Guillaume St-Jean, DVM, PhD, DACVP

26 Jan 2021

Address

Research interests

  • Development and physiology of the uterus
  • Pathogenesis of uterine diseases
  • Mechanisms of intracellular signaling pathways

Our primary field of interest is the roles played by signaling pathways in the development and function of the uterus and pathogenesis of uterine diseases in human and animals. The uterus is a dynamic organ. Numerous signaling pathways expressed during embryogenesis and adult life carefully coordinate its development and function. TGF-b, WNT and Hippo are counted amongst these pathways. They also contribute to the development of numerous diseases. Using functional genomics and comparative pathology approaches, we study the roles of some of these pathways in the pathogenesis of uterine diseases. Our current research study the roles of Hippo signaling in the uterine function and development of endometritis in cows. We are also interested in the development of uterine fibrosis and plan to study the roles of these signaling pathways in its development, which could lead to the identification of novel therapeutic targets.

Members of the laboratory

Etienne Blais, DVM, IPSAV
MSc student
etienne.blais.1@umontreal.ca

Publications

Sylvie Breton

Sylvie Breton, PhD

19 Aug 2020

Address

Research interests

  • Post-testicular regulation of male reproduction
  • Intercellular communication networks for the establishment of an optimal luminal environment for sperm maturation, protection and storage in the epididymis
  • Epithelial dynamics and mucosal immunity

Male infertility often results from the inability of spermatozoa to reach and fertilize an oocyte. These properties are acquired by the sperm cells as they transit through the epididymal tubule. However, this small organ is understudied and as such male infertility often remains unexplained.

The different epithelial cell types (clear, principal and basal cells) that line the lumen of the epididymis work in a concerted manner to maintain a unique acidic environment that contributes to the maturation and storage of spermatozoa in a dormant state. Our study aims at decoding this complex intercellular communication network.

Moreover, we recently uncovered unexpected roles for proton secreting clear cells in sperm maturation and immune defense. We showed that clear cells express mRNA transcripts and proteins that are acquired by the maturing sperm, and they establish close interactions with luminal spermatozoa via newly described “nanotubes”. Another important aspect of epithelial cell function is related to the fact that they constitute the first line of defense against infections. In the epididymis, a balance between tolerance to immunogenic spermatozoa and immune activation against pathogens must be maintained. In mechanistic studies, we found that clear cells respond to the presence of bacterial antigens in vivo by expressing chemokines, which induce the recruitment of macrophages into the epididymis. These recent findings thus revealed the participation of clear cells as sensors and mediators of inflammation. Characterizing these novel properties is another active research theme in our lab.

We use a multidisciplinary approach including high-resolution laser scanning confocal immunofluorescence microscopy, 3D reconstruction of single cells, intravital multiphoton microscopy, luminal perfusion of the epididymis in vivo, and monitoring of live cells in vivo and in vitro.

Members of the laboratory

Larissa Berloffa Belardin, PhD
Postdoctoral fellow

Christine Légaré, MSc
Research assistant

Publications

Jacques Lussier, DVM, PhD

28 May 2019

Address

Research interests

  • Follicular development and ovulation
  • Long non-coding RNA

Recent decades have witnessed a decline in reproductive efficiency in cattle resulting in economic losses for producers. The causes of this reduction in fertility are multifactorial and is partly related to the physiology of the ovary. The research program is to better understand the development of ovarian follicles by studying the physiology of granulosa cells (GCs) during the later stages of follicular growth, ovulation, and their contribution to corpus luteum formation. Our previous work (Fayad et al., 2004, 2007; Ndiaye et al., 2005; Lussier et al., 2017) have established an index of differentially expressed genes in GCs including: 1) the membrane receptor LRP8 (Low density lipoprotein Receptor related Protein 8); 2) as well as long non-coding RNAs (IncRNA).

1) LRP8 is exclusively expressed in GCs and is part of the LDL family of receptors, including VLDLR (Very-Low-Density Lipoprotein Receptor) and LDLR (Low-Density Lipoprotein Receptor). Only the expression of LRP8 is differentially expressed in GCs. LRP8 is well known in the central nervous system where it plays a key role in the development of the brain, cerebellum and in the modulation of synaptic plasticity, however, its role in GCs remains to be elucidated.

2) The long non-coding RNAs (lncRNA) have more than 200 nucleotides and intervene either in transcriptional control, epigenetics and post-transcriptional mechanisms. The FANTOM5 analysis identified 27,919 genes corresponding to human lncRNAs and demonstrated that 69% (19,175) are functional. Some of the lncRNAs are expressed only by certain cell types according to their stage of development. The index of genes differentially expressed in the GCs that we established allowed us to identify new lncRNAs expressed specifically in GCs. Our goal is to define their role during follicular development.

Members of the laboratory

Gabriel Benoit, DVM, IPSAV
MSc student
gabriel.benoit@umontreal.ca

Marianne Descarreaux
MSc student
marianne.descarreaux@umontreal.ca

Aly Warma, DVM
PhD student
aly.warma@umontreal.ca

Publications

Kalidou Ndiaye, PhD

26 Jun 2018

Address

Research interests

  • Ovarian function
  • Reproductive immunolgy
  • Follicular development

The primary field of research in the lab is directed toward the cellular and molecular mechanisms in reproduction with a focus on follicular development in bovine species. A secondary focus is on the reproductive immunology and the effects of immune cells on the ovarian function. We are approaching these projects by using a host of molecular technologies including yeast two-hybrid screening, RNA interference, plasmid-mediated protein over-expression and promoter-reporter assays to characterize the expression and study the functions of target genes in ovarian follicles and immune cells.

These approaches allow us to study the expression and function of genes that could influence follicular development and the quality of oocyte and impact bovine fertility. Our previous studies have demonstrated the induction of specific genes expression in the ovarian follicle during ovulation, some of which are involved in inflammatory processes. Other studies from our laboratory have also shown that some genes are present in growing dominant follicles and are repressed by the luteinizing hormone (LH). Our ongoing projects aim to elucidate the functions and mechanisms of action of some of these genes in granulosa cells of ovarian follicles using pharmacological inhibitors, the CRISPR-Cas9 technology as well as signal transduction analyses. We also study the mode of action of proteins encoded by these genes by defining their partners using the yeast two-hybrid approach and performing in vitro analyses.

Members of the laboratory

Soma Nosrat Pour
MSc student
Soma.nosrat.pour@umontreal.ca

Amir Zareifard
MSc student
Amir.zareifard@umontreal.ca

Daniela Naranjo
MSc student
dcng1994@gmail.com

Marianne Descarreaux
MSc student
Marianne.descarreaux@umontreal.ca

Aly Warma, MSc
PhD student
Aly.warma@umontreal.ca

Publications

Robert Sullivan, PhD

6 Feb 2018

Address

Research interests

  • Andrology
  • Male infertility
  • Cellular physiology

Male infertility affects humans as much as domestic animals, especially dairy cattle, a species in which artificial insemination is widespread. Our work focuses on the epididymis, an organ of the male reproductive system that is responsible for the acquisition of the fertilizing power of spermatozoa. Based on andrological data, we hypothesized that dysregulations of epididymal function are involved in the pathophysiology of male infertility. We also propose that spermatic proteins of epididymal origin can serve as markers of the functionality of male gametes. Our work, which involves both man and bull, uses proteomic, genomic and cellular physiology techniques to characterize the changes that sperm undergo during their epididymal transit. We also believe that these epididymal markers of sperm functionality can document damage to spermatozoa during cryopreservation and can, therefore, determine the susceptibility of different bulls’ semen to cryopreservation. In humans, we have demonstrated that vasectomy affects epididymal function and that this damage is not always reversible following vasovasotomy, ie the recanalization of vas deferens in vasectomized men to restore their reproductive function. This could explain the dichotomy between the surgical success of the vasovasotomy and the return to fertility.

Members of the laboratory

Christine Légaré, MSc
Research assistant
christine.legare@crchudequebec.ulaval.ca

Larissa Belardin, MSc
PhD student
larissabelardin@hotmail.com

Publications

Clémence Belleannée, PhD

13 Dec 2017

Address

Research interests

  • Role of small non-coding RNA in the control of post-testicular sperm maturation in the epididymis
  • Role of primary cilia in the controle of epididymis development and homeostasis

The epididymis plays important roles in the acquisition of sperm motility and fertilizing abilities. This organ is thus essential to the control of male fertility. Our laboratory is interested in the different intercellular communication systems that ensure proper sperm maturation in the epididymis. In particular, we study two signaling pathways important to the control of reproductive functions:

– one mediated by the small non-coding RNAs transported by the extracellular vesicles secreted in the epididymal fluid

– another mediated by the primary cilia located on the surface of epididymal cells and acting as a biological antenna.

These studies are carried out using complementary techniques in imaging (confocal and electronic microscopy, fluidic imaging), molecular and cellular biology (PCR, Western blotting, organotypic air-liquid culture), on cell models, transgenic mice and human samples. All this work will enable us to identify the molecular and cellular factors important to sperm maturation and to ultimately develop new tools for the control of male fertilizing ability applicable to livestock and human health.

Members of the laboratory

Hong Chen, MSc
PhD student
ch4973@gmail.com

Sepideh Fakhari, MSc
PhD student
sepideh.fakhari.1@ulaval.ca

Laura Girardet, MSc
PhD student
lauragirardet@hotmail.fr

Gabriel Campolina Silva, PhD
Postdoc
gabriel-henrique.campolina-silva@crchudequebec.ulaval.ca

Céline Augière, PhD
Postdoc
celine.augiere@gmail.com

Camille Lavoie-Ouellet, MSc
Research assistant
camille.lavoie-ouellet@crchudequebec.ulaval.ca

Publications

Gustavo Zamberlam DMV, PhD

5 Dec 2017

Address

Research interests

  • Ovarian physiology and dysfunction
  • Physiology of the pituitary gland: regulation of gonadotropins synthesis

Our main research interest is the study of ovarian physiology and dysfunction; particularly the regulation of ovarian follicle development and ovulation in the ovary of bovine and rodents. The first, an important agricultural species, and the second, a useful animal model for research. We have used in vitro and in vivo approaches to demonstrate novel roles of intracrine factors like the free radical gas nitric oxide and the secreted glycoproteins WNTs and SFRPs in mammalian ovarian granulosa cells. We are currently studying the physiological roles of Hippo signaling in bovine follicle cells. We have also expanded our studies to the level of gonadotropins synthesis at the pituitary gland. In a current research project with mice, we are using functional genomics approaches to determine whether the Hippo pathway is involved in regulating gonadotropin synthesis.

Members of the laboratory

Ariane Lalonde-Larue
DMV-MSc student
alalonde.larue@gmail.com

Esdras Correas Dos Santos, MSc
PhD student
esdras.correa.dos.santos@umontreal.ca

Publications

Lab team_Zamberlam

Marc-André Sirard, DMV, PhD

5 Dec 2017

Research interests

  • Reproduction and epigenetics in domestic animals
  • Genomic and transcriptomic analyses of the oocyte and the embryo
  • Follicular growth and differentiation using trancriptomics and the evaluation of the follicular quality

The main focus of our research concerns the oocyte competence, which essentially depends on the follicle status. Our genomic tools allow us to discover and study the markers of healthy follicles in both cattle and humans to improve practices, particularly in in vitro fertilization. More recently, our research includes epigenetic aspects that allow the transmission of non-genetic information and more particularly the metabolic status of the mother and its influence on the quality of the oocyte, the embryo and the future newborn.

Members of the laboratory

Martine Boulet, BSc
MSc student
martine.boulet.4@ulaval.ca

Julie-Pier Robichaud, BSc
MSc student
jprob36@ulaval.ca

Asma Arjoune
PhD student
asma.arjoune.1@ulaval.ca

Chloé Fortin, MSc
PhD student
chloe.fortin.1@ulaval.ca

Simon Lafontaine, MSc
PhD student
simon.lafontaine.4@ulaval.ca

Meishong Shi, MSc
PhD student
MESHI3@exch.ulaval.ca

Chongyand WU, MSc
PhD student
chongyang.wu.1@ulaval.ca

Ying Zhang, MSc
PhD student
ying.zhang.2@ulaval.ca

Mengqi Wang, MSc
PhD student
mengqi.wang.1@ulaval.ca

Muhammad Waqas, DVM, RVMP
PhD student
waqas_sk@yahoo.com

Camila Bruna De Lima, PhD
Postdoc
camila-bruna.de-lima.1@ulaval.ca

Erika Cristina, PhD
Postdoc
erika08unifesp@gmail.com

Publications

Christopher Price, PhD

23 Nov 2017

Address

Research interests

  • Folliculogenesis
  • Dairy cow fertility
  • Fibroblast growth factors and ovarian function

The overall objective of my laboratory is to understand better the mechanisms of follicle cell differentiation. During follicle development, there is significant growth of the follicle and proliferation and differentiation of granulosa cells.  We are currently studying roles of members of the fibroblast growth factor (FGF) family. This large family contains 22 peptides and 7 receptors (which result from alternative splicing of 4 FGFR genes).  We have described the expression of a number of these FGF genes in the bovine follicle, and we are determining which FGFs play important roles in follicle development. We are particularly interested in FGF18 which is an atypical growth factor as it induces granulosa cell death. We are currently studying the regulation of secretion of this protein from various cell types within the ovarian follicle.

Members of the laboratory

Lauriane Relav, MSc
PhD student
lauriane.relav@laposte.net

El-Arbi Abulghasem, MSc
PhD student
el.abulghasem@gmail.com

Publications

Bruce D. Murphy, PhD

23 Nov 2017

Address

Research interests

  • NR5A2 orphan receptor family
  • Ovulation and luteal function
  • Reactivation of the embryo at the termination of the diapause

My laboratory has focused on the role of orphan nuclear receptors of the NR5A family in regulation of reproductive events.  We have shown that NR5A2, aka liver receptor homolog-1, is essential for the processes of ovulation and luteal function. Its expression in the uterus is likewise necessary for establishment of gestation.  NR5A1, aka steroidogenic factor-1, is necessary for maturation of ovarian follicles.  Our current studies are aimed at exploring the multiple mechanisms by which NR5A1 and NR5A2 regulate ovarian events, including proliferation, differentiation and cytoskeletal remodeling. Our investigations are characterized by phenotypic analysis of targeted mutations in mice combined with global approaches to determining the widespread molecular changes that occur associated with depletion of the NR5A genes.

We have had a long-standing interest in the phenomenon of embryonic diapause, an evolutionary strategy whereby there is a predictable arrest in the development of the blastocyst.  This arrest results in the uncoupling of mating and parturition and allows for the birth of offspring when survival is optimal. We have shown that embryos enter diapause in carnivore and rodent species when the uterine signals are insufficient to allow continued development.  A class of compounds known as polyamines are key players in this mechanism, as a paucity of polyamines is associated with developmental arrest.  Our current studies focus on the events that take place in the embryo that interrupt embryogenesis and those which characterize the reactivation of the embryo at the termination of diapause.

Members of the laboratory

Olivia Smith, MSc
PhD student
olivia.e.smith@gmail.com

Fanny Morin, BSc
MSc student
fanny.morin@umontreal.ca

Camilla H.K. Hughes, PhD
Postdoc
camilla.hughes@umontreal.ca

Vickie Roussel
Laboratory technician
vickie.roussel@umontreal.ca

Publications

1 2

Search

+