Pamela L Wenzel

• PhD
• Professor (Associate) at The University of Texas Health Science Center at Houston

Mechanical stress is pervasive in egress routes of malignancy, yet the intrinsic effects of force on tumour cells remain poorly understood. Here, we demonstrate that frictional force characteristic of flow in the lymphatics stimulates YAP1 to drive cancer cell migration; whereas intensities of fluid wall shear stress (WSS) typical of venous or arte...

Purpose of Review Hematopoietic stem cells (HSCs) are reliant on intrinsic and extrinsic factors for tight control of self-renewal, quiescence, differentiation, and homing. Given the intimate relationship between HSCs and their niche, increasing numbers of studies are examining how biophysical cues in the hematopoietic microenvironment impact HSC f...

Mesenchymal stromal cell (MSC) metabolism plays a crucial role in the surrounding microenvironment in both normal physiology and pathological conditions. While MSCs predominantly utilize glycolysis in their native hypoxic niche within the bone marrow, new evidence reveals the importance of upregulation in mitochondrial activity in MSC function and...

The only available option to treat radiation-induced hematopoietic syndrome is allogeneic hematopoietic cell transplantation, a therapy unavailable to many patients undergoing treatment for malignancy, which would also be infeasible in a radiological disaster. Stromal cells serve as critical components of the hematopoietic stem cell niche and are t...

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 l...

Identification of isocitrate dehydrogenase (IDH) mutations has uncovered the crucial role of metabolism in gliomagenesis. Oncolytic herpes virus (oHSV) initiates direct tumor debulking by tumor lysis and activates anti-tumor immunity, however, little is known about the role of glioma metabolism in determining oHSV efficacy. Here we identify that oH...

Cancer cells autonomously rewire metabolism to meet increased bioenergetic demands. Oncolytic HSVs (oHSVs) are attenuated Herpes simplex type 1 derived viruses that lyse tumor cells releasing damage-associated molecules triggering antitumor immunity. Currently one oHSV-1 derived virus is approved for melanoma treatment in the USA and another for re...

Background Tumor antigen-specific CD8+ T cells offer a compelling method for therapeutic targeting of solid tumors. However, efforts to identify tumor antigen-specific T cells have been hampered by limitations such as the need to pre-select antigens, inherently biasing such analyses. Here, we propose a method called ATTACH (Assessment of T cells Te...

Runx1 is an essential transcriptional factor for hemogenic endothelial cells (HECs) to transit to hematopoietic stem/progenitors in mammalian embryos. In mice, it has been shown that Runx1 +23kb enhancer region (Runx1+23) marks HECs in the embryo and HSCs in the adult bone marrow (BM) specifically. In order to identify HECs in human embryonic stem...

Introduction Transplantation of hematopoietic stem cells (HSCs) is curative for many patients with bone marrow failure and blood cancers, yet two-thirds of these patients have no suitable donor [1]. This unmet need has driven enterprising efforts to identify cues that dictate HSC fate such that alternative sources can be produced in a dish [2]. To...

The mitochondrial permeability transition pore (mPTP) is a supramolecular channel that regulates exchange of solutes across cristae membranes, with executive roles in mitochondrial function and cell death. The contribution of the mPTP to normal physiology remains debated, although evidence implicates the mPTP in mitochondrial inner membrane remodel...

Mesenchymal stem/stromal cells (MSCs) are an attractive platform for cell therapy due to their safety profile and unique ability to secrete broad arrays of immunomodulatory and regenerative molecules. Yet, MSCs are well known to require preconditioning or priming to boost their therapeutic efficacy. Current priming methods offer limited control ove...

Mesenchymal stem/stromal cells (MSCs) are an attractive platform for cell therapy due to their safety profile and unique ability to secrete broad arrays of immunomodulatory and regenerative molecules. Yet, MSCs are well known to require preconditioning or priming to boost their therapeutic efficacy. Current priming methods offer limited control ove...

Glioblastoma Multiforme (GBM) is the most aggressive malignant primary brain tumor and has abysmal 5-year overall survival. With the approval of oHSV Imlygic by FDA for metastatic melanoma and more recently, conditional approval of G47Δ, marketed by Daiichi Sankyo for GBM treatment in Japan, oncolytic viral therapy has emerged as a promising biolog...

The mitochondrial permeability transition (mPT) is a process that permits rapid exchange of small molecules across the inner mitochondrial membrane (IMM) and thus plays a vital role in mitochondrial function and cellular signaling. Formation of the pore that mediates this flux is well-documented in injury and disease but its regulation has also eme...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Purpose of Review The contribution of biomechanical forces to hematopoietic stem cell (HSC) development in the embryo is a relatively nascent area of research. Herein, we address the biomechanics of the endothelial-to-hematopoietic transition (EHT), impact of force on organelles, and signaling triggered by extrinsic forces within the aorta-gonad-me...

The immune system plays critical roles in promoting tissue repair during recovery from neurotrauma but is also responsible for unchecked inflammation that causes neuronal cell death, systemic stress, and lethal immunodepression. Understanding the immune response to neurotrauma is an urgent priority, yet current models of traumatic brain injury (TBI...

Hematopoietic stem cells (HSCs) are used in the clinic to provide life-saving therapies to patients with a variety of hematological malignancies and disorders. Yet, serious deficiencies in our understanding of how HSCs develop and self-renew continue to limit our ability to make this therapy safer and more broadly available to those who have no ava...

The self-renewal ability is a unique property of fetal-derived innate-like B-1a lymphocytes, which survive and function without being replenished by bone marrow (BM) progenitors. However, the mechanism by which IgM-secreting mature B-1a lymphocytes self-renew is poorly understood. In this study, we showed that Bmi1 was critically involved in this p...

For several decades, multipotent mesenchymal stromal cells (MSCs) have been extensively studied for their therapeutic potential across a wide range of diseases. In the preclinical setting, MSCs demonstrate consistent ability to promote tissue healing, down-regulate excessive inflammation and improve outcomes in animal models. Several proposed mecha...

Precursors of hematopoietic stem cells (pre-HSCs) have been identified as intermediate precursors during the maturation process from hemogenic endothelial cells to HSCs in the aorta-gonad-mesonephros (AGM) region of the mouse embryo at embryonic day 10.5. Although pre-HSCs acquire an efficient adult-repopulating ability after ex vivo co-culture, th...

It is generally considered that mouse embryonic stem cell (ESC) differentiation into blood cells in vitro recapitulates yolk sac (YS) hematopoi-esis. As such, similar to YS-derived B-progenitors, we demonstrate here that ESC-derived B-progenitors differentiate into B-1 and marginal zone B cells, but not B-2 cells in immunodeficient mice after trans...

It is generally considered that mouse embryonic stem cell (ESC) differentiation into blood cells in vitro recapitulates yolk sac (YS) hematopoiesis. As such, similar to YS-derived B-progenitors, we demonstrate here that ESC-derived B-progenitors differentiate into B-1 and marginal zone B cells, but not B-2 cells in immunodeficient mice after transp...

Table S2. RNA Sequencing Gene Expression Tables Comparing YS- and ESC-Derived B-Progenitors and BM- and ESC-Derived B-Progenitors

Regulating HSC progenitors via cholesterol Atherosclerosis is characterized by the buildup of cholesterol-containing lipoproteins in the vascular wall. This increased cholesterol augments hematopoietic stem and progenitor cell (HSPC) counts, and the resultant increase in leukocytes is associated with increased cardiovascular disease. Gu et al. desc...

Physical forces associated with tumor growth and drainage alter cancer cell invasiveness and metastatic potential. We previously showed that fluid frictional force, or shear stress, typical of lymphatic flow induces YAP1/TAZ activation in prostate cancer cells to promote motility dependent upon YAP1 but not TAZ. Here, we show that shear stress elev...

The beneficial effects of mesenchymal stem cell (MSC)-based cellular therapies are believed to be mediated primarily by the ability odansf MSCs to suppress inflammation associated with chronic or acute injury, infection, autoimmunity, and graft-versus-host disease. To specifically address the effects of frictional force caused by blood flow, or wal...

Mesenchymal stromal cells (MSCs) have tremendous potential for use in regenerative medicine due to their multipotency and immune cell regulatory functions. Biomimetic physical forces have been shown to direct differentiation and maturation of MSCs in tissue engineering applications; however, the effect of force on immunomodulatory activity of MSCs...

Mesenchymal stromal cells (MSCs) are believed to mobilize from the bone marrow in response to inflammation and injury, yet the effects of egress into the vasculature on MSC function are largely unknown. Here we show that wall shear stress (WSS) typical of fluid frictional forces present on the vascular lumen stimulates antioxidant and anti-inflamma...

Traumatic brain injury (TBI) is soon predicted to become the third leading cause of death and disability worldwide. After the primary injury, a complex set of secondary injuries develops hours and days later with prolonged neuroinflammation playing a key role. TBI and other inflammatory conditions are currently being treated in pre-clinical and cli...

YAP1/TAZ fluorescent reporter activity under static culture conditions Video file shows 8xGTIIC-DsRed-Monomer activity in PC3 cells during 5 hr culture period under static conditions. Video speed is 10 frames per second.

YAP1 target genes evaluated for differential gene expression in WSSexposed PC3 cells Excel file containing list of YAP1 target genes derived from Lin et al. (2015) and Stein et al. (2015).

Supplementary Figures 1-11.

Differential gene expression analysis of PC3 cells exposed to 3 hr of WSS or static conditions Excel file containing differential gene expression analysis (P < 0.01); Static vs WSS

Migration of PC3 during exposure to fluid flow Video file shows PC3 cell migration over surface of PDMS channel during 6 hr culture while exposed to WSS of 0.05 dyne/cm2. Video speed is 7 frames per second.

YAP1/TAZ fluorescent reporter activity during exposure to fluid flow Video file shows 8xGTIIC-DsRed-Monomer activity in PC3 cells during 5 hr culture while exposed to WSS of 0.05 dyne/cm2 . Video speed is 10 frames per second.

Migration of PC3 under static culture conditions Video file shows PC3 cell migration over surface of PDMS channel during 6 hr culture period under static conditions. Video speed is 7 frames per second.

Differentially expressed genes from Illumina BeadChips filtered by candidacy for regulation by YAP1/TAZ/TEAD-bound enhancers Excel file containing list of significantly changed genes (P < 0.05) filtered by a gene set of 379 genes shown in a previous report of MDA-MB-231 breast cancer cells to be regulated by YAP1/TAZ/TEAD at enhancers and to exhibi...

Differential gene expression analysis of WSS-exposed PC3 cells treated with control or YAP1 siRNA Excel file containing differential gene expression analysis (P < 0.01, 1.3 fold threshold); siControl (with WSS) versus siYAP1 (with WSS).

Blood flow promotes emergence of definitive hematopoietic stem cells (HSCs) in the developing embryo, yet the signals generated by hemodynamic forces that influence hematopoietic potential remain poorly defined. Here we show that fluid shear stress endows long-term multilineage engraftment potential upon early hematopoietic tissues at embryonic day...

Hematopoietic and vascular development share many common features, including cell surface markers and sites of origin. Recent lineage tracing studies have established that definitive hematopoietic stem and progenitor cells arise from VE-cadherin(+) hemogenic endothelial cells of the aorta-gonad-mesonephros (AGM) region, but the genetic programs und...

During embryonic development, hemodynamic forces caused by blood flow support vascular remodeling, arterialization of luminal endothelium, and hematopoietic stem cell (HSC) emergence. Previously, we reported that fluid shear stress plays a key role in stimulating nitric oxide (NO) signaling in the aorta-gonad-mesonephros (AGM) and is essential for...

The first hematopoietic stem cells (HSCs) that engraft irradiated adult mice arise in the aorta-gonad-mesonephros (AGM) on embryonic day 11.5 (E11.5). However, at this stage, there is a discrepancy between the apparent frequency of HSCs depicted with imaging and their rarity when measured with limiting dilution transplant. We have attempted to reco...

The hematopoietic system is dynamic during development and in adulthood, undergoing countless spatial and temporal transitions during the course of one's life. Microenvironmental cues in the many unique hematopoietic niches differ, characterized by distinct soluble molecules, membrane-bound factors, and biophysical features that meet the changing n...

The evolutionarily ancient arm of the E2f family of transcription factors consisting of the two atypical members E2f7 and E2f8 is essential for murine embryonic development. However, the critical tissues, cellular processes, and molecular pathways regulated by these two factors remain unknown. Using a series of fetal and placental lineage-specific...

2344 The first hematopoietic stem cells (HSC) that give rise to robust, long-term, multi-lineage reconstitution in irradiated adult recipients arise in the murine embryo at embryonic day 11.5 (E11.5). However, long-term multi-lineage engraftment in neonatal recipients has been observed from E9.0 yolk sac, suggesting that the neonatal hematopoietic...

E2F transcription factors regulate the progression of the cell cycle by repression or transactivation of genes that encode cyclins, cyclin dependent kinases, checkpoint regulators, and replication proteins. Although some E2F functions are independent of the Retinoblastoma tumor suppressor (Rb) and related family members, p107 and p130, much of E2F-...

Supplementary Figure 1. Deletion of E2f1-3 does not impair ES cell growth or differentiation. a. PCR genotyping of multiple ES cell clones after electroporation with a cre-expressing plasmid driven by the elongation factor-1 promoter (EF1-cre). b. Expression levels of nanog, oct4, eomes and cdx2 were measured by quantitative RT-PCR in trophoblast s...

The activating E2f transcription factors (E2f1, E2f2 and E2f3) induce transcription and are widely viewed as essential positive cell cycle regulators. Indeed, they drive cells out of quiescence, and the 'cancer cell cycle' in Rb1 null cells is E2f-dependent. Absence of activating E2fs in flies or mammalian fibroblasts causes cell cycle arrest, but...

In the established model of mammalian cell cycle control, the retinoblastoma protein (Rb) functions to restrict cells from entering S phase by binding and sequestering E2f activators (E2f1, E2f2 and E2f3), which are invariably portrayed as the ultimate effectors of a transcriptional program that commit cells to enter and progress through S phase. U...

Osteoblasts and endothelium constitute functional niches that support haematopoietic stem cells in mammalian bone marrow. Adult bone marrow also contains adipocytes, the number of which correlates inversely with the haematopoietic activity of the marrow. Fatty infiltration of haematopoietic red marrow follows irradiation or chemotherapy and is a di...

Biomechanical forces are emerging as critical regulators of embryogenesis, particularly in the developing cardiovascular system. After initiation of the heartbeat in vertebrates, cells lining the ventral aspect of the dorsal aorta, the placental vessels, and the umbilical and vitelline arteries initiate expression of the transcription factor Runx1...

Supplementary Information accompanies the paper on www.nature.com/nature.

This paper presents a workflow designed to quantitatively characterize the 3D structural attributes of macroscopic tissue specimens acquired at a micron level resolution using light microscopy. The specific application is a study of the morphological change in a mouse placenta induced by knocking out the retinoblastoma gene. This workflow includes...

In this paper, we propose a technique for detecting pockets on a surface-of-interest. A sequence of propagating fronts converging to the target surface is used as the basis for inspection. We compute a correspondence function between the initial and the target surface. This leads to a natural definition of the local feature size measured as the evo...

It has long been known that loss of the retinoblastoma protein (Rb) perturbs neural differentiation, but the underlying mechanism has never been solved. Rb absence impairs cell cycle exit and triggers death of some neurons, so differentiation defects may well be indirect. Indeed, we show that abnormalities in both differentiation and light-evoked e...

Deleting E2f1, but Not E2f2 or E2f3, Rescues Ectopic Mitosis in the Rb KO Retina (A) Horizontal retinal sections of the indicated genotypes and ages were stained for nuclei (DAPI, blue) and M-phase (anti-PH3, red). Scale bar is 50 μm. (B) Quantification of all PH3+ cells. (C) Quantification of ectopic PH3+ cells. Error bars represent standard devia...

GABA Neurotransmitter in the Rb KO Retina and Abnormal SACs in Chx10-Cre;RbloxP/loxP Retina Horizontal sections of the indicated genotypes and ages of retina were stained for nuclei (DAPI, blue), and (A and B) GABA (red) and Slc18a3 (green) or (C) Chat and Slc18a3 (red). (A) In P18 WT retina, GABA labelled four IPL tracks, of which the two inner tr...

List of Antibodies and Marker Patterns in Rb/E2f1 DKO SACs (97 KB DOC)

Deleting E2f1, but Not E2f2 or E2f3, Rescues Ectopic Division and Cell Death in P0 and P18 Rb KO Retina Horizontal sections of the indicated genotypes and ages were stained for nuclei (DAPI, blue), and (A) S-phase (anti-BrdU, red) or (B) apoptosis (TUNEL, red). In Rb−/− retinas, BrdU+ cells extend beyond the normal boundaries at P0 (arrows), and ec...

Deleting E2f1 Rescues Ectopic Division and Apoptosis in the Embryonic Rb KO Retina Horizontal sections of the indicated genotypes and ages (E14 and E16, the period during which SACs are born) were stained for nuclei (DAPI, blue), and either S-phase (upper two panels, anti-BrdU, red) or apoptosis (lower two panels, TUNEL, red). In Rb−/− retinas, Brd...

Deleting E2f2 or E2f3 Does Not Rescue Ganglion, Rod, or Bipolar Cell Death in the Rb KO Retina (A) Horizontal retinal sections from mice of the indicated ages and genotypes were stained for nuclei (DAPI, blue) and markers that detect ganglion cells (Pou4f2, red), rods and cones (Sag [rod arrestin], green), and rod bipolar cells (Prkca, green). Scal...

Differentiation Defects in Rb KO SACs Horizontal retinal sections of indicated genotypes and ages were stained for nuclei (DAPI, blue) and Calb2 ([A], red; only densely stained cells were counted for Figure 3C), Camk2a ([B], green), and Slc18a3 ([C], red). Scale bars are 50 μm. (564 KB PDF)

Subcellular Distribution of E2f3a Isoform in the Developing Retina Nuclear and cytoplasmic extracts from an equivalent number of retinal cells from mice of the indicated genotypes and ages were analyzed by Western blotting to detect the E2f3a protein. Lysates from E2f3a−/− mice of matched ages were used as a control to confirm the location of E2f3a...

Real-Time RT-PCR Primers (49 KB DOC)

E2f1 Deletion Rescues α-Cre;RbloxP/loxP Retinal Function ERGs were recorded from the indicated genotypes under light adapted (photopic) conditions. (A) Intensity series. (B) The b-wave amplitudes as a function of the logarithm of the flash intensity. (383 KB PDF)

An increasing number of genes known to be critical for cell cycle control, differentiation, and tumor suppression have been found to impact development of the placenta. To elucidate how these genes contribute to development of embryonic and extra-embryonic lineages, we generated a transgenic mouse in which the Cre transgene is driven by placenta-sp...

The authors examine phenotype differences in wildtype and retinoblastoma (Rb) knockout specimens of mouse placenta. Their method for volume visualization of tissue-level intermixing at a microscopic scale reveals differences between the specimens that aren't obvious in a stack of 2D images alone

The inactivation of the retinoblastoma (Rb) tumor suppressor gene in mice results in ectopic proliferation, apoptosis, and impaired differentiation in extraembryonic, neural, and erythroid lineages, culminating in fetal death by embryonic day 15.5 (E15.5). Here we show that the specific loss of Rb in trophoblast stem (TS) cells, but not in trophobl...

We present an application problem of examining phenotype differences in wildtype and retinoblastoma (Rb) knockout specimens of mouse placenta. The lack of the Rb gene causes uncontrolled tissue growth which forces infiltrations into critical sections of mouse placenta that lead to fetal death. We briefly describe our method for volume visualization...

Inactivation of the retinoblastoma gene in mouse embryos causes tissue infiltrations into critical sections of the placenta, which has been shown to affect fetal survivability. Our collaborators in cancer genetics are extremely interested in examining the three dimensional nature of these infiltrations given a stack of two dimensional light microsc...

Retinoblastoma (Rb)-deficient embryos show severe defects in neurogenesis, erythropoiesis, and lens development and die at embryonic day 14.5. Our recent results demonstrated a drastic disorganization of the labyrinth layer in the placenta of Rb-deficient embryos, accompanied by reduced placental transport function. When these Rb-/- embryos were su...

The retinoblastoma (Rb) gene was the first tumour suppressor identified1. Inactivation of Rb in mice results in unscheduled cell proliferation, apoptosis and widespread developmental defects, leading to embryonic death by day 14.5 (refs 2-4). However, the actual cause of the embryonic lethality has not been fully investigated. Here we show that los...

Deceptive mimicry is one of several hypotheses for the evolution of song copying in oscine songbirds. This hypothesis predicts that a floater or immigrant male that sings local song types may be perceived as a territory owner and benefit from the reduced aggression commonly observed between established neighbours (‘dear enemy’ effect). The present...

The extent and spatial pattern of song-type sharing amen neighboring males in one subspecies of Song Sparrow, Melospiza melodia cooperi, were examined in two San Diego County populations. Repertoire size averaged 9.6 song types per male (range 7 to 13). Song-type sharing was greatest between neighbors and declined with distance between territories....

The extent and spatial pattern of song-type sharing among neighboring males in one subspecies of Song Sparrow, Melospiza melodia cooperi, were examined in two San Diego County populations. Repertoire size averaged 9.6 song types per male (range 7 to 14). Song-type sharing was greatest between neighbors and declined with distance between territories...

In this paper, we investigate the use of N -Point correlation functions from material science literature, for medical image segmentation, and introduce a classifier suitable for use with these functions. The N -point correlation functions serve as good estimators of component material distributions and their packing in a multi-phase heterogeneous m...