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Ledet MM, Harman RM, Fan JC, Schmitt-Matzen E, Diaz-Rubio ME, Zhang S, Van de Walle GR. Secreted sphingomyelins modulate low mammary cancer incidence observed in certain mammals. Sci Rep 2020; 10:20580. [PMID: 33239740 PMCID: PMC7689471 DOI: 10.1038/s41598-020-77639-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 11/13/2020] [Indexed: 12/02/2022] Open
Abstract
Determining mechanisms that naturally protect species from developing cancer is critical in order to prevent and treat cancer. Here, we describe a novel cancer-suppressing mechanism, via the secretion of bioactive factors by mammary cells, that is present in domesticated mammals with a low mammary cancer incidence. Specifically, these bioactive factors induced triple-negative breast cancer cell (TNBC) death in vitro and reduced tumorigenicity in a xenograft TNBC mouse model in vivo. RNA deep sequencing showed significant downregulation of genes associated with breast cancer progression in secretome-cultured TNBC cells. Further in-depth multi-omics analysis identified sphingomyelins as key secreted factors, and their role was confirmed via inhibition of the sphingomyelin signaling pathway. We speculate that secreted sphingomyelins in the mammary gland of mammals with a naturally low incidence of mammary cancer mediate the elimination of cancer cells. This study contributes to the growing list of protective mechanisms identified in cancer-proof species.
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Harman RM, Das SP, Bartlett AP, Rauner G, Donahue LR, Van de Walle GR. Beyond tradition and convention: benefits of non-traditional model organisms in cancer research. Cancer Metastasis Rev 2020; 40:47-69. [PMID: 33111160 DOI: 10.1007/s10555-020-09930-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/01/2020] [Indexed: 02/07/2023]
Abstract
Traditional laboratory model organisms are indispensable for cancer research and have provided insight into numerous mechanisms that contribute to cancer development and progression in humans. However, these models do have some limitations, most notably related to successful drug translation, because traditional model organisms are often short-lived, small-bodied, genetically homogeneous, often immunocompromised, are not exposed to natural environments shared with humans, and usually do not develop cancer spontaneously. We propose that assimilating information from a variety of long-lived, large, genetically diverse, and immunocompetent species that live in natural environments and do develop cancer spontaneously (or do not develop cancer at all) will lead to a more comprehensive understanding of human cancers. These non-traditional model organisms can also serve as sentinels for environmental risk factors that contribute to human cancers. Ultimately, expanding the range of animal models that can be used to study cancer will lead to improved insights into cancer development, progression and metastasis, tumor microenvironment, as well as improved therapies and diagnostics, and will consequently reduce the negative impacts of the wide variety of cancers afflicting humans overall.
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Fortier LA, Goodrich LR, Ribitsch I, Schnabel LV, Shepard DO, Van de Walle GR, Watts AE, Whealands Smith RK. One health in regenerative medicine: report on the second Havemeyer symposium on regenerative medicine in horses. Regen Med 2020; 15:1775-1787. [PMID: 32808582 DOI: 10.2217/rme-2019-0143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Regenerative medicine is commonly used in human and equine athletes. Potential therapies include culture expanded stem cells, stromal vascular fraction of adipose tissue, platelet-rich plasma, bone marrow concentrate, or autologous conditioned serum. The purpose of this manuscript is to disseminate findings from a workshop on the development of translational regenerative medicine in the equine field. Five themes emerged: stem cell characterization and tenogenic differentiation; interactions between mesenchymal stem cells, other cells and the environment; scaffolds and cell packaging; blood- and bone marrow-based regenerative medicines; clinical use of regenerative therapies. Evidence gained through the use of regenerative medicine applications in the horse should continue to translate to the human patient, bringing novel regenerative therapies to both humans and horses.
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Tomlinson JE, Wolfisberg R, Fahnøe U, Sharma H, Renshaw RW, Nielsen L, Nishiuchi E, Holm C, Dubovi E, Rosenberg BR, Tennant BC, Bukh J, Kapoor A, Divers TJ, Rice CM, Van de Walle GR, Scheel TKH. Equine pegiviruses cause persistent infection of bone marrow and are not associated with hepatitis. PLoS Pathog 2020; 16:e1008677. [PMID: 32649726 PMCID: PMC7375656 DOI: 10.1371/journal.ppat.1008677] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/22/2020] [Accepted: 06/02/2020] [Indexed: 12/20/2022] Open
Abstract
Pegiviruses frequently cause persistent infection (as defined by >6 months), but unlike most other Flaviviridae members, no apparent clinical disease. Human pegivirus (HPgV, previously GBV-C) is detectable in 1–4% of healthy individuals and another 5–13% are seropositive. Some evidence for infection of bone marrow and spleen exists. Equine pegivirus 1 (EPgV-1) is not linked to disease, whereas another pegivirus, Theiler’s disease-associated virus (TDAV), was identified in an outbreak of acute serum hepatitis (Theiler’s disease) in horses. Although no subsequent reports link TDAV to disease, any association with hepatitis has not been formally examined. Here, we characterized EPgV-1 and TDAV tropism, sequence diversity, persistence and association with liver disease in horses. Among more than 20 tissue types, we consistently detected high viral loads only in serum, bone marrow and spleen, and viral RNA replication was consistently identified in bone marrow. PBMCs and lymph nodes, but not liver, were sporadically positive. To exclude potential effects of co-infecting agents in experimental infections, we constructed full-length consensus cDNA clones; this was enabled by determination of the complete viral genomes, including a novel TDAV 3’ terminus. Clone derived RNA transcripts were used for direct intrasplenic inoculation of healthy horses. This led to productive infection detectable from week 2–3 and persisting beyond the 28 weeks of study. We did not observe any clinical signs of illness or elevation of circulating liver enzymes. The polyprotein consensus sequences did not change, suggesting that both clones were fully functional. To our knowledge, this is the first successful extrahepatic viral RNA launch and the first robust reverse genetics system for a pegivirus. In conclusion, equine pegiviruses are bone marrow tropic, cause persistent infection in horses, and are not associated with hepatitis. Based on these findings, it may be appropriate to rename the group of TDAV and related viruses as EPgV-2. Transmissible hepatitis in horses (Theiler’s disease) has been known for 100 years without knowledge of causative infectious agents. Recently, two novel equine pegiviruses (EPgV) were discovered. Whereas EPgV-1 was not associated to disease, the other was identified in an outbreak of acute serum hepatitis and therefore named Theiler’s disease-associated virus (TDAV). This finding was surprising since human and monkey pegiviruses typically cause long-term infection without associated clinical disease. Whereas no subsequent reports link TDAV to disease, the original association to hepatitis has not been formally examined. Here, we studied EPgV-1 and TDAV and found that their natural history of infection in horses were remarkably similar. Examination of various tissues identified the bone marrow as the primary site of replication for both viruses with no evidence of replication in the liver. To exclude potential effects of other infectious agents, we developed molecular full-length clones for EPgV-1 and TDAV and were able to initiate infection in horses using derived synthetic viral genetic material. This demonstrated long-term infection, but no association with hepatitis. These findings call into question the connection between TDAV, liver infection, and hepatitis in horses.
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Marx C, Gardner S, Harman RM, Van de Walle GR. The mesenchymal stromal cell secretome impairs methicillin-resistant Staphylococcus aureus biofilms via cysteine protease activity in the equine model. Stem Cells Transl Med 2020; 9:746-757. [PMID: 32216094 PMCID: PMC7308642 DOI: 10.1002/sctm.19-0333] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 02/17/2020] [Indexed: 12/19/2022] Open
Abstract
Mesenchymal stromal cells (MSCs) from various species, such as humans, mice, and horses, were recently found to effectively inhibit the growth of various bacteria associated with chronic infections, such as nonhealing cutaneous wounds, via secretion of antimicrobial peptides. These MSC antimicrobial properties have primarily been studied in the context of the planktonic phenotype, and thus, information on the effects on bacteria in biofilms is largely lacking. The objectives of this study were to evaluate the in vitro efficacy of the MSC secretome against various biofilm-forming wound pathogens, including the methicillin-resistant Staphylococcus aureus (MRSA), and to explore the mechanisms that affect bacterial biofilms. To this end, we used equine MSCs, because the horse represents a physiologically relevant model for human wound healing and offers a readily translatable model for MSC therapies in humans. Our salient findings were that the equine MSC secretome inhibits biofilm formation and mature biofilms of various bacteria, such as Pseudomonas aeruginosa, S. aureus, and Staphylococcus epidermidis. Furthermore, we demonstrated that equine MSC secrete cysteine proteases that destabilize MRSA biofilms, thereby increasing the efficacy of antibiotics that were previously tolerated by the biofilms. In light of the rise of antibiotic-resistant bacterial strains as an increasing global health threat, our results provide the rationale for using the MSC secretome as a complementary treatment for bacterial skin infections in both humans and horses.
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Vengust M, Jager MC, Zalig V, Cociancich V, Laverack M, Renshaw RW, Dubovi E, Tomlinson JE, Van de Walle GR, Divers TJ. First report of equine parvovirus-hepatitis-associated Theiler's disease in Europe. Equine Vet J 2020; 52:841-847. [PMID: 32145096 DOI: 10.1111/evj.13254] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/28/2020] [Accepted: 02/29/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Equine parvovirus-hepatitis (EqPV-H) has been proposed as the aetiological cause of Theiler's disease, also known as serum hepatitis. EqPV-H-associated Theiler's disease has not been previously reported in Europe. OBJECTIVES To determine whether EqPV-H infection was associated with a 2018-2019 outbreak of Theiler's disease in four horses on a studfarm. STUDY DESIGN Descriptive case series. METHODS The medical records of four horses from the same farm diagnosed with fatal Theiler's disease were examined retrospectively. Information collected included a clinical history, physical examination findings, tetanus antitoxin exposure, serum biochemistry and necropsy reports. Liver tissue from all four horses was tested for EqPV-H using PCR and in situ hybridisation (ISH) assays. RESULTS Three of the horses had a history of recent (7-11 weeks) tetanus antitoxin administration. Liver tissue from all four horses tested positive for EqPV-H with PCR. In situ hybridisation revealed a widespread distribution of viral nucleic acid in hepatocytes in one case, and a more sporadic distribution in the remaining three cases. MAIN LIMITATIONS Case controls were not available from the farm in question given the retrospective nature of analysis. CONCLUSIONS This case series documents the first reported EqPV-H-associated Theiler's disease in Europe and the first use of ISH to visualise the viral nucleic acid in liver tissues of horses with Theiler's disease.
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Tomlinson JE, Jager M, Struzyna A, Laverack M, Fortier LA, Dubovi E, Foil LD, Burbelo PD, Divers TJ, Van de Walle GR. Tropism, pathology, and transmission of equine parvovirus-hepatitis. Emerg Microbes Infect 2020; 9:651-663. [PMID: 32192415 PMCID: PMC7144241 DOI: 10.1080/22221751.2020.1741326] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Equine parvovirus-hepatitis (EqPV-H) has recently been associated with cases of Theiler's disease, a form of fulminant hepatic necrosis in horses. To assess whether EqPV-H is the cause of Theiler's disease, we first demonstrated hepatotropism by PCR on tissues from acutely infected horses. We then experimentally inoculated horses with EqPV-H and 8 of 10 horses developed hepatitis. One horse showed clinical signs of liver failure. The onset of hepatitis was temporally associated with seroconversion and a decline in viremia. Liver histology and in situ hybridization showed lymphocytic infiltrates and necrotic EqPV-H-infected hepatocytes. We next investigated potential modes of transmission. Iatrogenic transmission via allogeneic stem cell therapy for orthopedic injuries was previously suggested in a case series of Theiler's disease, and was demonstrated here for the first time. Vertical transmission and mechanical vectoring by horse fly bites could not be demonstrated in this study, potentially due to limited sample size. We found EqPV-H shedding in oral and nasal secretions, and in feces. Importantly, we could demonstrate EqPV-H transmission via oral inoculation with viremic serum. Together, our findings provide additional information that EqPV-H is the likely cause of Theiler's disease and that transmission of EqPV-H occurs via both iatrogenic and natural routes.
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Spertus CB, Pennington MR, Van de Walle GR, Badanes ZI, Judd BE, Mohammed HO, Ledbetter EC. Effects of orally administered raltegravir in cats with experimentally induced ocular and respiratory feline herpesvirus-1 infection. Am J Vet Res 2019; 80:490-497. [PMID: 31034270 DOI: 10.2460/ajvr.80.5.490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the effects of orally administered raltegravir in cats with experimentally induced ocular and respiratory feline herpesvirus-1 (FHV-1) infection. ANIMALS 14 healthy 6-month-old unvaccinated specific pathogen-free cats. PROCEDURES On day 0, all cats were experimentally inoculated by topical application of 0.1 mL of a solution containing 106 plaque-forming units of FHV-1 strain FH2CS to the inferior conjunctival fornix of each eye. Cats were randomly assigned to receive either raltegravir (80 mg; n = 7) or lactose (250 mg; vehicle; 7), PO, every 12 hours for 14 days beginning on day 1. Cats were assigned clinical ocular and respiratory disease scores every other day from days 0 to 30. Conjunctival swab specimens were collected for detection of FHV-1 by virus isolation and real-time PCR assay at 3-day intervals from days 0 to 30. Confocal microscopy was performed on days 0 and 10 to assess corneal epithelial leukocyte infiltration. The assessed variables and duration of FHV-1 shedding were compared between the 2 treatment groups. RESULTS Cats in both groups developed moderate to severe conjunctivitis and ulcerative keratitis characteristic of FHV-1 infection. Median duration of FHV-1 shedding was shorter and signs of ocular and respiratory disease were less severe for raltegravir-treated cats than for vehicle-treated cats. However, the mean conjunctival FHV-1 titer and corneal epithelial leukocyte count did not differ between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested orally administered raltegravir might be effective for alleviation of ocular and respiratory signs of FHV-1 infection in cats. (Am J Vet Res 2019;80:490-497).
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Tomlinson JE, Van de Walle GR, Divers TJ. What Do We Know About Hepatitis Viruses in Horses? Vet Clin North Am Equine Pract 2019; 35:351-362. [PMID: 31084975 DOI: 10.1016/j.cveq.2019.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Theiler disease (serum hepatitis or idiopathic acute hepatic necrosis) has long been suspected to have a viral etiology. Four viruses have been described in association with hepatitis in horses. Further investigation suggests equine pegivirus and Theiler disease-associated virus (a second pegivirus) are neither hepatotropic nor pathogenic. Nonprimate hepacivirus (NPHV) causes subclinical disease in experimental models and has been associated with hepatitis in some clinical cases. Equine parvovirus-hepatitis (EqPV-H) experimentally causes subclinical-to-clinical liver disease and is found in the vast majority of Theiler disease cases. EqPV-H is likely of clinical significance, whereas the significance of NPHV is unknown.
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Tomlinson JE, Tennant BC, Struzyna A, Mrad D, Browne N, Whelchel D, Johnson PJ, Jamieson C, Löhr CV, Bildfell R, McKenzie EC, Laverack M, Renshaw RW, Dubovi E, Kapoor A, Meirs RS, Belgrave R, Engiles J, Van de Walle GR, Divers TJ. Viral testing of 10 cases of Theiler's disease and 37 in-contact horses in the absence of equine biologic product administration: A prospective study (2014-2018). J Vet Intern Med 2018; 33:258-265. [PMID: 30520132 PMCID: PMC6335540 DOI: 10.1111/jvim.15362] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 10/24/2018] [Indexed: 11/30/2022] Open
Abstract
Background A novel equine parvovirus (EqPV‐H) was recently discovered in the equine liver with Theiler's disease. Objectives To determine the prevalence of EqPV‐H infection in naturally occurring Theiler's disease cases and in‐contact horses in the absence of historical equine biologic product administration. Animals Ten cases of Theiler's disease from 6 separate properties were included in the study, based on the criteria of acute onset of clinical signs of liver failure with laboratory or histopathologic findings characteristic of Theiler's disease and no history of receiving an equine biologic product within the preceding 4 months. In addition, 37 in‐contact horses from 4 of the 6 properties were screened for EqPV‐H infection and hepatitis. Methods In prospective case series, cases were diagnosed with Theiler's disease by the attending veterinarian and were tested for EqPV‐H by PCR of liver or serum. In‐contact horses were assessed via serum chemistry and PCR at the attending veterinarian's discretion. Hepatitis was defined as serum gamma‐glutamyltransferase activity above reference interval. The association of EqPV‐H with hepatitis was determined by Fisher's exact test. Results Nine of 10 (90%) Theiler's disease cases and 54% of tested in‐contact horses were EqPV‐H positive. Hepatitis was significantly associated with EqPV‐H infection (P = .036). Conclusions and Clinical Importance Although further study is required to identify EqPV‐H as the causative agent of Theiler's disease, EqPV‐H appears strongly associated with cases of fatal Theiler's disease and subclinical hepatitis in horses in contact with those cases. The prevalence of EqPV‐H infection on affected properties can be high.
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Tomlinson JE, Kapoor A, Kumar A, Tennant BC, Laverack MA, Beard L, Delph K, Davis E, Schott Ii H, Lascola K, Holbrook TC, Johnson P, Taylor SD, McKenzie E, Carter-Arnold J, Setlakwe E, Fultz L, Brakenhoff J, Ruby R, Trivedi S, Van de Walle GR, Renshaw RW, Dubovi EJ, Divers TJ. Viral testing of 18 consecutive cases of equine serum hepatitis: A prospective study (2014-2018). J Vet Intern Med 2018; 33:251-257. [PMID: 30520162 PMCID: PMC6335536 DOI: 10.1111/jvim.15368] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 10/24/2018] [Indexed: 02/06/2023] Open
Abstract
Background Three flaviviruses (equine pegivirus [EPgV]; Theiler's disease–associated virus [TDAV]; non‐primate hepacivirus [NPHV]) and equine parvovirus (EqPV‐H) are present in equine blood products; the TDAV, NPHV, and EqPV‐H have been suggested as potential causes of serum hepatitis. Objective To determine the prevalence of these viruses in horses with equine serum hepatitis. Animals Eighteen horses diagnosed with serum hepatitis, enrolled from US referral hospitals. Methods In the prospective case study, liver, serum, or both samples were tested for EPgV, TDAV, NPHV, and EqPV‐H by PCR. Results Both liver tissue and serum were tested for 6 cases, serum only for 8 cases, and liver only for 4 cases. Twelve horses received tetanus antitoxin (TAT) 4‐12.7 weeks (median = 8 weeks), 3 horses received commercial equine plasma 6‐8.6 weeks, and 3 horses received allogenic stem cells 6.4‐7.6 weeks before the onset of hepatic failure. All samples were TDAV negative. Two of 14 serum samples were NPHV‐positive. Six of 14 serum samples were EPgV‐positive. All liver samples were NPHV‐negative and EPgV‐negative. EqPV‐H was detected in the serum (N = 8), liver (N = 4), or both samples (N = 6) of all 18 cases. The TAT of the same lot number was available for virologic testing in 10 of 12 TAT‐associated cases, and all 10 samples were EqPV‐H positive. Conclusions and Clinical Importance We demonstrated EqPV‐H in 18 consecutive cases of serum hepatitis. EPgV, TDAV, and NPHV were not consistently present. This information should encourage blood product manufacturers to test for EqPV‐H and eliminate EqPV‐H–infected horses from their donor herds.
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Ledbetter EC, Nicklin AM, Spertus CB, Pennington MR, Van de Walle GR, Mohammed HO. Evaluation of topical ophthalmic ganciclovir gel for the treatment of dogs with experimentally induced ocular canine herpesvirus-1 infection. Am J Vet Res 2018; 79:762-769. [PMID: 29943639 DOI: 10.2460/ajvr.79.7.762] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the in vitro half maximal effective concentration (EC50) of ganciclovir for canine herpesvirus-1 (CHV-1) and to evaluate the efficacy of ganciclovir ophthalmic gel in dogs with experimentally induced ocular CHV-1 infection. ANIMALS 10 specific pathogen-free adult Beagles. PROCEDURES Cytotoxicity and EC50 of ganciclovir for CHV-1 were determined during in vitro experiments. During an in vivo experiment, dogs with experimentally induced ocular CHV-1 infections received 1 drop of 0.15% ganciclovir (ganciclovir group; n = 5) or artificial tear (control group; 5) ophthalmic gel in both eyes 5 times daily for 7 days, then 3 times daily for 7 days. For each dog, ophthalmic and confocal microscopic examinations were performed at predetermined times to determine severity of ocular disease and inflammation. Conjunctival swab specimens were collected at predetermined times for PCR assay analysis to determine CHV-1 shedding. RESULTS No in vitro cytotoxic effects were observed for ganciclovir concentrations ≤ 500μM. The EC50 of ganciclovir for CHV-1 was 37.7μM. No adverse effects associated with ganciclovir were observed during the in vivo experiment. Mean ocular disease and inflammation scores for the ganciclovir group were significantly lower than those for the control group. Mean duration of CHV-1 shedding for the ganciclovir group (0.4 days) was significantly shorter than that for the control group (6.2 days). CONCLUSIONS AND CLINICAL RELEVANCE Topical administration of 0.15% ganciclovir ophthalmic gel was well tolerated and effective in decreasing clinical disease scores, ocular tissue inflammation, and duration of viral shedding in dogs with experimentally induced ocular CHV-1 infection.
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Ledet MM, Oswald M, Anderson R, Van de Walle GR. Differential signaling pathway activation in 7,12-dimethylbenz[a] anthracene (DMBA)-treated mammary stem/progenitor cells from species with varying mammary cancer incidence. Oncotarget 2018; 9:32761-32774. [PMID: 30214683 PMCID: PMC6132353 DOI: 10.18632/oncotarget.25988] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/31/2018] [Indexed: 12/27/2022] Open
Abstract
A natural variation exists in the susceptibility to mammary cancer among wild and domestic mammalian species. Mammary stem/progenitor cells (MaSC) represent a primary target cell for transformation; however, little is known about the intrinsic response of these cells to carcinogenic insults. Polycyclic aromatic hydrocarbons (PAH), such as 7,12-dimethylbenz[a]anthracene (DMBA), are abundantly present in the environment and have been linked to the development of mammary cancer in humans and rodents. We treated MaSC from equine (mammary cancer-resistant) and canine (mammary cancer-susceptible) species with DMBA and assessed cytochrome P450 metabolic activity, DNA damage and viability. Our notable findings were that MaSC from both species showed DNA damage following DMBA treatment; however, equine MaSC initiated cell death whereas canine MaSC repaired this DNA damage. Follow-up studies, based on genome-wide transcriptome analyses, revealed that DMBA induced activation of both the intrinsic and extrinsic apoptotic pathways in equine, but not canine, MaSC. Based on these findings, we propose a hypothetical model in which undergoing apoptosis in response to an oncogenic event might contribute to a lower incidence of mammary cancer in certain mammalian species. Such a mechanism would allow for the elimination of DNA-damaged MaSC, and hence, reduce the risk of potential tumor-initiating mutations in these cells.
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Pennington MR, Grenier JK, Van de Walle GR. Transcriptome profiling of alphaherpesvirus-infected cells treated with the HIV-integrase inhibitor raltegravir reveals profound and specific alterations in host transcription. J Gen Virol 2018; 99:1115-1128. [PMID: 29916804 DOI: 10.1099/jgv.0.001090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Anti-microbial compounds typically exert their action by directly interfering with one or more stages of the pathogen's life cycle. However, some compounds also have secondary effects on the host that aid in pathogen clearance. Raltegravir is a human immunodeficiency virus (HIV)-integrase inhibitor that has been shown to alter the host immune response to HIV in addition to its direct antiviral effect. Interestingly, raltegravir can also directly inhibit the replication of various herpesviruses. However, the host-targeted effects of this drug in the context of a herpesvirus infection have not been explored. Here, we used felid alphaherpesvirus 1 (FHV-1), a close relative of human alphaherpesvirus 1 (HHV-1) that similarly causes ocular herpes, to characterize the host-targeted effects of raltegravir on corneal epithelial cells during an alphaherpesvirus infection. Using RNA deep sequencing, we found that raltegravir specifically boosts the expression of anti-angiogenic factors and promotes metabolic homeostasis in FHV-1-infected cells. In contrast, few changes in host gene transcription were found in uninfected cells. Importantly, we were able to demonstrate that these effects were specific to raltegravir and independent of the direct-acting antiviral effect of the drug, since treatment with the DNA polymerase inhibitor phosphonoacetic acid did not induce these host-targeted effects. Taken together, these results indicate that raltegravir has profound and specific effects on the host transcription profile of herpesvirus-infected cells that may contribute to the overall antiviral activity of the drug and could provide therapeutic benefits in vivo. Furthermore, this study provides a framework for future efforts evaluating the host-targeted effects of anti-microbial compounds.
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Cassano JM, Fortier LA, Hicks RB, Harman RM, Van de Walle GR. Equine mesenchymal stromal cells from different tissue sources display comparable immune-related gene expression profiles in response to interferon gamma (IFN)-γ. Vet Immunol Immunopathol 2018; 202:25-30. [PMID: 30078595 DOI: 10.1016/j.vetimm.2018.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/19/2018] [Accepted: 06/10/2018] [Indexed: 02/08/2023]
Abstract
Mesenchymal stromal cells (MSC) have the therapeutic potential to decrease inflammation due to their immunomodulatory properties. They can be isolated from various tissue sources such as bone marrow, adipose tissue, and blood, but it is unknown how the tissue source of origin affects the responses of MSC to inflammatory stimuli. Here, we conceptually addressed this question by evaluating the immune-related gene expression profiles of equine MSC from different tissue sources in response to interferon gamma (IFN-γ) stimulation, with the goal to determine if there is a preferable MSC source for clinical application in an inflammatory environment. The salient findings from this initial study were that the baseline expression of all immune related genes analyzed, with the exception of prostaglandin-endoperoxide synthase 2 (PTGS2), was variable in MSC depending on tissue source. Following IFN-γ stimulation, however, gene expression profiles became more similar across all tissue sources, suggesting that MSC from different sources will likely respond similarly in an inflammatory environment when used clinically.
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Tomlinson JE, Wagner B, Felippe MJB, Van de Walle GR. Multispectral fluorescence-activated cell sorting of B and T cell subpopulations from equine peripheral blood. Vet Immunol Immunopathol 2018; 199:22-31. [DOI: 10.1016/j.vetimm.2018.03.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/15/2018] [Accepted: 03/22/2018] [Indexed: 11/25/2022]
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Curtis TM, Hannett JM, Harman RM, Puoplo NA, Van de Walle GR. The secretome of adipose-derived mesenchymal stem cells protects SH-SY5Y cells from arsenic-induced toxicity, independent of a neuron-like differentiation mechanism. Neurotoxicology 2018; 67:54-64. [PMID: 29660375 DOI: 10.1016/j.neuro.2018.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/15/2018] [Accepted: 04/11/2018] [Indexed: 01/01/2023]
Abstract
Arsenic exposure through contaminated food, water, and air causes irreversible neural damage and affects millions of people worldwide. Several studies have demonstrated that the secreted factors (secretome) from mesenchymal stromal/stem cells (MSCs) can promote neural recovery after several forms of injury including stroke and neurodegenerative diseases. The present study was conducted to determine if the secretome from adipose-derived MSCs (ADSCs) prevents arsenic damage to SH-SY5Y cells. To this end, human neuroblastoma cells (SH-SY5Y) were pre-treated with the secretome from ADSCs and then challenged with different concentrations of arsenic. After various doses and exposure times, the extent of neuronal injury was assessed using MTT reduction and LDH release assays as well as LIVE/DEAD staining. These data demonstrate that the ADSC secretome protects SH-SY5Y cells from arsenic-induced toxicity. Previous reports have shown that the secretome of MSCs can induce neuroblast differentiation and mature neurons are less susceptible to chemical-induced toxicity. In the current study, proliferation assays, neurite length assessment, and quantitative RT-PCR of differentiation markers indicated that the ADSC secretome does not induce SH-SY5Y differentiation into a mature neuron-like phenotype. In contrast, our results demonstrated that soluble factor(s) in the ADSC secretome enhance SH-SY5Y cell substrate-dependent adhesion. The present study is the first to illustrate that the secretome from ADSCs protects SH-SY5Y cells from arsenic-induced toxicity. Additionally, we showed that protection against arsenic toxicity is not dependent on SH-SY5Y cell differentiation into a mature neuron-like phenotype, but involves soluble factor(s) in the secretome that appear to enhance cell survival by an adhesion-dependent mechanism.
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Ledet MM, Anderson R, Harman R, Muth A, Thompson PR, Coonrod SA, Van de Walle GR. BB-Cl-Amidine as a novel therapeutic for canine and feline mammary cancer via activation of the endoplasmic reticulum stress pathway. BMC Cancer 2018; 18:412. [PMID: 29649984 PMCID: PMC5898062 DOI: 10.1186/s12885-018-4323-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 03/29/2018] [Indexed: 11/24/2022] Open
Abstract
Background Mammary cancer is highly prevalent in dogs and cats and results in a poor prognosis due to critically lacking viable treatment options. Recent human and mouse studies have suggested that inhibiting peptidyl arginine deiminase enzymes (PAD) may be a novel breast cancer therapy. Based on the similarities between human breast cancer and mammary cancer in dogs and cats, we hypothesized that PAD inhibitors would also be an effective treatment for mammary cancer in these animals. Methods Canine and feline mammary cancer cell lines were treated with BB-Cl-Amidine (BB-CLA) and evaluated for viability and tumorigenicity. Endoplasmic reticulum stress was tested by western blot, immunofluorescence, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Canine and feline mammary cancer xenograft models were created using NOD scid gamma (NSG) mice, and were treated with BB-CLA for two weeks. Results We found that BB-CLA reduced viability and tumorigenicity of canine and feline mammary cancer cell lines in vitro. Additionally, we demonstrated that BB-CLA activates the endoplasmic reticulum stress pathway in these cells by downregulating 78 kDa Glucose-regulated Protein (GRP78), a potential target in breast cancer for molecular therapy, and upregulating the downstream target gene DNA Damage Inducible Transcript 3 (DDIT3). Finally, we established a mouse xenograft model of both canine and feline mammary cancer in which we preliminarily tested the effects of BB-CLA in vivo. Conclusion We propose that our established mouse xenograft models will be useful for the study of mammary cancer in dogs and cats, and furthermore, that BB-CLA has potential as a novel therapeutic for mammary cancer in these species. Electronic supplementary material The online version of this article (10.1186/s12885-018-4323-8) contains supplementary material, which is available to authorized users.
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Ledet MM, Vasquez AK, Rauner G, Bichoupan AA, Moroni P, Nydam DV, Van de Walle GR. The secretome from bovine mammosphere-derived cells (MDC) promotes angiogenesis, epithelial cell migration, and contains factors associated with defense and immunity. Sci Rep 2018; 8:5378. [PMID: 29599438 PMCID: PMC5876384 DOI: 10.1038/s41598-018-23770-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/16/2018] [Indexed: 12/26/2022] Open
Abstract
Treatment of bovine mastitis with intramammary antibiotics is common, yet several concerns exist including failed efficacy for individual hosts or pathogens and the inability of approved drugs to revert mastitis-induced tissue damage to healthy tissue capable of returning to full milk production. These issues, in addition to aspects of public health such as accidental antibiotic residues in saleable milk and the potential for antimicrobial resistance, support the need to find alternative therapies for this costly disease. This study shows that the secretome, or collective factors, produced by mammosphere-derived cells (MDC) promotes angiogenesis, epithelial cell migration, and contains proteins associated with immunity and defense; all of which are necessary for healing damaged mammary gland tissue. Furthermore, we found that the MDC secretome remains effective after freezing and thawing, enhancing its therapeutic potential. Our results provide a foundation for further characterization of the individual secreted factors and the rationale for using the MDC secretome as a complementary treatment for bovine mastitis.
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Tallmadge RL, Žygelytė E, Van de Walle GR, Kristie TM, Felippe MJB. Effect of a Histone Demethylase Inhibitor on Equine Herpesvirus-1 Activity In Vitro. Front Vet Sci 2018; 5:34. [PMID: 29594155 PMCID: PMC5857540 DOI: 10.3389/fvets.2018.00034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 02/16/2018] [Indexed: 01/12/2023] Open
Abstract
Equine herpesvirus type 1 (EHV-1) is a ubiquitous and highly contagious pathogen that causes a range of disease severities with outbreaks of notable economic impact. Given the limitations in immune protection of current vaccines and the limited effectiveness of antiviral drugs on EHV-1 infections in vivo, improved treatment measures are needed to control disease. The use of drugs that alter the epigenetic state of herpes simplex virus genome has been shown to limit viral primary infection and reactivation both in vitro and in vivo. Therefore, we tested the hypothesis that maintaining a repressive epigenetic state on the EHV-1 genome in the host equine cell would decrease viral load during lytic infection. Equine fetal kidney cells (EFKCs) or isolated peripheral blood leukocytes were treated in vitro with (a) the nucleoside analog ganciclovir; (b) the histone demethylase inhibitor OG-L002; (c) both ganciclovir and OG-L002; or (d) dimethyl sulfoxide (DMSO, vehicle control); and then infected with a clinical EHV-1 isolate. Treatment of EFKCs with ganciclovir (mean 22.3 DNA copies per cell, p = 0.0005), OG-L002 (mean 25.6, p = 0.005) or both ganciclovir and OG-L002 (mean 7.1, p = 0.0001) resulted in decreased EHV-1 viral load at 24 h post-infection (hpi) in comparison with DMSO (mean 42.0), with greater impact using the combined treatment. Further, EHV-1 gene expression at 3 hpi decreased when EFKCs were infected in the presence of ganciclovir (p = 0.04) and combined treatment of ganciclovir and OG-L002 (p = 0.0003). In contrast, under similar conditions, neither ganciclovir nor OG-L002 suppressed EHV-1 infection in leukocytes. Differences between cell types, drug penetrance, or drug turnover, may have contributed to the distinct effects observed in this study.
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Pennington MR, Ledbetter EC, Van de Walle GR. New Paradigms for the Study of Ocular Alphaherpesvirus Infections: Insights into the Use of Non-Traditional Host Model Systems. Viruses 2017; 9:E349. [PMID: 29156583 PMCID: PMC5707556 DOI: 10.3390/v9110349] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/14/2017] [Accepted: 11/16/2017] [Indexed: 12/22/2022] Open
Abstract
Ocular herpesviruses, most notably human alphaherpesvirus 1 (HSV-1), canid alphaherpesvirus 1 (CHV-1) and felid alphaherpesvirus 1 (FHV-1), infect and cause severe disease that may lead to blindness. CHV-1 and FHV-1 have a pathogenesis and induce clinical disease in their hosts that is similar to HSV-1 ocular infections in humans, suggesting that infection of dogs and cats with CHV-1 and FHV-1, respectively, can be used as a comparative natural host model of herpesvirus-induced ocular disease. In this review, we discuss both strengths and limitations of the various available model systems to study ocular herpesvirus infection, with a focus on the use of these non-traditional virus-natural host models. Recent work has demonstrated the robustness and reproducibility of experimental ocular herpesvirus infections in dogs and cats, and, therefore, these non-traditional models can provide additional insights into the pathogenesis of ocular herpesvirus infections.
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Pennington MR, Cossic BGA, Perkins GA, Duffy C, Duhamel GE, Van de Walle GR. First demonstration of equid gammaherpesviruses within the gastric mucosal epithelium of horses. Virus Res 2017; 242:30-36. [PMID: 28870469 DOI: 10.1016/j.virusres.2017.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 12/25/2022]
Abstract
Horses commonly develop gastric mucosal ulcers, similar to humans, a condition known as equine gastric ulcer syndrome (EGUS) that can lead to poor performance and lost training time and care expenses. Unlike humans, however, an infectious bacterial cause of ulcers has not been conclusively identified. Herpesviruses, while well-established causative agents of diseases such as cold sores, genital lesions, and certain types of cancer, have also been implicated in the development of a subset of gastric ulcers in humans. The presence of equid herpesviruses in the gastrointestinal tract and their potential contribution to EGUS has not been evaluated. Here, we provide the first evidence of equid gammaherpesviruses 2 and 5 (EHV-2 and -5) within the epithelium of the gastric mucosa of horses. These viruses were initially detected by a nested PCR screen of gastric tissue samples obtained from client- and university-owned horses with and without ulcers; however, no association with EGUS was found in this limited sample set. We then validated a highly sensitive in situ hybridization (ISH) assay and used this assay to characterize the distribution of these viruses in necropsy gastric tissue samples from five racehorses. Analyses revealed frequent EHV-2 and EHV-5 co-infections within the gastric mucosal epithelium, regardless of the ulcer status. These results are the first to demonstrate the presence of equid gammaherpesviruses in the gastric mucosa of horses and warrants further investigation to determine the contribution of these viruses to the development of EGUS and/or other gastrointestinal diseases.
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Rauner G, Ledet MM, Van de Walle GR. Conserved and variable: Understanding mammary stem cells across species. Cytometry A 2017; 93:125-136. [PMID: 28834173 DOI: 10.1002/cyto.a.23190] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 01/16/2023]
Abstract
Postnatal mammary gland development requires the presence of mammary stem and progenitor cells (MaSC), which give rise to functional milk-secreting cells and regenerate the mammary epithelium with each cycle of lactation. These long-lived, tissue-resident MaSC are also targets for malignant transformation and may be cancer cells-of-origin. Consequently, MaSC are extensively researched in relation to their role and function in development, tissue regeneration, lactation, and breast cancer. The basic structure and function of the mammary gland are conserved among all mammalian species, from the most primitive to the most evolved. However, species vary greatly in their lactation strategies and mammary cancer incidence, making MaSC an interesting focus for comparative research. MaSC have been characterized in mice, to a lesser degree in humans, and to an even lesser degree in few additional mammals. They remain uncharacterized in most mammalian species, including "ancient" monotremes, marsupials, wild, and rare species, as well as in common and domestic species such as cats. Identification and comparison of MaSC across a large variety of species, particularly those with extreme lactational adaptations or low mammary cancer incidence, is expected to deepen our understanding of development and malignancy in the mammary gland. Here, we review the current status of MaSC characterization across species, and underline species variations in lactation and mammary cancer through which we may learn about the role of MaSC in these processes. © 2017 International Society for Advancement of Cytometry.
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Harman RM, Yang S, He MK, Van de Walle GR. Antimicrobial peptides secreted by equine mesenchymal stromal cells inhibit the growth of bacteria commonly found in skin wounds. Stem Cell Res Ther 2017; 8:157. [PMID: 28676123 PMCID: PMC5496374 DOI: 10.1186/s13287-017-0610-6] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/05/2017] [Accepted: 06/14/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The prevalence of chronic skin wounds in humans is high, and treatment is often complicated by the presence of pathogenic bacteria. Therefore, safe and innovative treatments to reduce the bacterial load in cutaneous wounds are needed. Mesenchymal stromal cells (MSC) are known to provide paracrine signals that act on resident skin cells to promote wound healing, but their potential antibacterial activities are not well described. The present study was designed to examine the antibacterial properties of MSC from horses, as this animal model offers a readily translatable model for MSC therapies in humans. Specifically, we aimed to (i) evaluate the in vitro effects of equine MSC on the growth of representative gram-negative and gram-positive bacterial species commonly found in skin wounds and (ii) define the mechanisms by which MSC inhibit bacterial growth. METHODS MSC were isolated from the peripheral blood of healthy horses. Gram-negative E. coli and gram-positive S. aureus were cultured in the presence of MSC and MSC conditioned medium (CM), containing all factors secreted by MSC. Bacterial growth was measured by plating bacteria and counting viable colonies or by reading the absorbance of bacterial cultures. Bacterial membrane damage was detected by incorporation of N-phenyl-1-naphthylamine (NPN). Antimicrobial peptide (AMP) gene and protein expression by equine MSC were determined by RT-PCR and Western blot analysis, respectively. Blocking of AMP activity of MSC CM was achieved using AMP-specific antibodies. RESULTS We found that equine MSC and MSC CM inhibit the growth of E. coli and S. aureus, and that MSC CM depolarizes the cell membranes of these bacteria. In addition, we found that equine MSC CM contains AMPs, and blocking these AMPs with antibodies reduces the effects of MSC CM on bacteria. CONCLUSIONS Our results demonstrate that equine MSC inhibit bacterial growth and secrete factors that compromise the membrane integrity of bacteria commonly found in skin wounds. We also identified four specific AMPs produced by equine MSC. The secretion of AMPs may contribute to the value of MSC as a therapy for cutaneous wounds in both horses and humans.
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Harman RM, Bihun IV, Van de Walle GR. Secreted factors from equine mesenchymal stromal cells diminish the effects of TGF-β1 on equine dermal fibroblasts and alter the phenotype of dermal fibroblasts isolated from cutaneous fibroproliferative wounds. Wound Repair Regen 2017; 25:234-247. [DOI: 10.1111/wrr.12515] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 02/21/2017] [Indexed: 12/26/2022]
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