Combining α-Hederin with cisplatin increases the apoptosis of gastric cancer in vivo and in vitro via mitochondrial related apoptosis pathway

Alpha-hederin reprograms multi-miRNAs activity and overcome small extracellular vesicles-mediated paclitaxel resistance in NSCLC

Background: Small extracellular vesicles (sEVs) mediate intercellular communication in the tumor microenvironment (TME) and contribute to the malignant transformation of tumors, including unrestricted growth, metastasis, or therapeutic resistance. However, there is a lack of agents targeting sEVs to overcome or reverse tumor chemotherapy resistance through sEVs-mediated TME reprogramming. Methods: The paclitaxel (PTX)-resistant A549T cell line was used to explore the inhibitory effect of alpha-hederin on impeding the transmission of chemoresistance in non-small cell lung cancer (NSCLC) through the small extracellular vesicles (sEVs) pathway. This investigation utilized the CCK-8 assay and flow cytometry. Transcriptomics, Western blot, oil red O staining, and targeted metabolomics were utilized to evaluate the impact of alpha-hederin on the expression of signaling pathways associated with chemoresistance transmission in NSCLC cells before and after treatment. In vivo molecular imaging and immunohistochemistry were conducted to assess how alpha-hederin influences the transmission of chemoresistance through the sEVs pathway. RT-PCR was employed to examine the expression of miRNA and lncRNA in response to alpha-hederin treatment. Results: The resistance to PTX chemotherapy in A549T cells was overcome by alpha-hederin through its dependence on sEV secretion. However, the effectiveness of alpha-hederin was compromised when vesicle secretion was blocked by the GW4869 inhibitor. Transcriptomic analysis for 463 upregulated genes in recipient cells exposed to A549T-derived sEVs revealed that these sEVs enhanced TGFβ signaling and unsaturated fatty acid synthesis pathways. Alpha-hederin inhibited 15 types of unsaturated fatty acid synthesis by reducing the signaling activity of the sEVs-mediated TGFβ/SMAD2 pathway. Further, we observed that alpha-hederin promoted the production of three microRNAs (miRNAs, including miR-21-5p, miR-23a-3p, and miR-125b-5p) and the sorting to sEVs in A549T cells. These miRNAs targeted the TGFβ/SMADs signaling activity in sEVs-recipient cells and sensitized them to the PTX therapy. Conclusion: Our finding demonstrated that alpha-hederin could sensitize PTX-resistant NSCLC cells by sEV-mediated multiple miRNAs accumulation, and inhibiting TGFβ/SMAD2 pathways in recipient cells.

Molecular mechanism of α-Hederin in tumor progression

α-Hederin is a monosaccharide pentacyclic triterpene saponin compound derived from the Chinese herb, Pulsatilla. It has garnered considerable attention for its anti-tumor, anti-inflammatory, and spasmolytic pharmacological activities. Given the rising incidence of cancer and the pronounced adverse reactions associated with chemotherapy drugs-which profoundly impact the quality of life for cancer patients-there is an immediate need for safe and effective antitumor agents. Traditional drugs and their anticancer effects have become a focal point of research in recent years. Studies indicate that α-Hederin can hinder tumor cell proliferation and impede the advancement of various cancers, including breast, lung, colorectal, and liver cancers. The principal mechanism behind its anti-tumor activity involves inhibiting tumor cell proliferation, facilitating tumor cell apoptosis, and arresting the cell cycle process. Current evidence suggests that α-Hederin can exert its anti-tumor properties through diverse mechanisms, positioning it as a promising agent in anti-tumor therapy. However, a comprehensive literature search revealed a gap in the comprehensive understanding of α-Hederin. This paper aims to review the available literature on the anti-tumor mechanisms of α-Hederin, hoping to provide valuable insights for the clinical treatment of malignant tumors and the innovation of novel anti-tumor medications.

α-Hederin Saponin Augments the Chemopreventive Effect of Cisplatin against Ehrlich Tumors and Bioinformatic Approach Identifying the Role of SDF1/CXCR4/p-AKT-1/NFκB Signaling

Stromal cell-derived factor-1 (SDF1) and its C-X-C chemokine receptor type 4 receptor (CXCR4) are significant mediators for cancer cells’ proliferation, and we studied their expression in Ehrlich solid tumors (ESTs) grown in mice. α-Hederin is a pentacyclic triterpenoid saponin found in Hedera or Nigella species with biological activity that involves suppression of growth of breast cancer cell lines. The aim of this study was to explore the chemopreventive activity of α-hederin with/without cisplatin; this was achieved by measuring the reduction in tumor masses and the downregulation in SDF1/CXCR4/pAKT signaling proteins and nuclear factor kappa B (NFκB). Ehrlich carcinoma cells were injected in four groups of Swiss albino female mice (Group1: EST control group, Group2: EST + α-hederin group, Group3: EST + cisplatin group, and Group4: EST+α-hederin/cisplatin treated group). Tumors were dissected and weighed, one EST was processed for histopathological staining with hematoxylin and eosin (HE), and the second MC was frozen and processed for estimation of signaling proteins. Computational analysis for these target proteins interactions showed direct-ordered interactions. The dissected solid tumors revealed decreases in tumor masses (~21%) and diminished viable tumor regions with significant necrotic surrounds, particularly with the combination regimens. Immunohistochemistry showed reductions (~50%) in intratumoral NFκβ in the mouse group that received the combination therapy. The combination treatment lowered the SDF1/CXCR4/p-AKT proteins in ESTs compared to the control. In conclusion, α-hederin augmented the chemotherapeutic potential of cisplatin against ESTs; this effect was at least partly mediated through suppressing the chemokine SDF1/CXCR4/p-AKT/NFκB signaling. Further studies are recommended to verify the chemotherapeutic potential of α-hederin in other breast cancer models.

Integration of metagenomic and metabolomic insights into the effects of microcystin-LR on intestinal microbiota of Litopenaeus vannamei

Microcystin-LR (MC-LR) is a hazardous substance that threaten the health of aquatic animals. Intestinal microbes and their metabolites can interact with hosts to influence physiological homeostasis. In this study, the shrimp Litopenaeus vannamei were exposed to 1.0 μg/l MC-LR for 72 h, and the toxic effects of MC-LR on the intestinal microbial metagenomic and metabolomic responses of the shrimp were investigated. The results showed that MC-LR stress altered the gene functions of intestinal microbial, including ABC transporter, sulfur metabolism and riboflavin (VB2) metabolism, and induced a significant increase of eight carbohydrate metabolism enzymes. Alternatively, intestinal metabolic phenotypes were also altered, especially ABC transporters, protein digestion and absorption, and the biosynthesis and metabolism of amino acid. Furthermore, based on the integration of intestinal microbial metagenomic and metabolome, four bacteria species (Demequina globuliformis, Demequina sp. NBRC 110055, Sphingomonas taxi and Sphingomonas sp. RIT328) and three metabolites (yangonin, α-hederin and soyasaponin ii) biomarkers were identified. Overall, our study provides new insights into the effects of MC-LR on the intestinal microbial functions of L. vannamei.

Investigating the molecular mechanisms of glyoxal-induced cytotoxicity in human embryonic kidney cells: Insights from network toxicology and cell biology experiments

Glyoxal, a reactive carbonyl species, can be generated both endogenously (glucose metabolism) and exogenously (cigarette smoke and food system). Increasing evidence demonstrates that glyoxal exacerbates the development and progression of diabetic nephropathy, but the underlying mechanisms of glyoxal toxicity to human embryonic kidney (HEK293) cells remain unclear. In this work, the molecular mechanisms of glyoxal-induced cytotoxicity in HEK293 cells were explored with network toxicology and cell biology experiments. Network toxicology results showed that oxidative stress and advanced glycation end products (AGEs)/RAGE signaling pathways played a crucial role in glyoxal toxicity. Next, further validation was performed at the cellular level. Glyoxal activated the AGEs-RAGE signaling pathway, caused the increase of cellular ROS, and activated the p38MAPK and JNK signaling pathways, causing cellular oxidative stress. Furthermore, glyoxal caused the activation of the NF-κB signaling pathway and increased the expression of TGF-β1, indicating that glyoxal caused cellular inflammation. Moreover, glyoxal caused cellular DNA damage accompanied by the activation of DNA damage response pathways. Finally, the mitochondrial apoptosis pathway was activated. The results that obtained in cell biology were consistent with network toxicology, which corroborated each other and together indicated that glyoxal induced HEK293 cells damage via the process of oxidative stress, the AGEs-RAGE pathway, and their associated signaling pathways. This study provides the experimental basis for the cytotoxicity of glyoxal on HEK293 cells.

Glutamine deprivation impairs function of infiltrating CD8+ T cells in hepatocellular carcinoma by inducing mitochondrial damage and apoptosis

BACKGROUND

The functions of infiltrating CD8⁺ T cells are often impaired due to tumor cells causing nutrient deprivation in the tumor microenvironment. Thus, the mechanisms of CD8⁺ T cell dysfunction have become a hot research topic, and there is increased interest on how changes in metabolomics correlate with CD8⁺ T cell dysfunction.

AIM

To investigate whether and how glutamine metabolism affects the function of infiltrating CD8⁺ T cells in hepatocellular carcinoma.

METHODS

Immunohistochemical staining and immunofluorescence were performed on surgically resected liver tissues from patients. Differentially expressed genes in infiltrating CD8⁺ T cells in hepatocellular carcinoma were detected using RNA sequencing. Activated CD8⁺ T cells were co-cultured with Huh-7 cells for 3 d. The function and mitochondrial status of CD8⁺ T cells were analyzed by flow cytometry, quantitative real-time polymerase chain reaction, and transmission electron microscopy. Next, CD8⁺ T cells were treated with the mitochondrial protective and damaging agents. Functional alterations in CD8⁺ T cells were detected by flow cytometry. Then, complete medium without glutamine was used to culture cells and their functional changes and mitochondrial status were detected.

RESULTS

There were a large number of infiltrating PD-1⁺CD8⁺ T cells in liver cancer tissues. Next, we co-cultured CD8⁺ T cells and Huh-7 cells to explore the regulatory effect of hepatoma cells on CD8⁺ T cells. Flow cytometry results revealed increased PD-1 expression and decreased secretion of perforin (PRF1) and granzyme B (GZMB) by CD8⁺ T cells in the co-culture group. Meanwhile, JC-1 staining was decreased and the levels of reactive oxygen species and apoptosis were increased in CD8⁺ T cells of the co-culture group; additionally, the mitochondria of these cells were swollen. When CD8⁺ T cells were treated with the mitochondrial protective and damaging agents, their function was restored and inhibited, respectively, through the mitochondrial damage and apoptotic pathways. Subsequently, complete medium without glutamine was used to culture cells. As expected, CD8⁺ T cells showed functional downregulation, mitochondrial damage, and apoptosis.

CONCLUSION

Glutamine deprivation impairs the function of infiltrating CD8⁺ T cells in hepatocellular carcinoma through the mitochondrial damage and apoptotic pathways.

Deuterium-Reinforced Polyunsaturated Fatty Acids Prevent Diet-Induced Nonalcoholic Steatohepatitis by Reducing Oxidative Stress

Background and Objectives: Oxidative stress is implicated in the progression of nonalcoholic steatohepatitis (NASH) through the triggering of inflammation. Deuterium-reinforced polyunsaturated fatty acids (D-PUFAs) are more resistant to the reactive oxygen species (ROS)-initiated chain reaction of lipid peroxidation than regular hydrogenated (H-) PUFAs. Here, we aimed to investigate the impacts of D-PUFAs on oxidative stress and its protective effect on NASH. Materials and Methods: C57BL/6 mice were randomly divided into three groups and were fed a normal chow diet, a methionine-choline-deficient (MCD) diet, and an MCD with 0.6% D-PUFAs for 5 weeks. The phenotypes of NASH in mice were determined. The levels of oxidative stress were examined both in vivo and in vitro. Results: The treatment with D-PUFAs attenuated the ROS production and enhanced the cell viability in tert-butyl hydroperoxide (TBHP)-loaded hepatocytes. Concurrently, D-PUFAs decreased the TBHP-induced oxidative stress in Raw 264.7 macrophages. Accordingly, D-PUFAs increased the cell viability and attenuated the lipopolysaccharide-stimulated proinflammatory cytokine expression of macrophages. In vivo, the administration of D-PUFAs reduced the phenotypes of NASH in MCD-fed mice. Specifically, D-PUFAs decreased the liver transaminase activity and attenuated the steatosis, inflammation, and fibrosis in the livers of NASH mice. Conclusion: D-PUFAs may be potential therapeutic agents to prevent NASH by broadly reducing oxidative stress.

MicroRNA-135b-5p regulates trophoblast cell function by targeting phosphoinositide-3-kinase regulatory subunit 2 in preeclampsia

The level of miR‑135b-5p is lower in patients with preeclampsia (PE) superimposed on chronic hypertension than in healthy controls. However, the function of miR‑135b-5p in PE progression remains unknown. In the present study, we investigated the role of miR‑135b-5p in PE development and its possible mechanism for the first time. HTR8/SVneo cells (trophoblast cell line) were exposed to hypoxia/reoxygenation (H/R) to mimic PE in vitro. Hypoxia-inducible factor-1α (HIF-1α), forkhead box O3A (FOXO3a), and miR-135b-5p levels were measured using Real-time PCR. Cell proliferation, apoptosis and migration/invasion were evaluated using the Cell Counting Kit-8 (CCK-8), flow cytometry and transwell assays, respectively. Real-time PCR and Western blotting were performed to determine the levels of several pro- and anti-angiogenic factors. The binding of miR-135b-5p to the PIK3R2-3’ untranslated region (3ʹUTR) was confirmed by bioinformatics analysis and a dual-luciferase reporter assay. H/R exposure greatly upregulated HIF-1α, FOXO3a, and PIK3R2 levels, while downregulating miR-135b-5p levels in HTR8/SVneo cells. H/R exposure resulted in the inhibition of proliferation, migration, invasion, angiogenesis, and the induction of apoptosis. MiR-135b-5p overexpression reversed the effects of H/R on trophoblast cell function, while miR-135b-5p knockdown enhanced the effects. PIK3R2 knockdown had similar effects as miR-135b-5p overexpression on proliferation, apoptosis and angiogenesis. The effect of miR-135b-5p overexpression on H/R-exposed cells was enhanced by PIK3R2 knockdown. MiR-135b-5p downregulated PIK3R2 expression by pairing with its 3ʹUTR. Therefore, miR-135b-5p may regulate trophoblast function by targeting PIK3R2 in PE and could serve as a novel therapeutic target for PE.

Mitochondrial Dynamics Mediated by DRP1 and MFN2 Contributes to Cisplatin Chemoresistance in Human Ovarian Cancer SKOV3 cells

Cisplatin (DDP) is the first-line chemotherapeutic agent for ovarian cancer. However, the development of DDP resistance seriously influences the chemotherapeutic effect and prognosis of ovarian cancer. It was reported that DDP can directly impinge on the mitochondria and activate the intrinsic apoptotic pathway. Herein, the role of mitochondrial dynamics in DDP chemoresistance in human ovarian cancer SKOV3 cells was investigated. In DDP-resistant SKOV3/DDP cells, mitochondrial fission protein DRP1 was down-regulated, while mitochondrial fusion protein MFN2 was up-regulated. In accordance with the expression of DRP1 and MFN2, the average mitochondrial length was significantly increased in SKOV3/DDP cells. In DDP-sensitive parental SKOV3 cells, downregulation of DRP1 and upregulation of mitochondrial fusion proteins including MFN1,2 and OPA1 occurred at day 2~6 under cisplatin stress. Knockdown of DRP1 or overexpression of MFN2 promoted the resistance of SKOV3 cells to cisplatin. Intriguingly, weaker migration capability and lower ATP level were detected in SKOV3/DDP cells. Respective knockdown of DRP1 in parental SKOV3 cells or MFN2 in SKOV3/DDP cells using siRNA efficiently reversed mitochondrial dynamics, migration capability and ATP level. Moreover, MFN2 siRNA significantly aggravated the DDP-induced ROS production, mitochondrial membrane potential disruption, expression of pro-apoptotic protein BAX and Cleaved Caspase-3/9 in SKOV3/DDP cells. In contrast, DRP1 siRNA alleviated DDP-induced ROS production, mitochondrial membrane potential disruption, expression of pro-apoptotic protein BAX and Cleaved Caspase-3/9 in SKOV3 cells. Thus, these results indicate that mitochondrial dynamics mediated by DRP1 and MFN2 contributes to the development of DDP resistance in ovarian cancer cells, and will also provide a new strategy to prevent chemoresistance in ovarian cancer by targeting mitochondrial dynamics.

Ivermectin induces apoptosis of esophageal squamous cell carcinoma via mitochondrial pathway

Background

Esophageal squamous cell carcinoma (ESCC) is the most predominant primary malignant tumor among worldwide, especially in China. To date, the successful treatment remains a mainly clinical challenge, it is imperative to develop successful therapeutic agents.

Methods

The anti-proliferative effect of ivermectin on ESCC is investigated in cell model and in nude mice model. Cell apoptosis was assessed using flow cytometry, TUNEL assay and western blotting. Mitochondrial dysfunction was determined by reactive oxygen species accumulation, mitochondrial membrane potential and ATP levels.

Results

Our results determined that ivermectin significantly inhibited the proliferation of ESCC cells in vitro and in vivo. Furthermore, we found that ivermectin markedly mediated mitochondrial dysfunction and induced apoptosis of ESCC cells, which indicated the anti-proliferative effect of ivermectin on ESCC cells was implicated in mitochondrial apoptotic pathway. Mechanistically, ivermectin significantly triggered ROS accumulation and inhibited the activation of NF-κB signaling pathway and increased the ratio of Bax/Bcl-2.

Conclusions

These finding indicated that ivermectin has significant anti-tumour potential for ESSC and may be a potential therapeutic candidate against ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09021-x.

Histone Methyltransferase G9a Promotes the Development of Renal Cancer through Epigenetic Silencing of Tumor Suppressor Gene SPINK5

Background

Renal cell carcinoma (RCC) accounts for approximately 2–3% of malignant tumors in adults, while clear cell renal cell carcinoma accounts for 70–85% of kidney cancer cases, with an increasing incidence worldwide. G9a is the second histone methyltransferase found in mammals, catalyzing lysine and histone methylation. It regulates gene transcription by catalyzing histone methylation and interacting with transcription factors to alter the tightness of histone-DNA binding. The main purpose of this study is to explore the role and mechanism of G9a in renal cell carcinoma.

Methods

Firstly, we investigated the expression of G9a in 80 clinical tissues and four cell lines. Then, we explored the effect of G9a-specific inhibitor UNC0638 on proliferation, apoptosis, migration, and invasion of two renal cancer cell lines (786-O, SN12C). In order to study the specific mechanism, G9a knocking down renal cancer cell line was constructed by lentivirus. Finally, we identified the downstream target genes of G9a using ChIP experiments and rescue experiments.

Results

The results showed that the specific G9a inhibitor UNC0638 significantly inhibited the proliferation, migration, and invasion of kidney cancer in vivo and in vitro; similar results were obtained after knocking down G9a. Meanwhile, we demonstrated that SPINK5 was one of the downstream target genes of G9a through ChIP assay and proved that G9a downregulate the expression of SPINK5 by methylation of H3K9me2. Therefore, targeting G9a might be a new approach to the treatment of kidney cancer.

Conclusion

G9a was upregulated in renal cancer and could promote the development of renal cancer in vitro and in vivo. Furthermore, we identified SPINK5 as one of the downstream target genes of G9a. Therefore, targeting G9a might be a new treatment for kidney cancer.

A plant-based medicinal food inhibits the growth of human gastric carcinoma by reversing epithelial-mesenchymal transition via the canonical Wnt/β-catenin signaling pathway

Background

Natural products, especially those with high contents of phytochemicals, are promising alternative medicines owing to their antitumor properties and few side effects. In this study, the effects of a plant-based medicinal food (PBMF) composed of six medicinal and edible plants, namely, Coix seed, Lentinula edodes, Asparagus officinalis L., Houttuynia cordata, Dandelion, and Grifola frondosa, on gastric cancer and the underlying molecular mechanisms were investigated in vivo.

Methods

A subcutaneous xenograft model of gastric cancer was successfully established in nude mice inoculated with SGC-7901 cells. The tumor-bearing mice were separately underwent with particular diets supplemented with three doses of PBMF (43.22, 86.44, and 172.88 g/kg diet) for 30 days. Tumor volumes were recorded. Histopathological changes in and apoptosis of the xenografts were evaluated by hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, respectively. Serum levels of TNF-α, MMP-2, and MMP-9 were detected by enzyme-linked immunosorbent assay. The mRNA expression levels of β-catenin, GSK-3β, E-cadherin, N-cadherin, MMP-2/9, Snail, Bax, Bcl-2, Caspase-3/9, and Cyclin D1 were evaluated via real-time quantitative polymerase chain reaction. The protein expression levels of GSK-3β, E-cadherin, N-cadherin, and Ki-67 were determined by immunohistochemistry staining.

Results

PBMF treatment efficiently suppressed neoplastic growth, induced apoptosis, and aggravated necrosis in the xenografts of SGC-7901 cells. PBMF treatment significantly decreased the serum levels of MMP-2 and MMP-9 and significantly increased that of TNF-α. Furthermore, PBMF treatment notably upregulated the mRNA expression levels of GSK-3β, E-cadherin, Bax, Caspase-3, and Caspase-9 but substantially downregulated those of β-catenin, N-cadherin, MMP-2, MMP-9, Snail, and Cyclin D1 in tumor tissues. The Bax/Bcl-2 ratio was upregulated at the mRNA level. Moreover, PBMF treatment remarkably increased the protein expression levels of GSK-3β and E-cadherin but notably reduced those of Ki-67 and N-cadherin in tumor tissues.

Conclusions

The PBMF concocted herein exerts anti-gastric cancer activities via epithelial–mesenchymal transition reversal, apoptosis induction, and proliferation inhibition. The underlying molecular mechanisms likely rely on suppressing the Wnt/β-catenin signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03301-6.

Elucidating Role of Reactive Oxygen Species (ROS) in Cisplatin Chemotherapy: A Focus on Molecular Pathways and Possible Therapeutic Strategies

The failure of chemotherapy is a major challenge nowadays, and in order to ensure effective treatment of cancer patients, it is of great importance to reveal the molecular pathways and mechanisms involved in chemoresistance. Cisplatin (CP) is a platinum-containing drug with anti-tumor activity against different cancers in both pre-clinical and clinical studies. However, drug resistance has restricted its potential in the treatment of cancer patients. CP can promote levels of free radicals, particularly reactive oxygen species (ROS) to induce cell death. Due to the double-edged sword role of ROS in cancer as a pro-survival or pro-death mechanism, ROS can result in CP resistance. In the present review, association of ROS with CP sensitivity/resistance is discussed, and in particular, how molecular pathways, both upstream and downstream targets, can affect the response of cancer cells to CP chemotherapy. Furthermore, anti-tumor compounds, such as curcumin, emodin, chloroquine that regulate ROS and related molecular pathways in increasing CP sensitivity are described. Nanoparticles can provide co-delivery of CP with anti-tumor agents and by mediating photodynamic therapy, and induce ROS overgeneration to trigger CP sensitivity. Genetic tools, such as small interfering RNA (siRNA) can down-regulate molecular pathways such as HIF-1α and Nrf2 to promote ROS levels, leading to CP sensitivity. Considering the relationship between ROS and CP chemotherapy, and translating these findings to clinic can pave the way for effective treatment of cancer patients.

Ma xing shi gan decoction eliminates PM2.5-induced lung injury by reducing pulmonary cell apoptosis through Akt/mTOR/p70S6K pathway in rats

The present study was designed to investigate the anti-apoptosis effect of Ma xing shi gan decoction (MXD) on PM2.5-induced lung injury via protein kinase B (Akt)/mTOR/p70S6K pathway. A UPLC-MS/MS system was introduced for component analysis of MXD. Rats were instilled with PM2.5 solution suspension intratracheally to induce acute lung injury. The rats were then orally administered with MXD (16, 8, and 4 g/kg) once a day for 7 consecutive days. The therapeutic effects of MXD were evaluated by Hematoxylin and Eosin (HE) staining. The apoptotic cell death was analyzed by terminal-deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assay. The alterations in cytochrome c (Cytc) and cleaved-caspase-3 (C-caspase-3) were measured by immunohistochemistry (IHC). The expressions of Bax, B-cell lymphoma 2 (Bcl-2), p-Akt, p-mTOR and p-p70S6K were detected by Western blot. In vitro, PM2.5 exposure model was introduced in A549 cell, followed by incubation with MXD-medicated serum. Hoechst staining was used to determine apoptotic rate. The levels of Bax, Bcl-2, p-Akt, p-mTOR and p-p70S6K were detected by Western blot. Our results in vivo indicated that treatment with MXD decreased histopathological changes score, TUNEL-positive cells rate, expressions of Cytc and C-caspase-3. The in vitro results revealed that incubation with MXD-mediated serum decreased apoptotic rate. Both results in vivo and in vitro demonstrated that MXD inhibited pro-apoptotic protein Bax and promoted anti-apoptotic protein Bcl-2 expression. Likewise, MXD activated Akt/mTOR/p70S6K signal pathway, which was also confirmed by Western immunoblotting. In conclusion, MXD attenuates lung injury and the underlying mechanisms may relate to regulating the apoptosis via Akt/mTOR/p70S6K signaling pathway activation.

Natural Products Targeting the Mitochondria in Cancers

There are abundant sources of anticancer drugs in nature that have a broad prospect in anticancer drug discovery. Natural compounds, with biological activities extracted from plants and marine and microbial metabolites, have significant antitumor effects, but their mechanisms are various. In addition to providing energy to cells, mitochondria are involved in processes, such as cell differentiation, cell signaling, and cell apoptosis, and they have the ability to regulate cell growth and cell cycle. Summing up recent data on how natural products regulate mitochondria is valuable for the development of anticancer drugs. This review focuses on natural products that have shown antitumor effects via regulating mitochondria. The search was done in PubMed, Web of Science, and Google Scholar databases, over a 5-year period, between 2015 and 2020, with a keyword search that focused on natural products, natural compounds, phytomedicine, Chinese medicine, antitumor, and mitochondria. Many natural products have been studied to have antitumor effects on different cells and can be further processed into useful drugs to treat cancer. In the process of searching for valuable new drugs, natural products such as terpenoids, flavonoids, saponins, alkaloids, coumarins, and quinones cover the broad space.

Chemopreventive effect of α-hederin/carboplatin combination against experimental colon hyperplasia and impact on JNK signaling

Colon cancer is the commonest cancer worldwide. α-Hederin is a monodesmosidic triterpenoid saponin possessing diverse pharmacological activities. The running experiment was designed to test the chemopreventive activity of α-hederin when used as an adjuvant to carboplatin in an experimental model of mouse colon hyperplasia induced by 1,2-dimethylhydrazine (DMH). Fifty male Swiss albino mice were classified into five groups: group (I): saline group, group (II): DMH-induced colon hyperplasia control group, group (III): DMH + carboplatin (5 mg/kg) group, group (IV): DMH + α-hederin (80 mg/kg) group, and group (V): DMH + carboplatin (5 mg/kg)+α-hederin (80 mg/kg) group. Analyzing of colonic tissue indicated that the disease control group showed higher colon levels of phospho-PI3K to total-PI3K, phospho-AKT to total-AKT and cyclin D1 concurrent with lower phospho-JNK/total JNK ratio and caspase 3. However, treatment with α-hederin, in combination with carboplatin, favorably ameliorated phosphorylation of PI3K/AKT/JNK proteins, increased colon caspase 3 and downregulated cyclin D1. Microscopically, α-hederin, in combination with carboplatin, produced the most reduction in the histologic hyperplasia score, enhanced the goblet cell survival in periodic acid Schiff staining and reduced proliferation (Ki-67 immunostaining) in the current colon hyperplasia model. Collectively, the current study highlighted for the first time that using α-hederin as an adjuvant to carboplatin enhanced its chemopreventive activity, improved JNK signaling and increased apoptosis. Hence, further studies are warranted to test α-hederin as a promising candidate with chemotherapeutic agents in treating colon cancer.

Inhibiting endoplasmic reticulum stress by activation of G-protein-coupled estrogen receptor to protect retinal astrocytes under hyperoxia

Retinal vascularization is arrested at the early (hyperoxia) stage in retinopathy of prematurity (ROP), a leading cause of blindness in children. Estrogen was reported to alleviate ROP by inhibiting reactive oxygen species, the upstream signaling molecules of endoplasmic reticulum stress (ERS). Astrocytes have long been proposed to guide angiogenesis, because they form a reticular network that provides a substrate for migrating endothelial cells. However, the factors that control the vascularization of the immature retina and the therapeutic mechanism of estrogen in early ROP remain poorly understood. This study aimed to investigate the role of G-protein-coupled estrogen receptor (GPER), an estrogen receptor distributed in the endoplasmic reticulum (ER), in protecting retinal astrocytes under hyperoxia and the association with ERS. The results showed that GPER was widely expressed in retinal astrocytes. GPER activation increases cell viability, decreases apoptosis, and autophagy of retinal astrocytes, decreases inositol-1,4,5-triphosphate receptor activity, and increases Ca²⁺ concentration in ER of astrocytes under hyperoxia. GPER blockade reversed all of these changes. Together, our findings indicate that GPER can protect the survival of retinal astrocytes by inhibiting ERS under hyperoxia.

G-protein coupled estrogen receptor activation protects the viability of hyperoxia-treated primary murine retinal microglia by reducing ER stress

In this study, we investigated the effects of G-protein coupled estrogen receptor (GPER) activation in the early phase of retinopathy of prematurity (ROP) and its association with endoplasmic reticulum (ER) stress using primary murine retinal microglia as an experimental model. Fluorescence microscopy results show that the CD11c-positive primary retinal microglia in vitro cultured for 14 days were GPER-positive. GPER activation using GPER-agonist G-1 reduced autophagy and increased the viability of the hyperoxia-treated primary murine retinal microglia. Furthermore, GPER activation reduced the expression of ER stress-related proteins, IRE1α, PERK and ATF6 in the hyperoxia-treated primary murine retinal microglia compared to the corresponding controls. GPER activation significantly reduced a time-dependent increase in IP3R-dependent calcium release from the ER, thereby maintaining higher calcium levels in the ER of hyperoxia-treated primary retinal microglia. However, the protective effects of G-1 on the hyperoxia-treated primary retinal microglia were eliminated by inactivation of GPER using the GPER-antagonist, G-15. In conclusion, our study demonstrates that GPER activation enhances the survival of hyperoxia-treated primary retinal microglia by reducing ER stress. Our study demonstrates the therapeutic potential of GPER agonists such as G-1 in the early phase of ROP.

Improved antiproliferative activity of novel Pulsatilla saponin D/α-hederin derivatives containing nitric oxide donors

Conjugates of PSD and furoxan exhibited synergetic effects on enhancing antiproliferative activity and reducing hemolytic toxicity.