMCG) as a favorable buffer formulation. LNP3 suspension can be lyophilized into a thermally stable formulation to maintain activity after rehydration both in vitro and in vivo. Finally, LNP3 showed sustained release and organ specific targeting. Conclusion: We have developed an ideal lipid nanoformulation composed of DOTAP, DOPE and cholesterol for effective mRNA delivery.

DDR1 promotes LoVo cell proliferation by regulating energy metabolism.

Cellular energy metabolism dysregulation is associated with colorectal cancer (CRC) development and progression. Discoidin domain receptor 1a (DDR1a), one of the five DDR1 isoforms, is closely related to cell proliferation, invasion, and apoptosis in various tumors. Whether it participates in cellular metabolic reprogramming and regulates CRC initiation and progression remains unclear. In this study, we compared the expression of DDR1 in CRC tissues and adjacent tissues from 126 postoperative CRC samples. Moreover, lentivirus-mediated DDR1a overexpression and knockdown were performed in LoVo cells, and cell viability and proliferation were determined by CCK-8 and BrdU assays, respectively. Oxygen consumption rate, extracellular acidification rate, and lactate production were used to determine the effect of DDR1a on metabolic reprogramming. Clinically, CRC patients with high DDR1 expression had poor differentiation and were at an advanced TNM stage. DDR1a promoted LoVo cell proliferation, mitochondrial function, and extracellular acidification. Moreover, DDR1a knockdown inhibited intracellular lactic acid production in LoVo cells, while a pyruvate kinase inhibitor (diamide, 200 µM) significantly reversed this progression. Taken together, our results reveal that DDR1 plays a crucial role in maintaining intracellular environment homeostasis through metabolic reprogramming.

Construction and identification of an immortalized rat intestinal smooth muscle cell line.

BACKGROUND: Although intestinal smooth muscle cells (ISMCs) play an important role in the remodeling of the intestinal structure, considerably less is known about the molecular mechanisms that mediate the development and growth of ISMCs. A possible reason for this lag is the lack of cell lines that recapitulate ISMCs in vivo. METHODS: In this study, we separated the primary ISMCs from the rat intestinal tract and integrated the Simian Vacuolating virus 40 Large T antigen (SV40 LT) gene into the genome of the primary ISMC to construct an immortalized cell line named ISMC-Hc. KEY RESULTS: ISMC-Hc proliferated persistently without any signs of senescence up to 50 passages and without neoplasticity. Analysis of the genome isolated from ISMC-Hc confirmed that the SV40LT gene recombined in the genome, and mRNA reverse transcription PCR suggested that SV40LT could be expressed normally. In addition, ISMC-Hc had few morphological differences compared with the primary ISMC. Furthermore, ISMC-Hc showed the expression of the specific protein markers (alpha-smooth muscle actin and desmin) through immunofluorescence analysis. Further studies showed that ISMC-Hc had enhanced contractility and expressed the glial-derived neurotrophic factor, nerve growth factor, ciliary neurotrophic factor, and leukemia inhibitory factor after co-stimulation with IL-1 beta and TNF-alpha. CONCLUSIONS AND INFERENCES: ISMC-Hc showed characteristics similar to that of primary ISMC and can be used as an in vitro model to explore the cellular and molecular mechanisms of ISMC. Additionally, the immortalized ISMCs could help investigate the basic functional mechanisms of intestinal diseases.

Discoidin domain receptor 1a (DDR1a) confers 5-fluorouracil cytotoxicity in LoVo cell via PI3K/AKT/Bcl-2 pathway.

5-Fluorouracil (5-FU) is a common chemotherapy drug for patients with advanced colorectal cancer; however, many patients develop resistance to 5-FU and suffer from treatment failure. Discoidin domain receptor 1 (DDR1) is upregulated in multiple cancers and positively associated with chemoresistance. We explored the effect of DDR1a on the cytotoxicity induced by 5-FU in LoVo cells and the underlying mechanism. Therefore, DDR1a overexpression (DDR1ahigh) and knockdown in LoVo cell lines (shDDR1a) were constructed to detect cell viability and cytotoxicity induced by 5-FU. The results showed that cell viability of DDR1ahigh cells was higher in comparison with that of the control group. When 5-FU (5 µM) was administered, the percentage of apoptotic cells, cytochrome C release and caspase-3 activity was found to be higher in the shDDR1a group than that in the control group. Both of PI3K and MDM2 proteins level decreased in DDR1ahigh and shDDR1a, but the BAX/Bcl-2 level in the shDDR1a group increased compared to that in the control. Therefore, DDR1a might be a potential therapeutic target for 5-FU chemoresistance in colorectal cancer.

The Involvement of Glial Cell-Derived Neurotrophic Factor in Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBD) are chronic inflammatory gastrointestinal diseases characterized by dysregulation of the intestinal epithelial barrier (IEB) and intermittent relapses. Recent data show that the glial cell line-derived neurotrophic factor (GDNF) promotes IEB function and wound healing. Apart from protective effects of GDNF on enteric nervous system and IEB, an immunomodulatory role has been assumed. However, it is inconsistent whether GDNF levels are increased or decreased in the inflamed colon of patients with IBD. Furthermore, GDNF is 1 of 3 protein markers associated with relapse in a prospective cohort study in IBD patients with clinically and endoscopically quiescent disease. Additionally, not only enteric glial cells (EGCs), but also intestinal smooth muscle cells and enterocytes synthesize GDNF in significant amounts; in addition, its receptors are expressed in intestinal neurons, EGCs, immune cells and epithelial cells, which points to a potential auto- or paracrine signaling loop between some of these cells. Whether GDNF is involved in IBD-associated fibrosis and colitis-associated colorectal cancer remains to be confirmed. In this review we aim to summarize and discuss the current knowledge on the effects of GDNF and its potential role in the contribution to the pathogenesis of IBD.

The high-dose amoxicillin-proton pump inhibitor dual therapy in eradication of Helicobacter pylori infection.

INTRODUCTION: More attention has been paid to the eradication therapy of Helicobactor pylori with the enhancement of health awareness of patients. However, the increasing antibiotic resistance of H. pylori, due to the wide use and abuse of antibiotics, has become a critical factor affecting the efficacy of eradication. To effectively improve the eradication rate of H. pylori, high-dose amoxicillin-proton pump inhibitor (PPI) dual therapy has recently become one of the hot issues. AREAS COVERED: The authors review the schemes and efficacy of high-dose amoxicillin-PPI dual therapies in eradication of H. pylori infection. The review indicates that the H. pylori eradication rate of the dual therapy is overall comparable to or better than that of bismuth-containing quadruple therapy or standard triple therapy. It is more effective to administer both amoxicillin and PPI 3-4 times daily for 14 days in the high-dose amoxicillin-PPI dual therapy, and esomeprazole seems to be superior to other PPIs. EXPERT OPINION: The high-dose amoxicillin-PPI dual therapy is currently a promising H. pylori eradication regimen in clinical practice, deserving further verification and discussion. Much more attention should be paid to the influence of CYP2C19 polymorphisms and virulence genotyping on H. pylori eradication, and the homogeneity and objectivity of the comparison among different studies.

[IL-1ß and TNF-α up-regulate the expression of glial cell line-derived neurotrophic factor (GDNF) and down-regulate its receptors in rat intestinal smooth muscle cells].

Objective To observe the effects of interleukin 1ß (IL-1ß) and tumor necrosis factor α (TNF-α) on glial cell line-derived neurotrophic factor (GDNF) and its receptors in rat intestinal smooth muscle cells (ISMCs). Methods ISMCs were isolated by modified enzyme digestion in SD rats, and the positive rates of smooth muscle α-actin (α-SMA) and desmin were observed by immunocytochemical staining. ISMCs were treated with IL-1ß and TNF-α for 48 hours alone or in combination. The relative mRNA expression of GDNF, receptor tyrosine kinase (Ret) and GDNF family receptor alpha-1 (GFRα1) were measured by real-time quantitative PCR. Results High-purity ISMCs were obtained by modified enzyme digestion, and over 95% of the cells expressed α-SMA and desmin. Compared with the control group, TNF-α could promote the expression of GDNF and inhibit GFRα1, but had no effects on Ret. In contrast, IL-1ß could inhibit Ret but had no effects on GDNF and GFRα1. Notably, when IL-1ß and TNF-α were combined, the expression of GDNF was up-regulated, while RET and GFRα1 were down-regulated. Conclusion IL-1ß and TNF-α can up-regulate the expression of GDNF and down-regulate its receptors in rat ISMCs.

Engineered Photoactivatable Genetic Switches Based on the Bacterium Phage T7 RNA Polymerase.

Genetic switches in which the activity of T7 RNA polymerase (RNAP) is directly regulated by external signals are obtained with an engineering strategy of splitting the protein into fragments and using regulatory domains to modulate their reconstitutions. Robust switchable systems with excellent dark-off/light-on properties are obtained with the light-activatable VVD domain and its variants as regulatory domains. For the best split position found, working switches exploit either the light-induced interactions between the VVD domains or allosteric effects. The split fragments show high modularity when they are combined with different regulatory domains such as those with chemically inducible interaction, enabling chemically controlled switches. To summarize, the T7 RNA polymerase-based switches are powerful tools to implement light-activated gene expression in different contexts. Moreover, results about the studied split positions and domain organizations may facilitate future engineering studies on this and on related proteins.