Tamoxifen induces the development of hernia in mice by activating MMP-2 and MMP-13 expression

Activation of CTU2 expression by LXR promotes the development of hepatocellular carcinoma

Cytosolic thiouridylase 2 (CTU2) is an enzyme modifying transfer RNAs post-transcriptionally, which has been implicated in breast cancer and melanoma development. And we found CTU2 participated in hepatocellular carcinoma (HCC) progression here. HepG2 cells as well as xenograft nude mice model were employed to investigate the role of CTU2 in HCC development in vitro and in vivo respectively. Further, we defined CTU2 as a Liver X receptor (LXR) targeted gene, with a typical LXR element in the CTU2 promoter. CTU2 expression was activated by LXR agonist and depressed by LXR knockout. Interestingly, we also found CTU2 took part in lipogenesis by directly enhancing the synthesis of lipogenic proteins, which provided a novel mechanism for LXR regulating lipid synthesis. Meanwhile, lipogenesis was active during cell proliferation, particularly in tumor cells. Reduction of CTU2 expression was related to reduced tumor burden and synergized anti-tumor effect of LXR ligands by inducing tumor cell apoptosis and inhibiting cell proliferation. Taken together, our study identified CTU2 as an LXR target gene. Inhibition of CTU2 expression could enhance the anti-tumor effect of LXR ligand in HCC, identifying CTU2 as a promising target for HCC treatment and providing a novel strategy for the application of LXR agonists in anti-tumor effect.

Post-injury tendon mechanics are not affected by tamoxifen treatment

PURPOSE

A growing interest in the mechanisms that govern tendon healing has resulted in the develop-ment of tools, such as the tamoxifen-inducible mouse knockdown model, to address these questions. However, tamoxifen is a selective estrogen receptor modulator and may interfere with the tendon healing process. The objective of this study was to evaluate the effects of tamoxifen on post-injury tendon mechanics in wild-type mice.

METHODS

The mice underwent treatment at the time of injury using an established mouse injury model and the injured tendons were evaluated 3 weeks post-injury. The treatment contained tamoxifen suspended in corn oil and was compared to a treatment with only corn oil, as well as mice with no treatment. Tendons were evaluated by measuring the quasi-static and viscoelastic mechanics, collagen fiber realignment, cellularity, and nuclear morphology.

RESULTS

Mechanical testing of the tendons post-injury revealed no changes to viscoelastic mechanics, quasi-static mechanics, or collagen realignment during loading after tamoxifen treatment with the dosage regimen utilized (three daily injections of 4.5 mg/40 g body weight). Additionally, histological analysis revealed no changes to cellularity or cell nuclear shape.

CONCLUSION

Overall, this study revealed that tamoxifen treatment at the time of tendon injury did not result in changes to tendon mechanics or the histological parameters at 3 weeks post-injury.

Disruption of Growth Hormone Receptor in Adipocytes Improves Insulin Sensitivity and Lifespan in Mice

Growth hormone receptor knockout (GHRKO) mice have been used for 25 years to uncover some of the many actions of growth hormone (GH). Since they are extremely long-lived with enhanced insulin sensitivity and protected from multiple age-related diseases, they are often used to study healthy aging. To determine the effect that adipose tissue has on the GHRKO phenotype, our laboratory recently created and characterized adipocyte-specific GHRKO (AdGHRKO) mice, which have increased adiposity but appear healthy with enhanced insulin sensitivity. To test the hypothesis that removal of GH action in adipocytes might partially replicate the increased lifespan and healthspan observed in global GHRKO mice, we assessed adiposity, cytokines/adipokines, glucose homeostasis, frailty, and lifespan in aging AdGHRKO mice of both sexes. Our results show that disrupting the GH receptor gene in adipocytes improved insulin sensitivity at advanced age and increased lifespan in male AdGHRKO mice. AdGHRKO mice also exhibited increased fat mass, reduced circulating levels of insulin, c-peptide, adiponectin, resistin, and improved frailty scores with increased grip strength at advanced ages. Comparison of published mean lifespan data from GHRKO mice to that from AdGHRKO and muscle-specific GHRKO mice suggests that approximately 23% of lifespan extension in male GHRKO is due to GHR disruption in adipocytes vs approximately 19% in muscle. Females benefited less from GHR disruption in these 2 tissues with approximately 19% and approximately 0%, respectively. These data indicate that removal of GH's action, even in a single tissue, is sufficient for observable health benefits that promote long-term health, reduce frailty, and increase longevity.

Apparent Absence of BMAL1-Dependent Skeletal Muscle-Kidney Cross Talk in Mice

BMAL1 is a core mammalian circadian clock transcription factor responsible for the regulation of the expression of thousands of genes. Previously, male skeletal-muscle-specific BMAL1-inducible-knockout (iMS-BMAL1 KO) mice have been described as a model that exhibits an aging-like phenotype with an altered gait, reduced mobility, muscle weakness, and impaired glucose uptake. Given this aging phenotype and that chronic kidney disease is a disease of aging, the goal of this study was to determine if iMS-BMAL1 KO mice exhibit a renal phenotype. Male iMS-BMAL1 KO and control mice were challenged with a low potassium diet for five days. Both genotypes responded appropriately by conserving urinary potassium. The iMS-BMAL1 KO mice excreted less potassium during the rest phase during the normal diet but there was no genotype difference during the active phase. Next, iMS-BMAL1 KO and control mice were used to compare markers of kidney injury and assess renal function before and after a phase advance protocol. Following phase advance, no differences were detected in renal mitochondrial function in iMS-BMAL1 KO mice compared to control mice. Additionally, the glomerular filtration rate and renal morphology were similar between groups in response to phase advance. Disruption of the clock in skeletal muscle tissue activates inflammatory pathways within the kidney of male mice, and there is evidence of this affecting other organs, such as the lungs. However, there were no signs of renal injury or altered function following clock disruption of skeletal muscle under the conditions tested.

Adaptation to exercise-induced stress is not dependent on cardiomyocyte α1A-adrenergic receptors

The 'fight or flight' response to physiological stress involves sympathetic nervous system activation, catecholamine release and adrenergic receptor stimulation. In the heart, this induces positive inotropy, previously attributed to the β₁-adrenergic receptor subtype. However, the role of the α_1A-adrenergic receptor, which has been suggested to be protective in cardiac pathology, has not been investigated in the setting of physiological stress. To explore this, we developed a tamoxifen-inducible, cardiomyocyte-specific α_1A-adrenergic receptor knock-down mouse model, challenged mice to four weeks of endurance swim training and assessed cardiac outcomes. With 4-OH tamoxifen treatment, expression of the α_1A-adrenergic receptor was knocked down by 80-89%, without any compensatory changes in the expression of other adrenergic receptors, or changes to baseline cardiac structure and function. Swim training caused eccentric hypertrophy, regardless of genotype, demonstrated by an increase in heart weight/tibia length ratio (30% and 22% in vehicle- and tamoxifen-treated animals, respectively) and an increase in left ventricular end diastolic volume (30% and 24% in vehicle- and tamoxifen-treated animals, respectively) without any change in the wall thickness/chamber radius ratio. Consistent with physiological hypertrophy, there was no increase in fetal gene program (Myh7, Nppa, Nppb or Acta1) expression. In response to exercise-induced volume overload, stroke volume (39% and 30% in vehicle- and tamoxifen-treated animals, respectively), cardiac output/tibia length ratio (41% in vehicle-treated animals) and stroke work (61% and 33% in vehicle- and tamoxifen-treated animals, respectively) increased, regardless of genotype. These findings demonstrate that cardiomyocyte α_1A-adrenergic receptors are not necessary for cardiac adaptation to endurance exercise stress and their acute ablation is not deleterious.

Differential requirements for MDM2 E3 activity during embryogenesis and in adult mice

The p53 tumor suppressor protein is a potent activator of proliferative arrest and cell death. In normal cells, this pathway is restrained by p53 protein degradation mediated by the E3-ubiquitin ligase activity of MDM2. Oncogenic stress releases p53 from MDM2 control, so activating the p53 response. However, many tumors that retain wild-type p53 inappropriately maintain the MDM2-p53 regulatory loop in order to continuously suppress p53 activity. We have shown previously that single point mutations in the human MDM2 RING finger domain prevent the interaction of MDM2 with the E2/ubiquitin complex, resulting in the loss of MDM2's E3 activity without preventing p53 binding. Here, we show that an analogous mouse MDM2 mutant (MDM2 I438K) restrains p53 sufficiently for normal growth but exhibits an enhanced stress response in vitro. In vivo, constitutive expression of MDM2 I438K leads to embryonic lethality that is rescued by p53 deletion, suggesting MDM2 I438K is not able to adequately control p53 function through development. However, the switch to I438K expression is tolerated in adult mice, sparing normal cells but allowing for an enhanced p53 response to DNA damage. Viewed as a proof of principle model for therapeutic development, our findings support an approach that would inhibit MDM2 E3 activity without preventing MDM2/p53 binding as a promising avenue for development of compounds to activate p53 in tumors with reduced on-target toxicities.

Decreased collagen type III synthesis in skin fibroblasts is associated with parastomal hernia following colostomy

Parastomal hernia (PH) is a common complication following stoma formation. Abnormal collagen synthesis has been suggested to be involved in PH. The aim of the present study is to explore the effect and mechanism of the collagen synthesis on PH. Data from 157 patients with rectal cancer who received permanent colostomy were retrospectively collected and analyzed to identify the risk factors for PH. Primary culture of skin fibroblasts from patients with or without PH were performed. Cell viability, migration and invasion levels were detected by Cell Counting Kit‑8, and wound healing and Transwell assays, respectively. Reverse transcription quantitative polymerase chain reaction and western blot analysis assays were performed to measure the gene and protein expression levels, respectively. The risk factors of sex, body mass index, aperture size and collagen expression were closely associated with the occurrence of PH. α1 (III) procollagen expression levels were significantly increased in patients with PH, while no marked difference in α1 (I) procollagen mRNA expression levels were observed in patients with or without PH. The viability and motility of fibroblasts from the patients with hernia were suppressed. The expression levels of matrix metalloproteinase (MMP)‑2 and MMP‑9 were decreased while the levels of collagen III and metalloproteinase inhibitor 1 (TIMP‑1) were increased in the fibroblasts from the patients with PH. Silencing TIMP‑1 expression promoted fibroblast migration and invasion and reversed the patterns of MMP‑2, MMP‑9 and collagen III expression in fibroblasts from the patients with PH. Decreased collagen III may inhibit the development of PH, potentially through decreases in TIMP‑1 expression. Therefore, the results from the present study may provide a novel target for PH therapy.

Tamoxifen affects chronic pancreatitis-related fibrogenesis in an experimental mouse model: an effect beyond Cre recombination

Tamoxifen is very successfully used for the induction of Cre^ERT‐mediated genomic recombination in conditional mouse models. Recent studies, however, indicated that tamoxifen might also affect the fibrotic response in several disease models following administration, both in vitro and in vivo. In order to investigate a possible effect of tamoxifen on pancreatic fibrogenesis and to evaluate an optimal treatment scheme in an experimental pancreatitis mouse model, we administered tamoxifen by oral gavage to both male and female C57BL/6J mice and then waited for different periods of time before inducing chronic pancreatitis by cerulein. We observed a sex‐specific and time‐dependent effect of tamoxifen on the fibrotic response as measured by collagen deposition and the number of myofibroblasts and macrophages. The findings of in vitro studies, in which cerulein was administrated with or without 4‐hydroxytamoxifen to stimulate primary murine female and male pancreatic stellate cells, supported our in vivo observations. Real‐time PCR also indicated that this effect may be related to differences in ERα expression between female and male stellate cells. Our data demonstrate that tamoxifen administration has unignorable side effects, which affect the experimental outcome in a cerulein‐based model of chronic pancreatitis in mice. We suggest a 2‐week waiting period before cerulein administration to reduce side effects to a minimum for the described fibrosis model in female mice.

Inhibition of Vascular Calcification

Objective- Vascular calcification is a major risk factor for rupture of atherosclerotic plaques. High expression of BMP2 (bone morphogenetic protein 2) in lesions suggests its importance in vascular calcification during atherosclerosis. Teniposide is a Topo II (DNA topoisomerase II) inhibitor and is used for cancer treatment. Previously, we reported that teniposide activated macrophage ABCA1 (ATP-binding cassette transporter A1) expression and free cholesterol efflux indicating Topo II inhibitors may demonstrate antiatherogenic properties. Herein, we investigated the effects of teniposide on the development of atherosclerosis and vascular calcification in apoE^-/- (apoE deficient) mice. Approach and Results- apoE^-/- mice were fed high-fat diet containing teniposide for 16 weeks, or prefed high-fat diet for 12 weeks followed by high-fat diet containing teniposide for 4 weeks. Atherosclerosis and vascular calcification were determined. Human aortic smooth muscle cells were used to determine the mechanisms for teniposide-inhibited vascular calcification. Teniposide reduced atherosclerotic lesions. It also substantially reduced vascular calcification without affecting bone structure. Mechanistically, teniposide reduced vascular calcification by inactivating BMP2/(pi-Smad1/5/8 [mothers against decapentaplegic homolog 1, 5, and 8])/RUNX2 (runt-related transcription factor 2) axis in a p53-dependent manner. Furthermore, activated miR-203-3p by teniposide functioned as a link between activated p53 expression and inhibited BMP2 expression in inhibition of calcification. Conclusions- Our study demonstrates that teniposide reduces vascular calcification by regulating p53-(miR-203-3p)-BMP2 signaling pathway, which contributes to the antiatherogenic properties of Topo II inhibitors.

Hernia and Cancer: The Points Where the Roads Intersect

Introduction: This review aimed to present common points, intersections, and potential interactions or mutual effects for hernia and cancer. Besides direct relationships, indirect connections, and possible involvements were searched. Materials and Methods: A literature search of PubMed database was performed in July 2018 as well as a search of relevant journals and reference lists. The total number of screened articles was 1,422. Some articles were found in multiple different searches. A last PubMed search was performed during manuscript writing in December 2018 to update the knowledge. Eventually 427 articles with full text were evaluated, and 264 included, in this review. Results: There is no real evidence for a possible common etiology for abdominal wall hernias and any cancer type. The two different diseases had been found to have some common points in the studies on genes, integrins, and biomarkers, however, to date no meaningful relationship has been identified between these points. There is also some, albeit rather conflicting, evidence for inguinal hernia being a possible risk factor for testicular cancer. Neoadjuvant or adjuvant therapeutic modalities like chemotherapy and radiotherapy may cause postoperative herniation with their adverse effects on tissue repair. Certain specific substances like bevacizumab may cause more serious complications and interfere with hernia repair. There are only two articles in PubMed directly related to the topic of "hernia and cancer." In one of these the authors claimed that there was no association between cancer development and hernia repair with mesh. The other article reported two cases of squamous-cell carcinoma developed secondary to longstanding mesh infections. Conclusion: As expected, the relationship between abdominal wall hernias and cancer is weak. Hernia repair with mesh does not cause cancer, there is only one case report on cancer development following a longstanding prosthetic material infections. However, there are some intersection points between these two disease groups which are worthy of research in the future.

Activation of liver X receptor plays a central role in antiviral actions of 25-hydroxycholesterol

Production of 25-hydroxycholesterol (25HC), a potent inhibitor of viral infection, is catalyzed by cholesterol 25-hydroxylase (CH25H). We previously reported that 25HC induced CH25H expression in a liver X receptor (LXR)-dependent manner, implying that LXR can play an important role in antiviral infection. In this study, we determined that activation of LXR by 25HC or synthetic ligands [T0901317 (T317) or GW3965] inhibited infection of herpes simplex virus type 1 (HSV-1) or MLV-(VSV)-GFP in HepG2 cells or RAW 264.7 macrophages. Genetic deletion of LXRα, LXRβ, or CH25H expression in HepG2 cells by CRISPR/Cas9 method increased cell susceptibility to HSV-1 infection and attenuated the inhibition of LXR on viral infection. Lack of interferon (IFN)-γ expression also increased cell susceptibility to viral infection. However, it attenuated, but did not block, the inhibition of LXR on HSV-1 infection. In addition, expression of CH25H, but not IFN-γ, was inversely correlated to cell susceptibility to viral infection and the antiviral actions of LXR. Metabolism of 25HC into 25HC-3-sulfate (25HC3S) by cholesterol sulfotransferase-2B1b moderately reduced the antiviral actions of 25HC because 25HC3S is a weaker inhibitor of HSV-1 infection than 25HC. Furthermore, administration of T317 to BALB/c mice reduced HSV-1 growth in mouse tissues. Taken together, we demonstrate an antiviral system of 25HC with involvement of LXR activation, interaction between CH25H and IFN-γ, and 25HC metabolism.

All-Trans Retinoic Acid Ameliorates the Early Experimental Cerebral Ischemia-Reperfusion Injury in Rats by Inhibiting the Loss of the Blood-Brain Barrier via the JNK/P38MAPK Signaling Pathway

All-trans retinoic acid (ATRA) influences the outcomes of cerebral ischemic reperfusion (CIR) injury, but the mechanism remains unclear. The present study aimed to investigate the effects of ATRA on loss of the blood brain barrier (BBB) following CIR and to explore the possible mechanisms. Transient middle cerebral artery occlusion was performed on male SD rats to construct an in vivo CIR model. Neurological deficits, BBB permeability, brain edema, MRI and JNK/P38 MAPK proteins were detected at 24 h following CIR. We demonstrated that ATRA pretreatment could alleviate CIR-induced neurological deficits, increase of BBB permeability, infarct volume, degradation of tight junction proteins, inhibit MMP-9 protein expression and activity. ATRA treatment also reduced the p-P38 and p-JNK protein level. However the protective effect of ATRA on CIR could be reversed by administration of retinoic acid alpha receptor antagonist Ro41-5253. SP600125 and SB203580, which is the JNK/P38 pathway inhibitors has the same protective effect as ATRA. These results indicated that ATRA may inhibit the JNK/P38 MAPK pathway to alleviate BBB disruption and improve CIR outcomes.

25-Hydroxycholesterol activates the expression of cholesterol 25-hydroxylase in an LXR-dependent mechanism

Cholesterol 25-hydroxylase (CH25H) catalyzes the production of 25-hydroxycholesterol (25-HC), an oxysterol that can play an important role in different biological processes. However, the mechanisms regulating CH25H expression have not been fully elucidated. In this study, we determined that CH25H is highly expressed in mouse liver and peritoneal macrophages. We identified several liver X receptor (LXR) response elements (LXREs) in the human CH25H promoter. In HepG2 cells, activation of LXR by 25-HC or other oxysterols and synthetic ligands [T0901317 (T317) and GW3965] induced CH25H protein expression, which was associated with increased CH25H mRNA expression. 25-HC or T317 activated CH25H transcription in an LXRE-dependent manner. Thus, high-expressing LXRα or LXRβ activated CH25H expression, and the activation was further enhanced by LXR ligands. In contrast, inhibition of LXRα/β expression attenuated 25-HC or T317-induced CH25H expression. Deficiency of interferon γ expression reduced, but did not block, LXR ligand-induced hepatic CH25H expression. Activation of LXR also substantially induced macrophage CH25H expression. In vivo, administration of GW3965 to mice increased CH25H expression in both liver and peritoneal macrophages. Taken together, our study demonstrates that 25-HC can activate CH25H expression in an LXR-dependent manner, which may be an important mechanism to exert the biological actions of 25-HC.

The effect of estrogen on tendon and ligament metabolism and function

Tendons and ligaments are crucial structures inside the musculoskeletal system. Still many issues in the treatment of tendon diseases and injuries have yet not been resolved sufficiently. In particular, the role of estrogen-like compound (ELC) in tendon biology has received until now little attention in modern research, despite ELC being a well-studied and important factor in the physiology of other parts of the musculoskeletal system. In this review we attempt to summarize the available information on this topic and to determine many open questions in this field.

Anti-angiogenic properties of artemisinin derivatives (Review)

Angiogenesis, the process involving the development of new blood vessels from existing capillaries, is critical for growth and wound healing. However, pathological angiogenesis contributes to the pathogeneses of numerous diseases, including cancer, rheumatoid arthritis, diabetic retinopathy and macular degeneration. Hence, the inhibition of angiogenesis is an effective therapeutic approach for these diseases. Apart from its anti-malarial properties, artemisinin and its derivatives also exhibit potent anti-angiogenic properties. The molecular mechanisms underlying their inhibitory effects on angiogenesis have been studied by several groups. These investigations have revealed that artemisinins inhibit angiogenesis via the perturbations of cellular signaling pathways involved in the regulation of angiogenesis. Along with a brief introduction to artemisinin derivatives, this review provides a detailed summary of the effects of artemisinins on the mitogen-activated protein kinase (MAPK) pathway, the nuclear factor-κB (NF-κB) pathway and the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. Due to the multiplicity of their actions on relevant signaling pathways, artemisinins are promising candidates with potential for use as anti-angiogenic agents for the treatment of related diseases or disorders.

Metalloproteinases and Their Inhibitors in Patients with Inguinal Hernia

AIM

The aim of this prospective study is to investigate if there is a relationship between inguinal hernia, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs).

MATERIALS AND METHODS

This case control study was performed on patients admitted to the general surgery department of Erzincan University Hospital. Four groups were created: control, indirect hernia, direct hernia, and bilateral hernia. All groups were comprised of 11 patients. Serum and tissue levels of MMP-1, MMP-2, MMP-9, MMP-13, TIMP-1, TIMP-2, TIMP-3, and hydroxyproline were evaluated.

RESULTS

MMPs values were significantly high at hernia groups, especially at bilateral hernia group (p < 0.05), whereas TIMPs values were significantly low at bilateral hernia group (p < 0.05). MMPs values were increasing at hernia groups in an order as control, indirect, direct, and bilateral. TIMPs values were decreasing at hernia groups in an order as control, indirect, direct, and bilateral.

CONCLUSION

Increased levels of MMP-1-2-9-13 and decreased levels of TIMP-1-2-3 may have played role in the formation of inguinal hernia. Hernia is not only a local defect, but a reflection of systemic disease. This is even more significant for bilateral hernias.