Growth factors protect intestinal stem cells from radiation-induced apoptosis by suppressing PUMA through the PI3K/AKT/p53 axis

Stem Cell Therapy Using Bone Marrow-Derived Muse Cells Repairs Radiation-Induced Intestinal Injury Through Their Intestine-Homing via Sphingosine Monophosphate-Sphingosine Monophosphate Receptor 2 Interaction

Purpose

There is still no effective treatment for the gastrointestinal side effects of radiation therapy. Multilineage-differentiating stress-enduring (Muse) cells are tissue stem cells that have the ability to spontaneously home in on injured tissues and repair them. Several clinical trials have shown that stem cell therapy using human bone marrow-derived Muse (hBM-Muse) cells is effective in treating various diseases, but it is not known whether they are effective in treating radiation-induced intestinal injury. In this study, we investigated whether hBM-Muse cells are homing to the radiation-damaged intestine and promote its repair.

Methods and Materials

hBM-Muse cells were injected into the tail vein of mice 2 hours after high-dose total body irradiation. Then, homing analysis, crypt assay, bromodeoxyuridine assay, Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay, immunostaining, and survival time measurements were performed. In addition, we analyzed the expression of sphingosine monophosphate (S1P), a Muse cell-inducing factor, in the mouse small intestine after irradiation. Finally, we investigated whether the administration of JTE-013, an S1P receptor 2-specific antagonist, inhibits hBM-Muse cells homing to the injured intestine.

Results

S1P expression increased in mouse intestine after irradiation, with hBM-Muse cells homing in on the injured intestine. Injection of hBM-Muse cells after radiation exposure significantly increased the number of crypts, proliferating cells in the crypts, and small intestinal component cells such as intestinal stem cells inhibited radiation-induced apoptosis and prolonged mouse survival. Treatment with JTE-013 significantly inhibited intestinal homing and therapeutic effects of hBM-Muse cells. These findings indicate that hBM-Muse cells homed in on the injured intestine through the S1P-S1P receptor 2 interaction to exert therapeutic effects on the radiation-induced intestinal injury.

Conclusions

This study indicates that hBM-Muse cells are effective in treating radiation-induced intestinal injury, suggesting that hBM-Muse cell-based stem cell therapy has the potential to overcome gastrointestinal side effects that limit the indications for radiation therapy.

Berberine enhances the function of intestinal stem cells in healthy and radiation-injured mice

Intestinal stem cells (ISCs) are pivotal for the maintenance and regeneration of the intestinal epithelium. Berberine (BBR) exhibits diverse biological activities, but it remains unclear whether BBR can modulate ISCs' function. Therefore, we investigated the effects of BBR on ISCs in healthy and radiation-injured mice and explored the potential underlying mechanisms involved. The results showed that BBR significantly increased the length of the small intestines, the height of the villi, and the depth and density of the crypts, promoted the proliferation of cryptal epithelial cells and increased the number of OLFM4+ ISCs and goblet cells. Crypts from the BBR-treated mice were more capable of growing into enteroids than those from untreated mice. BBR alleviated WAI-induced intestinal injury. BBR suppressed the apoptosis of crypt epithelial cells, increased the quantity of goblet cells, and increased the quantity of OLFM4+ ISCs and tdTomato+ progenies of ISCs after 8 Gy WAI-induced injury. Mechanistically, BBR treatment caused a significant increase in the quantity of p-S6, p-STAT3 and p-ERK1/2 positive cryptal epithelial cells under physiological conditions and after WAI-induced injury. In conclusion, BBR is capable of enhancing the function of ISCs either physiologically or after radiation-induced injury, indicating that BBR has potential value in the treatment of radiation-induced intestinal injury.

LPA5-Dependent signaling regulates regeneration of the intestinal epithelium following irradiation

Lysophosphatidic acid (LPA) is a bioactive lipid molecule that regulates a wide array of cellular functions, including proliferation, differentiation, and survival, via activation of cognate receptors. The LPA5 receptor is highly expressed in the intestinal epithelium, but its function in restoring intestinal epithelial integrity following injury has not been examined. Here, we use a radiation-induced injury model to study the role of LPA5 in regulating intestinal epithelial regeneration. Control mice (Lpar5f/f) and mice with an inducible, epithelial cell-specific deletion of Lpar5 in the small intestine (Lpar5IECKO) were subjected to 10 Gy total body X-ray irradiation and analyzed during recovery. Repair of the intestinal mucosa was delayed in Lpar5IECKO mice with reduced epithelial proliferation and increased crypt cell apoptosis. These effects were accompanied by reduced numbers of OLFM4+ intestinal stem cells (ISCs). The effects of LPA5 on ISCs were corroborated by studies using organoids derived from Lgr5-lineage tracking reporter mice with deletion of Lpar5 in Lgr5+-stem cells (Lgr5Cont or Lgr5ΔLpar5). Irradiation of organoids resulted in fewer numbers of Lgr5ΔLpar5 organoids retaining Lgr5+-derived progenitor cells compared with Lgr5Cont organoids. Finally, we observed that impaired regeneration in Lpar5IECKO mice was associated with reduced numbers of Paneth cells and decreased expression of Yes-associated protein (YAP), a critical factor for intestinal epithelial repair. Our study highlights a novel role for LPA5 in regeneration of the intestinal epithelium following irradiation and its effect on the maintenance of Paneth cells that support the stem cell niche.NEW & NOTEWORTHY We used mice lacking expression of the lysophosphatidic acid receptor 5 (LPA5) in intestinal epithelial cells and intestinal organoids to show that the LPA5 receptor protects intestinal stem cells and progenitors from radiation-induced injury. We show that LPA5 induces YAP signaling and regulates Paneth cells.

Integrated Approaches Revealed the Therapeutic Mechanisms of Zuojin Pill Against Gastric Mucosa Injury in a Rat Model with Chronic Atrophic Gastritis

Background

The Zuojin Pill (ZJP) is widely used for treating chronic atrophic gastritis (CAG) in clinical practice, effectively ameliorating symptoms such as vomiting, pain, and abdominal distension in patients. However, the underlying mechanisms of ZJP in treating CAG has not been fully elucidated.

Purpose

This study aimed to clarify the characteristic function of ZJP in the treatment of CAG and its potential mechanism.

Methods

The CAG model was established by alternant administrations of ammonia solution and sodium deoxycholate, as well as an irregular diet. Therapeutic effects of ZJP on body weight, serum biochemical indexes and general condition were analyzed. HE staining and AB-PAS staining were analyzed to characterize the mucosal injury and the thickness of gastric mucosa. Furthermore, network pharmacology and molecular docking were used to predict the regulatory mechanism and main active components of ZJP in CAG treatment. RT-PCR, immunohistochemistry, immunofluorescence and Western blotting were used to measure the expression levels of apoptosis-related proteins, gastric mucosal barrier-associated proteins and PI3K/Akt signaling pathway proteins.

Results

The results demonstrated that ZJP significantly improved the general state of CAG rats, alleviated weight loss and gastric histological damage and reduced the serum biochemical indicators. Network pharmacology and molecular docking found that ZJP in treating CAG by inhibiting inflammation, suppressing apoptosis, and protecting the gastric mucosal barrier via the PI3K/Akt signaling pathway. Further experiments confirmed that ZJP obviously modulated the expression of key proteins involved in gastric mucosal cell apoptosis, such as Bax, Bad, Apaf-1, cleaved-caspase-3, cleaved-caspase-9, Cytochrome C, Bcl-2, and Bcl-xl. Moreover, ZJP significantly reversed the protein expression of Occludin, ZO-1, Claudin-4 and E-cadherin.

Conclusion

Our study revealed that ZJP treats CAG by inhibiting the PI3K/Akt signaling pathway. This research provided a scientific basis for the rational use of ZJP in clinical practice.

Exploration of the Molecular Mechanism of Curcuma aromatica Salisb's Anticolorectal Cancer Activity via the Integrative Approach of Network Pharmacology and Experimental Validation

Curcuma aromatica Salisb (Cur), a well-known herbal medicine, has a wide spectrum of anti-inflammatory, anticarcinogenic, and antioxidant activities. However, the roles of its active compounds and potential mechanisms in colorectal cancer remain unknown. This research utilized network pharmacology and experimental validation to explore the possible mechanisms by which Cur protects against colorectal cancer. The active compounds of Cur and related genes for colorectal cancer were obtained from public databases. The DrugBank database was used to search for anticolorectal cancer drugs licensed through the FDA and their targets, and a "drug-component-target" relationship network was created using the Cytoscape program. The String database produced the PPI network. The ability of these active ingredients to bind to core targets was confirmed by molecular docking using AutoDock Vina. Cell and animal experiments were then carried out. A total of 274 targets were obtained from Cur, 49 of which were potential therapeutic targets. Four key targets, PTGS2, AKT1, TP53, and estrogen receptor 1 (ESR1), were screened via the PPI network and the FDA drug-target network. Molecular docking results revealed that Cur had strong binding abilities to these targets. In vivo and in vitro experiments demonstrated that Cur suppressed the development of colorectal cancer by regulating its targets (PTGS2, AKT1, TP53, and ESR1), which play crucial roles in promoting apoptosis and suppressing cell proliferation, migration, and invasion. Collectively, Cur protects against colorectal cancer by regulating the AKT1/PTGS2/ESR1 and P53 pathways, which lays the groundwork for further research and clinical applications of Cur in colorectal cancer therapy.

Gallic acid attenuates metastatic potential of human colorectal cancer cells through the miR-1247-3p-modulated integrin/FAK axis

Colorectal cancer (CRC) exhibits highly metastatic potential even in the early stages of tumor progression. Gallic acid (GA), a common phenolic compound in plants, is known to possess potent antioxidant and anticancer activities, thereby inducing cell death or cell cycle arrest. However, whether GA reduces the invasiveness of CRC cells without inducing cell death remains unclear. Herein, we aimed to investigate the antimetastatic activity of low-dose GA on CRC cells and determine its underlying mechanism. Cell viability and tumorigenicity were analyzed by MTS, cell adhesion, and colony formation assay. Invasiveness was demonstrated using migration and invasion assays. Changes in protein phosphorylation and expression were assessed by Western blot. The involvement of microRNAs was validated by microarray analysis and anti-miR antagonist. Our findings showed that lower dose of GA (≤100 μM) did not affect cell viability but reduced the capabilities of colony formation, cell adhesion, and invasiveness in CRC cells. Cellularly, GA downregulated the cellular level of integrin αV/β3, talin-1, and tensin and diminished the phosphorylated FAK, paxillin, Src, and AKT in DLD-1 cells. Microarray results revealed that GA increased miR-1247-3p expression, and pretreatment of anti-miR antagonist against miR-1247-3p restored the GA-reduced integrin αV/β3 and the GA-inhibited paxillin activation in DLD-1 cells. Consistently, the in vivo xenograft model showed that GA administration inhibited tumor growth and liver metastasis derived from DLD-1 cells. Collectively, our findings indicated that GA inhibited the metastatic capabilities of CRC cells, which may result from the suppression of integrin/FAK axis mediated by miR1247-3p.

The pharmacological effects of Berberine and its therapeutic potential in different diseases: Role of the phosphatidylinositol 3-kinase/AKT signaling pathway

The phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway plays a central role in cell growth and survival and is disturbed in various pathologies. The PI3K is a kinase that generates phosphatidylinositol-3,4,5-trisphosphate (PI (3-5) P3), as a second messenger responsible for the translocation of AKT to the plasma membrane and its activation. However, due to the crucial role of the PI3K/AKT pathway in regulation of cell survival processes, it has been introduced as a main therapeutic target for natural compounds during the progression of different pathologies. Berberine, a plant-derived isoquinone alkaloid, is known because of its anti-inflammatory, antioxidant, antidiabetic, and antitumor properties. The effect of this natural compound on cell survival processes has been shown to be mediated by modulation of the intracellular pathways. However, the effects of this natural compound on the PI3K/AKT pathway in various pathologies have not been reviewed so far. Therefore, this paper aims to review the PI3K/AKT-mediated effects of Berberine in different types of cancer, diabetes, cardiovascular, and central nervous system diseases.

Therapeutic mechanism of Liangxue-Guyuan-Yishen decoction on intestinal stem cells and tight junction proteins in gastrointestinal acute radiation syndrome rats

On the basis of the previous research, the Traditional Chinese Medicine theory was used to improve the drug composition for gastrointestinal acute radiation syndrome (GI-ARS). The purpose of this study was to study the therapeutic mechanism of Liangxue-Guyuan-Yishen decoction (LGYD) on GI-ARS and to provide a new scheme for the treatment of radiation injury. Here, we investigated the effects of LGYD on intestinal stem cells (ISCs) in a GI-ARS rat model. Rat health and survival and the protective efficacy of LGYD on the intestines were analyzed. The active principles in LGYD were detected using liquid chromatography-mass spectrometry (LC-MS). ISC proliferation, intestinal epithelial tight junction (TJ) protein expression and regulatory pathways were explored using immunohistochemistry, western blotting (WB) and reverse transcription quantitative polymerase chain reaction (RT-qPCR), respectively. Involvement of the WNT and MEK/ERK pathways in intestinal recovery was screened using network pharmacology analysis and validated by WB and RT-qPCR. LGYD administration significantly improved health and survival in GI-ARS rats. Pathological analysis showed that LGYD ameliorated radiation-induced intestinal injury and significantly promoted LGR5+ stem cell regeneration in the intestinal crypts, upregulated TJ protein, and accelerated crypt reconstruction in the irradiated rats. LC-MS revealed ≥13 constituents that might contribute to LGYD's protective effects. Collectively, LGYD can promote crypt cell proliferation and ISCs after radiation damage, the above effect may be related to WNT and MEK/ERK pathway.

PTBP1 controls intestinal epithelial regeneration through post-transcriptional regulation of gene expression

The intestinal epithelial regeneration is driven by intestinal stem cells under homeostatic conditions. Differentiated intestinal epithelial cells, such as Paneth cells, are capable of acquiring multipotency and contributing to regeneration upon the loss of intestinal stem cells. Paneth cells also support intestinal stem cell survival and regeneration. We report here that depletion of an RNA-binding protein named polypyrimidine tract binding protein 1 (PTBP1) in mouse intestinal epithelial cells causes intestinal stem cell death and epithelial regeneration failure. Mechanistically, we show that PTBP1 inhibits neuronal-like splicing programs in intestinal crypt cells, which is critical for maintaining intestinal stem cell stemness. This function is achieved at least in part through promoting the non-productive splicing of its paralog PTBP2. Moreover, PTBP1 inhibits the expression of an AKT inhibitor PHLDA3 in Paneth cells and permits AKT activation, which presumably maintains Paneth cell plasticity and function in supporting intestinal stem cell niche. We show that PTBP1 directly binds to a CU-rich region in the 3' UTR of Phlda3, which we demonstrate to be critical for downregulating the mRNA and protein levels of Phlda3. Our results thus reveal the multifaceted in vivo regulation of intestinal epithelial regeneration by PTBP1 at the post-transcriptional level.

The Characterization and Differential Analysis of m6A Methylation in Hycole Rabbit Muscle and Adipose Tissue and Prediction of Regulatory Mechanism about Intramuscular Fat

N6-methyladenosine (m⁶A) widely participates in various life processes of animals, including disease, memory, growth and development, etc. However, there is no report on m⁶A regulating intramuscular fat deposition in rabbits. In this study, m⁶A modification of Hycole rabbit muscle and adipose tissues were detected by MeRIP-Seq. In this case, 3 methylases and 12 genes modified by m⁶A were found to be significantly different between muscle and adipose tissues. At the same time, we found 3 methylases can regulate the expression of 12 genes in different ways and the function of 12 genes is related to fat deposition base on existing studies. 12 genes were modified by m⁶A methylase in rabbit muscle and adipose tissues. These results suggest that 3 methylases may regulate the expression of 12 genes through different pathways. In addition, the analysis of results showed that 6 of the 12 genes regulated eight signaling pathways, which regulated intramuscular fat deposition. RT-qPCR was used to validate the sequencing results and found the expression results of RT-qPCR and sequencing results are consistent. In summary, METTL4, ZC3H13 and IGF2BP2 regulated intramuscular fat by m⁶A modified gene/signaling pathways. Our work provided a new molecular basis and a new way to produce rabbit meat with good taste.

Involvement of caveolin-1 in skin diseases

The skin is the outermost layer and largest organ in the human body. Since the skin interfaces with the environment, it has a variety of roles, including providing a protective barrier against external factors, regulating body temperature, and retaining water in the body. It is also involved in the immune system, interacting with immune cells residing in the dermis. Caveolin-1 (CAV-1) is essential for caveolae formation and has multiple functions including endocytosis, lipid homeostasis, and signal transduction. CAV-1 is known to interact with a variety of signaling molecules and receptors and may influence cell proliferation and migration. Several skin-related disorders, especially those of the inflammatory or hyperproliferative type such as skin cancers, psoriasis, fibrosis, and wound healing, are reported to be associated with aberrant CAV-1 expression. In this review, we have explored CAV-1 involvement in skin physiology and skin diseases.

Mitigation of Ionizing Radiation-Induced Gastrointestinal Damage by Insulin-Like Growth Factor-1 in Mice

Purpose: Insulin-like growth factor-1 (IGF-1) stimulates epithelial regeneration but may also induce life-threatening hypoglycemia. In our study, we first assessed its safety. Subsequently, we examined the effect of IGF-1 administered in different dose regimens on gastrointestinal damage induced by high doses of gamma radiation.

Material and methods: First, fasting C57BL/6 mice were injected subcutaneously with IGF-1 at a single dose of 0, 0.2, 1, and 2 mg/kg to determine the maximum tolerated dose (MTD). The glycemic effect of MTD (1 mg/kg) was additionally tested in non-fasting animals. Subsequently, a survival experiment was performed. Animals were irradiated (⁶⁰Co; 14, 14.5, or 15 Gy; shielded head), and IGF-1 was administered subcutaneously at 1 mg/kg 1, 24, and 48 h after irradiation. Simultaneously, mice were irradiated (⁶⁰Co; 12, 14, or 15 Gy; shielded head), and IGF-1 was administered subcutaneously under the same regimen. Jejunum and lung damage were assessed 84 h after irradiation. Finally, we evaluated the effect of six different IGF-1 dosage regimens administered subcutaneously on gastrointestinal damage and peripheral blood changes in mice 6 days after irradiation (⁶⁰Co; 12 and 14 Gy; shielded head). The regimens differed in the number of doses (one to five doses) and the onset of administration (starting at 1 [five regimens] or 24 h [one regimen] after irradiation).

Results: MTD was established at 1 mg/kg. MTD mitigated lethality induced by 14 Gy and reduced jejunum and lung damage caused by 12 and 14 Gy. However, different dosing regimens showed different efficacy, with three and four doses (administered 1, 24, and 48 h and 1, 24, 48, and 72 h after irradiation, respectively) being the most effective. The three-dose regimens supported intestinal regeneration even if the administration started at 24 h after irradiation, but its potency decreased.

Conclusion: IGF-1 seems promising in the mitigation of high-dose irradiation damage. However, the selected dosage regimen affects its efficacy.

Durability of and role of AKT in FGF7p urothelial protection against cyclophosphamide

We previously identified a peptide derived from human fibroblast growth factor 7 (FGF7p) that blocks urothelial apoptosis similar to full-length FGF7, although effects of FGF7p on urothelial repair are unknown. Also, while urothelial AKT activation downstream of FGF7p correlated with the anti-apoptotic effects, we have not directly interrogated the role of AKT in mediating the cytoprotection. Our goal was to assess effects of FGF7p on urothelial repair and the role of AKT signaling in mediating the cytoprotective effects of FGF7p. We performed hematoxylin and eosin (H&E), TUNEL, and/or immunofluorescence (IF) staining for various markers in FGF7p-treated mice 28 days after giving cyclophosphamide or after co-administering a systemic AKT antagonist with FGF7p 24 h after cyclophosphamide. Vehicle-treated and injured mice had hyperplastic urothelium, incomplete return of mature superficial cell markers, ongoing proliferation, and continued presence of basal progenitor markers 28 days after injury; conversely, FGF7p-treated mice had normal numbers of urothelial cell layers, nearly complete return of superficial cell markers, limited proliferation and fewer basal progenitor cells 28 days post-injury. Vehicle-treated mice also had ectopic lumenal basal progenitor cell markers, while FGF7p had none 28 days after cyclophosphamide. Co-administration of an AKT inhibitor largely abrogated FGF7p-driven AKT activation and cytoprotection in urothelium 24 h after injury. Thus, FGF7p drives faster and higher fidelity urothelial repair by limiting apoptotic injury via AKT signaling, similar to full-length FGF7. Finally, FGF7p is much less expensive to synthesize and has a longer shelf life and higher purity than FGF7.

AKT Signaling Downstream of KGF Is Necessary and Sufficient for Blocking Cyclophosphamide Bladder Injury

Keratinocyte growth factor (KGF) drives phosphorylated (activated) AKT (pAKT) in bladder urothelium, which correlates with cytoprotection from cyclophosphamide. The current study determined whether: i) KGF modifies AKT targets [B-cell lymphoma protein 2-associated agonist of cell death (BAD) and mammalian target of rapamycin complex (mTORC)-1] that could block apoptosis; ii) AKT signaling is required for KGF cytoprotection; iii) direct AKT activation drives cytoprotection; iv) co-administration of KGF and an AKT inhibitor blocks urothelial cytoprotection and AKT and AKT-target activation; and v) an AKT agonist prevents cyclophosphamide-induced urothelial apoptosis. Mice were given KGF and cyclophosphamide (or sham injury), and pBAD (readout of BAD inhibition) or p-p70S6k (pS6, readout of mTORC1 signaling) was assessed. KGF induced pBAD urothelial staining and prevented cyclophosphamide-induced loss of urothelial pS6 staining (likely stabilizing mTORC1 activity). Co-administration of KGF and AKT inhibitor blocked KGF-driven urothelial cytoprotection from cyclophosphamide and prevented pAKT, pBAD, and pS6 urothelial expression. Conversely, systemic AKT agonist blocked cyclophosphamide-induced urothelial apoptosis and induced pAKT, pBAD, and pS6, similar to KGF. Thus, the KGF-AKT signaling axis appeared to phosphorylate (suppress) BAD and prevent cyclophosphamide-induced loss of mTORC1 signaling, both of which likely suppress apoptosis. Additionally, AKT signaling was required for KGF-driven cytoprotection, and direct AKT activation was sufficient for blocking apoptosis. Thus, AKT may be a therapeutic target for blocking urothelial apoptosis from cyclophosphamide.

Human Milk Growth Factors and Their Role in NEC Prevention: A Narrative Review

Growing evidence demonstrates human milk's protective effect against necrotizing enterocolitis (NEC). Human milk derives these properties from biologically active compounds that influence intestinal growth, barrier function, microvascular development, and immunological maturation. Among these protective compounds are growth factors that are secreted into milk with relatively high concentrations during the early postnatal period, when newborns are most susceptible to NEC. This paper reviews the current knowledge on human milk growth factors and their mechanisms of action relevant to NEC prevention. It will also discuss the stability of these growth factors with human milk pasteurization and their potential for use as supplements to infant formulas with the goal of preventing NEC.

Interferon b drives intestinal regeneration after radiation

The cGAS-STING cytosolic DNA sensing pathway is critical for host defense. Here, we report that cGAS-STING–dependent type 1 interferon (IFN) response drives intestinal regeneration and animal recovery from radiation injury. STING deficiency has no effect on radiation-induced DNA damage or crypt apoptosis but abrogates epithelial IFN-β production, local inflammation, innate transcriptional response, and subsequent crypt regeneration. cGAS KO, IFNAR1 KO, or CCR2 KO also abrogates radiation-induced acute crypt inflammation and regeneration. Impaired intestinal regeneration and survival in STING-deficient mice are fully rescued by a single IFN-β treatment given 48 hours after irradiation but not by wild-type (WT) bone marrow. IFN-β treatment remarkably improves the survival of WT mice and Lgr5+ stem cell regeneration through elevated compensatory proliferation and more rapid DNA damage removal. Our findings support that inducible IFN-β production in the niche couples ISC injury and regeneration and its potential use to treat acute radiation injury.

Anwulignan Ameliorates the Intestinal Ischemia/Reperfusion

Anwulignan is one of the monomer compounds in the lignans from Schisandra sphenanthera In this study, we observed the effect of anwulignan on intestinal ischemia/reperfusion (II/R) injury in male Sprague-Dawley rats and explored the underlying mechanisms. The results showed that pretreatment with oral anwulignan could significantly increase the mesenteric blood microcirculatory flow velocity; relieve the congestion and pathologic injury of jejunum; enhance the autonomic tension of jejunum smooth muscle and its reactivity to acetylcholine; increase the activities of superoxide dismutase, catalase, glutathione S-transferase, and choline acetyltransferase; increase the contents of acetylcholine and glutathione in the serum or jejunal tissue; decrease the activities of myeloperoxidase, protein kinase C, and nicotinamide adenine dinucleotide phosphate oxidase; reduce the contents of malondialdehyde, 8-hydroxy-2-deoxyguanosine, nicotinamide adenine, reactive oxygen species, tumor necrosis factor-α, interleukin (IL)-6, and IL-1β; increase the expression levels of muscarinic receptor 3, PI3K, phosphorylation protein kinase B, p-GSK3β Ser9, Nrf2, p-Nrf2, heme oxygenase (decycling) 1, and b-cell lymphoma 2 in the jejunal tissue; and decrease the expression levels of p-GSK3β Tyr216, kelch-like ECH-associated protein 1, Bax, and cleaved caspase-3, suggesting that anwulignan can ameliorate II/R-induced jejunal tissue injury in rats and that the mechanism may be related to its activating the PI3K/protein kinase B pathway and then regulating the Nrf2/Anti-oxidative Response Element signaling pathway and the expression of apoptosis-related proteins to play antioxidant and antiapoptotic roles. SIGNIFICANCE STATEMENT: Anwulignan can significantly reduce jejunal tissue injury and the production of inflammatory factors in rats with intestinal ischemia-reperfusion injury, improve the antioxidant capacity, and reduce the apoptosis of jejunal tissue, and it has the effect of significantly improving intestinal ischemia-reperfusion injury in rats, suggesting that anwulignan may be used as a potential drug for the prevention and treatment of intestinal ischemia-reperfusion injury or a resource for the development of health food.

Linc-ROR promotes arsenite-transformed keratinocyte proliferation by inhibiting P53 activity

Linc-ROR is an oncogenic long non-coding RNA over-expressed in many kinds of cancer that promotes cancer cell proliferation. Arsenite is a determined carcinogen that increases the risk of skin cancer, but the carcinogenic mechanism of arsenite remains unclear. To explore whether and how linc-ROR plays a role in arsenite-induced carcinogenesis of skin cancer, we established arsenite-transformed keratinocyte HaCaT cells by exposing them to 1 μM arsenite for 50 passages. Then we examined the linc-ROR expression during the transformation and explored the effect of linc-ROR on the cell proliferation of arsenite-transformed HaCaT cells. We found that the linc-ROR level in HaCaT cells was gradually increased during arsenite-induced malignant transformation, and the activity of P53 was decreased, but the P53 expression was not significantly altered, indicating that linc-ROR may play a role in arsenite-induced HaCaT cell transformation that is associated with P53 activity but not P53 expression. We further demonstrated that linc-ROR down-regulation by siRNA significantly inhibited the cellular proliferation and restored P53 activity in arsenite-transformed HaCaT cells, suggesting that linc-ROR promotes proliferation of arsenite-transformed HaCaT cells by inhibiting P53 activity. Moreover, linc-ROR siRNA also down-regulated the PI3K/AKT pathway in arsenite-transformed HaCaT cells, and treatment with AKT inhibitor wortmannin restored P53 activity, implying that linc-ROR inhibits P53 activity by activating the PI3K/AKT pathway. Taken together, the present study shows that linc-ROR promotes arsenite-transformed keratinocyte proliferation by inhibiting P53 activity through activating PI3K/AKT, providing a novel carcinogenic mechanism of arsenite-induced skin cancer.

Chemical and biological basis for development of novel radioprotective drugs for cancer therapy

Ionizing radiation (IR) causes chemical changes in biological systems through direct interaction with the macromolecules or by causing radiolysis of water. This property of IR is harnessed in the clinic for radiotherapy in almost 50% of cancers patients. Despite the advent of stereotactic radiotherapy instruments and other advancements in shielding techniques, the inadvertent deposition of radiation dose in the surrounding normal tissue can cause late effects of radiation injury in normal tissues. Radioprotectors, which are chemical or biological agents, can reduce or mitigate these toxic side-effects of radiotherapy in cancer patients and also during radiation accidents. The desired characteristics of an ideal radioprotector include low chemical toxicity, high risk to benefit ratio and specific protection of normal cells against the harmful effects of radiation without compromising the cytotoxic effects of IR on cancer cells. Since reactive oxygen species (ROS) are the major contributors of IR mediated toxicity, plethora of studies have highlighted the potential role of antioxidants to protect against IR induced damage. However, owing to the lack of any clinically approved radioprotector against whole body radiation, researchers have shifted the focus toward finding alternate targets that could be exploited for the development of novel agents. The present review provides a comprehensive insight in to the different strategies, encompassing prime molecular targets, which have been employed to develop radiation protectors/countermeasures. It is anticipated that understanding such factors will lead to the development of novel strategies for increasing the outcome of radiotherapy by minimizing normal tissue toxicity.

Retroductal Delivery of Epidermal Growth Factor Protects Salivary Progenitors after Irradiation

Salivary gland hypofunction after irradiation is associated with a deficit of epithelial stem/progenitors in salivary glands. Although epidermal growth factor (EGF) is known to stimulate the proliferation of epithelial cells, the therapeutic effect of EGF on salivary epithelial stem/progenitors remains undetermined. In this study, we administered EGF to submandibular glands (SMGs) via a retrograde route through the SMG excretory duct before fractionated irradiation and examined whether EGF could protect salivary epithelial progenitor cells from radiation and alleviate radiation-induced salivary hypofunction. EGF-treated mice exhibited greater body and gland weights at 12 wk after irradiation than untreated mice. The retroductal delivery of EGF improved salivary secretory function and increased salivary amylase activity in a dose-dependent manner. Histological examinations highlighted the amelioration of the loss of keratine-14⁺ (KRT14⁺) basal ductal and/or MIST1⁺ acinar cells, as well as induction of fibrosis, following irradiation in EGF-treated mice. An additional in vitro experiment using a salivary gland organoid irradiation model indicated that the radioprotective effects of EGF promoted the growth and inhibited the apoptotic cell death of salivary epithelial cells. Our results suggest that retroductal delivery of EGF may be a promising therapeutic option for preventing radiation-induced salivary gland hypofunction.

Downregulation of PUMA underlies resistance to FGFR1 inhibitors in the stem cell leukemia/lymphoma syndrome

Resistance to molecular therapies frequently occur due to genetic changes affecting the targeted pathway. In myeloid and lymphoid leukemias/lymphomas resulting from constitutive activation of FGFR1 kinases, resistance has been shown to be due either to mutations in FGFR1 or deletions of PTEN. RNA-Seq analysis of the resistant clones demonstrates expression changes in cell death pathways centering on the p53 upregulated modulator of apoptosis (Puma) protein. Treatment with different tyrosine kinase inhibitors (TKIs) revealed that, in both FGFR1 mutation and Pten deletion-mediated resistance, sustained Akt activation in resistant cells leads to compromised Puma activation, resulting in suppression of TKI-induced apoptosis. This suppression of Puma is achieved as a result of sequestration of inactivated p-Foxo3a in the cytoplasm. CRISPR/Cas9 mediated knockout of Puma in leukemic cells led to an increased drug resistance in the knockout cells demonstrating a direct role in TKI resistance. Since Puma promotes cell death by targeting Bcl2, TKI-resistant cells showed high Bcl2 levels and targeting Bcl2 with Venetoclax (ABT199) led to increased apoptosis in these cells. In vivo treatment of mice xenografted with resistant cells using ABT199 suppressed leukemogenesis and led to prolonged survival. This in-depth survey of the underlying genetic mechanisms of resistance has identified a potential means of treating FGFR1-driven malignancies that are resistant to FGFR1 inhibitors.

miRNA-216 knockdown has effects to suppress osteosarcoma via stimulating PTEN

The aim of this study is to explain the effects and mechanism of miRNA-216 in osteosarcoma. We firstly evaluated the PTEN expression in 30 pairs of tumor and adjacent tissues which were from the 30 osteosarcoma patients. In the following cell experiments, we measured the cell proliferation, cell cycle, cell invasion, and migration abilities of NC (normal control) group, BL (blank) group, siRNA (miRNA-216 inhibitor) group, and siRNA+PTEN inhibitor group. Furthermore, we measured the relative protein expression of difference groups by WB to explain the mechanism of miRNA-216 in osteosarcoma. The PTEN was confirmed the target gene of miRNA-216 by double luciferase target test. In conclusion, miRNA-216 was an oncogene in osteosarcoma. miRNA-216 knockdown had effects to suppress cancer cell proliferation, invasion and migration and improve cell apoptosis by keeping in G1 phase via PTEN.

Me6TREN targets β-catenin signaling to stimulate intestinal stem cell regeneration after radiation

Background: Acute gastrointestinal syndrome (AGS) is one of the most severe clinical manifestations after exposure to high doses of radiation, and is life-threatening in radiological emergency scenarios. However, an unmet challenge is lacking of an FDA-approved drug that can ameliorate the damage of radiation-exposed intestinal tissues and accelerate the regeneration of injured epithelia. In this study, we investigated whether the small molecule Me6TREN (Me6) can regulate intestinal stem cell (ISC) proliferation and promote crypt regeneration after irradiation.

Methods: Lethally irradiated mice were administered with Me6 or PBS to study the survival rate, and sections of their small intestine were subjected to immunostaining to evaluate epithelial regeneration. An intestinal organoid culture system was employed to detect the role of Me6 in organoid growth and ISC proliferation. We further investigated the key signaling pathways associated with Me6 using microarray, western blotting, and RNA interference techniques.

Results: We identified the small molecule Me6 as a potent intestinal radiation countermeasure. Systemic administration of Me6 significantly improved ISC and crypt cell regeneration and enhanced the survival of mice after high doses of radiation. Using an in vitro intestinal organoid culture system, we found that Me6 not only induced ISC proliferation but also increased the budding rate of intestinal organoids under unirradiated and irradiated conditions. Me6 remarkably activated the expression of ISC-associated and proliferation-promoting genes, such as Ascl2, Lgr5, Myc, and CyclinD1. Mechanistically, Me6 strongly stimulated the phosphorylation of β-catenin at the S552 site and increased the transcriptional activity of β-catenin, a key signaling pathway for ISC self-renewal and proliferation. This is further evidenced by the fact that knockdown of β-catenin abolished the effect of Me6 on intestinal organoid growth in vitro and crypt regeneration in irradiated mice.

Conclusion: The small molecule Me6TREN induced ISC proliferation, enhanced intestinal organoid growth in vitro, and promoted intestinal tissue regeneration after radiation injury by activating β-catenin signaling.

m6A Reader YTHDC2 Promotes Radiotherapy Resistance of Nasopharyngeal Carcinoma via Activating IGF1R/AKT/S6 Signaling Axis

N6-methyladenosine (m⁶A) modification has been reported as a critical regulator of gene transcript expression. Although m⁶A modification plays important roles in tumor development, its role in therapeutic resistance remains unknown. In this study, we aimed to examine the expression level of m⁶A-modification related proteins and elucidate the effect of m⁶A-related proteins on radiation response in nasopharyngeal carcinoma (NPC). Among the genes that participated in m⁶A modification, YTHDC2, a m⁶A reader, was found to be consistently highly expressed in radioresistant NPC cells. Knocking down of YTHDC2 expression in radioresistant NPC cells improved the therapeutic effect of radiotherapy in vitro and in vivo, whereas overexpression of YTHDC2 in radiosensitive NPC cells exerted an opposite effect. Bioinformatics and mechanistic studies revealed that YTHDC2 could physically bound to insulin-like growth factor 1 receptor (IGF1R) messenger RNA and promoted translation initiation of IGF1R mRNA, which in turn activated the IGF1R-AKT/S6 signaling pathway. Thus, the present study suggests that YTHDC2 promotes radiotherapy resistance of NPC cells by activating the IGF1R/ATK/S6 signaling axis and may serve as a potential therapeutic target in radiosensitization of NPC cells.

Salinomycin and Sulforaphane Exerted Synergistic Antiproliferative and Proapoptotic Effects on Colorectal Cancer Cells by Inhibiting the PI3K/Akt Signaling Pathway in vitro and in vivo

Background

Both salinomycin (SAL) and sulforaphane (SFN) exert their antitumorigenic effects in various types of cancer We investigated whether combining salinomycin (SAL, an antibiotic ionophore) with sulforaphane (SFN, a phytochemical) exerted synergistic antiproliferative and proapoptotic activities in colorectal cancer (CRC) cells in vitro and in vivo by evaluating the proliferative and apoptotic responses of two CRC cell lines.

Materials and Methods

The combination index (CI) was calculated using the Chou-Talalay method, and the effects of the synergistic combination (CI<1) of lower doses of SAL and SFN were selected for further studies. Anti-tumor effect of the combination of SAL and SFN was tested both in vitro and in vivo.

Results

Cotreatment effectively inhibited proliferation, migration and invasion and enhanced apoptosis. The xenograft model also showed similar results. Furthermore, we evaluated the molecular mechanism behind SAL- and SFN-mediated CRC cell apoptosis. The combination treatment induced apoptosis in Caco-2 and CX-1 cells by inhibiting the PI3K/Akt pathway, which increased the expression of the tumor suppressor protein p53. The treatment also decreased the expression of the survival protein Bcl-2 and increased the expression of the proapoptotic protein Bax, which increased the Bax/Bcl-2 ratio, as well as enhanced poly ADP-ribose polymerase (PARP) cleavage. Upon inhibiting the PI3K/Akt pathway with LY294002 prior to cotreatment, we detected enhanced PARP cleavage compared to that in the cotreatment only group.

Conclusion

We investigated whether the combination of SAL and SFN had antiproliferative and proapoptotic effects in CRC cells both in vitro and in vivo. Cotreatment also significantly decreased migration and invasion compared to that of the control and SAL or SFN monotherapies. This novel combination of SAL and SFN might provide a potential strategy to treat CRC.

Insulin-like Growth Factor-1 and mTORC1 Signaling Promote the Intestinal Regenerative Response After Irradiation Injury

BACKGROUND & AIMS

Intestinal crypts have a remarkable capacity to regenerate after injury from loss of crypt base columnar (CBC) stem cells. After injury, facultative stem cells (FSCs) are activated to replenish the epithelium and replace lost CBCs. Our aim was to assess the role of insulin-like growth factor-1 (IGF-1) to activate FSCs for crypt repair.

METHODS

The intestinal regenerative response was measured after whole body 12-Gy γ-irradiation of adult mice. IGF-1 signaling or its downstream effector mammalian target of rapamycin complex 1 (mTORC1) was inhibited by administering BMS-754807 or rapamycin, respectively. Mice with inducible Rptor gene deletion were studied to test the role of mTORC1 signaling in the intestinal epithelium. FSC activation post-irradiation was measured by lineage tracing.

RESULTS

We observed a coordinate increase in growth factor expression, including IGF-1, at 2 days post-irradiation, followed by a surge in mTORC1 activity during the regenerative phase of crypt repair at day 4. IGF-1 was localized to pericryptal mesenchymal cells, and IGF-1 receptor was broadly expressed in crypt progenitor cells. Inhibition of IGF-1 signaling via BMS-754807 treatment impaired crypt regeneration after 12-Gy irradiation, with no effect on homeostasis. Similarly, rapamycin inhibition of mTORC1 during the growth factor surge blunted the regenerative response. Analysis of Villin-CreERT2;Rptorfl/fl mice showed that epithelial mTORC1 signaling was essential for crypt regeneration. Lineage tracing from Bmi1-marked cells showed that rapamycin blocked FSC activation post-irradiation.

CONCLUSIONS

Our study shows that IGF-1 signaling through mTORC1 drives crypt regeneration. We propose that IGF-1 release from pericryptal cells stimulates mTORC1 in FSCs to regenerate lost CBCs.

Keratinocyte Growth Factor Reduces Injury and Leads to Early Recovery from Cyclophosphamide Bladder Injury

Keratinocyte growth factor (KGF) improves cyclophosphamide-induced bladder injury. To understand the mechanisms, we subcutaneously administered KGF to mice 24 hours before i.p. cyclophosphamide administration, followed by histologic assays and immunostaining. In vehicle (phosphate-buffered saline)-pretreated mice, nonapoptotic superficial cell death from 2 to 6 hours and apoptosis in intermediate and basal cells from 4 to 24 hours was observed after cyclophosphamide. Despite superficial cell loss, KGF suppressed intermediate and basal cell apoptosis, likely via AKT signaling. At 6 and 24 hours after cyclophosphamide, KGF-pretreated mice also had apparent extracellular signal-regulated kinase (ERK)-driven proliferation of mostly keratin 5 (KRT5)+/KRT14- intermediate cells. At 1 to 28 days after cyclophosphamide treatment, mostly KRT14+ basal progenitor cells proliferated in response to injury, peaking at 3 days in both treatment groups; however, proliferation rates were lower in the KGF group at 3 days, consistent with less injury. Three days after injury, unlike controls, KGF-pretreated mice had regenerated superficial cells. At 10 and 28 days after cyclophosphamide treatment, KGF-pretreated mice had little proliferation and marked restoration of urothelial layers, whereas the phosphate-buffered saline group had ongoing regeneration. Administration of KGF to uninjured mice reproduced ERK-driven KRT5+/KRT14- proliferation seen in injured mice; KRT14+ cells were unaffected. KGF pretreatment blocks cyclophosphamide-induced intermediate and basal cell apoptosis, likely by phosphorylated AKT, and drives phosphorylated ERK-mediated KRT5+/KRT14- cell proliferation, leading to early urothelial regeneration.

Discordant gene responses to radiation in humans and mice and the role of hematopoietically humanized mice in the search for radiation biomarkers

The mouse (Mus musculus) is an extensively used model of human disease and responses to stresses such as ionizing radiation. As part of our work developing gene expression biomarkers of radiation exposure, dose, and injury, we have found many genes are either up-regulated (e.g. CDKN1A, MDM2, BBC3, and CCNG1) or down-regulated (e.g. TCF4 and MYC) in both species after irradiation at ~4 and 8 Gy. However, we have also found genes that are consistently up-regulated in humans and down-regulated in mice (e.g. DDB2, PCNA, GADD45A, SESN1, RRM2B, KCNN4, IFI30, and PTPRO). Here we test a hematopoietically humanized mouse as a potential in vivo model for biodosimetry studies, measuring the response of these 14 genes one day after irradiation at 2 and 4 Gy, and comparing it with that of human blood irradiated ex vivo, and blood from whole body irradiated mice. We found that human blood cells in the hematopoietically humanized mouse in vivo environment recapitulated the gene expression pattern expected from human cells, not the pattern seen from in vivo irradiated normal mice. The results of this study support the use of hematopoietically humanized mice as an in vivo model for screening of radiation response genes relevant to humans.

Dietary delphinidin inhibits human colorectal cancer metastasis associating with upregulation of miR-204-3p and suppression of the integrin/FAK axis

Delphinidin is a flavonoid belonging to dietary anthocyanidin family that has been reported to possess diverse anti-tumoral activities. However, the effects of delphinidin on colorectal cancer (CRC) cells and the underlying mechanisms are not fully understood. Thus, we aimed to investigate the anti-cancer activity of delphinidin in CRC cells and the underlying molecular mechanisms. The effects of delphinidin on the viability, metastatic characteristics, signaling, and microRNA (miR) profile of human CRC cell lines used were analyzed. In vivo metastasis was also evaluated using xenograft animal models. Our findings showed that delphinidin (<100 μM) inhibited the colony formation of DLD-1, SW480, and SW620 cells, but non-significantly affected cell viability. Delphinidin also suppressed the migratory ability and invasiveness of the tested CRC cell lines, downregulated integrin αV/β3 expression, inhibited focal adhesion kinase (FAK)/Src/paxillin signaling, and interfered with cytoskeletal construction. Analysis of the miR expression profile revealed a number of miRs, particularly miR-204-3p, that were significantly upregulated and downregulated by delphinidin. Abolishing the expression of one upregulated miR, miR-204-3p, with an antagomir restored delphinidin-mediated inhibition of cell migration and invasiveness in DLD-1 cells as well as the αV/β3-integrin/FAK/Src axis. Delphinidin also inhibited the lung metastasis of DLD-1 cells in the xenograft animal model. Collectively, these results indicate that the migration and invasion of CRC cells are inhibited by delphinidin, and the mechanism may involve the upregulation of miR-204-3p and consequent suppression of the αV/β3-integrin/FAK axis. These findings suggest that delphinidin exerts anti-metastatic effects in CRC cells by inhibiting integrin/FAK signaling and indicate that miR-204-3p may play an important role in CRC metastasis.

EDNRB Reverses Methylprednisolone-Mediated Decrease in Neural Progenitor Cell Viability via Regulating PI3K/Akt Pathway and lncRNA Expression

OBJECTIVE

To investigate the functions and mechanisms of methylprednisolone (MP) through endothelin receptor B (EDNRB) on the cell proliferation of neural progenitor cells (NPCs) to regulate spinal cord injury.

METHODS

Primary NPCs were isolated from fetal mice and subjected to treatments with MP and IRL-1620 (EDNRB agonist). The cell viability was determined using the MTS assay. Total RNA was extracted from the cells, and RNA-seq was performed to screen for lncRNAs. The targets of the candidate lncRNAs were predicted by GO and KEGG analyses, and the expressions of lncRNAs were validated via qPCR. Furthermore, protein levels of the PI3K-AKT pathway were determined via Western blotting, and the expression of lncRNAs was detected after inhibiting the pathway with AKT inhibitor.

RESULTS

MTS assays revealed that MP decreased the cell viability of NPCs, whereas the EDNRB agonist reversed this effect of MP. NPCs were used for RNA-seq in the following three groups: normal control (NC), MP, and MP combined with EDNRB agonist (MP + EDNRB). Our results suggested that the NONRATT030699.2, NONRATT004088.2, and NONRATT005601.2 lncRNAs might be involved in the signaling pathway that is correlated to MP and the EDNRB agonist. GO and KEGG pathway analyses revealed that this was the PI3K/AKT pathway. The relevant genes involved in the pathway were validated by Western blotting. The EDNRB agonist promoted cell proliferation mainly via the activation of the PI3K/AKT pathway; however, it suppressed the expression of p-ERK, thereby increasing the expression of cyclin D1 and attenuating the effect of MP in suppressing cell proliferation. Meanwhile, after the AKT signal pathway was inhibited, these lncRNA expressions were consistent with those in the MP + EDNRB group.

CONCLUSION

MP inhibits NPC proliferation, whereas EDNRB activation reverses the effect of MP via lncRNA.

Acetaminophen Intoxication Rapidly Induces Apoptosis of Intestinal Crypt Stem Cells and Enhances Intestinal Permeability

Acetaminophen (APAP)‐induced liver injury is the most common cause of acute liver failure (ALF) in the Western world. APAP toxicity progresses to multiorgan dysfunction and thus has broader whole‐body implications. Importantly, greater 30‐day mortality has been observed in liver transplant recipients following ALF due to APAP‐related versus non‐APAP‐related causes. Reasons for this discrepancy have yet to be determined. Extrahepatic toxicities of APAP overdose may represent underappreciated and unaddressed comorbidities within this patient population. In the present study, rapid induction of apoptosis following APAP overdose was observed in the intestine, an organ that greatly influences the physiology of the liver. Strikingly, apoptotic cells appeared to be strictly restricted to the intestinal crypts. The use of leucine‐rich repeat‐containing G protein–coupled receptor 5 (LGR5) reporter mice confirmed that the LGR5‐positive (+) crypt base stem cells were disproportionately affected by APAP‐induced cell death. Although the apoptotic cells were cleared within 24 hours after APAP treatment, potentially long‐lived consequences on the intestine due to APAP exposure were indicated by prolonged deficits in gut barrier function. Moreover, small intestinal cell death was found to be independent of tumor necrosis factor receptor signaling and may represent a direct toxic insult to the intestine by exposure to high concentrations of APAP. Conclusion: APAP induces intestinal injury through a regulated process of apoptotic cell death that disproportionately affects LGR5⁺ stem cells. This work advances our understanding of the consequences of APAP toxicity in a novel organ that was not previously considered as a significant site of injury and thus presents potential new considerations for patient management.

Semaphorin 3E regulates apoptosis in the intestinal epithelium during the development of colitis

Semaphorin 3E (SEMA3E) has emerged as an axon-guiding molecule that regulates various biological processes including the immune responses and apoptosis. However, its role in the pathophysiology of colitis remains elusive. We investigated the role of SEMA3E in intestinal epithelial cells (IECs) activation, using biopsies from patients with active ulcerative colitis (UC), a mouse model of UC, and an in-vitro model of intestinal mucosal healing. In this study, we confirmed that the mRNA level of SEMA3E is reduced significantly in patients with UC and demonstrated a negative linear association between SEMA3E mRNA and p53-associated genes. In mice, genetic deletion of Sema3e resulted in an increase onset and severity of colitis, p53-associated genes, apoptosis, and IL-1beta production. Recombinant SEMA3E treatment protected against colitis and decreased these effects. Furthermore, in stimulated epithelial cells, recombinant SEMA3E treatment enhanced wound healing, resistance to oxidative stress and decreased apoptosis and p53-associated genes. Together, these findings identify SEMA3E as a novel regulator in intestinal inflammation that regulates IECs apoptosis and suggest a potential novel approach to treat UC.

Mechanisms of apoptosis modulation by curcumin: Implications for cancer therapy

Cancer incidences are growing and cause millions of deaths worldwide. Cancer therapy is one of the most important challenges in medicine. Improving therapeutic outcomes from cancer therapy is necessary for increasing patients' survival and quality of life. Adjuvant therapy using various types of antibodies or immunomodulatory agents has suggested modulating tumor response. Resistance to apoptosis is the main reason for radioresistance and chemoresistance of most of the cancers, and also one of the pivotal targets for improving cancer therapy is the modulation of apoptosis signaling pathways. Apoptosis can be induced by intrinsic or extrinsic pathways via stimulation of several targets, such as membrane receptors of tumor necrosis factor-α and transforming growth factor-β, and also mitochondria. Curcumin is a naturally derived agent that induces apoptosis in a variety of different tumor cell lines. Curcumin also activates redox reactions within cells inducing reactive oxygen species (ROS) production that leads to the upregulation of apoptosis receptors on the tumor cell membrane. Curcumin can also upregulate the expression and activity of p53 that inhibits tumor cell proliferation and increases apoptosis. Furthermore, curcumin has a potent inhibitory effect on the activity of NF-κB and COX-2, which are involved in the overexpression of antiapoptosis genes such as Bcl-2. It can also attenuate the regulation of antiapoptosis PI3K signaling and increase the expression of MAPKs to induce endogenous production of ROS. In this paper, we aimed to review the molecular mechanisms of curcumin-induced apoptosis in cancer cells. This action of curcumin could be applicable for use as an adjuvant in combination with other modalities of cancer therapy including radiotherapy and chemotherapy.

Morphological and functional impairment in the gut in a partial body irradiation minipig model of GI-ARS

Purpose: Göttingen minipig (G-MP) displays classic gastrointestinal acute radiation syndrome (GI-ARS) following total body irradiation (TBI) at GI doses which are lethal by 10-14 days. In collaboration with BARDA, we are developing a hemi-body/partial body irradiation (PBI) model by exposing only the abdomen and lower extremities to study GI structure/function impairment, natural history of injury and recovery, as well as correlative biomarkers out to 30 days.Materials and methods: Twenty-four G-MP were exposed to either 12 or 16 Gy (LINAC Elekta); head, forelimbs, and thorax were outside the irradiation field, sparing ∼50% of the bone marrow. Animals were followed for 30 days with euthanasia scheduled at pre-set intervals to study the time course of GI injury and recovery. Hematological profiles, clinical symptoms, gross- and histo-pathology including markers of proliferation and apoptosis in the small intestines, gut function parameters (food tolerance, digestion, absorption, citrulline production), and levels of two biomarkers, CRP and IGF-1, were evaluated.Results: PBI at 16 Gy yielded higher lethality than 12 Gy. Unlike TBI, PBI did not cause severe pancytopenia or external hemorrhage, as expected, and allowed to focus the injury on GI organs while sparing the radiation sensitive heart and lung. Compromised animals showed inactivity, anorexia, vomiting, diarrhea, and weight loss. Histology revealed that in 12 Gy irradiated animals, lesions recovered overtime. In 16 Gy irradiated animals, lesions were more pronounced and persistent. BrdU and Ki67 labelling demonstrated dose-dependent loss of crypts and subsequent mucosal ulceration which recovered over time. Minimal apoptosis was observed at both doses. Reductions in food tolerance, digestion, absorption, and citrulline production were time and dose-dependent. Loss of citrulline reached a nadir between 6-12 days and then recovered partially. CRP and IGF-1 were upregulated following PBI at GI doses.Conclusions: This lower hemi-body irradiation model allowed for extended survival at GI-specific ARS doses and development of a well-controlled GI syndrome with minimal hematopoietic injury or confounding mortality from cardiopulmonary damage. A dose-dependent impairment in the intestinal structure resulted in overall decreased gut functionality followed by a partial recovery. However, while the structure appeared to be recovered, not all functionality was attained. PBI induced systemic inflammation and altered the IGF-1 hormone indicating that these can be used as biomarkers in the minipig even under partial body conditions. This PBI model aligns with other minipig models under BARDA's large animal consortium to test medical countermeasure efficacy against a less complex GI-specific ARS injury.

Crosstalk between Phosphoinositide 3-kinase/Akt signaling pathway with DNA damage response and oxidative stress in cancer

The phosphatidylinositol 3-kinases (PI3K)/Akt signaling pathway is one of the well-characterized and most important signaling pathways activated in response to DNA damage. This review discusses the most recent discoveries on the involvement of PI3K/Akt signaling pathway in cancer development, as well as stimulation of some important signaling networks involved in the maintenance of cellular homeostasis upon DNA damage, with an exploration of how PI3K/Akt signaling pathway contributes to the regulation of modulators and effectors underlying DNA damage response, the intricate, protein-based signal transduction network, which decides between cell cycle arrest, DNA repair, and apoptosis, the elimination of irreparably damaged cells to maintain homeostasis. The review continues by looking at the interplay between cell cycle checkpoints, checking the repair of damage inflicted to the DNA before entering DNA replication to facilitate DNA synthesis, and PI3K/Akt signaling pathway. We then investigate the challenges the cells overcome to ameliorate damages induced by oxidative activities, for example, the recruitment of many pathways and factors to maintain integrity and hemostasis. Finally, the review provides a discussion of how cells use the PI3K/Akt signaling pathway to regulate the balance between these networks.

Neulasta Regimen for the Hematopoietic Acute Radiation Syndrome: Effects Beyond Neutrophil Recovery

PURPOSE

Understanding the physiopathology underlying the acute radiation syndrome (ARS) and the mechanism of action of drugs known to ameliorate ARS is expected to help identify novel countermeasure candidates and improve the outcome for victims exposed to radiation. Granulocyte colony-stimulating factor (G-CSF) has been approved by the US Food and Drug Administration for treatment of hematopoietic ARS (H-ARS) because of its ability to alleviate myelosuppression. Besides its role in hematopoiesis, G-CSF is known to protect the cardiovascular and neurologic systems, to attenuate vascular injury and cardiac toxicity, to preserve gap junction function, and to modulate inflammation and oxidative stress. Here, we characterized the protective effects of G-CSF beyond neutrophil recovery in minipigs exposed to H-ARS doses.

METHODS AND MATERIALS

Twenty male Göttingen minipigs were exposed to total body, acute ionizing radiation. Animals received either pegylated G-CSF (Neulasta) or dextrose at days 1 and 8 after irradiation. Survival was monitored over a 45-day period.

RESULTS

Neulasta decreased mortality compared with the control, reduced nadir and duration of neutropenia, and lowered prevalence of organ hemorrhage and frank bleeding episodes. Neulasta also increased plasma concentration of IGF-1 hormone, activated the cardiovascular protective IGF-1R/PI3K/Akt/eNOS/NO pathway, and enhanced membrane expression of VE-cadherin in the heart, improving vascular tone and barrier function. Expression of the acute phase protein CRP, a mediator of cardiovascular diseases and a negative regulator of the IGF-1 pathway, was also induced but at much lower extent compared with IGF-1. Activity of catalase and superoxide dismutase (SOD-1) was only marginally affected, whereas activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was downregulated.

CONCLUSIONS

In addition to a neutrophilic effect, amelioration of endothelial homeostasis and barrier function and reduction in NADPH oxidase contribute to the beneficial effects of Neulasta for the treatment of H-ARS.

Intestinal epithelial cell-specific IGF1 promotes the expansion of intestinal stem cells during epithelial regeneration and functions on the intestinal immune homeostasis

It is well known that insulin-like growth factor 1 (IGF1) acts as a trophic factor in small intestine under both physiological and pathophysiological conditions. However, it still lacks direct in vivo evidence of the functions of intestinal epithelial cell (IEC)-specific IGF1 under both normal and pathological conditions. Using IEC-specific IGF1-knockout (cKO) mice and Lgr5-eGFP-CreERT mice, we demonstrate that IEC-specific IGF1 can enhance nutrient uptake, reduce protein catabolism and energy consumption, and promote the proliferation and expansion of intestinal epithelial cells, including intestinal epithelial stem cells and intestinal secretory cells. Next, we showed that IEC-specific IGF1 renders IECs resistant to irradiation and promotes epithelial regeneration. Strikingly, transcriptome profiling assay revealed that many differentially expressed genes involved in the differentiation and maturation of lymphoid lineages were significantly suppressed in the cKO mice as compared with the control mice. We demonstrated that deletion of IGF1 in IECs enhances bacterial translocation to the mesenteric lymph nodes and liver. Furthermore, high-throughput sequencing of 16S ribosomal RNA genes of gut microbiota revealed that IEC-specific IGF1 loss profoundly affected the gut microbial composition at various levels of classification. Therefore, our findings shed light on the in vivo roles of IEC-specific IGF1 in intestinal homeostasis, epithelial regeneration, and immunity, broadening our current insights on IGF1 functions.

Expression levels of hnRNP K and p21WAF1/CIP1 are associated with resistance to radiochemotherapy independent of p53 pathway activation in rectal adenocarcinoma

Ionizing radiation (IR) is frequently applied in the treatment of rectal adenocarcinoma, however, there is marked variance in the response to radiochemotherapy between individual tumors. In our previous investigations, it was shown that the overexpression of heterogeneous nuclear ribonucleoprotein K (hnRNP K) confers radioresistance to malignant melanoma and colorectal carcinoma (CRC) in vitro, however, the underlying mechanism remains to be elucidated. As hnRNP K, a p53 binding partner and cofactor for the transcriptional activation of p53 target genes, is overexpressed in CRC, the present study investigated the possible radioprotective effect of the hnRNP K/p53-induced upregulation of p21 (also known as WAF1/CIP1) in rectal adenocarcinoma. Immunohistochemistry was performed for hnRNP K, p53 and p21 in a series of 68 consecutive cases of rectal adenocarcinoma with full molecular characterization following radiochemo-therapy and 14 corresponding pre-therapeutic biopsies, and the results were correlated with clinicopathological characteristics and the percentage of vital tumor cells following therapy. In addition, pathway analyses, protein immunoprecipitation, western immunoblotting and immunofluorescence microscopy were performed to identify dysregulated kinase signaling and hnRNP K targets upon exposure of CRC cells to IR. Although the fraction of vital tumor cells upon neoadjuvant therapy was significantly higher in hnRNP K/p21-positive tumors (P=0.0047 and P=0.0223, Students’ t-test), no significant association was found between the protein expression levels of hnRNP K, p53 and p21 (P>0.05, χ² test). Irradiation enhanced apoptotic pathway activation via p53/CHK2 phosphorylation and poly (ADP-ribose) polymerase cleavage, and induced the overexpression and interaction of hnRNP K and p53. However, p53 Ser15-phosphorylation was independent of the presence of hnRNP K, and there was no measurable effect of hnRNP K on the expression of p21 in vitro. Taken together, the results of the present study support a radioprotective role for hnRNP K, which may be mediated through an interaction with p53, however, this effect appears to be independent of the hnRNP K/p53-induced upregulation of p21 in rectal adenocarcinoma.

Selective Insulin-like Growth Factor Resistance Associated with Heart Hemorrhages and Poor Prognosis in a Novel Preclinical Model of the Hematopoietic Acute Radiation Syndrome

Although bone marrow aplasia has been considered for the past decades as the major contributor of radiation-induced blood disorders, cytopenias alone are insufficient to explain differences in the prevalence of bleeding. In this study, the minipig was used as a novel preclinical model of hematopoietic acute radiation syndrome to assess if factors other than platelet counts correlated with bleeding and survival. We sought to determine whether radiation affected the insulin-like growth factor-1 (IGF-1) pathway, a growth hormone with cardiovascular and radioprotective features. Gottingen and Sinclair minipigs were exposed to ionizing radiation at hematopoietic doses. The smaller Gottingen minipig strain was more sensitive to radiation; differences in IGF-1 levels were minimal, suggesting that increased sensitivity could depend on weak response to the hormone. Radiation caused IGF-1 selective resistance by inhibiting the anti-inflammatory anti-oxidative stress IRS/PI3K/Akt but not the pro-inflammatory MAPK kinase pathway, shifting IGF-1 signaling towards a pro-oxidant, pro-inflammatory environment. Selective IGF-1 resistance associated with hemorrhages in the heart, poor prognosis, increase in C-reactive protein and NADPH oxidase 2, uncoupling of endothelial nitric oxide synthase, inhibition of nitric oxide (NO) synthesis and imbalance between the vasodilator NO and the vasoconstrictor endothelin-1 molecules. Selective IGF-1 resistance is a novel mechanism of radiation injury, associated with a vicious cycle amplifying reactive oxygen species-induced damage, inflammation and endothelial dysfunction. In the presence of thrombocytopenia, selective inhibition of IGF-1 cardioprotective function may contribute to the development of hemostatic disorders. This finding may be particularly relevant for individuals with low IGF-1 activity, such as the elderly or those with cardiometabolic dysfunctions.

Hypoxia-Activated Adipose Mesenchymal Stem Cells Prevents Irradiation-Induced Salivary Hypofunction by Enhanced Paracrine Effect Through Fibroblast Growth Factor 10

To explore the effects and mechanisms of paracrine factors secreted from human adipose mesenchymal stem cell (hAdMSCs) that are activated by hypoxia on radioprotection against irradiation-induced salivary hypofunction in subjects undergoing radiotherapy for head and neck cancers. An organotypic spheroid coculture model to mimic irradiation (IR)-induced salivary hypofunction was set up for in vitro experiments. Human parotid gland epithelial cells were organized to form three-dimensional (3D) acinus-like spheroids on growth factor reduced -Matrigel. Cellular, structural, and functional damage following IR were examined after cells were cocultured with hAdMSCs preconditioned with either normoxia (hAdMSC^NMX ) or hypoxia (hAdMSC^HPX ). A key paracrine factor secreted by hAdMSCs^HPX was identified by high-throughput microarray-based enzyme-linked immunosorbent assay. Molecular mechanisms and signaling pathways on radioprotection were explored. Therapeutic effects of hAdMSCs^HPX were evaluated after in vivo transplant into mice with IR-induced salivary hypofunction. In our 3D coculture experiment, hAdMSCs^HPX significantly enhanced radioresistance of spheroidal human parotid epithelial cells, and led to greater preservation of salivary epithelial integrity and acinar secretory function relative to hAdMSCs^NMX . Coculture with hAdMSCs^HPX promoted FGFR expression and suppressed FGFR diminished antiapoptotic activity of hAdMSCs^HPX . Among FGFR-binding secreted factors, we found that fibroblast growth factor 10 (FGF10) contributed to therapeutic effects of hAdMSCs^HPX by enhancing antiapoptotic effect, which was dependent on FGFR-PI3K signaling. An in vivo transplant of hAdMSCs^HPX into irradiated salivary glands of mice reversed IR-induced salivary hypofunction where hAdMSC-released FGF10 contributed to tissue remodeling. Our results suggest that hAdMSCs^HPX protect salivary glands from IR-induced apoptosis and preserve acinar structure and functions by activation of FGFR-PI3K signaling via actions of hAdMSC-secreted factors, including FGF10. Stem Cells 2018;36:1020-1032.

Synergistic actions of FGF2 and bone marrow transplantation mitigate radiation-induced intestinal injury

Unwanted radiological or nuclear exposure remains a public health risk for which effective therapeutic countermeasures are lacking. Here, we evaluated the efficacy of fibroblast growth factor-2 (FGF2) in treating radiation-induced gastrointestinal syndrome (RIGS) incurred by lethal whole-body irradiation (WBI) when administered in conjunction with bone marrow transplantation (BMT). In vitro experiments indicated FGF2 treatment increased proliferation, reduced apoptosis, and upregulated AKT–GSK3β/β–catenin signaling in irradiated IEC-6 cells. We next established and analyzed mice cohorts consisting of sham irradiation (Group Sh); 12 Gy WBI (Group A); WBI with BMT (Group B); WBI with FGF2 treatment (Group F); and WBI with BMT and FGF2 treatment (Group BF). At 2 weeks post-irradiation, Group BF showed a dramatic increase in survival over all other groups. Intestinal epithelium of Group BF, but not Group B or F, showed augmented proliferation, decreased apoptosis, and preserved crypt numbers and morphology. Furthermore, Group BF maintained intestinal barrier function with minimal inflammatory disturbances in a manner comparable to Group Sh. In accordance, transcriptomic analyses showed significant upregulation of intestinal barrier and stem cell markers in Group BF relative to Groups A and B. Taken together, parenteral FGF2 synergizes with BMT to confer potent mitigation against RIGS.

Targeting p53-dependent stem cell loss for intestinal chemoprotection

The gastrointestinal (GI) epithelium is the fastest renewing adult tissue and is maintained by tissue-specific stem cells. Treatment-induced GI side effects are a major dose-limiting factor for chemotherapy and abdominal radiotherapy and can decrease the quality of life in cancer patients and survivors. p53 is a key regulator of the DNA damage response, and its activation results in stimulus- and cell type-specific outcomes via distinct effectors. We demonstrate that p53-dependent PUMA induction mediates chemotherapy-induced intestinal injury in mice. Genetic ablation of Puma, but not of p53, protects against chemotherapy-induced lethal GI injury. Blocking chemotherapy-induced loss of LGR5+ stem cells by Puma KO or a small-molecule PUMA inhibitor (PUMAi) prevents perturbation of the stem cell niche, rapid activation of WNT and NOTCH signaling, and stem cell exhaustion during repeated exposures. PUMAi also protects human and mouse colonic organoids against chemotherapy-induced apoptosis and damage but does not protect cancer cells in vitro or in vivo. Therefore, targeting PUMA is a promising strategy for normal intestinal chemoprotection because it selectively blocks p53-dependent stem cell loss but leaves p53-dependent protective effects intact.

Mesenchymal stem cells over-expressing cxcl12 enhance the radioresistance of the small intestine

The chemokine C-X-C motif chemokine 12 (CXCL12) greatly impacts various biological processes in mammals, including cell survival, growth and migration. Mesenchymal stem cells (MSCs) are promising tools for carrying foreign genes to treat radiation-induced injuries in the intestinal epithelium. In this study, human adipose-derived MSCs were constructed to over-express the mouse cxcl12 gene to treat such injuries. In vitro, because of the high levels of mouse CXCL12 in conditioned medium produced by mouse cxcl12 gene-modified cells, phosphorylation of Akt at Ser473 and Erk1/2 at Thr202/Thr204 was increased within crypt cells of irradiated organoids compared with unmodified controls. Moreover, intracellular stabilization of β-catenin was achieved after treatment of mouse cxcl12 gene-modified cells with conditioned medium. As a result, survival of crypt cells was maintained and their proliferation was promoted. When delivering mouse cxcl12 gene-modified cells into irradiated BALB/c nude mice, mice were rescued despite the clearance of cells from the host within 1 week. Irradiated mice that received mouse cxcl12 gene-modified MSCs exhibited reduced serum levels of interleukin-1α (IL-1α) and IL-6 as well as elevated levels of CXCL12. Additionally, epithelial recovery from radiation stress was accelerated compared with the irradiated-alone controls. Moreover, mouse cxcl12 gene-modified MSCs were superior to unmodified cells at strengthening host repair responses to radiation stress as well as presenting increased serum CXCL12 levels and decreased serum IL-1α levels. Furthermore, the number of crypt cells that were positive for phosphorylated Akt at Ser473 and phosphorylated Erk1/2 at Thr202/Thr204 increased following treatment with mouse cxcl12 gene-modified MSCs. Thus, cxcl12 gene-modified MSCs confer radioresistance to the intestinal epithelium.

The Role of Intestinal Stem Cells in Epithelial Regeneration Following Radiation-Induced Gut Injury

Purpose of Review

Intestinal epithelial cells show remarkable plasticity in regenerating the epithelium following radiation injury. In this review, we explore the regenerative capacity and mechanisms of various populations of intestinal stem cells (ISCs) in response to ionizing radiation.

Recent Findings

Ionizing radiation targets mitotic cells that include “active” ISCs and progenitor cells. Lineage-tracing experiments showed that several different cell types identified by a single or combination of markers are capable of regenerating the epithelium, confirming that ISCs exhibit a high degree of plasticity. However, the identities of the contributing cells marked by various markers require further validation.

Summary

Following radiation injury, quiescent and/or radioresistant cells become active stem cells to regenerate the epithelium. Looking forward, understanding the mechanisms by which ISCs govern tissue regeneration is crucial to determine therapeutic approaches to promote intestinal epithelial regeneration following injury.

Radioprotective effects of Keratinocyte Growth Factor-1 against irradiation-induced salivary gland hypofunction

Irradiation can cause salivary gland hypofunction, with hyposalivation producing discomfort, health risks, and reducing function in daily life. Despite increasing translational research interest in radioprotection, there are no satisfactory treatments available. Keratinocyte growth factor-1 stimulates proliferation of salivary epithelial cells or salivary stem/progenitor cells. However, the exact mechanism of its radioprotection against radiation-induced salivary hypofunction is not fully elucidated. Our results reveal that the radioprotective effects of keratinocyte growth factor-1 involved alleviation of growth inhibition and anti-apoptotic cell death of human parotid epithelial cells. Furthermore, keratinocyte growth factor-1 protected human parotid epithelial cells through the phosphoinositide 3-kinase - protein kinase B (Akt) pathway and inhibition of p53-mediated apoptosis through activation of mouse double minute 2. Local delivery of keratinocyte growth factor-1 into the irradiated salivary glands could protect radiation-induced salivary cell damages, suppress p53-mediated apoptosis and prevent salivary hypofunction in vivo. This suggests that keratinocyte growth factor-1 is a promising candidate to prevent radiation-induced salivary hypofunction and raise rational development keratinocyte growth factor-1 local delivery system.

Fractionated abdominal irradiation induces intestinal microvascular changes in an in vivo model of radiotherapy-induced gut toxicity

PURPOSE

Radiotherapy-induced gut toxicity (RIGT) is associated with diarrhoea, pain and rectal bleeding and can occur as an acute or chronic toxicity. The microvasculature has been shown to be altered in the development of RIGT; however, the features are not yet characterized. We hypothesized that apoptosis of microvascular cells would occur early in the gastrointestinal tract following fractionated irradiation, followed by late microvascular changes, including sclerosis and telangiectasis.

METHODS

Female Dark Agouti rats were treated with a 6-week fractionated radiation schedule of 3 × 2.5 Gy doses per week localized to the abdomen. At 3, 6 and 15 weeks, the intestines were assessed for markers of acute and chronic injury including morphological changes, collagen deposition, apoptosis and proliferation.

RESULTS

Apoptosis of microvascular cells significantly increased at 6 and 15 weeks in the jejunum (p = 0.0026 and p = 0.0062, respectively) and at 6 and 15 weeks in the colon (p < 0.0001 and p = 0.0005, respectively) in rats receiving fractionated radiation to the abdomen. Histopathological changes of the colon microvasculature were also seen from week 3, including thickening of the lamina propria and dilated, thickened, telangiectatic vessels.

CONCLUSIONS

Findings of this study provide evidence of regional and timing-specific changes in the intestinal microvasculature in response to fractionated radiotherapy which may play a role in development of both acute and chronic RIGT.

Activation of the Akt-CREB signalling axis by a proline-rich heptapeptide confers resistance to stress-induced cell death and inflammation

Cell stress of various kinds can lead to the induction of cell death and a damaging inflammatory response. Hence, a goal of therapeutic cell-stress management is to develop agents that might effectively regulate undesirable cell death and inflammation. To that end, we developed a synthetic peptide of seven amino acids based on structural mimicry to a functional domain of p53, a key factor in the responses of cells to stressful stimuli. This heptapeptide, which we term Stressin-1, was found to inhibit both cell death and the secretion of inflammatory mediators by various cell types in response to different stressful agents in vitro. The combined anti-inflammatory and anti-apoptotic activities of Stressin-1 were associated with a cellular signalling cascade that induced activation of Akt kinase and activation of the cAMP response element-binding protein (CREB) transcription factor. These immediate signalling events led to the inhibition of the signal transducer and activator of transcription and nuclear factor-κB pathways 24 hr later. Unexpectedly, we found no evidence for a direct involvement of p53 in the effects produced by Stressin-1. Intraperitoneal administration of 100 μg of Stressin-1 to lethally irradiated mice significantly protected them from death. These findings show that activating the Akt-CREB axis with Stressin-1 can counteract some of the undesirable effects of various cell stresses. Stressin-1 may have clinical usefulness.

Targeting the apoptotic Mcl-1-PUMA interface with a dual-acting compound

Despite intensive efforts in the search for small molecules with anti-cancer activity, it remains challenging to achieve both high effectiveness and safety, since many agents lack the selectivity to only act on cancer cells. The interface of two apoptotic proteins, myeloid cell leukemia-1 (Mcl-1) and p53 upregulated modulator of apoptosis (PUMA), has been recently affirmed as a target for treating cancers, as the disruption of Mcl-1-PUMA binding can reduce cancer cell survival and protect normal cells from apoptosis. However, therapeutic agents that target this interface are yet to be found. In this work, we combined pharmacophore modelling and biological tests to seek small molecules which target the Mcl-1-PUMA interface. For the first time, a small-molecule compound was identified. Its dual activity has been validated to reduce PUMA-dependent apoptosis while deactivating Mcl-1-mediated anti-apoptosis in cancer cells. Our results would provide a new avenue for the development of effective and safe anti-cancer agents.