Abstract: 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. 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. 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. 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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The study focuses on the antibacterial properties of equine Mesenchymal Stromal Cells (MSC) as an innovative treatment for skin wounds in humans.
Objective and Methods
The primary objective of the research was to study the antibacterial properties of MSC in horses and understand if those properties could be translated to possible therapies in humans. Specifically, the researchers targeted gram-negative and gram-positive bacterial species that typically exist in skin wounds.
Mesenchymal Stromal Cells (MSC) were isolated from the peripheral blood of healthy horses. Bacterial growth was then measured using gram-negative E. coli and gram-positive S. aureus, cultured in the presence of MSC and MSC conditioned medium (MSC CM) – a solution containing all elements secreted by MSC.
Bacterial growth was measured by two methods – by plating the bacteria and counting viable colonies and by measuring the absorbance of bacterial cultures.
MSC’s impact on bacterial cell membrane integrity was detected using N-phenyl-1-naphthylamine (NPN). Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Western blot analysis were used to identify antimicrobial peptide (AMP) gene and protein expression in equine MSC.
The researchers also blocked the AMP activity using AMP-specific antibodies to study the effects on bacteria.
Findings
The study found that both equine MSC and MSC CM inhibit the growth of E. coli and S. aureus, indicating potential antimicrobial properties.
Interestingly, it was discovered that factors present in MSC conditioned medium (MSC CM) compromise or depolarize the cell membranes of these bacteria. This implies that MSC secretes elements influencing bacterial cell membrane integrity.
Evidence of antimicrobial peptides (AMPs) was found in MSC CM. When the AMP action in MSC CM was blocked using specific AMP antibodies, the antibacterial effects were reduced, thereby indicating a significant role of AMPs in hindering bacterial growth.
Four specific AMPs were identified as the products of equine MSC.
Conclusions and implications
This research demonstrates that equine MSC not only inhibits bacterial growth but also secretes factors that compromise the cell membranes of bacteria commonly associated with skin wounds.
The secretion of antimicrobial peptides (AMPs) may enhance the potential applications of Mesenchymal Stromal Cells (MSC) in treating skin wounds in horses, and subsequently, it might be translated into human therapies.
Cite This Article
APA
Harman RM, Yang S, He MK, Van de Walle GR.
(2017).
Antimicrobial peptides secreted by equine mesenchymal stromal cells inhibit the growth of bacteria commonly found in skin wounds.
Stem Cell Res Ther, 8(1), 157.
https://doi.org/10.1186/s13287-017-0610-6
Mustoe TA, O’Shaughnessy K, Kloeters O. Chronic wound pathogenesis and current treatment strategies: a unifying hypothesis.. Plast Reconstr Surg 2006;117(7 Suppl):35S–41S.
Westgate SJ, Percival SL, Knottenbelt DC, Clegg PD, Cochrane CA. Chronic equine wounds: what is the role of infection and biofilms?. Wounds 2010;22:138–45.
Ono I, Yamashita T, Hida T, Jin H-Y, Ito Y, Hamada H. Local administration of hepatocyte growth factor gene enhances the regeneration of dermis in acute incisional wounds.. J Surg Res 2004;120:47–55.
Madrigal M, Rao KS, Riordan NH. A review of therapeutic effects of mesenchymal stem cell secretions and induction of secretory modification by different culture methods.. J Transl Med 2014;12:240.
Krasnodembskaya A, Song Y, Fang X, Gupta N, Serikov V, Lee J-W. Antibacterial effect of human mesenchymal stem cells is mediated in part from secretion of the antimicrobial peptide LL-37.. Stem Cells 2010;28:2229–38.
Devaney J, Horie S, Masterson C, Elliman S, Barry F, O’Brien T. Human mesenchymal stromal cells decrease the severity of acute lung injury induced by E. coli in the rat.. Thorax 2015;70:625–35.
Alcayaga-Miranda F, Cuenca J, Martin A, Contreras L, Figueroa FE, Khoury M. Combination therapy of menstrual derived mesenchymal stem cells and antibiotics ameliorates survival in sepsis.. Stem Cell Res Ther 2015;6:199.
Bara JJ, McCarthy HE, Humphrey E. Bone marrow-derived mesenchymal stem cells become antiangiogenic when chondrogenically or osteogenically differentiated: Implications for bone and cartilage tissue engineering.. Tissue Eng Part A 2014;20:147–59.
Harman RM, Curtis TM, Argyle DJ, Coonrod SA, Van de Walle GR. A Comparative study on the in vitro effects of the DNA methyltransferase inhibitor 5-azacytidine (5-AzaC) in breast/mammary cancer of different mammalian species.. J Mammary Gland Biol Neoplasia 2016;21:51–66.
Liu L, Wang L, Jia HP, Zhao C, Heng HH, Schutte BC. Structure and mapping of the human beta-defensin HBD-2 gene and its expression at sites of inflammation.. Gene 1998;222:237–44.
Sung DK, Chang YS, Sung SI, Yoo HS, Ahn SY, Park WS. Antibacterial effect of mesenchymal stem cells against Escherichia coli is mediated by secretion of beta- defensin- 2 via toll- like receptor 4 signaling: Antibacterial effects of MSCs via beta defensin-2.. Cell Microbiol 2016;18:424–36.
Loh B, Grant C, Hancock RE. Use of the fluorescent probe 1-N-phenylnaphthylamine to study the interactions of aminoglycoside antibiotics with the outer membrane of Pseudomonas aeruginosa.. Antimicrob Agents Chemother 1984;26:546–51.
Bellemare A, Vernoux N, Morin S, Gagné SM, Bourbonnais Y. Structural and antimicrobial properties of human pre-elafin/trappin-2 and derived peptides against Pseudomonas aeruginosa.. BMC Microbiol 2010;10:253.
Zavascki AP, Goldani LZ, Li J, Nation RL. Polymyxin B for the treatment of multidrug-resistant pathogens: a critical review.. J Antimicrob Chemother 2007;60:1206–15.
Bruhn O, Grötzinger J, Cascorbi I, Jung S. Antimicrobial peptides and proteins of the horse - insights into a well-armed organism.. Vet Res 2011;42:98.
Kalinina N, Kharlampieva D, Loguinova M, Butenko I, Pobeguts O, Efimenko A. Characterization of secretomes provides evidence for adipose-derived mesenchymal stromal cells subtypes.. Stem Cell Res Ther 2015;6:221.
Gupta N, Krasnodembskaya A, Kapetanaki M, Mouded M, Tan X, Serikov V. Mesenchymal stem cells enhance survival and bacterial clearance in murine Escherichia coli pneumonia.. Thorax 2012;67:533–9.
Niyonsaba F, Kiatsurayanon C, Chieosilapatham P, Ogawa H. Friends or Foes? Host defense (antimicrobial) peptides and proteins in human skin diseases.. Exp Dermatol 2017.
Zhong L. To Investigate the Antibacterial and Antibiofilm Activity of the Antimicrobial Peptide FP-CATH against Carbapenem-Resistant Klebsiella pneumoniae. ACS Omega 2025 Oct 7;10(39):45465-45470.
Bicer M, Öztürk E, Sener F, Hakki SS, Fidan Ö. Antifungal Efficacy of 3D-Cultured Palatal Mesenchymal Stem Cells and Their Secreted Factors against Candida albicans. ACS Infect Dis 2025 Oct 10;11(10):2894-2906.
He XY, Wang JQ, Chen Y, Yuan TX, Zhao X, Sun YJ, Liu YM, Wang ZY, Cai YB, Gao W, Cui CP, Yi ZJ, Li Q. Antimicrobial peptide PK34 modification enhances the antibacterial and anti-inflammatory effects of bone-derived mesenchymal stem cells in Mycobacterium tuberculosis infection. Stem Cell Res Ther 2025 Aug 29;16(1):469.
Elfar MY, Brown HL, Clayton A, Stephens P. Antibiotic carry over is a confounding factor for cell-based antimicrobial research applications. Sci Rep 2025 Aug 3;15(1):28310.
Mollabashi M, Klopfer A, Lunardon T, Darzenta N, Davis E, Murray M, Sumner SM, Naskou MC. Plasma and complement proteins are essential for the antimicrobial activity of canine platelet lysate. Front Vet Sci 2025;12:1605649.
Joseph J, Boby S, Mooyottu S, Muyyarikkandy MS. Antibiotic potentiators as a promising strategy for combating antibiotic resistance. NPJ Antimicrob Resist 2025 Jun 6;3(1):53.
Khan SS, Luqman S. Antimicrobial Plant Peptides: Structure, Classification, Mechanism and Therapeutic Potential. Curr Top Med Chem 2025;25(27):3103-3156.
Hoseinzadeh A, Esmaeili SA, Sahebi R, Melak AM, Mahmoudi M, Hasannia M, Baharlou R. Fate and long-lasting therapeutic effects of mesenchymal stromal/stem-like cells: mechanistic insights. Stem Cell Res Ther 2025 Feb 4;16(1):33.
Danev N, Poggi JM, Dewever EA, Bartlett AP, Oliveira L, Huntimer L, Harman RM, Van de Walle GR. Immortalized mammosphere-derived epithelial cells retain a bioactive secretome with antimicrobial, regenerative, and immunomodulatory properties. Stem Cell Res Ther 2024 Nov 14;15(1):429.
Liu ZX, Liu GQ, Lin ZX, Chen YQ, Chen P, Hu YJ, Yu B, Jiang N. Effects of Staphylococcus aureus on stem cells and potential targeted treatment of inflammatory disorders. Stem Cell Res Ther 2024 Jun 27;15(1):187.
Bagheri-Josheghani S, Saffari M, Radaei T, Mirzaei H, Rashki S, Fatemi-Nasab ZS, Derakhshan-Nezhad E, Bakhshi B. The effect of mesenchymal stem cell conditioned medium incorporated within chitosan nanostructure in clearance of common gastroenteritis bacteria in-vitro and in-vivo. Sci Rep 2024 Jun 20;14(1):14274.
Pokorska J, Sawicki S, Gabryś J, Kułaj D, Bauer EA, Lenart-Boroń A, Bulanda K, Kuchta-Gładysz M, Grzesiakowska A, Kemilew J, Barton PM, Lasek O, Bugno-Poniewierska M. The use of stem cells in the treatment of mastitis in dairy cows. Sci Rep 2024 May 6;14(1):10349.
Appiah C, Chen S, Pori AI, Retyunskiy V, Tzeng C, Zhao Y. Study of alloferon, a novel immunomodulatory antimicrobial peptide (AMP), and its analogues. Front Pharmacol 2024;15:1359261.
Yudintceva N, Bobkov D, Sulatsky M, Mikhailova N, Oganesyan E, Vinogradova T, Muraviov A, Remezova A, Bogdanova E, Garapach I, Maslak O, Esmedlyaeva D, Dyakova M, Yablonskiy P, Ziganshin R, Kovalchuk S, Blum N, Sonawane SH, Sonawane A, Behl A, Shailja Singh, Shevtsov M. Mesenchymal stem cells-derived extracellular vesicles for therapeutics of renal tuberculosis. Sci Rep 2024 Feb 24;14(1):4495.
Danev N, Li G, Duan JE, Van de Walle GR. Comparative transcriptomic analysis of bovine mesenchymal stromal cells reveals tissue-source and species-specific differences. iScience 2024 Feb 16;27(2):108886.
Tyagi A, Shetty J, Shetty S, Kumar BM, Shetty AV, Nair MR. Antibacterial and Immunomodulatory Properties of Stem Cells from Human Exfoliated Deciduous Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023 Nov;16(Suppl 3):240-246.
Bicer M, Fidan O. Can mesenchymal stem/stromal cells and their secretomes combat bacterial persisters?. World J Microbiol Biotechnol 2023 Aug 12;39(10):276.
Danev N, Harman RM, Oliveira L, Huntimer L, Van de Walle GR. Bovine milk-derived cells express transcriptome markers of pluripotency and secrete bioactive factors with regenerative and antimicrobial activity. Sci Rep 2023 Aug 3;13(1):12600.
Bakare OO, Gokul A, Niekerk LA, Aina O, Abiona A, Barker AM, Basson G, Nkomo M, Otomo L, Keyster M, Klein A. Recent Progress in the Characterization, Synthesis, Delivery Procedures, Treatment Strategies, and Precision of Antimicrobial Peptides. Int J Mol Sci 2023 Jul 24;24(14).
Devi A, Pahuja I, Singh SP, Verma A, Bhattacharya D, Bhaskar A, Dwivedi VP, Das G. Revisiting the role of mesenchymal stem cells in tuberculosis and other infectious diseases. Cell Mol Immunol 2023 Jun;20(6):600-612.
Manna C, Das K, Mandal D, Banerjee D, Mukherjee J, Ganguly I, Naskar S, Bag S. Canine umbilical cord tissue derived mesenchymal stem cells naturally express mRNAs of some antimicrobial peptides. Vet Res Commun 2023 Dec;47(4):2229-2233.
Cui J, Zhang S, Cheng S, Shen H. Current and future outlook of loaded components in hydrogel composites for the treatment of chronic diabetic ulcers. Front Bioeng Biotechnol 2023;11:1077490.
Muraviov AN, Vinogradova TI, Remezova AN, Ariel BM, Gorelova AA, Orlova NV, Yudintceva NM, Esmedliaeva DS, Dyakova ME, Dogonadze MZ, Zabolotnykh NV, Garapach IA, Maslak OS, Kirillov YA, Timofeev SE, Krylova YS, Yablonskiy PK. The Use of Mesenchymal Stem Cells in the Complex Treatment of Kidney Tuberculosis (Experimental Study). Biomedicines 2022 Nov 28;10(12).
Yu P, Yang L, Wang J, Su C, Qin S, Zeng C, Chen L. Genomic and Transcriptomic Analysis Reveal Multiple Strategies for the Cadmium Tolerance in Vibrio parahaemolyticus N10-18 Isolated from Aquatic Animal Ostrea gigas Thunberg. Foods 2022 Nov 23;11(23).
Yudintceva N, Mikhailova N, Fedorov V, Samochernych K, Vinogradova T, Muraviov A, Shevtsov M. Mesenchymal Stem Cells and MSCs-Derived Extracellular Vesicles in Infectious Diseases: From Basic Research to Clinical Practice. Bioengineering (Basel) 2022 Nov 8;9(11).
Bazaid AS, Aldarhami A, Patel M, Adnan M, Hamdi A, Snoussi M, Qanash H, Imam M, Monjed MK, Khateb AM. The Antimicrobial Effects of Saudi Sumra Honey against Drug Resistant Pathogens: Phytochemical Analysis, Antibiofilm, Anti-Quorum Sensing, and Antioxidant Activities. Pharmaceuticals (Basel) 2022 Sep 30;15(10).
Broncano-Lavado A, Senhaji-Kacha A, Santamaría-Corral G, Esteban J, García-Quintanilla M. Alternatives to Antibiotics against Mycobacterium abscessus. Antibiotics (Basel) 2022 Sep 28;11(10).
Harman RM, Churchill KA, Parmar S, Van de Walle GR. Mesenchymal stromal cells isolated from chicken peripheral blood secrete bioactive factors with antimicrobial and regenerative properties. Front Vet Sci 2022;9:949836.
Eiro N, Fraile M, González-Jubete A, González LO, Vizoso FJ. Mesenchymal (Stem) Stromal Cells Based as New Therapeutic Alternative in Inflammatory Bowel Disease: Basic Mechanisms, Experimental and Clinical Evidence, and Challenges. Int J Mol Sci 2022 Aug 10;23(16).
Moeinabadi-Bidgoli K, Rezaee M, Rismanchi H, Mohammadi MM, Babajani A. Mesenchymal Stem Cell-Derived Antimicrobial Peptides as Potential Anti-Neoplastic Agents: New Insight into Anticancer Mechanisms of Stem Cells and Exosomes. Front Cell Dev Biol 2022;10:900418.
Johnson V, Chow L, Harrison J, Soontararak S, Dow S. Activated Mesenchymal Stromal Cell Therapy for Treatment of Multi-Drug Resistant Bacterial Infections in Dogs. Front Vet Sci 2022;9:925701.
Zohrabi M, Dehghan Marvast L, Izadi M, Mousavi SA, Aflatoonian B. Potential of Mesenchymal Stem Cell-Derived Exosomes as a Novel Treatment for Female Infertility Caused by Bacterial Infections. Front Microbiol 2021;12:785649.
Izadi M, Dehghan Marvast L, Rezvani ME, Zohrabi M, Aliabadi A, Mousavi SA, Aflatoonian B. Mesenchymal Stem-Cell Derived Exosome Therapy as a Potential Future Approach for Treatment of Male Infertility Caused by Chlamydia Infection. Front Microbiol 2021;12:785622.
Kudinov VA, Artyushev RI, Zurina IM, Lapshin RD, Snopova LB, Mukhina IV, Grinakovskaya OS, Saburina IN. Antimicrobial and Regenerative Effects of Placental Multipotent Mesenchymal Stromal Cell Secretome-Based Chitosan Gel on Infected Burns in Rats. Pharmaceuticals (Basel) 2021 Dec 4;14(12).
Kraskiewicz H, Hinc P, Krawczenko A, Bielawska-Pohl A, Paprocka M, Witkowska D, Mohd Isa IL, Pandit A, Klimczak A. HATMSC Secreted Factors in the Hydrogel as a Potential Treatment for Chronic Wounds-In Vitro Study. Int J Mol Sci 2021 Nov 12;22(22).
Zhang QY, Yan ZB, Meng YM, Hong XY, Shao G, Ma JJ, Cheng XR, Liu J, Kang J, Fu CY. Antimicrobial peptides: mechanism of action, activity and clinical potential. Mil Med Res 2021 Sep 9;8(1):48.
Raghav A, Tripathi P, Mishra BK, Jeong GB, Banday S, Gautam KA, Mateen QN, Singh P, Singh M, Singla A, Ahmad J. Mesenchymal Stromal Cell-Derived Tailored Exosomes Treat Bacteria-Associated Diabetes Foot Ulcers: A Customized Approach From Bench to Bed. Front Microbiol 2021;12:712588.
Zhang X, Xie Q, Ye Z, Li Y, Che Z, Huang M, Zeng J. Mesenchymal Stem Cells and Tuberculosis: Clinical Challenges and Opportunities. Front Immunol 2021;12:695278.
Harman RM, Marx C, Van de Walle GR. Translational Animal Models Provide Insight Into Mesenchymal Stromal Cell (MSC) Secretome Therapy. Front Cell Dev Biol 2021;9:654885.
Cao Y, Yan J, Liu H. [Clinical research progress of mesenchymal stem cells in treatment of chronic wounds]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2021 Apr 15;35(4):496-501.
Fernández-Francos S, Eiro N, Costa LA, Escudero-Cernuda S, Fernández-Sánchez ML, Vizoso FJ. Mesenchymal Stem Cells as a Cornerstone in a Galaxy of Intercellular Signals: Basis for a New Era of Medicine. Int J Mol Sci 2021 Mar 30;22(7).
Russell KA, Garbin LC, Wong JM, Koch TG. Mesenchymal Stromal Cells as Potential Antimicrobial for Veterinary Use-A Comprehensive Review. Front Microbiol 2020;11:606404.
Bujňáková D, Čuvalová A, Čížek M, Humenik F, Salzet M, Čížková D. Canine Bone Marrow Mesenchymal Stem Cell Conditioned Media Affect Bacterial Growth, Biofilm-Associated Staphylococcus aureus and AHL-Dependent Quorum Sensing. Microorganisms 2020 Sep 26;8(10).
Saberpour M, Bakhshi B, Najar-Peerayeh S. Evaluation of the Antimicrobial and Antibiofilm Effect of Chitosan Nanoparticles as Carrier for Supernatant of Mesenchymal Stem Cells on Multidrug-Resistant Vibrio cholerae. Infect Drug Resist 2020;13:2251-2260.
Yagi H, Chen AF, Hirsch D, Rothenberg AC, Tan J, Alexander PG, Tuan RS. Antimicrobial activity of mesenchymal stem cells against Staphylococcus aureus. Stem Cell Res Ther 2020 Jul 17;11(1):293.
Çankirili NK, Kart D, Çelebi-Saltik B. Evaluation of the biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa on human umbilical cord CD146+ stem cells and stem cell-based decellularized matrix. Cell Tissue Bank 2020 Jun;21(2):215-231.
Lange-Consiglio A, Gusmara C, Manfredi E, Idda A, Soggiu A, Greco V, Bonizzi L, Cremonesi F, Zecconi A. Antimicrobial Effects of Conditioned Medium From Amniotic Progenitor Cells in vitro and in vivo: Toward Tissue Regenerative Therapies for Bovine Mastitis. Front Vet Sci 2019;6:443.
Ocansey DKW, Wang L, Wang J, Yan Y, Qian H, Zhang X, Xu W, Mao F. Mesenchymal stem cell-gut microbiota interaction in the repair of inflammatory bowel disease: an enhanced therapeutic effect. Clin Transl Med 2019 Dec 23;8(1):31.
Chow L, Johnson V, Impastato R, Coy J, Strumpf A, Dow S. Antibacterial activity of human mesenchymal stem cells mediated directly by constitutively secreted factors and indirectly by activation of innate immune effector cells. Stem Cells Transl Med 2020 Feb;9(2):235-249.
Kadam S, Shai S, Shahane A, Kaushik KS. Recent Advances in Non-Conventional Antimicrobial Approaches for Chronic Wound Biofilms: Have We Found the 'Chink in the Armor'?. Biomedicines 2019 Apr 30;7(2).
Marrazzo P, Crupi AN, Alviano F, Teodori L, Bonsi L. Exploring the roles of MSCs in infections: focus on bacterial diseases. J Mol Med (Berl) 2019 Apr;97(4):437-450.
Cuenca J, Le-Gatt A, Castillo V, Belletti J, Díaz M, Kurte G M, Gonzalez PL, Alcayaga-Miranda F, Schuh CMAP, Ezquer F, Ezquer M, Khoury M. The Reparative Abilities of Menstrual Stem Cells Modulate the Wound Matrix Signals and Improve Cutaneous Regeneration. Front Physiol 2018;9:464.
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 Mar 29;8(1):5378.