Transition of autophagy and apoptosis in fibroblasts depends on dominant expression of HIF-1α or p53

Bacteria in hypertrophic scars promote scar formation through HSBP1-mediated autophagy

Bacterial colonisation in hypertrophic scars (HSs) has been reported, yet the precise mechanism of their contribution to scar formation remains elusive. To address this, we examined HS and normal skin (NS) tissues through Gram staining and immunofluorescence. We co-cultured fibroblasts with heat-inactivated Staphylococcus aureus (S. aureus) and evaluated their levels of apoptosis and proliferation by flow cytometry and Cell Counting Kit-8 assay, respectively. Additionally, we performed proteomic analysis and western blotting to identify upregulated proteins. To assess autophagy levels, we examined light chain 3 (LC3) expression through western blotting and immunofluorescence, and transmission electron microscopy (TEM) was performed to detect autophagy-associated vesicles. Our results demonstrated a notable increase in bacterial load, primarily S. aureus, in HS tissues. Furthermore, S. aureus promoted fibroblast proliferation and enhanced the expression of profibrotic markers such as transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), collagen I, collagen III and α smooth muscle actin (α-SMA). Proteomic analysis highlighted heat shock factor-binding protein 1 (HSBP1) as a key upregulated protein mediating the profibrotic effects induced by S. aureus. Knockdown of HSBP1 reversed these effects. Intriguingly, HSBP1 also upregulated LC3 and Beclin-1 expression and increased the number of autophagosomes in fibroblasts. Finally, when fibroblasts stimulated by S. aureus were treated with HSBP1 siRNA, autophagy levels decreased significantly. Collectively, our findings suggest that S. aureus, via HSBP1, stimulates fibroblast proliferation and promotes their transition into myofibroblasts, triggering autophagy and fibrosis. These results underscore the potential of HSBP1 as a therapeutic target for the management of HSs.

The therapeutic potential of PX-478 in a murine model of pelvic organ prolapse

BACKGROUND

Pelvic organ prolapse (POP), characterised by the downward displacement of pelvic organs, is a prevalent disorder that affects adult women. This study explored the therapeutic potential of PX-478, a selective hypoxia-inducible factor-1α (HIF-1α) inhibitor, in a murine POP model.

METHODS

A murine POP model was established through ovariectomy, mimicking oestrogen deprivation. Fifteen C57BL/6J mice were randomly assigned to control, POP, and PX-478 groups. PX-478, targeting HIF-1α, was administered intravaginally. The analysis of fibroblasts, macrophage and inflammation was performed through Masson staining, immunofluorescence, and ELISA. Collagen distribution was assessed using Sirius Red staining. Expression levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP-1) were determined through immunohistochemistry and western blot. Fibroblast proliferation and apoptosis were evaluated by CCK-8 assay and flow cytometry.

RESULTS

PX-478 treatment significantly reduced vaginal length, indicating a therapeutic effect on POP severity. Masson staining revealed reduced fibrotic changes and collagen disruption in PX-478-treated mice. Immunofluorescence showed increased fibroblast markers (Vimentin, α-SMA) and collagen fibres by PX-478. Sirius Red staining indicated PX-478 mitigated damage to Type I and Type III collagen fibres. PX-478 significantly reduced MMP-2 and MMP-9 expression while increased TIMP-1. In macrophages, PX-478 decreased M1 and M2 markers (CD80, CD206) and IL-18 secretion. Fibroblasts exhibited increased proliferation, reduced apoptosis, and altered MMP/TIMP expression under PX-478 influence.

CONCLUSION

PX-478 demonstrates a therapeutic potential in the mice POP model. It reduces vaginal length, attenuates fibrosis, and modulates collagen synthesis. Its immunomodulation is evident through reduced M1 and M2 macrophages and suppressed IL-18 secretion.

Induction of Peroxiredoxin 1 by Hypoxia Promotes Cellular Autophagy and Cell Proliferation in Oral Leukoplakia via HIF-1α/BNIP3 Pathway

Hypoxia is a key trigger in the transformation of oral leukoplakia into oral cancer. However, it is still too early to determine the role of hypoxia in the development of oral leukoplakia. Prx1, an antioxidant protein, upregulated by hypoxia, regulates cellular autophagy in leukoplakia. This study aimed to understand the mechanisms by which hypoxia induces Prx1 expression during autophagy in oral leukoplakia. We used an experimental model of tongue epithelial hyperplasia induced by 4-nitroquinoline-1-oxide (4NQO) and dysplastic oral keratinocytes. Prx1 knockdown DOK cells, Leuk-1 cells and control cells were harvested, and cell proliferation was assayed using the Cell Counting Kit-8. Several hypoxia and autophagy-related proteins were examined using quantitative real-time polymerase chain reaction, immunohistochemistry, immunofluorescence, and western blotting in cells and mouse tongue tissues. In addition, the ultrastructure of the cells was observed by transmission electron microscopy. Hypoxia induces cell proliferation, autophagic vesicles and the expression of Prx1, BNIP3, LC3II/I and Beclin-1 in DOK and Leuk-1 cells. However, these effects were all attenuated by Prx1 knockdown. Histologically, 4NQO induced epithelial hyperplasia in the tongue mucosa. The expression of proliferation marker PCNA, autophagy-related proteins LC3B and Beclin-1, as well as HIF-1α/BNIP3 was significantly lower in the tongue tissues of Prx1flox/flox:Cre+ mice compared with Prx1flox/flox mice. In Prx1flox/flox:Cre+ mice, an increased expression of HIF-1α/BNIP3, LC3B and Beclin-1 was detected in epithelial hyperplasia tongue tissues compared to normal tissues. The current study suggests that Prx1 may promotes cell proliferation and autophagy in oral leukoplakia cells via the HIF-1α/BNIP3 pathway.

Effect of black cloth ointment on hypertrophic scar formation: An investigation using integrated network pharmacology and animal assay

BACKGROUND

Hypertrophic scars (HS) are a common disfiguring condition in daily clinical encounters which brings a lot of anxieties and concerns to patients, but the treatment options of HS are limited. Black cloth ointment (BCO), as a cosmetic ointment applicable to facial scars, has shown promising therapeutic effects for facial scarring. However, the molecular mechanisms underlying its therapeutic effects remain unclear.

MATERIAL AND METHODS

Network pharmacology was first applied to analyze the major active components of BCO and the related signaling pathways. Subsequently, rabbit ear scar model was successfully established to determine the pharmacological effects of BCO and its active component β-elemene on HS. Finally, the molecular mechanism of BCO and β-elemene was analyzed by Western blot.

RESULTS

Through the network pharmacology, it showed that β-elemene was the main active ingredient of BCO, and it could significantly improve the pathological structure of HS and reduce collagen deposition. BCO and β-elemene could increase the expression of ER stress-related markers and promote the increase of apoptotic proteins in the Western blot experiment and induce the apoptosis of myofibroblasts.

CONCLUSIONS

Our findings indicate that the material basis for the scar-improving effects of the BCO is β-elemene, and cellular apoptosis is the key mechanism through which the BCO and β-elemene exert their effects.

Resveratrol-laden mesoporous silica nanoparticles regulate the autophagy and apoptosis via ROS-mediated p38-MAPK/HIF-1a /p53 signaling in hypertrophic scar fibroblasts

Background

During the regression of hypertrophic scars, autophagy and apoptosis are the main ways of cell death. Recent investigations demonstrated effective inhibition of resveratrol on hypertrophic scar fibroblasts (HSFs). But its therapeutic value is limited by chemical instability and hydrophobicity, as well as the mechanism of its role in regulation of autophagy and apoptosis remains unknown.

Aim of the study

We prepared a mesoporous silica nanoparticle laden with resveratrol (MSN@Res) which can effectively improve the solubility and stability of resveratrol. The purpose of this study was to investigate whether MSN@Res regulate autophagy and apoptosis of HSFs via inhibition of ROS/p38/HIF-1α/p53 signaling axis, as to reveal its pharmacological action and target.

Materials and methods

Network pharmacology, molecular docking, and in vitro assays were carried out in this study. An in vitro model of fibroblasts cultivated in hypoxic and ischemic situations was established to simulate the scar in the proliferative phase.

Results

MSN@Res surpresses HSFs by reducing physiological autophagy and inducing apoptosis, autosis may be another cell death involed in this process. According to the network pharmacological analysis and molecular docking, the mechanism by which MSN@Res alleviates hypertrophic scar may be closely related to the MAPK signaling pathway. MSN@Res significantly downregulate the expression of HIF-1α and p53 through the inhibition of ROS induced p38-MAPK phosphorylation with corresponding changes in the expression of autophagy and apoptosis related protein.

Conclusion

MSN@Res is a novel drug delivery system with excellent chemical stability and drug release performance. It can inhibit protective autophagy of fibroblasts in hypoxic environment, and induce the apoptosis and autosis via the ROS -mediated p38-MAPK/HIF-1α/p53 signaling axis.

Shikonin promotes hypertrophic scar repair by autophagy of hypertrophic scar-derived fibroblasts

PURPOSE

To investigate the Shikonin (SHI) induce autophagy of hypertrophic scar-derived fibroblasts (HSFs) and the mechanism of which in repairing hypertrophic scar.

METHODS

This study showed that SHI induced autophagy from HSFs and repaired skin scars through the AMPK/mTOR pathway. Alamar Blue and Sirius red were used to identify cell activity and collagen. Electron microscopy, label-free quantitative proteomic analysis, fluorescence and other methods were used to identify autophagy. The differences in the expression of autophagy and AMPK/mTOR pathway-related proteins after SHI treatment were quantitatively analyzed by Western blots. A quantitative real-time polymerase chain reaction assay was used to detect the expression of LC3, AMPK and ULK after adding chloroquine (CQ) autophagy inhibitor.

RESULTS

After treatment with SHI for 24 hours, it was found that the viability of HSFs was significantly reduced, the protein expression of LC3-II/LC3-I and Beclin1 increased, while the protein expression of P62 decreased. The expression of phosphorylated AMPK increased and expression of phosphorylated mTOR decreased. After the use of CQ, the cell autophagy caused by SHI was blocked. The key genes LC3 and P62 were then reexamined by immunohistochemistry using a porcine full-thickness burn hypertrophic scar model, and the results verified that SHI could induce autophagy in vivo.

CONCLUSIONS

These findings suggested that SHI promoted autophagy of HSFs cells, and the potential mechanism may be related to the AMPK/mTOR signal pathway, which provided new insights for the treatment of hypertrophic scars.

Baohuoside I inhibits resistance to cisplatin in ovarian cancer cells by suppressing autophagy via downregulating HIF-1α/ATG5 axis

Since chemotherapy's therapeutic impact is diminished by drug resistance, treating ovarian cancer is notably challenging. Thereafter, it is critical to develop cutting-edge approaches to treating ovarian cancer. Baohuoside I (derived from Herba Epimedii) is reported to have antitumor properties in various malignancies. It is unknown, however, what role Baohuoside I plays in cisplatin (DDP)-resistant ovarian cancer cells. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT), colony formation, and flow cytometry assay were used to investigate the impact of Baohuoside I on ovarian cancer A2780 cells and DDP-resistant A2780 (A2780/DDP) cells. The level of microtubule associated protein 1 light chain 3 (LC3) was determined using immunofluorescence staining. Utilizing the mRFP-GFP-LC3B tandem fluorescent probe allowed us to analyse the autophagy flux. Analysis of mRNA and protein level was performed using RT-qPCR and Western blot analysis, respectively. The interaction between hypoxia inducible factor 1 subunit alpha (HIF-1α) and autophagy related 5 (ATG5) promoter was investigated by dual luciferase and ChIP assay. Additionally, evaluation of Baohuoside I's role in ovarian cancer was performed using a nude mouse xenograft model. Baohuoside I decreased the viability and proliferation and triggered the apoptosis of both A2780 and A2780/DDP cells in a concentration-dependent manner. Baohuoside I also increased the sensitivity of A2780/DDP cells to DDP. Concurrently, HIF-1α could promote A2780/DDP cells resistance to DDP. In addition, HIF-1α could induce the autophagy of A2780/DDP cells through transcriptionally activating ATG5, and Baohuoside I imporved the chemosensitivity of A2780/DDP cells to DDP by downregulating HIF-1α. Moreover, Baohuoside I could inhibit the chemoresistance to DDP in ovarian cancer in vivo. Baohuoside I sensitizes ovarian cancer cells to DDP by suppressing autophagy via downregulating the HIF-1α/ATG5 axis. Consequently, Baohuoside I might be evaluated as a new agent for enhancing the chemotherapeutic efficacy of drug treatment for ovarian cancer.

Role of HIF-1α in pathogenic mechanisms of keloids

BACKGROUDS AND OBJECTIVE

Keloids are defined as overrepairing products that develop after skin lesions. Keloids are characterized by the proliferation of fibroblasts and the overaccumulation of extracellular matrix components (mainly collagen), leading to a locally hypoxic microenvironment. Hence, this article was aimed to review hypoxia in pathogenesis of keloids.

METHODS

We reviewed and summarized the relevant published studies.

RESULTS

Hypoxia results in the accumulation of hypoxia-inducible factor 1α (HIF-1α) in keloids, contributing to overactivation of the fibrotic signaling pathway, epithelial-mesenchymal transition, and changes in metabolism, eventually leading to aggravated fibrosis, infiltrative growth, and radiotherapy resistance.

CONCLUSION

It is, therefore, essential to understand the role of HIF-1α in the pathogenic mechanisms of keloids in order to develop new therapeutic approaches.

Targeting TRMT5 suppresses hepatocellular carcinoma progression via inhibiting the HIF-1α pathways

Accumulating evidence has confirmed the links between transfer RNA (tRNA) modifications and tumor progression. The present study is the first to explore the role of tRNA methyltransferase 5 (TRMT5), which catalyzes the m1G37 modification of mitochondrial tRNAs in hepatocellular carcinoma (HCC) progression. Here, based on bioinformatics and clinical analyses, we identified that TRMT5 expression was upregulated in HCC, which correlated with poor prognosis. Silencing TRMT5 attenuated HCC proliferation and metastasis both in vivo and in vitro, which may be partially explained by declined extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Mechanistically, we discovered that knockdown of TRMT5 inactivated the hypoxia-inducible factor-1 (HIF-1) signaling pathway by preventing HIF-1α stability through the enhancement of cellular oxygen content. Moreover, our data indicated that inhibition of TRMT5 sensitized HCC to doxorubicin by adjusting HIF-‍1α. In conclusion, our study revealed that targeting TRMT5 could inhibit HCC progression and increase the susceptibility of tumor cells to chemotherapy drugs. Thus, TRMT5 might be a carcinogenesis candidate gene that could serve as a potential target for HCC therapy.

miR-195-3p/BDNF axis regulates hypoxic injury by targeting P-ERK1/2 expression

OBJECTIVES

Coronary heart disease (CHD) is the most common heart disease and the leading cause of cardiovascular deaths worldwide. Decreased endothelial cell (EC) proliferation, increased apoptosis, inflammation, and vascular dysfunction are considered vital factors in CHD. In this study, we aimed to determine the expression and role of microRNA-195-3p and brain-derived neurotrophic factor (BDNF) in hypoxic-treated human umbilical vein endothelial cells (HUVECs).

MEASURES

We induced hypoxia in HUVECs using the "anaerobic tank method."

RESULTS

We found that the levels of microRNA-195-3p and BDNF were upregulated and apoptosis was increased. Furthermore, we found that BDNF/P-ERK1/2 regulated the expression of the mitochondrial apoptosis pathway proteins Bcl-2/BAX, which was downregulated under hypoxic conditions. Finally, the microRNA-195-3p inhibitor downregulated BDNF and P-ERK1/2, upregulated the Bcl-2/BAX axis, and partially reversed the effects of hypoxic-induced injury in HUVECs.

CONCLUSIONS

Therapeutic intervention using the microRNA-195-3p/BDNF/P-ERK1/2/Bcl-2/BAX axis could maintain EC function under hypoxic conditions, improve cell activity, and serve as a new treatment strategy for CHDs.