The Oviedo Lab
​​Stem Cell Research

Mechanisms of Stem Cell Regulation 

Stem cells are undifferentiated cells critical for embryonic development, adult tissue maintenance and injury repair. Stem cells play essential role in cancer and degenerative diseases, but the molecular basis regulating their behavior remains poorly understood. Our group investigates the fundamental mechanisms of stem cell regulation to gain insights on the process of regeneration, malignant cell transformation and the renewal of adult tissues.  

Research in our lab uses planarians, a remarkable animal model that allows observation of stem cells in their natural environment. Planarians are flatworms with a large and accessible adult stem cell population called neoblasts. Neoblasts continuously divide, migrate, and differentiate to support cellular turnover and repair of damaged tissues. Planarians possess astonishing regenerative capacity as well as evolutionary conservation of cellular signaling pathways. We apply cutting-edge molecular and computational techniques to study planarian' stem cells under three different scenarios:
Tissue Regeneration
​Planarians regenerate any missing/damaged tissues in their body. We study signals and molecules guiding the stem cell-mediated process of regeneration in planarians. Our group applies an intersdisciplinary approach that bridges molecular genetics, electrophysiology, immunology, and genomics to understand the mechanisms that underlie tissue regeneration.
​Manipulation of tumor suppressor genes and DNA repair mechanisms leads to cancer-like phenotypes in planarians. Our work in planarians aims at identifying molecular targets driving cellular transformation and uncontrollable stem cell proliferation. The long-term goal of this research is to selectively eliminate cancer cells without disrupting tissue physiology.    
Tissue Maintenance
The replacement of old and damaged cells is critical to maintain body homeostasis. Neoblasts continuously divide (yellow dots on the right picture) to support renewal of tissues throughout the planarian body. We investigate the process of cellular turnover in planarians by focusing on genetic and epigenetic signals that guide the behavior of progenitor cells.      


DNA damage and tissue repair: What we can learn from planaria
           Barghouth PG, Thiruvalluvan M,  LeGro M, Oviedo NJ.
                  Semin Cell Dev Biol. 2018 May 3. pii: S1084-9521(17)30237-9. doi: 10.1016/j.semcdb.2018.04.013

Platyhelminthes: Molecular dissection of the planarian innate immune system
           Maciel E, Oviedo NJ.
                    Advances in Comparative Immunology. 2018 Edwin L Cooper (editor). ISBN 978-3-319-76768-0

SUMOylation controls stem cell proliferation and regional cell death through Hedgehog signaling in planarians
           Thiruvalluvan M, Barghouth PG, Tsur A, Broday L, Oviedo NJ.

Essential role for the planarian intestinal GATA transcription factor in stem cells and regeneration.
         Flores N, Oviedo NJ, Sage J.
                  Dev Biol. 2016 Oct 1; 418(1):179-188

Regional signals in the planarian body guide stem cell fate in the presence of genomic instability.
Peiris TH, Ramirez D, Barghouth PG, Ofoha U, Davidian D, Weckerle F, Oviedo NJ.

The Akt signaling pathway is required for tissue maintenance and regeneration in planarians.
Peiris TH, Ramirez D, Barghouth PG, Oviedo NJ.

Alternative flow cytometry strategies to analyze stem cells and cell death in planarians.
Peiris TH, García-Ojeda ME, Oviedo NJ.
Regeneration. 2016 Mar 16;3(2):123-35  

Bioelectrical regulation of cell cycle and the planarian model system.
Barghouth PG, Thiruvalluvan M, Oviedo NJ.

Innate immune system and tissue regeneration in planarians: an area ripe for exploration.
Peiris TH, Hoyer KK, Oviedo NJ.

 ​Gap junction proteins: master regulators of the planarian stem cell response to tissue maintenance and injury.
Peiris TH, Oviedo NJ.

TOR signaling regulates planarian stem cells and controls localized and organismal growth.
Peiris TH, Weckerle F, Ozamoto E, Ramirez D, Davidian D, García-Ojeda ME, Oviedo NJ.

Long-range neural and gap junction protein-mediated cues control polarity during planarian regeneration.
Oviedo NJ, Morokuma J, Walentek P, Kema IP, Gu MB, Ahn JM, Hwang JS, Gojobori T, Levin M.

Regeneration: The origin of cancer or a possible cure?
Oviedo NJ, Beane WS.
        Semin Cell Dev Biol. 2009 Jul;20(5):557-64

Planarian PTEN homologs regulate stem cells and regeneration through TOR signaling.
Oviedo NJ, Pearson BJ, Levin M, Sánchez Alvarado A.

Live Imaging of Planarian Membrane Potential Using DiBAC4(3).
Oviedo NJ, Nicolas CL, Adams DS, Levin M.

Gene knockdown in planarians using RNA interference.
Oviedo NJ, Nicolas CL, Adams DS, Levin M.

Establishing and maintaining a colony of planarians.
Oviedo NJ, Nicolas CL, Adams DS, Levin M.

Planarians: a versatile and powerful model system for molecular studies of regeneration, adult stem cell regulation, aging, and behavior.
Oviedo NJ, Nicolas CL, Adams DS, Levin M.

smedinx-11 is a planarian stem cell gap junction gene required for regeneration and homeostasis.
Oviedo NJ, Levin M.

Gap junctions provide new links in left-right patterning.
Oviedo NJ, Levin M.

The plasma membrane Ca2+-ATPase protein from red blood cells is not modified in preeclampsia.
Oviedo NJ, Benaim G, Cervino V, Proverbio T, Proverbio F, Marín R.

SMEDWI-2 is a PIWI-like protein that regulates planarian stem cells.
Reddien PW, Oviedo NJ, Jennings JR, Jenkin JC, Sánchez Alvarado A.

Calcium-ATPase activity of red blood cell ghosts from preeclamptic women, antepartum and postpartum.
López TT, Limongi F, Proverbio T, Oviedo NJ, Proverbio F, Marín R.

Allometric scaling and proportion regulation in the freshwater planarian Schmidtea mediterranea.
Oviedo NJ, Newmark PA, Sánchez Alvarado A.

Hiking at Yosemite National Park
Summer, 2016

Current Lab Members

  1. Néstor J Oviedo
    Néstor J Oviedo
    Principal Investigator
  2. Edelweiss Pfister
    Edelweiss Pfister
    Research Associate
  3. Paul Barghouth
    Paul Barghouth
    Graduate Student
  4. Devon Davidian
    Devon Davidian
    Graduate Student
  5. Melanie LeGro
    Melanie LeGro
    Graduate Student
  6. Eli Maciel
    Eli Maciel
    Graduate Student
  7. Salvador Rojas
    Salvador Rojas
    Graduate Student
  8. Manish Thiruvalluvan
    Manish Thiruvalluvan
    Graduate Student
  9. Ben Ziman
    Ben Ziman
    Graduate Student
  10. Peter Karabinis
    Peter Karabinis
    Undergraduate Student
  11. Andrew Betancourt
    Andrew Betancourt
    Undergraduate Student

Former Lab Members

Graduate Students
Natasha Flores
T. Harshani Peiris 
Daniel Ramirez
Udokanma Ofoha
Elyse Ozamoto

Frank Weckerle
Tanya Carroll

Visiting Researchers
Margaux Afriat
Cécile Etzi
Claire Ducatillion
Marcela Bolanos

Undergraduate Students

Ashley Marin
Lacey O'dell
Ivy Pham
Carlos Gomez
Camille Hassel
​Marco Rodriguez
Emma Tkachuk
Katie Wang
Michael Chow
Kristianne Amurao
Nicole Corder
Adam Meng
Tanya Verstak
Sejal Mistry
Swaroop Mistry
Jan Panajon
Jackee Barragan
Linh Khan Nguyen
​Yuan Niu
Ammar Mandvi

Lab Photos

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In the News

Flatworms help scientists discover link between brain and cancer
By James Leonard and Robert Mills

Cancer cells divide with more frequency and are more resilient when they are closer to the brain, indicating a potential link between cell growth and the nervous system, according to new research from Professor Néstor J. Oviedo of the University of California, Merced.​ Read more
Protein critical for tissue regeneration discovered
Researchers have shown that a protein found in humans stops regeneration when disabled in planaria, providing a potential strategy for preventing the growth of cancer cells.​  Read more.
Contact Us
The Oviedo Lab 
Dept of Molecular & Cell Biology
​University of California, Merced
5200 North Lake Road. Merced, CA, 95343, U.S.A
 (209) 229-4381

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