Abstract Background Lymphangiogenesis plays a critical role in various liver diseases, yet its function in liver fibrosis remains controversial. This study aimed to explore the role of lymphangiogenesis in liver fibrogenesis and its underlying regulatory mechanisms. Methods Liver fibrotic mice were established by carbon tetrachloride (CCl 4 ) or Thioacetamide (TAA)-induced injection or bile duct ligation. Lymphatic vessels were marked by podoplain (Pdpn) staining in mice and D2-40 staining in clinical samples. Lymphatic vessels area and density were measured to indicate lymphangiogenesis. Multiplexing immunohistochemistry was used to detect co-localization of proteins. Results In the present study, we first verified increased lymphangiogenesis in human and murine fibrotic livers. Afterwards, we identified VEGFC rather than VEGFD as the primary driver of lymphangiogenesis in liver fibrosis. Furthermore, we demonstrated that M1 macrophages serve as the major source of VEGFC. Founctional studies revealed that VEGFC-mediated lymphangiogenesis exacerbates hepatic fibrosis, while its inhibition alleviated fibrosis. Bioinformatic analysis uncovered Midkine (MDK) as a key downstream of lymphangiogenesis. Both in vivo and in vitro studies confirmed that exogenous MDK promotes liver fibrosis via activating hepatic stellate cells (HSCs), whereas MDK inhibition counteracts the profibrotic effects of VEGFC-induced lymphangiogenesis. Importantly, we discovered that MDK activates HSCs through the Hippo/YAP signaling pathway. Conclusions M1 macrophage-mediated lymphangiogenesis aggravates liver fibrosis via MDK secretion, which activates HSCs. These findings provide novel insights into coordinated crosstalk between macrophages, lymphatic endothelial cells and HSCs in liver fibrosis and suggest lymphangiogenesis and MDK as potential therapeutic targets for fibrotic liver diseases.

Tumor-targeting drug delivery holds great promise for cancer treatment but faces significant challenges in penetrating solid tumors to achieve optimal therapeutic efficacy. By harnessing the natural tissue-penetration effect conferred by the CendR motif, we identified that the nucleolin (NCL)-targeted peptide F3 possesses tumor-penetrating capabilities. Co-administration of F3 with doxorubicin and the apoptosis-inducing protein TRAIL enhanced effective tumor penetration and improved antitumor activity. Taking advantage of TRAIL's natural self-trimerization, we developed a novel fusion protein, F3-TRAIL. This design enabled the trivalent assembly of F3 when fused with TRAIL, significantly enhancing its binding to NCL-positive tumor endothelial and parenchymal cells, resulting in deeper tumor penetration and superior antitumor effects compared to TRAIL alone. Mechanistic studies revealed that the multivalent F3-enhanced engagement with tumor cells potentiated TRAIL to trigger death receptor-dependent apoptosis signaling, even in TRAIL-resistant tumor cells. Building on this success, we constructed F3-HexaTR using the SpyCatcher/SpyTag superglue ligation system to generate a hexameric TRAIL, further amplifying cytotoxicity and antitumor efficacy. Combined analysis of data from TCGA and GTEx revealed significantly elevated NCL expression across 18 solid tumor types, underscoring the clinical potential of F3-directed targeted therapy. These findings highlight that F3-mediated NCL targeting is an effective strategy to overcome tumor penetration barriers, particularly for protein drug delivery. This multivalent assembly approach represents an innovative avenue for enhancing the therapeutic efficacy of various agents in the treatment of solid tumors.

Liver fibrosis is a chronic progressive disease that can advance to cirrhosis or hepatocellular carcinoma if untreated. While liver transplantation remains the only curative option for end-stage fibrosis, the development of alternative therapies is urgently needed. In this study, we investigated the role of vitamin D-binding protein (VDBP) in hepatic fibrosis using clinical samples and a CCl4-induced mouse model. We observed significant downregulation of VDBP in fibrotic human and murine livers, suggesting that VDBP may serve as a potential biomarker for disease progression. VDBP knockout (VDBP-KO) mice exhibited exacerbated fibrosis, iron overload, and ferroptosis activation, accompanied by dysregulation of the Hippo-YAP pathway. In vitro, VDBP overexpression reversed these effects, while in vivo treatment with the YAP inhibitor verteporfin attenuated fibrosis, normalized iron homeostasis, and suppressed ferroptosis in VDBP-KO mice. Our findings demonstrate that VDBP plays a pivotal role in maintaining iron balance, inhibiting YAP signaling, and preventing ferroptosis during fibrogenesis. Elucidating the molecular mechanisms of VDBP and its downstream pathways may provide novel therapeutic targets for liver fibrosis. This could significantly improve the clinical management of hepatic fibrosis and offer new hope for patients suffering from this debilitating disease.

Dinaciclib, a cyclin-dependent kinase-5 (CDK5) inhibitor, has significant anti-tumor properties. However, the precise mechanism of dinaciclib requires further investigation. Herein, we investigated the anti-tumor functions and molecular basis of dinaciclib in pancreatic ductal adenocarcinoma (PDAC). PDAC and matched para-carcinoma specimens were collected from the patients who underwent radical resection. Immunohistochemistry was performed to assess CDK5 expression. Cell proliferation ability, migration, and invasion were measured using Cell Counting Kit-8, wound healing, and transwell assay, respectively. The cell cycle and apoptosis were assessed using flow cytometry. Gene expression was examined using RNA-seq and quantitative real-time PCR. Protein expression of proteins was measured by western blot analysis and immunofluorescence microscopy. Tumor-bearing mice were intraperitoneally injected with dinaciclib. CDK5 is highly expressed in PDAC. The expression level of CDK5 was significantly related to tumor size, T stage, and the American Joint Committee on Cancer stage. High CDK5 expression can predict poor survival in PDAC patients. In addition, the expression level of CDK5 might be an independent prognostic factor for PDAC patients. Dinaciclib inhibits the growth and motility of PDAC cells and induces apoptosis and cell cycle arrest in the G2/M phase. Mechanistically, dinaciclib down-regulated yes-associated protein (YAP) mRNA and protein expression by reducing β-catenin expression. Moreover, dinaciclib significantly inhibited PDAC cell growth in vivo . Our findings reveal a novel anti-tumor mechanism of dinaciclib in which it decreases YAP expression by down-regulating β-catenin at the transcriptional level rather than by activating Hippo pathway-mediated phosphorylation-dependent degradation.

Nonalcoholic fatty liver disease (NAFLD) has become an increasingly common disease in Western countries and has become the major cause of liver cirrhosis or hepatocellular carcinoma (HCC) in addition to viral hepatitis in recent decades. Furthermore, studies have shown that NAFLD is inextricably linked to the development of extrahepatic diseases. However, there is currently no effective treatment to cure NAFLD. In addition, in 2020, NAFLD was renamed metabolic dysfunction fatty liver disease (MAFLD) to show that its pathogenesis is closely related to metabolic disorders. Recent studies have reported that the development of MAFLD is inextricably associated with mitochondrial dysfunction in hepatocytes and hepatic stellate cells (HSCs). Simultaneously, mitochondrial stress caused by structural and functional disorders stimulates the occurrence and accumulation of fat and lipo-toxicity in hepatocytes and HSCs. In addition, the interaction between mitochondrial dysfunction and the liver-gut axis has also become a new point during the development of MAFLD. In this review, we summarize the effects of several potential treatment strategies for MAFLD, including antioxidants, reagents, and intestinal microorganisms and metabolites.

Glucagon like peptide-1 receptor agonists (GLP-1RAs) belong to the class of incretin drugs. Incretin is a hormone secreted into blood by intestinal cells after food stimulation that induces insulin secretion. Liraglutide is a long-acting GLP-1RA that can reduce blood pressure, blood lipids, and inflammation. Previous studies showed that liraglutide can promote white fat browning and improve renal outcomes in patients with type 2 diabetes mellitus. However, no studies have linked white fat browning to kidney damage. The objective of this study was to investigate the effects of liraglutide-induced white fat browning on podocyte apoptosis in diabetic nephropathy. We also aimed to determine whether podocytes express glucagon like peptide-1 receptor (GLP-1R) and if liraglutide directly affects podocytes via GLP-1R. We assessed fat and renal function in db/db and wild-type mice and the effects of adipocyte conditioned medium on cultured podocytes. Liraglutide (400 mg/kg/d) was subcutaneously injected for 8 weeks. Liraglutide promoted white fat browning in vivo. During adipogenic differentiation of 3T3-L1 cells in vitro, liraglutide also upregulated expression of peroxisome proliferator-activated receptor γ coactivator-1 alpha (PGC1α) and uncoupling protein 1 (UCP1), which can induce white fat browning in vitro. Furthermore, we found that supernatant from 3T3-L1 cells stimulated by liraglutide reduced podocyte apoptosis. The inhibitory effect of liraglutide on apoptosis was eliminated by exogenous TNF-α. Finally, podocytes express GLP-1R. In vivo and in vitro studies showed that the apoptosis of podocytes in diabetic nephropathy may be related to the effect of liraglutide on promoting white lipid browning. Similarly, liraglutide may directly affect podocytes via GLP-1R.

BACKGROUND:Solid pseudopapillary tumor (SPT) is a rare pancreatic tumor. Considering its malignant behaviors, SPT has been classified as a low-grade malignant tumor. Indeed, only 9.2% of all SPT patients are initially diagnosed as malignant with invasion or metastasis. Thus, one of the challenges in managing SPT patients is predicting malignant behavior. AIM:To investigate the malignant behavior and tumor-associated macrophage (TAM) infiltration between different histopathologic features of SPT patients. METHODS:Twenty-five formalin-fixed paraffin-embedded tissue samples from 22 patients pathologically diagnosed with an SPT between 2009 and 2019 at West China Hospital were included in this retrospective study. Integrity of the capsule and growth pattern of the tumor cells was assessed microscopically in hematoxylin-eosin (HE)-stained sections. Based on the histopathological features, the SPT patients were divided into two groups: capsule or invasion. Clinical features, malignant behavior, and TAM infiltration were compared between the two groups. RESULTS:Among the 22 SPT patients, 11 were identified for each group, having either a capsule or invasion histopathologic feature. Malignant behavior was more frequent in the invasion group, including 2 patients who had peripheral organ invasion, 3 with liver metastasis, and 1 with both lymph node and spleen metastases (P= 0.045). Ki-67 index of more than 3% was also more frequent in the invasion group (P = 0.045). Immunohistochemical analysis showed that the invasion group had a significant increase of CD68-positive TAMs in intratumor and peritumor sites in comparison with the capsule group (all P < 0.0001). Similarly, CD163-positive M2-like macrophages were also markedly increased in the intratumor and peritumor sites in the invasion group (all P < 0.0001). At the liver metastasis site, both intratumor and peritumor tissues showed relatively high-level CD68-positive TAMs and CD163-positive M2-like macrophages infiltration. However, the differences between the intratumor, peritumor and normal hepatic tissues did not reach statistical significance (all P > 0.05). CONCLUSION:SPT patients with invasion evident under microscope were more likely to exhibit malignant behavior and TAM infiltration, especially M2-like macrophages. This finding can help in future investigations of the underlying mechanism of TAM-mediated SPT malignant behavior.

Chronic alcohol consumption, which is observed worldwide, can damage pancreatic tissue and promote pancreatitis. Rhubarb is a widely used traditional Chinese herbal medicine for treating pancreatitis in China. However, few pharmacological studies have investigated its epigenetic regulation. In this study, we investigated whether chronic exposure to alcohol can alter inflammatory gene expression and the epigenetic regulation effect of cooked rhubarb in the pancreatic tissue of rats. First, changes in inflammatory cytokine DNA methylation (IL-10, IL-1α, TNF-α, NF-κB and TGF-β) were detected in pancreatic tissue of Sprague-Dawley rats with varying alcohol exposure times (4, 6, 8, or 12 weeks), and then with varying doses of cooked rhubarb treatment (3, 6, or 12 g/day). DNA methylation levels, related RNA concentrations and protein expression of specific inflammatory cytokines, and histopathological score were analysed in pancreatic tissue of Sprague-Dawley rats. The results showed that chronic alcohol exposure (8 weeks) reduced the level of IL-1α DNA methylation and increased its protein expression in acinar cells (P < 0.05). In the acinar cells, the level of IL-10 DNA methylation increased, resulting in a reduction of protein expression (P < 0.05). Simultaneously, chronic alcohol exposure increased the pathological damage to the pancreas (P < 0.05). Finally, cooked rhubarb treatment (3 g/kg/day) effectively alleviated these changes in pancreatic tissue from chronic alcohol exposure (P < 0.05). These results indicate that chronic exposure to alcohol leads to changes in DNA methylation and protein expression of inflammatory genes, and cooked rhubarb may have a protective effect on the pancreatic tissue of rats.

Previous studies have demonstrated dysregulated mitochondrial dynamics in fibrotic livers and hepatocytes. Little is currently known about how mitochondrial dynamics are involved, nor is it clear how mitochondrial dynamics participate in hepatic stellate cell (HSC) activation. In the present study, we investigated the role of mitochondrial dynamics in HSC activation and the underlying mechanisms. We verified that mitochondrial fission was enhanced in human and mouse fibrotic livers and active HSCs. Moreover, increased mitochondrial fission driven by fis1 overexpression could promote HSC activation. Inhibiting mitochondrial fission using mitochondrial fission inhibitor-1 (Mdivi-1) could inhibit activation and induce apoptosis of active HSCs, indicating that increased mitochondrial fission is essential for HSC activation. Mdivi-1 treatment also induced apoptosis in active HSCs in vivo and thus ameliorated CCl4-induced liver fibrosis. We also found that oxidative phosphorylation (OxPhos) was increased in active HSCs, and OxPhos inhibitors inhibited activation and induced apoptosis in active HSCs. Moreover, increasing mitochondrial fission upregulated OxPhos, while inhibiting mitochondrial fission downregulated OxPhos, suggesting that mitochondrial fission stimulates OxPhos during HSC activation. Next, we found that inhibition of oxidative stress using mitoquinone mesylate (mitoQ) and Tempol inhibited mitochondrial fission and OxPhos and induced apoptosis in active HSCs, suggesting that oxidative stress contributes to excessive mitochondrial fission during HSC activation. In conclusion, our study revealed that oxidative stress contributes to enhanced mitochondrial fission, which triggers OxPhos during HSC activation. Importantly, inhibiting mitochondrial fission has huge prospects for alleviating liver fibrosis by eliminating active HSCs.

We explored the interplay between energy metabolism and the impact of rapamycin (Rapa) on regulatory T cell (Treg) differentiation. Naïve CD4+ T cells were stimulated under Treg-polarizing conditions with or without Rapa. Rapa promoted Treg induction, as the expression of Foxp3 and Treg phenotypic markers were enhanced. Rapa disrupts glycolysis while favoring mitochondrial metabolism in induced Tregs (iTregs). Metabolic profiling showed reduced glycolytic metabolites in Rapa-treated iTregs, in line with the downregulation of glucose uptake and the expression of glycolytic enzymes. Conversely, Rapa increased the ratios of ATP/ADP and ATP/AMP, the production of mitochondrial ATP, and the expression of ATP5A. Treatment with oxidative phosphorylation inhibitors suppressed Foxp3 expression in Rapa-treated cells. Moreover, Rapa decreased oleic acid and palmitoleic acid levels and increased l-carnitine and acetylcarnitine levels and CPT1A expression in iTregs, indicative of augmented fatty acid oxidation. In conclusion, Rapa induces metabolic reprogramming in Tregs, affecting their differentiation.

Purpose Acute myeloid leukemia (AML) is associated with a poor overall prognosis. PIM family genes, including PIM1, PIM2, and PIM3, are proto-oncogenes that are aberrantly overexpressed in different types of human cancers. In this study, we aimed to explore and clarify the function of PIM3 in AML. Patients and Methods The expression of the three PIM genes in AML was detected using the Gene Expression Omnibus. The expression of PIM3 and PIM3 in patient samples and AML cell lines was measured using quantitative real-time polymerase chain reaction or Western blot analyses. The cellular behaviors of PIM3-overexpressing AML cell lines were detected using a CCK-8 assay, flow cytometry, Western blotting, immunofluorescence staining, and a cell migration assay. The interactions between PIM3 and phosphorylated CXCR4 (pCXCR4) were explored via immunoprecipitation. Results Higher PIM3 expression was detected in primary AML cells than in healthy donor cells. Second, PIM3 overexpression promoted AML cell proliferation and protected against spontaneous apoptosis by phosphorylating BAD (pBAD) at Ser112. Furthermore, PIM3 overexpression might promote the migration of AML cells via CXCR4. PIM3-overexpressing AML cell lines exhibited increased CXCR4 phosphorylation at Ser339, and pCXCR4 interacted with PIM3. Conclusion Our findings suggest that PIM3 regulates the proliferation, survival, and chemotaxis of AML cell lines. Moreover, pCXCR4 might mediate the regulation of PIM3-induced chemotaxis. Therefore, the inhibition of PIM3 expression may be a promising therapeutic target in AML.

目的 探索研究p53与线粒体共定位的最佳免疫荧光条件,为检测蛋白质与线粒体共定位的研究提供参考.方法 低氧处理HeLa细胞,免疫印迹检测p53表达;分别使用甲醇固定HeLa细胞、甲醇:丙酮混合液(体积比1:1)固定HeLa细胞、4％多聚甲醛固定HeLa细胞,前二者不作通透处理,后者用0.1％聚乙二醇辛基苯基醚(Triton-X 100)通透,同时染色p53和线粒体;用4％多聚甲醛固定HeLa细胞后,降低Triton-X 100浓度至0.05％、0.025％、0.01％和0.005％,同时染色p53和线粒体;用4％多聚甲醛固定HeLa细胞后,Triton-X 100浓度降至0.01％和0.005％,通透标记p53后再次使用0.1％ Triton-X 100重新通透细胞器膜染色线粒体.结果 低氧后p53表达上调(P＜0.01),可用于后续免疫荧光实验.使用甲醇和混合液固定组均可同时在细胞核及细胞质内观察到明显的p53信号,并可观测到其与线粒体的共定位,混合液组共定位更明显.多聚甲醛固定组用0.1％Triton-X 100通透后p53信号主要在细胞核内,未能观察到共定位;使用4％多聚甲醛固定后,降低Triton-X 100浓度至0.05％和0.025％在一定程度上削弱p53核内信号,增强共定位信号,但细胞核内信号仍强于细胞质,当降低至0.01％和0.005％,细胞质内检测到p53信号,细胞核内未检测到p53信号,提示此条件下核膜未被通透,但同样也未能通透线粒体膜,导致线粒体标记失败;二次通透完全规避p53核内信号,并成功标记线粒体,检测到p53与线粒体的共定位.结论 使用甲醇或混合液固定可观察到p53与线粒体共定位,其中混合液效果更佳;使用4％多聚甲醛固定结合2次通透可有效避免核内信号,检测到p53和线粒体的共定位.

Natural regulatory T cells (nTregs) play a dominant role in maintaining immunological homeostasis and they are known to undergo metabolic reprogramming during immune responses. Transforming growth factor-β1 (TGF-β1), an anti-inflammatory cytokine, can promote the induction of regulatory T cells. Here, we investigated the effects of TGF-β1 on the stability and metabolism of nTregs stimulated in vitro. CD4+CD25+ nTregs were isolated from mouse spleens and stimulated with anti-CD3 and anti-CD28 antibodies plus IL-2 in the presence or absence of TGF-β1. Exposure to TGF-β1 induced the activation of STAT5 and sustained the expression of the nTregs transcription factor Foxp3. In addition, TGF-β1 inhibited glycolysis, as shown by reduced lactate production and diminished expression of Glut1, Hk2, Enolase1, and Hif-1α. nTregs treated with TGF-β1 exhibited downregulated mTORC1 signaling but enhanced activation of the serine-threonine phosphatase PP2A. Moreover, treat with the PP2A inhibitor okadaic acid disrupted the maintenance of Foxp3 expression by TGF-β1. Thus, TGF-β1 serves to maintain Foxp3 expression in cultured nTregs, possibly via PP2A activation and suppression of mTORC1-regulated glycolysis.

Background and Aims Nonalcoholic fatty liver disease (NAFLD) is an alarming global health problem that is predicted to be the major cause of cirrhosis, hepatocellular carcinoma, and liver transplantation by next decade. Gut microbiota have been revealed playing an important role in the pathogenesis of NAFLD. Sheng-Jiang Powder (SJP), an empirical Chinese medicine formula to treat NAFLD, showed great hepatoprotective properties, but the impact on gut microbiota has never been identified. Therefore, we performed this study to investigate the effect of SJP on gut microbiota in NAFLD mice. Methods NAFLD was induced by 12 weeks' high-fat diet (HFD) feeding. Mice were treated with SJP/normal saline daily for 6 weeks. Blood samples were obtained for serum biochemical indices and inflammatory cytokines measurement. Liver tissues were obtained for pathological evaluation and oil red O staining. The expression of lipid metabolism-related genes was quantified by RT-PCR and Western blotting. Changes in gut microbiota composition were analyzed by the 16s rDNA sequencing technique. Results HFD feeding induced significant increase in bodyweight and serum levels of TG, TC, ALT, and AST. The pathological examination revealed obvious hepatic steatosis in HFD feeding mice. Coadministration of SJP effectively protected against bodyweight increase and lipid accumulation in blood and liver. Increased expression of PPARγ mRNA was observed in HFD feeding mice, but a steady elevation of PPARγ protein level was only found in SJP-treated mice. Meanwhile, the expression of FASN was much higher in HFD feeding mice. Microbiome analysis revealed obvious changes in gut microbiota composition among diverse groups. SJP treatment modulated the relative abundance of short-chain fatty acids (SCFAs) producing bacteria, including norank-f-Erysipelotrichaceae and Roseburia. Conclusions SJP is efficient in attenuating HFD-induced NAFLD, and it might be partly attributed to the regulation of gut microbiota.

OBJECTIVE:To compare the effects of mitochondria staining between specific mitochondrial fluorescent probes and anti-mitochondrial protein antibody in cell and tissue samples.METHODS:The HepG2 cells fixed by 4% paraformaldehyde were stained with MitoTracker Deep Red (100 nmol/L) or anti-Grp75 antibody (75 nmol/L or 100 nmol/L). The human healthy liver tissue samples fixed by 4% paraformaldehyde were stained with 150 nmol/L MitoTracker Deep Red or anti-Grp75 antibody. The above stained cell and tissue samples were observed using confocal microscopy.RESULTS:We found non-specific staining in HeLa cells and obscure mitochondrial image using MitoTracker Deep Red probes, while clear tubular and punctate distribution using anti-Grp75 antibody. In contrast, we observed more specific and better effects of MitoTracker Deep Red probes-stained liver tissue samples as compared to the antibody.CONCLUSION:To visualize mitochondria, the anti-Grp75 antibody staining worked better on cells and the MitoTracker Deep Red probes are more suitable for tissue samples.

Hongmei Luo* Ruixue Sun * Yuhuan Zheng* Jingcao Huang Fangfang Wang Dan Long Yu Wu 1 1Department of Hematology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China; 2State Key Laboratory of Biotherapy and Cancer Center, Sichuan University, Chengdu, People’s Republic of China; 3Key Laboratory of Transplant Engineering and Immunology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China

OBJECTIVE:To investigate the mitochondrial translocation of hypoxia inducible factor-3α (HIF-3α) under normoxia and hypoxia and its physiological and pathological meanings.METHODS:① After hypoxic (1%O2) or DMOG, CoCl2 treatments mimicking the hypoxic treatment, Western blot and immunofluorescence were used to examine the HIF-3α expression in mitochondria of HeLa and ACHN cells, respectively. ②The protease sensitivity experiment was used to explore the sub-organelle localization of HIF-3α in mitochondria. ③Western blot was used to examine mitochondrial HIF-3α in the normal mouse tissues and human liver carcinoma tissues.RESULTS:① In HeLa and ACHN cells, HIF-3α translocated to mitochondria under normoxia and hypoxia, and its mitochondrial expression was higher under hypoxia; ②The protease sensitivity of HIF-3α was similar to proteins locating in the mitochondrial outer membrane; ③Mitochondrial HIF-3α expressed in multiple normal mouse tissues; The expression of mitochondrial HIF-3α was higher in human liver carcinoma tissues than the normal and adjacent tissues.CONCLUSIONS:HIF-3α translocated to mitochondrial outer membrane under both normoxia and hypoxia, and hypoxia could up-regulated HIF-3α mitochondrial translocation. Meanwhile, the phenomenon may be involved in the process of liver carcinoma.

Bone and tooth, fundamental parts of the craniofacial skeleton, are anatomically and developmentally interconnected structures. Notably, pathological processes in these tissues underwent together and progressed in multilevels. Extracellular vesicles (EVs) are cell-released small organelles and transfer proteins and genetic information into cells and tissues. Although EVs have been identified in bone and tooth, particularly EVs have been identified in the bone formation and resorption, the concrete roles of EVs in bone and tooth development and diseases remain elusive. As such, we review the recent progress of EVs in bone and tooth to highlight the novel findings of EVs in cellular communication, tissue homeostasis, and interventions. This will enhance our comprehension on the skeletal biology and shed new light on the modulation of skeletal disorders and the potential of genetic treatment.

The transcription factor hypoxia inducible factor-1α (HIF-1α) mediates adaptive responses to oxidative stress by nuclear translocation and regulation of gene expression. Mitochondrial changes are critical for the adaptive response to oxidative stress. However, the transcriptional and non-transcriptional mechanisms by which HIF-1α regulates mitochondria in response to oxidative stress are poorly understood. Here, we examined the subcellular localization of HIF-1α in human cells and identified a small fraction of HIF-1α that translocated to the mitochondria after exposure to hypoxia or H2O2 treatment. Moreover, the livers of mice with CCl4-induced fibrosis showed a progressive increase in HIF-1α association with the mitochondria, indicating the clinical relevance of this finding. To probe the function of this HIF-1α population, we ectopically expressed a mitochondrial-targeted form of HIF-1α (mito-HIF-1α). Expression of mito-HIF-1α was sufficient to attenuate apoptosis induced by exposure to hypoxia or H2O2-induced oxidative stress. Moreover, mito-HIF-1α expression reduced the production of reactive oxygen species, the collapse of mitochondrial membrane potential, and the expression of mitochondrial DNA-encoded mRNA in response to hypoxia or H2O2 treatment independently of nuclear pathways. These data suggested that mitochondrial HIF-1α protects against oxidative stress induced-apoptosis independently of its well-known role as a transcription factor.

BACKGROUND AND AIMS:Nonalcoholic fatty liver disease (NAFLD) is an alarming public health problem that directly contributes to increased prevalence of liver cirrhosis and hepatic cell cancer, but without any specific pharmacological option. Sheng-jiang powder (SJP), an empirical Chinese medicine formula to treat NAFLD, showed great efficacy but the specific mechanisms have never been reported. Therefore, we performed this study to explore the effect of SJP on NAFLD and the potential mechanism.METHODS:NAFLD was induced by high fat diet (HFD) feeding. Rats were treated with SJP/normal saline daily for 10 weeks and all rats were euthanized after 12 weeks' feeding. Liver tissue samples were obtained for biochemistry test and pathological evaluation. Additionally, oleic acid induced LO2 cells were employed to simulate a cell model of NAFLD. Cells were subjected to western blotting for Akt, mTOR, S6, SREBP1-c, and FASN detection after coincubated with SJP, LY294002 (a selective PI3K inhibitor), or the combination for 24h.RESULTS:HFD significantly induced hepatic steatosis. Plenty of lipid droplets were observed under transmission electron microscope. The ultrastructure of liver cells showed distinct changes with obvious endoplasmic reticulum expansion, mitochondrial contraction, and cell matrix solidification. Although no difference was detected in serum hepatic enzymes and tissue proinflammatory cytokines, the tissue level of SOD and GSH-px was much lower and the pathologic injuries were much severe in HFD feeding rats. However, SJP treatment significantly attenuated the ultrastructure changes and protected rat liver against inflammatory injury. Abundant of lipid droplets and high expression of pAkt, pmTOR, pS6, and FASN were observed in oleic acid treated LO2 cells, while these changes were restored by SJP treatment.CONCLUSIONS:SJP is efficient in attenuating HFD induced NAFLD in rats and this effect might be partly related to the inhibition of Akt/mTOR/S6 pathway.