Disruption of epithelial cell-matrix interactions induces apoptosis

Extracellular and Intracellular Skeletons: How Do They Involve in Apoptosis

Apoptosis plays a key role in removing abnormal or senescent cells, maintaining the overall health of the tissue, and coordinating individual development. Recently, it has been discovered that the intracellular cytoskeleton plays a role in the apoptotic process. In addition, the regulatory role of extracellular matrix (ECM) fibrous proteins, which can be considered as the extracellular skeleton, in the process of apoptosis is rarely summarized. In this review, we collect the latest knowledge about how fibrous proteins inside and outside cells regulate apoptosis. We describe how ECM fibrous proteins participate in the regulation of death receptor and mitochondrial pathways through various signaling cascades mediated by integrins. We then explore the molecular mechanisms by which intracellular intermediate filaments regulate cell apoptosis by regulating death receptors on the cell membrane surface. Similarly, we report on novel supporting functions of microtubules in the execution phase of apoptosis and discuss their formation mechanisms. Finally, we discuss that the polypeptide fragments formed by caspase degradation of ECM fibrous proteins and intracellular intermediate filament act as local regulatory signals to play different regulatory roles in apoptosis.

Pressure Drives Rapid Burst-Like Coordinated Cellular Motion from 3D Cancer Aggregates

A key behavior observed during morphogenesis, wound healing, and cancer invasion is that of collective and coordinated cellular motion. Hence, understanding the different aspects of such coordinated migration is fundamental for describing and treating cancer and other pathological defects. In general, individual cells exert forces on their environment in order to move, and collective motion is coordinated by cell-cell adhesion-based forces. However, this notion ignores other mechanisms that encourage cellular movement, such as pressure differences. Here, using model tumors, it is found that increased pressure drove coordinated cellular motion independent of cell-cell adhesion by triggering cell swelling in a soft extracellular matrix (ECM). In the resulting phenotype, a rapid burst-like stream of cervical cancer cells emerged from 3D aggregates embedded in soft collagen matrices (0.5 mg mL-1 ). This fluid-like pushing mechanism, recorded within 8 h after embedding, shows high cell velocities and super-diffusive motion. Because the swelling in this model system critically depends on integrin-mediated cell-ECM adhesions and cellular contractility, the swelling is likely triggered by unsustained mechanotransduction, providing new evidence that pressure-driven effects must be considered to more completely understand the mechanical forces involved in cell and tissue movement as well as invasion.

Application of Porcine Kidney-Derived Extracellular Matrix as Coating, Hydrogel, and Scaffold Material for Renal Proximal Tubular Epithelial Cell

Background

Human renal proximal tubular epithelial (RPTE) cell is a very useful tool for kidney-related experiments in vitro/ex vivo. However, only a few primary RPTE cells can be obtained through kidney biopsy, the proliferation rate of primary cell is very low, and the cultured cell properties are easily altered in artificial conditions. Thus, RPTE cell usage is very tricky; we applied porcine kidney-derived extracellular matrix (renal ECM) as coating, hydrogel, and scaffold material to increase cell proliferation and maintain cellular properties providing three-dimensional (3D) niche, which can be a valuable cell delivery vehicle.

Methods

Porcine renal ECM was prepared by decellularization using 1% Triton X-100, solubilized with 0.5 M acetic acid. The final protein concentration was adjusted to 10 μg/μL (pH 7.0). The efficacies as coating, hydrogel, and scaffold materials were analyzed through cell morphology, proliferation rate, renal-associated gene expressions, chemical composition, and microstructure evaluation. The efficacies as a coating material were compared with Matrigel, collagen type 1 (col1), gelatin, fibrinogen, and thrombin. After confirmation of coating effects, the effective concentration range was decided. The efficacies as hydrogel and scaffold materials were compared with hyaluronic acid (HA) and col1, respectively.

Results

As the coating material, renal ECM showed a higher cell proliferation rate compared to other materials, except for Matrigel. Renal-associated gene expressions were significantly enhanced in the renal ECM than other materials. Coating effect on cell proliferation was dependent on the renal ECM concentration, and the effective concentration ranged from 30 to 100 μg. As the hydrogel material, renal ECM showed a distinct inner cell network morphology and significantly increased renal-associated gene expressions, compared to HA hydrogel. As the scaffold material, renal ECM showed specific amide peaks, enhanced internal porosity, cell proliferation rate, and renal-associated gene expression compared to the col1 scaffold.

Conclusions

We concluded that renal ECM can be a suitable material for RPTE cell culture and usage. More practically, the coated renal ECM stimulates RPTE cell proliferation, and the hydrogel and scaffold of renal ECM provide useful 3D culture niche and cell delivery vehicles maintaining renal cell properties.

Integrin-linked kinase (ILK): the known vs. the unknown and perspectives

Integrin-linked kinase (ILK) is a multifunctional molecular actor in cell-matrix interactions, cell adhesion, and anchorage-dependent cell growth. It combines functions of a signal transductor and a scaffold protein through its interaction with integrins, then facilitating further protein recruitment within the ILK-PINCH-Parvin complex. ILK is involved in crucial cellular processes including proliferation, survival, differentiation, migration, invasion, and angiogenesis, which reflects on systemic changes in the kidney, heart, muscle, skin, and vascular system, also during the embryonal development. Dysfunction of ILK underlies the pathogenesis of various diseases, including the pro-oncogenic activity in tumorigenesis. ILK localizes mostly to the cell membrane and remains an important component of focal adhesion. We do know much about ILK but a lot still remains either uncovered or unclear. Although it was initially classified as a serine/threonine-protein kinase, its catalytical activity is now questioned due to structural and functional issues, leaving the exact molecular mechanism of signal transduction by ILK unsolved. While it is known that the three isoforms of ILK vary in length, the presence of crucial domains, and modification sites, most of the research tends to focus on the main isoform of this protein while the issue of functional differences of ILK2 and ILK3 still awaits clarification. The activity of ILK is regulated on the transcriptional, protein, and post-transcriptional levels. The crucial role of phosphorylation and ubiquitylation has been investigated, but the functions of the vast majority of modifications are still unknown. In the light of all those open issues, here we present an extensive literature survey covering a wide spectrum of latest findings as well as a past-to-present view on controversies regarding ILK, finishing with pointing out some open questions to be resolved by further research.

Role of coiled-coil domain containing proteins in development of gastric cancer

Coiled-coil domain containing proteins (CCDCs) are a class of oligomeric proteins consisting of two or more coiled-coil domains. About 40 coiled coil family genes are associated with disease, and they can act as both pro-oncogenes and anti-oncogenes in the pathogenesis of tumors, regulating tumor proliferation, metastasis, angiogenesis, and apoptosis. Therefore, they are closely related to tumor development. This paper reviews the recent progress in the understanding of the role of CCDCs in gastric cancer, and explores their different roles and functions in the development of this malignancy.

Metabolic Reprogramming Underlying Brain Metastasis of Breast Cancer

The development of brain metastasis is a major cause of death in patients with breast cancer, characterized by rapid progression of the disease and poor prognosis, and lack of effective treatment has existed as an unresolved issue clinically. Extensive research has shown that a variety of metabolic changes associated with cellular metastasis exist in primary breast cancer or brain metastases, therefore to elucidate metabolic characteristics at each step of the metastasis cascade will provide important clues to the efficient treatment. In this review, we discuss the changes in metabolic patterns of breast cancer cells at every step of metastasis for exploring the potential therapeutic target based on metabolic reprogramming, and provide new insights on the design and development of drugs for breast cancer brain metastasis.

Evaluation of the antiapoptotic and anti-inflammatory properties of chitosan in methotrexate-induced oral mucositis in rats

BACKGROUND

Methotrexate (MTX), a chemotherapeutic agent, is known to cause oral mucositis. Chitosan has been shown to have a protective effect in inflammatory animal models. This research aimed to examine the protective effect of chitosan against oral mucositis caused by MTX.

METHODS AND RESULTS

Wistar albino rats were randomly divided into three groups. Control (n = 8), (saline via oral gavage for 5 days), MTX (n = 8), (60 mg/kg single dose MTX intraperitoneally on the 1st day and for the following 4 days saline via oral gavage), and MTX + chitosan (n = 8), (1st day single dose 60 mg/kg MTX intraperitoneally and followed with 200 mg/kg chitosan via oral gavage for 4 days). After 24 h of the last dose, the animals were euthanised. Blood, tongue, buccal and palatal mucosa tissues were collected. Serum interleukin 1-beta (IL1-β), tumour necrosis factor-alpha (TNF-α), matrix metalloproteinase (MMP-1, and MMP-2) activities, tissue bcl-2/bax ratio and the expression of caspase-3 (casp-3), and casp-9 were detected. The tissues were also examined histologically. Serum TNF-α, IL1-β, MMP-1 and MMP-2 activities and tissue casp-3 and casp-9 activities significantly increased but the bcl-2/bax ratio significantly decreased in the MTX group compared those of the control group. Histologically, diffuse inflammatory cells were observed in MTX group. However, In the MTX + chitosan group, all the values were close to those of the control group.

CONCLUSION

It was demonstrated that chitosan has a protective effect against oral mucosal damage caused by MTX. Thus, it may be a candidate agent against MTX induced oral mucositis.

Cell adhesion suppresses autophagy via Src/FAK-mediated phosphorylation and inhibition of AMPK

Autophagy is a multi-step process regulated in part by AMP-activated protein kinase (AMPK). Phosphorylation of threonine 172 on the AMPK α-subunit enhances AMPK kinase activity, resulting in activation of downstream signaling. Integrin-mediated cell adhesion activates Src/ Focal Adhesion Kinase (FAK) signaling complex, which regulates multiple cellular processes including cell survival. We show here that Src signaling leads to direct phosphorylation of the AMPK-α subunit on a novel site, tyrosine 179, resulting in suppression of AMPK-T172 phosphorylation and autophagy upon integrin-mediated cell adhesion. By using chemical inhibitors, genetic cell models and targeted mutagenesis, we confirm an important role for Src and FAK in suppressing AMPK signaling and autophagy induced by various additional stimuli, including glucose starvation. Furthermore, we found that autophagy suppression by hydroxychloroquine promotes apoptosis in a cancer cell model that had been treated with Src inhibitors. Our findings reveal a link between the Src/ FAK complex and AMPK/ autophagy regulation, which may play an important role in the maintenance of normal cellular homeostasis and tumor progression.

Dendritic Polyglycerol Amine: An Enhanced Substrate to Support Long-Term Neural Cell Culture

Long-term stable cell culture is a critical tool to better understand cell function. Most adherent cell culture models require a polymer substrate coating of poly-lysine or poly-ornithine for the cells to adhere and survive. However, polypeptide-based substrates are degraded by proteolysis and it remains a challenge to maintain healthy cell cultures for extended periods of time. Here, we report the development of an enhanced cell culture substrate based on a coating of dendritic polyglycerol amine (dPGA), a non-protein macromolecular biomimetic of poly-lysine, to promote the adhesion and survival of neurons in cell culture. We show that this new polymer coating provides enhanced survival, differentiation and long-term stability for cultures of primary neurons or neurons derived from human induced pluripotent stem cells (hiPSCs). Atomic force microscopy analysis provides evidence that greater nanoscale roughness contributes to the enhanced capacity of dPGA-coated surfaces to support cells in culture. We conclude that dPGA is a cytocompatible, functionally superior, easy to use, low cost and highly stable alternative to poly-cationic polymer cell culture substrate coatings such as poly-lysine and poly-ornithine.

Summary statement

Here, we describe a novel dendritic polyglycerol amine-based substrate coating, demonstrating superior performance compared to current polymer coatings for long-term culture of primary neurons and neurons derived from induced pluripotent stem cells.

Peri-implantation expression and regulation of ITGB8 in goat uterus

Ruminants have a superficial implantation pattern. The extended conceptus attaches to the receptive endometrium to form the cotyledonary placenta. During the attachment, a large number of events occur at the maternal-fetal interface. However, the related molecular mechanisms have not been fully understood. Integrin beta8 (ITGB8) is a subunit of integrin beta involved in embryo implantation. In this study, we determined peri-implantation expression and regulation of ITGB8 in goat uterus. The mRNA and protein levels of ITGB8 were both high in goat endometrial luminal epithelium (LE) and superficial glandular epithelium (sGE) during the adhesion period (Days 16-19 of pregnancy). Such expression profile was opposite to that of microRNA-187 (miR-187). Then, we validated that miR-187 targeted the 3' untranslated region (UTR) of ITGB8 in primary goat endometrial epithelial cells (EECs). In EECs, inhibition of miR-187 resulted in not only up-regulated ITGB8 level but also reduced cell proliferation and focal adhesion kinase (FAK) activity. Moreover, ITGB8 and miR-187 were regulated by interferon tau (IFNT). Altogether, in goat, the miR-187/ITGB8 axis may be involved in conceptus attachment and is downstream of IFNT. Our results will help us better understand the mechanisms of ruminant implantation and may provide a useful tool to improve the reproduction ratio for ruminants.

Controversies in Podocyte Loss: Death or Detachment?

Glomerular podocytes are characterized by terminally differentiated epithelial cells with limited proliferating ability; thus, podocyte loss could not be fully compensated by podocyte regeneration. A large body of clinical studies collectively demonstrated that podocyte loss correlated with glomerular diseases progression. Both podocyte death and podocyte detachment lead to podocyte loss; however, which one is the main cause remains controversial. Up to date, multiple mechanisms are involved in podocyte death, including programmed apoptotic cell death (apoptosis and anoikis), programmed nonapoptotic cell death (autophagy, entosis, and podoptosis), immune-related cell death (pyroptosis), and other types of cell death (necroptosis and mitotic catastrophe-related cell death). Apoptosis is considered a common mechanism of podocyte loss; however, most of the data were generated in vitro and the evidence of in vivo podocyte apoptosis is limited. The isolation of podocytes in the urine and subsequent culture of urinary podocytes in vitro suggest that detachment of viable podocytes could be another important mechanism for podocyte loss. In this review, we summarize recent advances that address this controversial topic on the specific circumstances of podocyte loss.

Sustained AMPK Activation and Proline Metabolism Play Critical Roles in the Survival of Matrix-Deprived Transformed Cells

Attachment to the matrix is critical for the survival of adherent cells, whereas detachment triggers death by apoptosis. Therefore, solid tumors must acquire the ability to survive the stress of matrix-detachment to transit through circulation and seed metastases. Although a central role for energy metabolism in cancer progression is well established, what distinguishes its role in the cellular state of the matrix-deprived form compared to the matrix-attached form is not fully understood yet. Using an in vitro transformation model dependent on simian virus 40 (SV40) small t (ST) antigen for cellular survival and proliferation in matrix-deprived conditions, we demonstrate that 5′-adenosine monophosphate-activated protein kinase (AMPK) activity is elevated and sustained under matrix-deprived conditions in ST-expressing fibroblasts. Additionally, these cells display elevated energy (ATP) levels under matrix-deprived conditions in contrast to cells lacking ST expression. The elevated ATP levels are coupled to increased levels of proline in ST-expressing cells, as revealed by metabolomics studies. The AMPK-dependent upregulation of proline oxidase, an enzyme of proline degradation, is a key link for elevated ATP levels. This functional link is further established by proline supplementation concomitant with AMPK activation in matrix-deprived cells lacking ST antigen, yielding ATP and enhancing survival. Thus, our data establishes a key role for AMPK-dependent regulation of proline metabolism in mediating energy homeostasis and promoting survival of matrix-deprived cells. These findings identify key markers that distinguish the metabolic states of matrix-detached and matrix-attached transformed cells and have implications in developing novel therapeutic strategies for specifically targeting matrix-detached metastasizing cancer cells.

SGK1-regulated metabolism: key for the survival of cells detached from the extracellular matrix

Cells that lack attachment to the extracellular matrix (ECM) experience metabolic defects that can lead to caspase-independent cell death. Recently, we discovered that serum and glucocorticoid kinase-1 (SGK1) plays a critical role in the regulation of glucose metabolism, the promotion of energy production, and ultimately the survival of ECM-detached cells. Abbreviations: ECM, extracellular matrix; SGK1, serum and glucocorticoid kinase-1; ROS, reactive oxygen species; CCCP, cyanide m-chlorophenyl hydrazine; PPP, pentose phosphate pathway; G3P, glyceraldhyde-3-phosphate; shRNA, short hairpin RNA; TCA, tricarboxylic acid.

Cadmium induced Fak -mediated anoikis activation in kidney via nuclear receptors (AHR/CAR/PXR)-mediated xenobiotic detoxification pathway

Cadmium (Cd) is a toxic heavy metal of considerable toxicity, possessing a serious environmental problem that threatening food safety and human health. However, the underlying mechanisms of Cd-induced nephrotoxicity and detoxification response remain largely unclear. Cd was administered at doses of 35, 70, and 140 mg/kg diet with feed for 90 days and produced potential damage to chickens' kidneys. The results showed that Cd exposure induced renal anatomical and histopathological injuries. Cd exposure up-regulated cytochrome P450 enzymes (CYP450s), activated nuclear xenobiotic receptors (NXRs) response, including aryl hydro-carbon receptor (AHR), constitutive androstane receptor (CAR), and pregnane X receptor (PXR) by low and moderate doses of Cd, and induced an increase in CYP isoforms expression. Cd exposure down-regulated phase II detoxification enzymes (glutathione-S-transferase (GST), glutathione peroxidase (GSH-PX) activities, and glutathione (GSH) content), and GST isoforms transcription . Furthermore, ATP-binding cassette (ABC) transporters, multidrug resistance protein (MRP1), and P-glycoprotein (P-GP) levels were elevated by low dose, but high dose inhibited the P-GP expression. Activation of detoxification enzymes lost their ability of resistance as increasing dose of Cd, afterwards brought into severe renal injury. Additionally, Cd suppressed focal adhesion kinase (Fak) and integrins protein expression as well as activated extrinsic pathway and intrinsic pathways, thereby producing anoikis. In conclusion, these results indicated that Cd induced Fak-mediated anoikis activation in the kidney via nuclear receptors (AHR/CAR/PXR)-mediated xenobiotic detoxification pathway.

RNA modifications act as regulators of cell death

Currently, more than one hundred types of RNA modifications have been found, and many of these modifications are reversible and dynamically regulated. RNA modifications can regulate RNA stability and translation and are thus involved in multiple biological activities. Recently, RNA modifications have been shown to have important roles in the regulation of cell death. Cell death is a critical process that maintains tissue homoeostasis and is regulated by multiple pathways in response to specific stimuli. In this review, we summarize the current understanding of the roles of RNA modifications in cell death mediation and discuss the prospects of such research.Abbreviations: m6A, N6-Methyladenosine; m6Am, N6,2'-O-Dimethyladenosine; m1A, N1-Methyladenosine; m5C, 5-Methylcytosine; hm5C, 5-Hydroxymethylcytosine; Ψ, pseudouridine; A-to-I, adenosine-to- inosine; hnRNPs, heterogeneous nuclear ribonucleoproteins; MOMP, mitochondrial outer membrane permeabilization; DD, death domain; DISC, death-inducing signalling complex; DED, death effector domain; FADD, FAS-associated protein with the death domain; TRADD, TNF receptor-associated protein with death domain; CMA, chaperone- mediated autophagy; PE, phosphatidylethanolamine; AD, alzheimer's disease; AML, acute myeloid leukaemia; miR, microRNA; 6-OHDA, 6-hydroxydopamine hydrochloride; R-2HG, R-2-hydroxyglutarate; IRES, internal ribosome entry site; BMSCs, bone-derived mesenchymal stem cells; NPCs, nucleus pulposus cells; HsCG, human chorionic gonadotropin; snoRNAs, small nucleolar RNAs; ER, endoplasmic reticulum; lncRNAs, long noncoding RNAs; TNM, tumour-node-metastasis.

Cooperation of cell adhesion and autophagy in the brain: Functional roles in development and neurodegenerative disease

Cellular adhesive connections directed by the extracellular matrix (ECM) and maintenance of cellular homeostasis by autophagy are seemingly disparate functions that are molecularly intertwined, each regulating the other. This is an emerging field in the brain where the interplay between adhesion and autophagy functions at the intersection of neuroprotection and neurodegeneration. The ECM and adhesion proteins regulate autophagic responses to direct protein clearance and guide regenerative programs that go awry in brain disorders. Concomitantly, autophagic flux acts to regulate adhesion dynamics to mediate neurite outgrowth and synaptic plasticity with functional disruption contributed by neurodegenerative disease. This review highlights the cooperative exchange between cellular adhesion and autophagy in the brain during health and disease. As the mechanistic alliance between adhesion and autophagy has been leveraged therapeutically for metastatic disease, understanding overlapping molecular functions that direct the interplay between adhesion and autophagy might uncover therapeutic strategies to correct or compensate for neurodegeneration.

IL1RAP Pulls a Double Shift in the Cysteine Factory

Anoikis is a critical barrier to cancer cell metastasis. In this issue of Cancer Discovery, Zhang and colleagues identify that IL1 receptor accessory protein suppresses anoikis in Ewing sarcoma by promoting both the activity of the system X_c ^- cystine/glutamate antiporter and cystathionine γ-lyase (CTH) transcription to sustain cysteine levels for reactive oxygen species detoxification.See related article by Zhang et al., p. 2884.

Intracranially injectable multi-siRNA nanomedicine for the inhibition of glioma stem cells

Background

Nanoparticle siRNA-conjugates are promising clinical therapeutics as indicated by recent US-FDA approval. In glioma stem cells (GSC), multiple stemness associated genes were found aberrant. We report intracranially injectable, multi-gene-targeted siRNA nanoparticle gel (NPG) for the combinatorial silencing of 3 aberrant genes, thus inhibiting the tumorogenic potential of GSCs.

Methods

NPG loaded with siRNAs targeted against FAK, NOTCH-1, and SOX-2 were prepared by the self-assembly of siRNAs with protamine-hyaluronic acid combination. Electron microscopy, DLS, and agarose gel electrophoresis were used for the physicochemical characterization. Cell transfection and gene-silencing efficiency were studied using human mesenchymal stem cells and rat C6 glioma-derived GSCs. Neurosphere inhibition was tested in vitro using GSCs derived from C6 cell line and glioma patient samples. Patient-derived xenograft model and orthotopic rat glioma model were used to test the effect of NPG on in vivo tumorigenicity.

Results

The siRNA nanoparticles with an average size ~ 250 nm and ~ 95% loading efficiency showed cellular uptake in ~95.5% GSCs. Simultaneous gene silencing of FAK, NOTCH-1, and SOX-2 led to the inhibition of neurosphere formation by GSCs, whereas normal stem cells remained unaffected and retained neuronal differentiation capability. GBM PDX models manifested significant impairment in the tumorigenic potential of NPG treated GSCs. Intracranial injection of NPG inhibited tumor growth in orthotopic rat brain tumor model.

Conclusion

Intracranially injectable n-siRNA NPG targeted to multiple stem-cell signaling impairs glioma initiation capabilities of GSCs and inhibited tumor growth in vivo.

Tethering Cells via Enzymatic Oxidative Crosslinking Enables Mechanotransduction in Non-Cell-Adhesive Materials

Cell-matrix interactions govern cell behavior and tissue function by facilitating transduction of biomechanical cues. Engineered tissues often incorporate these interactions by employing cell-adhesive materials. However, using constitutively active cell-adhesive materials impedes control over cell fate and elicits inflammatory responses upon implantation. Here, an alternative cell-material interaction strategy that provides mechanotransducive properties via discrete inducible on-cell crosslinking (DOCKING) of materials, including those that are inherently non-cell-adhesive, is introduced. Specifically, tyramine-functionalized materials are tethered to tyrosines that are naturally present in extracellular protein domains via enzyme-mediated oxidative crosslinking. Temporal control over the stiffness of on-cell tethered 3D microniches reveals that DOCKING uniquely enables lineage programming of stem cells by targeting adhesome-related mechanotransduction pathways acting independently of cell volume changes and spreading. In short, DOCKING represents a bioinspired and cytocompatible cell-tethering strategy that offers new routes to study and engineer cell-material interactions, thereby advancing applications ranging from drug delivery, to cell-based therapy, and cultured meat.

The 'Yin and Yang' of Cancer Cell Growth and Mechanosensing

In cancer, two unique and seemingly contradictory behaviors are evident: on the one hand, tumors are typically stiffer than the tissues in which they grow, and this high stiffness promotes their malignant progression; on the other hand, cancer cells are anchorage-independent-namely, they can survive and grow in soft environments that do not support cell attachment. How can these two features be consolidated? Recent findings on the mechanisms by which cells test the mechanical properties of their environment provide insight into the role of aberrant mechanosensing in cancer progression. In this review article, we focus on the role of high stiffness on cancer progression, with particular emphasis on tumor growth; we discuss the mechanisms of mechanosensing and mechanotransduction, and their dysregulation in cancerous cells; and we propose that a 'yin and yang' type phenomenon exists in the mechanobiology of cancer, whereby a switch in the type of interaction with the extracellular matrix dictates the outcome of the cancer cells.

Oncogenic signaling inhibits c-FLIPL expression and its non-apoptotic function during ECM-detachment

Inhibition of programmed cell death pathways is frequently observed in cancer cells where it functions to facilitate tumor progression. However, some proteins involved in the regulation of cell death function dichotomously to both promote and inhibit cell death depending on the cellular context. As such, understanding how cell death proteins are regulated in a context-dependent fashion in cancer cells is of utmost importance. We have uncovered evidence that cellular FLICE-like Inhibitory Protein (c-FLIP), a well-known anti-apoptotic protein, is often downregulated in tumor tissue when compared to adjacent normal tissue. These data argue that c-FLIP may have activity distinct from its canonical role in antagonizing cell death. Interestingly, we have discovered that detachment from extracellular matrix (ECM) serves as a signal to elevate c-FLIP transcription and that oncogenic signaling blocks ECM-detachment-induced c-FLIP elevation. In addition, our data reveal that downregulation of c-FLIP promotes luminal filling in mammary acini and that c-FLIP overexpression in cancer cells inhibits colony formation in cells exposed to ECM-detachment. Taken together, our study reveals an unexpected, non-apoptotic role for c-FLIP during ECM-detachment and raises the possibility that c-FLIP may have context-dependent roles during tumorigenesis.

Role of Calcium Homeostasis in Modulating EMT in Cancer

Calcium is essential for cells to perform numerous physiological processes. In cancer, the augmentation of calcium signaling supports the more proliferative and migratory cells, which is a characteristic of the epithelial-to-mesenchymal transition (EMT). By genetically and epigenetically modifying genes, channels, and entire signaling pathways, cancer cells have adapted to survive with an extreme imbalance of calcium that allows them to grow and metastasize in an abnormal manner. This cellular remodeling also allows for the evasion of immune surveillance and the development of drug resistance, which lead to poor prognosis in patients. Understanding the role calcium flux plays in driving the phenotypes associated with invasion, immune suppression, metastasis, and drug resistance remains critical for determining treatments to optimize clinical outcomes and future drug discovery.

Almost famous: Human adenoviruses (and what they have taught us about cancer)

Papillomaviruses, polyomaviruses and adenoviruses are collectively categorized as the small DNA tumour viruses. Notably, human adenoviruses were the first human viruses demonstrated to be able to cause cancer, albeit in non-human animal models. Despite their long history, no human adenovirus is a known causative agent of human cancers, unlike a subset of their more famous cousins, including human papillomaviruses and human Merkel cell polyomavirus. Nevertheless, seminal research using human adenoviruses has been highly informative in understanding the basics of cell cycle control, gene expression, apoptosis and cell differentiation. This review highlights the contributions of human adenovirus research in advancing our knowledge of the molecular basis of cancer.

Recombinant angiopoietin-like protein 4 attenuates intestinal barrier structure and function injury after ischemia/reperfusion

BACKGROUND

Intestinal barrier breakdown, a frequent complication of intestinal ischemia-reperfusion (I/R) including dysfunction and the structure changes of the intestine, is characterized by a loss of tight junction and enhanced permeability of the intestinal barrier and increased mortality. To develop effective and novel therapeutics is important for the improvement of outcome of patients with intestinal barrier deterioration. Recombinant human angiopoietin-like protein 4 (rhANGPTL4) is reported to protect the blood-brain barrier when administered exogenously, and endogenous ANGPTL4 deficiency deteriorates radiation-induced intestinal injury.

AIM

To identify whether rhANGPTL4 may protect intestinal barrier breakdown induced by I/R.

METHODS

Intestinal I/R injury was elicited through clamping the superior mesenteric artery for 60 min followed by 240 min reperfusion. Intestinal epithelial (Caco-2) cells and human umbilical vein endothelial cells were challenged by hypoxia/ reoxygenation to mimic I/R in vitro.

RESULTS

Indicators including fluorescein isothiocyanate-conjugated dextran (4 kilodaltons; FD-4) clearance, ratio of phosphorylated myosin light chain/total myosin light chain, myosin light chain kinase and loss of zonula occludens-1, claudin-2 and VE-cadherin were significantly increased after intestinal I/R or cell hypoxia/reoxygenation. rhANGPTL4 treatment significantly reversed these indicators, which were associated with inhibiting the inflammatory and oxidative cascade, excessive activation of cellular autophagy and apoptosis and improvement of survival rate. Similar results were observed in vitro when cells were challenged by hypoxia/reoxygenation, whereas rhANGPTL4 reversed the indicators close to normal level in Caco-2 cells and human umbilical vein endothelial cells significantly.

CONCLUSION

rhANGPTL4 can function as a protective agent against intestinal injury induced by intestinal I/R and improve survival via maintenance of intestinal barrier structure and functions.

Loss of CDCP1 triggers FAK activation in detached prostate cancer cells

A major metastasis suppressing mechanism is the rapid apoptotic death of cancer cells upon detachment from extracellular matrix, a process called anoikis. Focal adhesion kinase (PTK2/FAK) is a key enzyme involved in evasion of anoikis. We show that loss of the Cub-domain containing protein-1 (CDCP1), paradoxically stimulates FAK activation in the detached state of prostate cancer cells. In CDCP1low DU145 and PC3 prostate cancer cells, detachment-activation of FAK occurs through local production of PI(4,5)P2. PI(4,5)P2 is generated by the PIP5K1c-201 splicing isoform of PIP5K1c, which contains a unique SRC phosphorylation site. In the detached state, reduced expression of CDCP1 and an alternative CDCP1-independent SRC activation mechanism triggers PIP5K1c-pY644 phosphorylation by SRC. This causes a switch of Talin binding from β1-integrin to PIP5K1c-pY644 and leads to activation of PIP5K1c-FAK. Reduced CDCP1 expression also inactivates CDK5, a negative regulator of PIP5K1c. Furthermore, immersion of prostate cancer cells in 10% human plasma or fetal bovine serum is required for activation of PIP5K1c-FAK. The PIP5K1c induced detachment-activation of FAK in preclinical models sensitizes CDCP1low prostate cancer cells to FAK inhibitors. In patients, CDCP1High versus CDCP1low circulating tumor cells differ in expression of AR-v7, ONECUT2 and HOXB13 oncogenes and TMPRSS2 and display intra-patient heterogeneity of FAK-pY397 expression. Taken together, CDCP1low and CDCP1high detached prostate cancer cells activate distinct cytoplasmic kinase complexes and targetable transcription factors, which has important therapeutic implications.

Prognostic impact and potential predictive role of baseline circulating tumor cells in locally advanced head and neck squamous cell carcinoma

OBJECTIVES

The prognostic impact of circulating tumor cells (CTCs) or circulating tumor microemboli (CTM) in locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is yet to be determined, with conflicting results in previous trials. The role of induction chemotherapy (ICT) in the management of LA-HNSCC is controversial with no predictive biomarkers to guide treatment strategy in this scenario. The aim of this trial is to determine the prognostic impact of CTCs and CTM, their biomarkers expression by immunocytochemistry (ICC), and its potential role as predictors of ICT benefit in LA-HNSCC.

MATERIALS AND METHODS

Prospective study, with newly diagnosed stage III/IV non-metastatic LA-HNSCC patients treated with curative intent. Blood samples analyzed for CTCs and CTM before treatment using the ISET method.

RESULTS

A total of 83 patients were included. CTCs counts were an independent prognostic factor for overall survival (OS; HR: 1.17; 95 %CI: 1.05-1.31; p = 0.005) and progression free survival (PFS; HR:1.14; 95 %CI: 1.03-1.26; p = 0.007). Using the Lausen and Schumacher technique, 2.8 CTCs/mL for OS and 3.8 CTCs/mL for PFS were defined as the best cut-offs. CTM were detected in 27.7% of patients, correlating with worse PFS (HR = 2.70; IC95%: 1.30-5.58; p = 0.007). MRP-7 expression in CTM correlated with worse OS (HR = 3.49; 95 %CI: 1.01-12.04; p = 0.047) and PFS (HR = 3.62; 95 %CI: 1.08-12.13; p = 0.037). CTCs counts were predictive of complete response to treatment (OR = 0.74; 95 %CI: 0.58-0.95; p = 0.022) and high counts (cut-off 3.8/mL) and CTM were potential predictors of ICT benefit.

CONCLUSION

CTCs/CTM had significant prognostic impact and potential role as predictors of ICT benefit in LA-HNSCC.

Synergistic effect of cold atmospheric pressure plasma and free or liposomal doxorubicin on melanoma cells

The aim of the present study was to investigate combined effects of cold atmospheric plasma (CAP) and the chemotherapeutic drug doxorubicin (DOX) on murine and human melanoma cells, and normal cells. In addition to free drug, the combination of CAP with a liposomal drug (DOX-LIP) was also studied for the first time. Thiazolyl blue tetrazolium bromide (MTT) and Trypan Blue exclusion assays were used to evaluate cell viability; the mechanism of cell death was evaluated by flow cytometry. Combined treatment effects on the clonogenic capability of melanoma cells, was also tested with soft agar colony formation assay. Furthermore the effect of CAP on the cellular uptake of DOX or DOX-LIP was examined. Results showed a strong synergistic effect of CAP and DOX or DOX-LIP on selectively decreasing cell viability of melanoma cells. CAP accelerated the apoptotic effect of DOX (or DOX-LIP) and dramatically reduced the aggressiveness of melanoma cells, as the combination treatment significantly decreased their anchorage independent growth. Moreover, CAP did not result in increased cellular uptake of DOX under the present experimental conditions. In conclusion, CAP facilitates DOX cytotoxic effects on melanoma cells, and affects their metastatic potential by reducing their clonogenicity, as shown for the first time.

Role of α- and β-adrenergic signaling in phenotypic targeting: significance in benign and malignant urologic disease

The urinary tract is highly innervated by autonomic nerves which are essential in urinary tract development, the production of growth factors, and the control of homeostasis. These neural signals may become dysregulated in several genitourinary (GU) disease states, both benign and malignant. Accordingly, the autonomic nervous system is a therapeutic target for several genitourinary pathologies including cancer, voiding dysfunction, and obstructing nephrolithiasis. Adrenergic receptors (adrenoceptors) are G-Protein coupled-receptors that are distributed throughout the body. The major function of α1-adrenoceptors is signaling smooth muscle contractions through GPCR and intracellular calcium influx. Pharmacologic intervention of α-and β-adrenoceptors is routinely and successfully implemented in the treatment of benign urologic illnesses, through the use of α-adrenoceptor antagonists. Furthermore, cell-based evidence recently established the antitumor effect of α1-adrenoceptor antagonists in prostate, bladder and renal tumors by reducing neovascularity and impairing growth within the tumor microenvironment via regulation of the phenotypic epithelial-mesenchymal transition (EMT). There has been a significant focus on repurposing the routinely used, Food and Drug Administration-approved α1-adrenoceptor antagonists to inhibit GU tumor growth and angiogenesis in patients with advanced prostate, bladder, and renal cancer. In this review we discuss the current evidence on (a) the signaling events of the autonomic nervous system mediated by its cognate α- and β-adrenoceptors in regulating the phenotypic landscape (EMT) of genitourinary organs; and (b) the therapeutic significance of targeting this signaling pathway in benign and malignant urologic disease. Video abstract.

Burn Injury: Mechanisms of Keratinocyte Cell Death

Cutaneous burn injury is associated with epidermal loss in the zone of coagulation zone and delayed tissue loss in the zone of stasis. Thus, thermal stress can trigger both necrosis and regulated cell death (RCD) or apoptosis. Experimental in vitro and in vivo work has clearly demonstrated apoptotic events of thermally injured keratinocytes that are accompanied by morphological and biochemical markers of regulated cell death. However, in vivo data for the different pathways of regulated cell death are sparse. In vitro experiments with heat-stressed human keratinocytes have demonstrated death receptor involvement (extrinsic apoptosis), calcium influx, and disruption of mitochondrial membrane potential (intrinsic apoptosis) in regulated cell death. In addition, caspase-independent pathways have been suggested in regulated cell death. Keratinocyte heat stress leads to reduced proliferation, possibly as a result of reduced keratinocyte adhesion (anoikis) or oncogene involvement. Understanding the underlying mechanisms of RCD and the skin’s responses to thermal stress may lead to improved strategies for treating cutaneous burn trauma.

Effects of Bacillus cereus PAS38 on Immune-Related Differentially Expressed Genes of Spleen in Broilers

This study mainly explored the immunomodulatory mechanisms of the probiotic Bacillus cereus PAS38 (PB) on broiler spleen. A total of 120 avian white feather broilers were randomly divided into 4 groups (N = 30), as follows: control (CNTL, fed with basal diet), PB (fed with diet supplemented with probiotic B. cereus PAS38), vaccine (VAC, fed with basal diet and injected with Newcastle disease virus vaccine), and vaccine + PB group (PBVAC, fed with basal diet supplemented with B. cereus PAS38 and injected with NDV vaccine). The experiment was conducted for 42 days. Twelve spleens were collected from four different groups, weighed, and cut into histological sections, and transcriptome analysis was performed using RNA-seq. Results of the spleen and histological section relative weights showed that feeding with probiotic B. cereus PAS38 and vaccination had a similar tendency to promote spleen development. Compared with the CNTL group, 21 immune-related genes were significantly downregulated in the PB and PBVAC groups. These genes were mainly involved in attenuating inflammatory response. The upregulated antimicrobial peptide NK-lysin and guanylate-binding protein 1 expression levels indicated that this strain enhanced the body's antimicrobial capacity. B. cereus PAS38 also amplified the broilers' immune response to the vaccine, which mainly reflected on nonspecific immunity. Hence, probiotic B. cereus PAS38 can regulate and promote the immune function of broilers.

Methods for studying MLO-Y4 osteocytes in collagen-hydroxyapatite scaffolds in the rotary cell culture system

Purpose: The rotary cell culture system (RCCS) is a common clinorotation device for cell culture. It is also used as a low-shear suspension culture bioreactor to form functionalized 3D tissue constructs and to model microgravity. We sought to develop a 3D scaffold composed of type I collagen and hydroxyapatite (collagen-HA) to characterize MLO-Y4 osteocytes following suspension culture or clinorotation.Materials and Methods: MLO-Y4 cells were embedded in collagen-HA. The scaffold was formed into droplets for suspension culture or wall-adhered to the RCCS for clinorotation. AFM, rheometry, immunofluorescence and qRT-PCR were employed to measure the scaffold stiffness, cell viability and gene expression of cells in collagen-HA scaffolds. Dendritic cells were visualized and quantified and gene expression after suspension culture and clinorotation was compared to static controls.Results: The optimized scaffold for the RCCS consisted of collagen with 6 mg/mL HA which had a stiffness of < 1 kPa. MLO-Y4 cell viability was higher in collagen-HA scaffolds, compared to scaffolds without HA. Collagen-HA scaffolds induced higher osteocyte-specific gene expression compared to cells cultured on 2D plastic. Cells in the scaffold downregulated DMP1, E11, IL-6, and RANKL, and had fewer dendritic cells following suspension culture whereas clinorotation downregulated DMP1 and E11 genes, compared to static controls.Conclusions: Suspension culture for 3 days in collagen-HA stimulates growth of osteocytes but may also desensitize them to mechanical cues. Clinorotation for 3 days in collagen-HA does not stimulate proliferation or expression of mechanosensitive genes, indicating that it may be an effective mechanical unloading environment.

Ex vivo gene modification therapy for genetic skin diseases-recent advances in gene modification technologies and delivery

Genetic skin diseases, also known as genodermatoses, are inherited disorders affecting skin and constitute a large and heterogeneous group of diseases. While genodermatoses are rare with the prevalence rate of less than 1 in 50,000 - 200,000, they frequently occur at birth or early in life and are generally chronic, severe, and could be life-threatening. The quality of life of patients and their families are severely compromised by the negative psychosocial impact of disease, physical manifestations, and the lack or loss of autonomy. Currently, there are no curative treatments for these conditions. Ex vivo gene modification therapy that involves modification or correction of mutant genes in patients' cells in vitro and then transplanted back to patients to restore functional gene expression has being developed for genodermatoses. In this review, the ex vivo gene modification therapy strategies for genodermatoses are reviewed, focusing on current advances in gene modification and correction in patients' cells and delivery of genetically modified cells to patients with discussions on gene therapy trials which have been performed in this area.

Epidermal growth factor receptor and integrins meet redox signaling through P66shc and Rac1

This review examines the concerted role of Epidermal Growth Factor Receptor (EGFR) and integrins in regulating Reactive oxygen species (ROS) production through different signaling pathways. ROS as such are not always deleterious to the cells but they also act as signaling molecules, that regulates numerous indespensible physiological fuctions of life. Many adaptor proteins, particularly Shc and Grb2, are involved in mediating the downstream signaling pathways stimulated by EGFR and integrins. Integrin-induced activation of EGFR and subsequent tyrosine phosphorylation of a class of acceptor sites on EGFR leads to alignment and tyrosine phosphorylation of Shc, PLCγ, the p85 subunit of PI-3 K, and Cbl, followed by activation of the downstream targets Erk and Akt/PKB. Functional interactions between these receptors result in the activation of Rac1 via these adaptor proteins, thereby leading to Reactive Oxygen Species. Both GF and integrin activation can produce oxidants independently, however synergistically there is increased ROS generation, suggesting a mutual cooperation between integrins and GFRs for redox signalling. The ROS produced further promotes feed-forward stimulation of redox signaling events such as MAPK activation and gene expression. This relationship has not been reviewed previously. The literature presented here can have multiple implications, ranging from looking at synergistic effects of integrin and EGFR mediated signaling mechanisms of different proteins to possible therapeutic interventions operated by these two receptors. Furthermore, such mutual redox regulation of crosstalk between EGFR and integrins not only add to the established models of pathological oxidative stress, but also can impart new avenues and opportunities for targeted antioxidant based therapeutics.

Comprehensive understanding of anchorage-independent survival and its implication in cancer metastasis

Detachment is the initial and critical step for cancer metastasis. Only the cells that survive from detachment can develop metastases. Following the disruption of cell-extracellular matrix (ECM) interactions, cells are exposed to a totally different chemical and mechanical environment. During which, cells inevitably suffer from multiple stresses, including loss of growth stimuli from ECM, altered mechanical force, cytoskeletal reorganization, reduced nutrient uptake, and increased reactive oxygen species generation. Here we review the impact of these stresses on the anchorage-independent survival and the underlying molecular signaling pathways. Furthermore, its implications in cancer metastasis and treatment are also discussed.

Detection of Anoikis Using Cell Viability Dye and Quantitation of Caspase Activity

Anoikis is a type of programmed cell death triggered by the loss of cellular interaction with the extracellular matrix (ECM) and culminates in the activation of caspases. Specific interaction between cellular receptors such as integrins and the ECM is important to maintain cellular homeostasis in normal tissues through multiple cascades. This interaction provides not only physical attachment, but more importantly, vital interaction with the actin cytoskeleton and growth factors. Normal epithelial and endothelial cells require this interaction with ECM to survive. In cancer, the acquisition of anoikis resistance is a hallmark of malignant transformation and is required in the process of metastasis formation. As such, strategies to inhibit and/or counteract anoikis resistance are important in controlling cancer progression. In this chapter, we describe the method for detecting anoikis using cell viability and caspase activity assays.

The CD44/COL17A1 pathway promotes the formation of multilayered, transformed epithelia

At the early stage of cancer development, oncogenic mutations often cause multilayered epithelial structures. However, the underlying molecular mechanism still remains enigmatic. By performing a series of screenings targeting plasma membrane proteins, we have found that collagen XVII (COL17A1) and CD44 accumulate in RasV12-, Src-, or ErbB2-transformed epithelial cells. In addition, the expression of COL17A1 and CD44 is also regulated by cell density and upon apical cell extrusion. We further demonstrate that the expression of COL17A1 and CD44 is profoundly upregulated at the upper layers of multilayered, transformed epithelia in vitro and in vivo. The accumulated COL17A1 and CD44 suppress mitochondrial membrane potential and reactive oxygen species (ROS) production. The diminished intracellular ROS level then promotes resistance against ferroptosis-mediated cell death upon cell extrusion, thereby positively regulating the formation of multilayered structures. To further understand the functional role of COL17A1, we performed comprehensive metabolome analysis and compared intracellular metabolites between RasV12 and COL17A1-knockout RasV12 cells. The data imply that COL17A1 regulates the metabolic pathway from the GABA shunt to mitochondrial complex I through succinate, thereby suppressing the ROS production. Moreover, we demonstrate that CD44 regulates membrane accumulation of COL17A1 in multilayered structures. These results suggest that CD44 and COL17A1 are crucial regulators for the clonal expansion of transformed cells within multilayered epithelia, thus being potential targets for early diagnosis and preventive treatment for precancerous lesions.

Tissue Imaging and Quantification Relying on Endogenous Contrast

Cell-matrix interactions play an important role in regulating a variety of essential processes in multicellular organisms, and are closely associated with numerous diseases. Modified interactions have major effects upon key features of both cells and extracellular matrix (ECM), and a thorough understanding of changes in these features can lead to critically important insights of diseases as well as the identification of effective therapeutic targets. Here, we summarize recent advances in quantitative, optical imaging of cellular metabolism and ECM spatial organization using endogenous sources of contrast. Specifically, we focus on the two-photon excited fluorescence (TPEF) imaging of autofluorescent cellular coenzymes, NAD(P)H and FAD, for the extraction of metabolic information described by optical biomarkers including cellular redox state, NAD(P)H fluorescence lifetime, and mitochondrial clustering. We show representative applications in assessing adipose tissue function and detecting malignant lesions in human skin, and further demonstrate that a combination of these optical metrics can provide complementary insights into the underlying biological mechanisms. In addition, we review the development of quantitative analysis methods to extract spatial orientation and organization metrics of collagen fibers, a major ECM component, and demonstrate applications of these approaches in two and three dimensions in several diseases, including would healing, osteoarthritis and cancer, as well as assessments of matrix remodeling in hormone-regulated engineered breast tissues. Finally, we summarize this chapter and discuss important research directions that we expect will evolve in the near future.

Atovaquone Suppresses the Growth of Metastatic Triple-Negative Breast Tumors in Lungs and Brain by Inhibiting Integrin/FAK Signaling Axis

Triple-negative breast cancer (TNBC) is considered to be the most aggressive and malignant neoplasm and is highly metastatic in nature. In the current study, we investigated the anti-metastatic potential of atovaquone, a protozoal drug prescribed for Pneumocystis pneumonia. We showed that atovaquone induced apoptosis and reduced the survival of several aggressive metastatic TNBC cell lines including metastatic patient-derived cells by reducing the expression of integrin α6, integrin β4, FAK, Src, and Vimentin. In order to study the efficacy of atovaquone in suppressing metastasized breast tumor cells in brain and lungs, we performed three in vivo experiments. We demonstrated that oral administration of 50 mg/kg of atovaquone suppressed MDA-MB-231 breast tumor growth by 90% in lungs in an intravenous metastatic tumor model. Anti-metastatic effect of atovaquone was further determined by intracardiac injection of 4T1-luc breast tumor cells into the left ventricle of mouse heart. Our results showed that atovaquone treatment suppressed the growth of metastatic tumors in lungs, liver and brain by 70%, 50% and 30% respectively. In an intracranial model, the growth of HCC1806-luc brain tumors in atovaquone treated mice was about 55% less than that of control. Taken together, our results indicate the anti-metastatic effects of atovaquone in vitro and in vivo in various breast tumor metastasis models.

Mechanisms of Regulated Cell Death: Current Perspectives

Balancing cell survival and cell death is fundamental to development and homeostasis. Cell death is regulated by multiple interconnected signaling pathways and molecular mechanisms. Regulated cell death (RCD) is implicated in fundamental processes such as organogenesis and tissue remodeling, removal of unnecessary structures or cells, and regulation of cell numbers. RCD can also be triggered by exogenous perturbations of the intracellular or extracellular microenvironment when the adaptive processes that respond to stress fail. During the past few years, many novel forms of non-apoptotic RCD have been identified, and the characterization of RCD mechanisms at a molecular level has deepened our understanding of diseases encountered in human and veterinary medicine. Given the complexity of these processes, it has become clear that the identification of RCD cannot be based simply on morphologic characteristics and that descriptive and diagnostic terms presently used by pathologists-such as individual cell apoptosis or necrosis-appear inadequate and possibly misleading. In this review, the current understanding of the molecular machinery of each type of non-apoptotic RCD mechanisms is outlined. Due to the continuous discovery of new mechanisms or nuances of previously described processes, the limitations of the terms apoptosis and necrosis to indicate microscopic findings are also reported. In addition, the need for a standard panel of biomarkers and functional tests to adequately characterize the underlying RCD and its role as a mechanism of disease is considered.

Targeting Gα13-integrin interaction ameliorates systemic inflammation

Systemic inflammation as manifested in sepsis is an excessive, life-threatening inflammatory response to severe bacterial or viral infection or extensive injury. It is also a thrombo-inflammatory condition associated with vascular leakage/hemorrhage and thrombosis that is not effectively treated by current anti-inflammatory or anti-thrombotic drugs. Here, we show that MB2mP6 peptide nanoparticles, targeting the Gα13-mediated integrin "outside-in" signaling in leukocytes and platelets, inhibited both inflammation and thrombosis without causing hemorrhage/vascular leakage. MB2mP6 improved mouse survival when infused immediately or hours after onset of severe sepsis. Furthermore, platelet Gα13 knockout inhibited septic thrombosis whereas leukocyte Gα13 knockout diminished septic inflammation, each moderately improving survival. Dual platelet/leukocyte Gα13 knockout inhibited septic thrombosis and inflammation, further improving survival similar to MB2mP6. These results demonstrate that inflammation and thrombosis independently contribute to poor outcomes and exacerbate each other in systemic inflammation, and reveal a concept of dual anti-inflammatory/anti-thrombotic therapy without exacerbating vascular leakage.

Living-DNA Nanogel Appendant Enables In Situ Modulation and Quantification of Regulation Effects on Membrane Proteins

Screening appendants on membrane proteins to understand their varied regulation effects is desirable for finding the potential candidates of the membrane-protein-targeted drugs. However, most artificial appendants can hardly support in situ condition screening because they cannot evolve in situ, neither can they send out signals to reflect the modulation. Here, we designed living-DNA appendants to enable such screening. First, the living-cell rolling-circle amplification (LCRCA) strategy was developed to elongate the DNA appendants for self-tangled physical nanogels. The nanogels unify both the functions of membrane-protein modulation and quantification: their sizes increase with the increased time length of LCRCA, which change the regulation effect on the membrane proteins; their large number of repeating short sequences allow quantification of their sizes in the presence of the complementary fluorophore-tagged short DNA. Then, the performance of the living-DNA appendants was examined taking α6β4 integrins as the target, where effective regulation over the distribution of actin filaments, cell viability, and chances of anoikis are all validated. The screening also clearly elucidates the interesting nonlinear relationships between the regulations and the effects. We hope this screening strategy based on living-DNA appendants can stand for a prototype for deeper understanding of natural behaviors of membrane proteins and help in the accurate designing of the membrane-protein-targeted drugs.

Angiopoietin-like protein 2 decreases peritoneal metastasis of ovarian cancer cells by suppressing anoikis resistance

Peritoneal metastasis is a common mode of spread of ovarian cancer. Despite therapeutic advances, some patients have intractable peritoneal metastasis. Therefore, in-depth characterization of the molecular mechanism of peritoneal metastasis is a key imperative. Angiopoietin-like protein 2 (ANGPTL2) is an inflammatory factor which activates NF-κB signaling and plays an important role in the pathogenesis of various inflammatory diseases including cancers, such as lung and breast cancer. In this study, we examined the role of ANGPTL2 in ovarian cancer peritoneal metastasis. We observed no difference of cell proliferation between ANGPTL2-expressing and control cells. In the mouse intraperitoneal xenograft model, formation of peritoneal metastasis by ANGPTL2-expressing cells was significantly decreased compared to control. In the in vitro analysis, the expressions of integrin α5β1, α6, and β4, but not those of αvβ3, α3, α4, and β1, were significantly decreased in ANGPTL2-expressing cells compared to control cells. ANGPTL2-expressing cells showed significantly inhibited adherence to laminin compared to control. In addition, we observed upregulation of anoikis (a form of programmed cell death occurring under an anchorage-independent condition) and significant decrease in the expression of Bcl-2 in ANGPTL2-expressing cells as compared to control cells. These results suggest that ANGPTL2 expression in ovarian cancer cells represses peritoneal metastasis by suppressing anoikis resistance.

Production of a Foot-and-Mouth Disease Vaccine Antigen Using Suspension-Adapted BHK-21 Cells in a Bioreactor

The baby hamster kidney-21 (BHK-21) cell line is a continuous cell line used to propagate foot-and-mouth disease (FMD) virus for vaccine manufacturing. BHK-21 cells are anchorage-dependent, although suspension cultures would enable rapid growth in bioreactors, large-scale virus propagation, and cost-effective vaccine production with serum-free medium. Here, we report the successful adaptation of adherent BHK-21 cells to growth in suspension to a viable cell density of 7.65 × 10⁶ cells/mL on day 3 in serum-free culture medium. The suspension-adapted BHK-21 cells showed lower adhesion to five types of extracellular matrix proteins than adherent BHK-21 cells, which contributed to the suspension culture. In addition, a chemically defined medium (selected by screening various prototype media) led to increased FMD virus production yields in the batch culture, even at a cell density of only 3.5 × 10⁶ cells/mL. The suspension BHK-21 cell culture could be expanded to a 200 L bioreactor from a 20 mL flask, which resulted in a comparable FMD virus titer. This platform technology improved virus productivity, indicating its potential for enhancing FMD vaccine production.

Cell death as a result of calcium signaling modulation: A cancer-centric prospective

Calcium ions (Ca²⁺) and the complex regulatory system governed by Ca²⁺ signaling have been described to be of crucial importance in numerous aspects related to cell life and death decisions, especially in recent years. The growing attention given to this second messenger is justified by the pleiotropic nature of Ca²⁺-binding proteins and transporters and their consequent involvement in cell fate decisions. A growing number of works highlight that deregulation of Ca²⁺ signaling and homoeostasis is often deleterious and drives pathological conditions; in particular, a disruption of the main Ca²⁺-mediated death mechanisms may lead to uncontrolled cell growth that results in cancer. In this work, we review the latest useful evidence to better understand the complex network of pathways by which Ca²⁺ regulates cell life and death decisions.

Embryo size regulates the timing and mechanism of pluripotent tissue morphogenesis

Mammalian embryogenesis is a paradigm of regulative development as mouse embryos show plasticity in the regulation of cell fate, cell number, and tissue morphogenesis. However, the mechanisms behind embryo plasticity remain largely unknown. Here, we determine how mouse embryos respond to an increase in cell numbers to regulate the timing and mechanism of embryonic morphogenesis, leading to the formation of the pro-amniotic cavity. Using embryos and embryonic stem cell aggregates of different size, we show that while pro-amniotic cavity formation in normal-sized embryos is achieved through basement membrane-induced polarization and exocytosis, cavity formation of increased-size embryos is delayed and achieved through apoptosis of cells that lack contact with the basement membrane. Importantly, blocking apoptosis, both genetically and pharmacologically, alters pro-amniotic cavity formation but does not affect size regulation in enlarged embryos. We conclude that the regulation of embryonic size and morphogenesis, albeit concomitant, have distinct molecular underpinnings.

Protein Substrate Alters Cell Physiology in Primary Culture of Vocal Fold Epithelial Cells

The basement membrane interacts directly with the vocal fold epithelium. Signaling between the basement membrane and the epithelium modulates gene regulation, differentiation, and proliferation. The purpose of this study was to identify an appropriate simple single-protein substrate for growth of rabbit vocal fold epithelial cells. Vocal folds from 3 New Zealand white rabbits (Oryctolagus cuniculus) were treated to isolate epithelial cells, and cells were seeded onto cell culture inserts coated with collagen I, collagen IV, laminin, or fibronectin. Transepithelial electrical resistance (TEER) was measured, and phase contrast microscopy, PanCK, CK14, and E-cadherin immunofluorescence were utilized to assess for epithelial cell-type characteristics. Further investigation via immunofluorescence labeling was conducted to assess proliferation (Ki67) and differentiation (Vimentin). There was a significant main effect of substrate on TEER, with collagen IV eliciting the highest, and laminin the lowest resistance. Assessment of relative TEER across cell lines identified a larger range of TEER in collagen I and laminin. Phase contrast imaging identified altered morphology in the laminin condition, but cell layer depth did not appear to be related to TEER, differentiation, or morphology. Ki67 staining additionally showed no significant difference in proliferation. All conditions had confluent epithelial cells and dispersed mesenchymal cells, with increased mesenchymal cell numbers over time; however, a higher proportion of mesenchymal cells was observed in the laminin condition. The results suggest collagen IV is a preferable basement membrane substrate for in vitro vocal fold epithelial primary cell culture, providing consistent TEER and characteristic cell morphology, and that laminin is an unsuitable substrate for vocal fold epithelial cells and may promote mesenchymal cell proliferation.

Guaiazulene Triggers ROS-Induced Apoptosis and Protective Autophagy in Non-small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is one of the most frequent cancers worldwide, yet effective treatment remains a clinical challenge. Guaiazulene (GYZ), a cosmetic color additive, has previously been characterized as a potential antitumor agent due to observed anticancer effects. However, the efficacy of GYZ in the treatment of NSCLC and the involved molecular mechanisms remain largely unknown. Here, we indicated a role for GYZ in the suppression of NSCLC both in vitro and in vivo via triggering reactive oxygen species (ROS)-induced apoptosis. Concomitantly, GYZ induced complete autophagic flux in NSCLC cells via inhibiting the Akt/mTOR signaling pathway, which displayed cytoprotective effect against GYZ-induced growth suppression. Accompanied with autophagy inhibition obviously enhanced the effects of GYZ. Notably, GYZ acts synergistically with paclitaxel in the suppression of NSCLC in vitro. Together, our results for the first time reported that GYZ suppressed the proliferation of NSCLC and suggested a potential strategy for inhibiting NSCLC growth by combinational use of GYZ and autophagy inhibitors.

Fibronectin regulates anoikis resistance via cell aggregate formation

The loss of cell-matrix interactions induces apoptosis, known as anoikis. For successful distant metastasis, circulating tumor cells (CTCs) that have lost matrix attachment need to acquire anoikis resistance in order to survive. Cell aggregate formation confers anoikis resistance, and CTC clusters are more highly metastatic compared to single cells; however, the molecular mechanisms underlying this aggregation are not well understood. In this study, we demonstrated that cell detachment increased cell aggregation and upregulated fibronectin (FN) levels in lung and breast cancer cells, but not in their normal counterparts. FN knockdown decreased cell aggregation and increased anoikis. In addition, cell detachment induced cell-cell adhesion proteins, including E-cadherin, desmoglein-2, desmocollin-2/3, and plakoglobin. Interestingly, FN knockdown decreased the levels of desmoglein-2, desmocollin-2/3, and plakoglobin, but not E-cadherin, suggesting the involvement of desmosomal junction in cell aggregation. Accordingly, knockdown of desmoglein-2, desmocollin-2, or plakoglobin reduced cell aggregation and increased cell sensitivity to anoikis. Previously, we reported that NADPH oxidase 4 (Nox4) upregulation is important for anoikis resistance. Nox4 inhibition by siRNA or apocynin decreased cell aggregation and increased anoikis with the downregulation of FN, and, consequently, decreased desmoglein-2, desmocollin-2/3, or plakoglobin. The coexpression of Nox4 and FN was found to be significant in lung and breast cancer patients, based on cBioPortal data. In vivo mouse lung metastasis model showed that FN knockdown suppressed lung metastasis and thus enhanced survival. FN staining of micro tissue array revealed that FN expression was positive for human lung cancer (61%) and breast cancer (58%) patients. Furthermore, the expression levels of FN, desmoglein-2, desmocollin-2, and plakoglobin were significantly correlated with the poor survival of lung and breast cancer patients, as per the Kaplan-Meier plotter analysis. Altogether, our data suggest that FN upregulation and enhanced desmosomal interactions are critical for cell aggregation and anoikis resistance upon cell detachment.

Cell death pathways and viruses: Role of microRNAs

Viral infections lead to the death of more than a million people each year around the world, both directly and indirectly. Viruses interfere with many cell functions, particularly critical pathways for cell death, by affecting various intracellular mediators. MicroRNAs (miRNAs) are a major example of these mediators because they are involved in many (if not most) cellular mechanisms. Virus-regulated miRNAs have been implicated in three cell death pathways, namely, apoptosis, autophagy, and anoikis. Several molecules (e.g., BECN1 and B cell lymphoma 2 [BCL2] family members) are involved in both apoptosis and autophagy, while activation of anoikis leads to cell death similar to apoptosis. These mechanistic similarities suggest that common regulators, including some miRNAs (e.g., miR-21 and miR-192), are involved in different cell death pathways. Because the balance between cell proliferation and cell death is pivotal to the homeostasis of the human body, miRNAs that regulate cell death pathways have drawn much attention from researchers. miR-21 is regulated by several viruses and can affect both apoptosis and anoikis via modulating various targets, such as PDCD4, PTEN, interleukin (IL)-12, Maspin, and Fas-L. miR-34 can be downregulated by viral infection and has different effects on apoptosis, depending on the type of virus and/or host cell. The present review summarizes the existing knowledge on virus-regulated miRNAs involved in the modulation of cell death pathways. Understanding the mechanisms for virus-mediated regulation of cell death pathways could provide valuable information to improve the diagnosis and treatment of many viral diseases.