The application of transgenic and gene knockout mice in the study of gastric precancerous lesions

Efficacy and potential therapeutic mechanism of Weiwei decoction on Spasmolytic polypeptide-expressing metaplasia in Helicobacter pylori-infected and Atp4a-knockout mice

ETHNOPHARMACOLOGICAL RELEVANCE

Spasmolytic polypeptide-expressing metaplasia (SPEM) is characterized by mucus cell morphologies at the base of gastric glands, which is considered advanced SPEM when accompanied with an increase in transcripts associated with intestinal-type gastric cancer. Weiwei decoction (WWD) was modified from "Si-Jun-Zi Tang," which has been used for thousands of years in China against gastric atrophy and metaplasia.

AIM OF THE STUDY

To investigate the effects and potential mechanisms of WWD against advanced SPEM.

MATERIALS AND METHODS

Liquid chromatography-mass spectrometry was employed to analyze the constituents of WWD. Five-month-infected Helicobacter pylori (H. pylori) Sydney strain 1 C57BL/6J mice and 6-week-old ATPase H+/K+ transporting subunit alpha-knockout mice (Atp4a-/-) were given folic acid (1.95 mg/kg) or WWD (13.65 g/kg, 27.30 g/kg, 54.60 g/kg) by gavage for one month.

RESULTS

WWD demonstrated beneficial effects on gastric mucosal pathology and mucus secretion. In H. pylori-infected mice, WWD effectively reduced the expression of GSII and inhibited the mRNA levels of key markers associated with advanced SPEM, including Clu, Cftr, Wfdc2, Dmbt1, and Gpx2. Similarly, in Atp4a-/- mice, WWD significantly decreased the expressions of GSII and Clusterin, and inhibited the mRNA levels of Wfdc2, Cftr, Dmbt1, and Gpx2. Notably, WWD restored the expression of markers for chief cells (PGC, GIF) and parietal cells (ATP4A), particularly in the medium- and high-dose groups, indicating its potential anti-atrophy effect on H. pylori-infected and Atp4a-/- mice. WWD administration resulted in a decline in TFF2 expression to baseline levels, suggesting that the mucous protection mediated by TFF2 was unaffected. Furthermore, the infiltration of CD163+F4/80+ M2 macrophages in the gastric mucosa of H. pylori-infected mice was reduced after WWD treatment, indicating a potential modulatory role of WWD on M2 macrophages.

CONCLUSION

WWD exerted protective effects against SPEM in H. pylori-infected and Atp4a-/- mice. The optimal doses of WWD were found to be medium doses in H. pylori-infected mice and high doses in Atp4a-/- mice. These effects include inhibition of transcripts associated with intestinal-type gastric adenocarcinoma, restoration of ATP4A and PGC expression, and reduction of M2 macrophage infiltration. These findings provide valuable insights into the therapeutic effects of WWD on advanced SPEM and highlight its potential as a treatment option.

16S rRNA sequencing-based evaluation of the protective effects of Hua-Zhuo-Jie-Du on rats with chronic atrophic gastritis

Background

Disturbance of the intestinal flora is a pathogenic factor for chronic atrophic gastritis (CAG). Hua-Zhuo-Jie-Du (HZJD) has been shown to be an effective Chinese herbal preparation for treating CAG. However, the effects of HZJD on the intestinal flora of CAG is unclear. In this study, we probed the regulating effects of HZJD on intestinal microbes in CAG rats using 16S rRNA gene sequencing.

Methods

High-performance liquid chromatography (HPLC) analysis was used to perform quality control of HZJD preparations. We then administered 1-methyl-3-nitro-1-nitrosoguanidine (200 μg/ml) to Sprague–Dawley rats to establish a CAG model. HZJD and vitacoenzyme were administered orally to these rats over a 10 week period. Hematoxylin and eosin (H&E) staining was performed to observe the histopathology of CAG rats. A rarefaction curve, species accumulation curve, Chao1 index, and ACE index were calculated to assess the alpha diversity. Principal component analysis (PCA), non-metric multi-dimensional scaling (NMDS), and unweighted pair group method with arithmetic mean (UPGMA) were conducted to examine the beta diversity. The LEfSe method was used to identify differential bacteria. Differential function analysis used PCA based on KEGG function prediction.

Results

HPLC showed that our HZJD preparation method was feasible. H&E staining showed that HZJD significantly improved the pathological state of the gastric mucosa in CAG rats. The rarefaction curve and species accumulation curve showed that the sequencing data were reasonable. The Chao1 and ACE indices were significantly increased in CAG rats compared to the N group. Following HZJD and vitacoenzyme treatment, the Chao1 and ACE indices were decreased. PCA, NMDS, and UPGMA results showed that the M group was separated from the N, HZJD, and V groups, and LEfSe results showed that the relative abundance of Akkermansia, Oscillospira, Prevotella, and CF231 were significantly higher in the N group. Proteobacteria and Escherichia were significantly enriched in the M group, Allobaculum, Bacteroides, Jeotgalicoccus, Corynebacterium, and Sporosarcina were significantly enriched in the V group, and Firmicutes, Lactobacillus, and Turicibacter were significantly enriched in the HZJD group.

Conclusion

HZJD exhibited a therapeutic effect on the intestinal flora of CAG rats.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03542-z.

Developmental analysis of reconstructed embryos of second-generation cloned transgenic goats

To improve the efficiency of the production of transgenic cloned goats by somatic cell nuclear transfer (SCNT), the development of reconstructed embryos of first-generation (G1) and second-generation (G2) cloned transgenic goats were compared and analyzed. Primary transgenic fetal fibroblasts were used as donor cells for G1 somatic cell nuclear transfer (SCNT). When the G1 transgenic embryos developed to 35 days in the recipient goats, transgenic fetal fibroblasts were isolated from them and used as donor cells for the G2 clone. In the G1 clones, the average fusion rate of reconstructed embryos was 73.62±2.9%, the average development rate (2-4 cells) was 33.96±2.36%, and the pregnancy rate of transplant recipients was 31.91%. In the G2 clones, the average fusion rate of the reconstructed embryos was 90.29±2.03%, the average development rate was 66.46±3.30%, and the pregnancy rate was 58.14%. These results indicate that in the G2 clones, the fusion rate of eggs, the development rate of reconstructed embryos, and the pregnancy rate of transplant recipients were significantly higher than those of G1 clones. We believe these results will lay a solid foundation for the efficient production of transgenic cloned animals in the future.

Stomach-specific c-Myc overexpression drives gastric adenoma in mice through AKT/mammalian target of rapamycin signaling

Gastric cancer (GC) is one of the most common malignant cancers in the world. c-Myc, a well-known oncogene, is commonly amplified in many cancers, including gastric cancer. However, it is still not completely understood how c-Myc functions in GC. Here, we generated a stomach-specific c-Myc transgenic mouse model to investigate its role in GC. We found that overexpression of c-Myc in Atp4b+ gastric parietal cells could induce gastric adenoma in mice. Mechanistically, c-Myc promoted tumorigenesis via the AKT/mTOR pathway. Furthermore, AKT inhibitor (MK-2206) or mTOR inhibitor (Rapamycin) inhibited the proliferation of c-Myc overexpressing gastric cancer cell lines. Thus, our findings highlight that gastric tumorigenesis can be induced by c-Myc overexpression through activation of the AKT/mTOR pathway.

What Is the Impact of Depletion of Immunoregulatory Genes on Wound Healing? A Systematic Review of Preclinical Evidence

Cytokines and growth factors are known to play an important role in the skin wound closure process; however, in knockout organisms, the levels of these molecules can undergo changes that result in the delay or acceleration of this process. Therefore, we systematically reviewed evidence from preclinical studies about the main immunoregulatory molecules involved in skin repair through the analysis of the main mechanisms involved in the depletion of immunoregulatory genes, and we carried out a critical analysis of the methodological quality of these studies. We searched biomedical databases, and only original studies were analyzed according to the PRISMA guidelines. The included studies were limited to those which used knockout animals and excision or incision wound models without intervention. A total of 27 studies were selected; data for animal models, gene depletion, wound characteristics, and immunoregulatory molecules were evaluated and compared whenever possible. Methodological quality assessments were examined using the ARRIVE and SYRCLE's bias of risk tool. In our review, the extracellular molecules act more negatively in the wound healing process when silenced and the metabolic pathway most affected involved in these processes was TGF-β/Smad, and emphasis was given to the importance of the participation of macrophages in TGF-β signaling. Besides that, proinflammatory molecules were more evaluated than anti-inflammatory ones, and the main molecules evaluated were, respectively, TGF-β1, followed by VEGF, IL-6, TNF-α, and IL-1β. Overall, most gene depletions delayed wound healing, negatively influenced the concentrations of proinflammatory cytokines, and consequently promoted a decrease of inflammatory cell infiltration, angiogenesis, and collagen deposition, compromising the formation of granulation tissue. The studies presented heterogeneous data and exhibited methodological limitations; therefore, mechanistic and highly controlled studies are required to improve the quality of the evidence.

Gastric precancerous lesions present in ApcMin/+ mice

The Apc^Min/+ mouse is an animal model for familial adenomatous polyposis, and aged Apc^Min/+ mice also spontaneously develop multiple tumors in their stomachs. However, gastric premalignant lesions in Apc^Min/+ mice have not been well characterized. The stomachs of Apc^Min/+ mice were compared with those of their wild type littermates at 24 weeks with hematoxylin and eosin (H&E) staining and alcian blue staining. Ki67, CD68 and CA199 expression was analyzed by immunohistochemistry. The results revealed the presence of epithelial proliferation and inflammatory infiltration in the forestomachs, glandular atrophy and intestinal metaplasia in the gastric bodies, and dysplasia in the gastric antra. The effect of mutations in the Apc gene on chronic gastritis and gastric precancerous lesions was characterized in Apc^Min/+ mice. These results suggest that Apc^Min/+ mice represent a genetic model for mechanistic studies and drug discovery in gastric precancerous lesions.

Weipiling ameliorates gastric precancerous lesions in Atp4a-/- mice

Background

Altered cellular metabolism is considered to be one of the hallmarks of cancer (Coller, Am J Pathol 184:4–17, 2014; Kim and Bae, Curr Opin Hematol 25:52–59, 2018). However, few studies have investigated the role of metabolism in the development of gastric precancerous lesions (GPLs). Weipiling (WPL), a traditional Chinese medicine formula for treatment of GPLs. In this study, we evaluated the amelioration of GPLs by WPL and investigated the possible role of WPL in regulating glucose metabolism.

Methods

Firstly, the major components of WPL are chemically characterized by HPLC analytical method. In this study, we chose the Atp4a^−/− mouse model (Spicer etal., J Biol Chem 275:21555–21565, 2000) for GPL analysis. Different doses of WPL were administered orally to mice for 10 weeks. Next, the pathological changes of gastric mucosa were assessed by the H&E staining and AB-PAS staining. In addition, TUNEL staining was used to evaluate apoptosis, and we further used immunohistochemically labelled CDX2, MUC2, ki-67, PTEN, and p53 proteins to assess the characteristic changes of gastric mucosa in precancerous lesions. The levels of such transporters as HK-II, PKM2, ENO1, MPC1, and LDHA were determined by Western blot analysis. Finally, we assessed the expression of mTOR, HIF-1α, AMPK, Rheb, TSC1 and TSC2 protein in the gastric mucosa of Atp4a^−/−mice.

Results

In this work, we evaluated the protective effect of WPL on gastric mucosa in mice with precancerous lesions. The aberrant apoptosis in gastric mucosa of gastric pre-cancerous lesions was controlled by WPL (P<0.05). Furthermore, WPL suppressed the expression of CDX2, MUC2, ki-67, PTEN and p53, as the levels of these proteins decreased significantly compared with the model group (P<0.05). In parallel, WPL significantly suppressed the expression of transporters, such as HK-II, PKM2, ENO1, MPC1 and LDHA (P<0.05). In addition, mTOR, HIF-1a, AMPK, Rheb, TSC1 and TSC2 protein levels in gastric mucosa of Atp4a^−/− mice in the high- and low-dose WPL groups were significantly lower than those in the model group (P<0.05), while the expression of TSC1 and TSC2 protein was significantly higher (P<0.05).

Conclusions

Conclusively, WPL could ameliorate GPLs in Atp4a^−/− mice by inhibiting the expression of transporters and suppressing the aberrant activation of mTOR/HIF-1α.