Lymphatic drainage generates force that induces prostate cancer cell motility via activation of Yes‐associated protein (YAP), but whether this response to fluid force is conserved across cancer types is unclear. Here, we show that shear stress corresponding to fluid flow in the initial lymphatics modifies taxis in breast cancer, whereas some cell lines use rapid amoeboid migration behavior in response to fluid flow, a separate subset decrease movement. Positive responders displayed transcriptional profiles characteristic of an amoeboid cell state, which is typical of cells advancing at the edges of neoplastic tumors. Regulation of the HIPPO tumor suppressor pathway and YAP activity also differed between breast subsets and prostate cancer. Although subcellular localization of YAP to the nucleus positively correlated with overall velocity of locomotion, YAP gain‐ and loss‐of‐function demonstrates that YAP inhibits breast cancer motility but is outcompeted by other pro‐taxis mediators in the context of flow. Specifically, we show that RhoA dictates response to flow. GTPase activity of RhoA, but not Rac1 or Cdc42 Rho family GTPases, is elevated in cells that positively respond to flow and is unchanged in cells that decelerate under flow. Disruption of RhoA or the RhoA effector, Rho‐associated kinase (ROCK), blocked shear stress–induced motility. Collectively, these findings identify biomechanical force as a regulator amoeboid cell migration and demonstrate stratification of breast cancer subsets by flow‐sensing mechanotransduction pathways.

Nerve dependence in regeneration has been established more than 200 years ago but the mechanisms by which nerves are necessary to regeneration remain to be fully elucidated. Aside from their direct impact in stimulating cellular growth, nerves also have a role on the establishment of body polarities (antero‐posterior and dorso‐ventral patterns) and this has been particularly well studied in nereid annelid worms. Nereids can regenerate appendages (parapodia) and the tail (body segments). In both parapodia and tail regeneration, the presence of the nerve cord is necessary to the establishment of body polarities. In this review, we will detail the experimental procedures which have been conducted in nereids to elucidate the role of the nerve cord in the establishment of the antero‐posterior and dorso‐ventral polarities. Most of the studies reported here were published several decades ago and based on anatomical and histological analyses; this review should constitute a knowledgebase and an inspiration for needed modern‐time explorations at the molecular levels to elucidate the impact of the nervous system in the acquisition of body polarities.

Inhalation of trace amounts of ricin toxin, a plant‐derived ribosome‐inactivating protein, results in ablation of alveolar macrophages, widespread epithelial damage, and the onset of acute respiratory distress syndrome (ARDS). While ricin's receptors are ubiquitous, certain cell types are more sensitive to ricin‐induced cell death than others for reasons that remain unclear. For example, we demonstrate in side‐by‐side studies that macrophage‐like differentiated THP‐1 (dTHP‐1) cells are hyper‐sensitive to ricin, while lung epithelium‐derived A549 cells are relatively insensitive, even though both cell types experience similar degrees of translational inhibition and p38 MAPK activation in response to ricin. Using a variety of small molecule inhibitors, we provide evidence that ER stress contributes to ricin‐mediated cytotoxicity of dTHP‐1 cells, but not A549 cells. On the other hand, the insensitivity of A549 cells to ricin was overcome by the addition of (TNF)‐related apoptosis‐inducing ligand (TRAIL; CD253), a known stimulator of extrinsic programmed cell death. These results have implications for understanding the complex pathophysiology of ricin‐induced ARDS in that they demonstrate that intrinsic (e.g., ER stress) and extrinsic (e.g., TRAIL) factors may ultimately determine the fate of specific cell types following ricin intoxication.

The identification of nerves in the tumor microenvironment has ushered in a new area of research in cancer biology. Numerous studies demonstrate the presence of various types of peripheral nerves (sympathetic, parasympathetic, sensory) within the tumor microenvironment; moreover, an increased density of nerves in the tumor microenvironment correlates with worse prognosis. In this review, we address the current understanding of nerve‐mediated alterations of the tumor microenvironment and how they impact disease through a variety of processes, including direct nerve‐cancer cell communication, alteration of the infiltrative immune population, and alteration of stromal components.

To harmoniously coordinate the activities of all its different cell types, a multicellular organism critically depends on intercellular communication. One recently discovered mode of intercellular cross‐talk is based on the exchange of "extracellular vesicles" (EVs). EVs are nano‐sized heterogeneous lipid bilayer vesicles enriched in a variety of biomolecules that mediate short‐ and long‐distance communication between different cells, and between cells and their environment. Numerous studies have demonstrated important aspects pertaining to the dynamics of their release, their uptake, and sub‐cellular fate and roles in vitro. However, to demonstrate these and other aspects of EV biology in a relevant, fully physiological context in vivo remains challenging. In this review we analyze the state of the art of EV imaging in vivo, focusing in particular on zebrafish as a promising model to visualize, study, and characterize endogenous EVs in real‐time and expand our understanding of EV biology at cellular and systems level.

Non‐invasive procedures are needed for prostate cancer management, and urine represents a potential source of new biomarkers with translational value. Recent evidence has shown that the growth of new nerves in the tumor microenvironment is essential to prostate cancer progression. Neurotrophic growth factors are expressed by prostate cancer cells and contribute to prostate tumor innervation, but their presence in urine is unclear. In the present study, we have assayed the concentration of neurotrophic factors in the urine of prostate cancer patients. Urine was collected from a prospective cohort of 45 men with prostate cancer versus 30 men without cancer and enzyme‐linked immunosorbent assay was used to quantify nerve growth factor (NGF) and its precursor proNGF, brain‐derived neurotrophic factor (BDNF) and proBDNF, neurotrophin‐3, neurotrophin‐4/5, and glia‐derived neurotrophic growth factor. The results show that neurotrophic factors are detectable in various concentrations in both cancer and healthy urine, but no significant difference was found. Also, no association was observed between neurotrophic factor concentrations and prostate cancer grade. This study is the first quantification of neurotrophins in urine, and although no significant differences were observed between prostate cancer patients versus those without prostate cancer, or between prostate cancers of various grades, the potential value of neurotrophins for prostate cancer diagnosis and prognosis warrants further investigations in larger patient cohorts.

Epithelial–mesenchymal transition (EMT) plays an important role in tissue fibrosis following chronic exposure to hyperglycemia. This study investigates the role of chronic diabetes in regulating tuberin/snail/AMPK to enhance EMT and increase renal fibrosis. A new mouse model of db/db/TSC2+/− was generated by backcrossing db/db mice and TSC2+/− mice. Wild type (WT), db/db, TSC2+/− and dbdb/TSC2+/− mice were sacrificed at ages 6 and 8 months old. Tuberin protein level was significantly decreased in kidneys from diabetic compared to WT mice at both ages. In addition, tuberin and E‐cadherin protein levels were significantly decreased in dbdb/TSC2+/− compared to TSC2+/− and db/db mice. In contrast, p‐PS6K, NFkB, snail, vimentin, fibronectin, and α‐SMA protein levels were significantly increased in dbdb/TSC2+/− compared to db/db and TSC2+/− mice at ages 6 and 8 months. Both downregulation of AMPK by DN‐AMPK and downregulation of tuberin by siRNA resulted in increased NFkB, snail, and fibronectin protein expression and decreased E‐cadherin protein expression in mouse primary renal proximal tubular cells. Interestingly, downregulation of snail by siRNA increased tuberin expression via feedback through activation of AMPK and reversed the expression of epithelial proteins such as E‐cadherin as well as mesenchymal proteins such as fibronectin, NF‐KB, vimentin, and α‐SMA in mouse primary renal proximal tubular cells isolated from kidneys of four mice genotypes. The data show that chronic diabetes significantly decreases tuberin expression and that provides strong evidence that tuberin is a major key protein involved in regulating EMT. These data also demonstrated a novel role for snail in regulating of AMPK/tuberin to enhance EMT and renal cell fibrosis in diabetes.

One of the side effects of oral antiaging retinoids is increased hair shedding. Retinoids promote the expression of TGF‐β2 from fibroblasts, which stimulate collagen expression but silences keratinocytes. Since keratinocytes normally influence differentiation of dermal papilla cells at the base of the hair follicle, retinoids feasibly inhibit hair growth via the increased expression of TGF‐β2, which inhibits Wnt/β‐catenin signaling. Fortunately, the plant kingdom provides an array of alternatives as dual‐acting nutricosmetics and topicals that work independently of TGF‐β2 to confer dermal antiaging and hair health effects. These alternatives include “plant hormones” such as cytokinins and phytoestrogens. Many cytokinins are agonists of the G‐coupled adenosine receptors. Partial agonism of adenosine receptors promotes collagen synthesis independently of TGF‐β2 signaling. Adenosine expression is potentially also the mechanism of minoxidil in promotion of scalp hair growth. Because of crosstalk between adenosine and cannabinoid receptors it makes sense to try combinations of specific CB2 agonists and cytokinins (or phytoestrogens). However, dual‐acting cosmetics including peptides with high numbers of positively charged amino acids, such as lysine or arginine, offer real potential as they can be processed from multiple botanical candidates, including almond, fenugreek, pea sprouts, soy, and seaweeds. The current review summarizes much of what is known about retinoid alternatives in the plant kingdom and identifies potentially fruitful new areas of research.

ABSTRACTAlpha‐Klotho is a multi‐functional protein essential for maintenance of a myriad of cell functions. αKlotho is a single transmembrane protein with a large extracellular segment consisting of two domains (termed Kl1 and Kl2) which is shed into the extracellular fluid by proteolytic cleavage to furnish circulating soluble αKlotho. Based on cDNA sequence, an alternatively spliced mRNA is predicted to translate to a putative soluble αKlotho protein in mouse and human with only the Kl1 domain that represents a “spliced αKlotho Kl1” (spKl1) and is released from the cell without membrane targeting or cleavage. The existence of this protein remains in silico for two decades. We generated a novel antibody (anti‐spE15) against the 15 amino acid epitope (E15; VSPLTKPSVGLLLPH) which is not present in Kl1 or full‐length αKlotho and validated its specific reactivity against spKl1 in vitro. Using anti‐spE15 and two well‐established anti‐αKlotho monoclonal antibodies, we performed immunoblots, immunoprecipitation, and immunohistochemistry to investigate for expression of spKl1 in the mouse brain. We found anti‐spE15 labeling in mouse brain but were not able to see co‐labelling of Kl1 and spE15 epitopes on the same protein, which is the pre‐requisite for the existence of a spKl1 polypeptide, indicating that anti‐spE15 likely binds to another protein other than the putative spKl1. In isolated choroid plexus from mouse brain, we found strong staining with anti‐spE15, but did not find the spliced αKlotho transcript. We conclude that using reliable reagents and inclusion of proper controls, there is no evidence of the spKl1 protein in the mouse brain.