scholarly journals Traditional Chinese medicine Lingguizhugan decoction ameliorate HFD-induced hepatic-lipid deposition in mice by inhibiting STING-mediated inflammation in macrophages

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Lin Cao ◽  
Erjin Xu ◽  
Rendong Zheng ◽  
Zhili Zhangchen ◽  
Rongling Zhong ◽  
...  

Abstract Background Stimulator of IFN genes (STING) is highly expressed in the livers of non-alcoholic fatty liver disease (NAFLD) patients and high fat diet (HFD) induced NAFLD mice model. The STING signaling-mediated inflammation has been shown to play a critical role in metabolic disorders. Lingguizhugan decoction (LGZG), a Traditional Chinese herbal decoction, has been applied to treat metabolic disorders for many years. However, whether LGZG can alleviate the progression of NAFLD through inhibiting inflammation remains unclear. This study was to determine the role of STING-mediated inflammation in the HFD-induced hepatic-lipid deposition treated with LGZG. Methods The anti-inflammatory and anti-steatotic effects of LGZG in vivo were detected by H&E staining, immunofluorescence and immuno-chemistry. Mice bone-marrow-derived macrophages (BMDMs) and primary liver macrophages were treated with STING-specific agonist (DMXAA), LGZG and its critical components respectively. The treated culture supernatant of BMDMs and primary liver macrophages from each group was co-cultured with palmitic acid-treated mouse primary hepatocytes or mouse liver cell line AML-12 respectively to detect whether the activation of STING-mediated pathway is involved in the anti-steatotic effect of LGZG. The hepatocyte lipid deposition in vivo and in vitro were detected by oil red staining. Mitochondrial DNA release of mouse liver extracts were detected by real time PCR. The expression of proteins and inflammatory cytokines related to STING-TBK1-NF-κB pathway was detected by western blotting and ELISA. Results LGZG significantly ameliorated HFD induced hepatic steatosis, oxidative stress, hepatic mitochondrial damage and mitochondrial DNA release, which was correlated with reduction of the expression level of STING as well as the infiltration of STING-positive macrophages in the livers of HFD fed mice. The critical components of LGZG directly inhibited the activation of STING-TBK1-NF-κB pathway in liver macrophages induced by DMXAA, LPS, thereby reducing the release of IFNβ and TNFα. Co-incubating the culture supernatant of LGZG treated liver macrophages and PA-stimulated hepatocytes significantly inhibited the PA-induced lipid deposition. Conclusion This study demonstrates that LGZG can ameliorate HFD-induced hepatic-lipid deposition through inhibiting STING-TBK1-NF-κB pathway in liver macrophages, which provides novel insight for elucidating the molecular mechanism of LGZG alleviating HFD induced hepatic steatosis.

2021 ◽  
Author(s):  
Lin Cao ◽  
Erjin Xu ◽  
Rendong Zheng ◽  
Rongling Zhong ◽  
Fei Huang ◽  
...  

Abstract Background: Stimulator of IFN genes (STING) is highly expressed in the livers of non-alcoholic fatty liver disease(NAFLD) patients and HFD induced NAFLD mice model. The STING signaling induced inflammation has been shown to be a critical role in metabolic disorders, such as NAFLD and Type 2 diabetes. Lingguizhugan decoction (LGZG), a Traditional Chinese herbal decoction, has been applied to treat metabolic disorders for many years. However, whether LGZG can alleviate the progression of NAFLD through inhibiting inflammation is not fully understood. This study was to determine the role of STING-mediated inflammation in the HFD- induced hepatic-lipid deposition treated with LGZG.Methods: The anti-inflammatory and anti- hepatic-lipid deposition effects of LGZG in vivo were detected by H&E staining, immunofluorescence and immunochemistry. Mice bone-marrow-derived macrophages (BMDMs) were co-incubated with palmitic acid-induced lipid deposition HepG2 cell model (BMDM+PA-HepG2) and treated with LGZG.STING-specific agonist or blockers respectively to detect whether the activation of STING-mediated pathway is involved in the anti-hepatocyte lipid deposition effect of LGZG. Mitochondrial DNA was detected by real time PCR. The expression of inflammatory cytokines related to STING-TBK1-NF-κB pathway was detected by western blotting and ELISA.Results: LGZG significantly ameliorated HFD induced hepatic steatosis, alleviated insulin resistance (IR) and reduced the oxidative stress. Furthermore, LGZG reduced hepatic mitochondrial damage and mitochondrial DNA release, which corresponded to reducing the expression of STING as well as the the infiltration of STING-positive Kupffer cells in the liver of HFD fed mice. LGZG directly inhibited the activation of STING-TBK1-NF-κB pathway in BMDM induced by DMXAA, LPS, thereby reducing the release of IFNβ and TNFα. Co-incubation LGZG treated BMDM and PA-stimulated HepG2 significantly reduced PA-induced lipid deposition in HepG2 cells by inhibiting STING- mediated signal pathways. Conclusion: This study demonstrates that LGZG can ameliorate HFD-induced hepatic -lipid deposition through inhibiting STING-TBK1-NF-κB pathway in macrophages, which provides novel insight for elucidating the molecular mechanism of LGZG alleviating HFD induced hepatic steatosis.


2020 ◽  
Vol 61 (7) ◽  
pp. 1052-1064 ◽  
Author(s):  
Minjuan Ma ◽  
Rui Duan ◽  
Lulu Shen ◽  
Mengting Liu ◽  
Yaya Ji ◽  
...  

Excessive lipid deposition is a hallmark of NAFLD. Although much has been learned about the enzymes and metabolites involved in NAFLD, few studies have focused on the role of long noncoding RNAs (lncRNAs) in hepatic lipid accumulation. Here, using in vitro and in vivo models of NAFLD, we found that the lncRNA Gm15622 is highly expressed in the liver of obese mice fed a HFD and in murine liver (AML-12) cells treated with free fatty acids. Investigating the molecular mechanism in the liver-enriched expression of Gm15622 and its effects on lipid accumulation in hepatocytes and on NAFLD pathogenesis, we found that Gm15622 acts as a sponge for the microRNA miR-742-3p. This sponging activity increased the expression of the transcriptional regulator SREBP-1c and promoted lipid accumulation in the liver of the HFD mice and AML-12 cells. Moreover, further results indicated that metformin suppresses Gm15622 and alleviates NAFLD-associated lipid deposition in mice. In conclusion, we have identified an lncRNA Gm15622/miR-742-3p/SREBP-1c regulatory circuit associated with NAFLD in mice, a finding that significantly advances our insight into how lipid metabolism and accumulation are altered in this metabolic disorder. Our results also suggest that Gm15622 may be a potential therapeutic target for managing NAFLD.


Thorax ◽  
2020 ◽  
Vol 75 (9) ◽  
pp. 717-724
Author(s):  
Kris Genelyn Dimasuay ◽  
Niccolette Schaunaman ◽  
Richard J Martin ◽  
Nicole Pavelka ◽  
Christena Kolakowski ◽  
...  

IntroductionParkin (Park2), an E3 ubiquitin ligase, is critical to maintain mitochondrial function by regulating mitochondrial biogenesis and degradation (mitophagy), but recent evidence suggests the involvement of Parkin in promoting inflammation. In the present study, we determined if Parkin regulates airway mitochondrial DNA (mtDNA) release and inflammatory responses to type 2 cytokine interleukin (IL)-13 and allergens.MethodsWe measured Parkin mRNA expression in brushed bronchial epithelial cells and mtDNA release in the paired bronchoalveolar lavage fluid (BALF) from normal subjects and asthmatics. Parkin-deficient primary human tracheobronchial epithelial (HTBE) cells generated using the CRISPR-Cas9 system were stimulated with IL-13. To determine the in vivo function of Parkin, Parkin knockout (PKO) and wild-type (WT) mice were treated with IL-13 or allergen (house dust mite, HDM) in the presence or absence of mtDNA isolated from normal mouse lungs.ResultsParkin mRNA expression in asthmatic airway epithelium was upregulated, which positively correlated with the levels of released mtDNA in BALF. IL-13-stimulated HTBE cells increased Parkin expression. Moreover, IL-13 induced mtDNA release in Parkin-sufficient, but not in Parkin-deficient HTBE cells. PKO (vs WT) mice attenuated airway mtDNA release and inflammation following IL-13 or HDM treatments. mtDNA amplified airway inflammation in mice treated with IL-13 or HDM. Notably, Parkin also mediated mtDNA-induced exacerbation of airway inflammation.ConclusionOur research findings suggest that Parkin promotes mtDNA release and inflammation in airways, thus improving our understanding of the complex role of Parkin and mitochondrial dysfunction in asthma pathogenesis.


1988 ◽  
Vol 8 (6) ◽  
pp. 2361-2366 ◽  
Author(s):  
K A Jarrell ◽  
R C Dietrich ◽  
P S Perlman

A self-splicing group II intron of yeast mitochondrial DNA (aI5g) was divided within intron domain 4 to yield two RNAs that trans-spliced in vitro with associated trans-branching of excised intron fragments. Reformation of the domain 4 secondary structure was not necessary for the trans reaction, since domain 4 sequences were shown to be dispensable. Instead, the trans reaction depended on a previously unpredicted interaction between intron domain 5, the most highly conserved region of group II introns, and another region of the RNA. Domain 5 was shown to be essential for cleavage at the 5' splice site. It stimulated that cleavage when supplied as a trans-acting RNA containing only 42 nucleotides of intron sequence. The relevance of our findings to in vivo trans-splicing mechanisms is discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Renata R. Braga ◽  
Barbara M. Crisol ◽  
Rafael S. Brícola ◽  
Marcella R. Sant’ana ◽  
Susana C. B. R. Nakandakari ◽  
...  

AbstractThe maintenance of mitochondrial activity in hypothalamic neurons is determinant to the control of energy homeostasis in mammals. Disturbs in the mitochondrial proteostasis can trigger the mitonuclear imbalance and mitochondrial unfolded protein response (UPRmt) to guarantee the mitochondrial integrity and function. However, the role of mitonuclear imbalance and UPRmt in hypothalamic cells are unclear. Combining the transcriptomic analyses from BXD mice database and in vivo experiments, we demonstrated that physical training alters the mitochondrial proteostasis in the hypothalamus of C57BL/6J mice. This physical training elicited the mitonuclear protein imbalance, increasing the mtCO-1/Atp5a ratio, which was accompanied by high levels of UPRmt markers in the hypothalamus. Also, physical training increased the maximum mitochondrial respiratory capacity in the brain. Interestingly, the transcriptomic analysis across several strains of the isogenic BXD mice revealed that hypothalamic mitochondrial DNA-encoded genes were negatively correlated with body weight and several genes related to the orexigenic response. As expected, physical training reduced body weight and food intake. Interestingly, we found an abundance of mt-CO1, a mitochondrial DNA-encoded protein, in NPY-producing neurons in the lateral hypothalamus nucleus of exercised mice. Collectively, our data demonstrated that physical training altered the mitochondrial proteostasis and induced the mitonuclear protein imbalance and UPRmt in hypothalamic cells.


2017 ◽  
Vol 3 (3) ◽  
pp. e160 ◽  
Author(s):  
Sailaja Golla ◽  
Jimin Ren ◽  
Craig R. Malloy ◽  
Juan M. Pascual

Objective:There is a paucity of objective, quantifiable indicators of mitochondrial disease available for clinical and scientific investigation.Methods:To this end, we explore intramyocellular lipid (IMCL) accumulation noninvasively by 7T magnetic resonance spectroscopy (MRS) as a reporter of metabolic dysfunction in MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes). We reasoned that mitochondrial dysfunction may impair muscle fat metabolism, resulting in lipid deposition (as is sometimes observed in biopsies), and that MRS is well suited to quantify these lipids.Results:In 10 MELAS participants and relatives, IMCL abundance correlates with percent mitochondrial DNA mutation abundance and with disease severity.Conclusions:These results indicate that IMCL accumulation is a novel potential disease hallmark in MELAS.


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