Irena Pastar - Academia.edu (original) (raw)

Papers by Irena Pastar

Journal of Investigative Dermatology

The Journal of Immunology

Staphylococcus epidermidis (SE), nonvirulent Gram-positive (G+) bacterium, is a member of the nor... more Staphylococcus epidermidis (SE), nonvirulent Gram-positive (G+) bacterium, is a member of the normal human skin microbiota with beneficial relationship with the host. Gamma delta (GD) T cells as the major T cell population in epithelial tissues have been implicated in maintaining tissue integrity, regulating inflammation and defending against pathogens. Perforin-2 (P-2) is a recently described antimicrobial protein responsible for clearance of intracellular G+ and G− bacteria. We examine the relationship between SE and P-2 expression in the human skin. Healthy human skin tissue was used for flow cytometric and bacterial infection analyses. We analyzed P-2 expression at a single cell resolution using an amplified fluorescence in situ hybridization (FISH) technique for detection of P-2 mRNA in combination with immune-phenotyping. Methicillin resistant Staphylococcus aureus (MRSA) intracellular killing assay was performed on the skin cells that were pretreated with S. epidermidis for 2...

The Journal of Immunology

Effective and precisely timed immune response is vital for efficient wound closure. Cutaneous gam... more Effective and precisely timed immune response is vital for efficient wound closure. Cutaneous gamma delta T (GDT) cells are poised to perform skin-specific roles in inflammation and repair while factors that shape gamma delta T cell activity are still not known. GDT cell deficient mice exhibit significantly delayed wound closure compared to WT mice. We found that GDT cells constitutively express novel antimicrobial protein Perforin-2 (P-2), and we postulated that P-2 contributes to GDT cell activation and recruitment in response to wounding. We induced full thickness wounds on the dorsal skin of 2- or 10-month-old C57/BL6 WT and P-2 deficient (−/−) mice and assessed healing at day 3 and 6 post wounding. We analyzed re-epithelialization and keratinocyte activation using histomorphometry and Keratin-6 staining. We found that in 10-month old mice, wound re-epithelialization was significantly delayed at day 6 in P-2 −/− mice compared to WT. This delay was accompanied by significantly de...

Current Dermatology Reports

BackgroundMicroRNAs (miRNA) and other components contained in extracellular vesicles may reflect ... more BackgroundMicroRNAs (miRNA) and other components contained in extracellular vesicles may reflect the presence of a disease. Lung tissue, sputum and sera of individuals with idiopathic pulmonary fibrosis (IPF) show alterations in miRNA expression. We designed this study to test whether urine and/or tissue derived exosomal miRNAs from individuals with IPF carry cargo that can promote fibrosis.MethodsExosomes were isolated from urine (U-IPFexo), lung tissue myofibroblasts (MF-IPFexo), serum from individuals with IPF (n=16) and age/sex-matched controls without lung disease (n=10). We analyzed microRNA expression of isolated exosomes and their in vivo bio-distribution. We investigated the effect on ex vivo skin wound healing and in in vivo mouse lung models.ResultsU-IPFexo or MF-IPFexo expressed miR let-7d, miR-29a-5p, miR 181b-3p and miR-199a-3p consistent with previous reports of miRNA expression obtained from lung tissue/sera from patients with IPF. In vivo bio-distribution experiment...

MicroRNAs (miR) are important posttranscriptional regulators and exhibit a high potential to be u... more MicroRNAs (miR) are important posttranscriptional regulators and exhibit a high potential to be utilized in diagnosis and therapy. However, our insufficient knowledge of the miR-mediated gene regulation in human skin wound healing severely hinders the identification of clinically relevant miRs. Here, we performed paired small RNA and long RNA sequencing in human tissue samples, including matched skin and acute wounds collected at each healing stage and chronic non-healing venous ulcers (VU). With integrative small and long RNA-omics analysis, we developed a compendium (https://www.xulandenlab.com/humanwounds-mirna-mrna), which will be an open, comprehensive resource to broadly aid wound healing research. With this first clinical, wound-centric resource of miRs and mRNAs, we identified 17 pathologically relevant miRs that exhibited abnormal VU expression and displayed their targets enriched explicitly in the VU gene signature. Intermeshing regulatory networks controlled by these miRs...

Journal of Investigative Dermatology, 2021

Severe angiopathy is a major driver for diabetes associated secondary complications. Knowledge on... more Severe angiopathy is a major driver for diabetes associated secondary complications. Knowledge on underlying mechanisms essential for advanced therapies to attenuate these pathologies is limited. Injection of ABCB5+ stromal precursors (SPs) at the edge of non-healing diabetic wounds in a murine db/db model, closely mirroring human type II diabetes, profoundly accelerates wound closure. Strikingly, enhanced angiogenesis was substantially enforced by the release of the ribonuclease angiogenin from ABCB5+ SPs. This compensates for the profoundly reduced angiogenin expression in non-treated murine chronic diabetic wounds. Silencing of angiogenin in ABCB5+ SPs prior to injection significantly reduced angiogenesis and delayed wound closure in diabetic db/db mice implying an unprecedented key role for angiogenin in tissue regeneration in diabetes. These data hold significant promise for further refining SPs-based therapies of non-healing diabetic foot ulcers and other pathologies with impaired angiogenesis.

Frontiers in Immunology

Hidradenitis Suppurativa (HS) is a chronic multifactorial inflammatory skin disease with incomple... more Hidradenitis Suppurativa (HS) is a chronic multifactorial inflammatory skin disease with incompletely understood mechanisms of disease pathology. HS is characterized by aberrant activation of the innate immune system, resulting in activation of pathways that aim to protect against pathogenic microorganisms, and also contribute to failure to resolve inflammation. Imbalance in innate immunity is evident in deregulation of host antimicrobial peptides (AMPs) and the complement system associated with the microbiome dysbiosis. The pathology is further complicated by ability of pathogens associated with HS to overcome host immune response. Potential roles of major AMPs, cathelicidin, defensins, dermcidin, S100 proteins, RNAse 7 and complement proteins are discussed. Dysregulated expression pattern of innate immunity components in conjunction with bacterial component of the disease warrants consideration of novel treatment approaches targeting both host immunity and pathogenic microbiome in...

Contemporary Diabetes, 2018

Journal of Investigative Dermatology, 2021

Journal of Wound Technology, 2014

Wound Repair and Regeneration, 2019

Journal of cellular physiology, Jan 22, 2017

Fibrosis can develop in nearly any tissue leading to a wide range of chronic fibrotic diseases. H... more Fibrosis can develop in nearly any tissue leading to a wide range of chronic fibrotic diseases. However, current treatment options are limited. In this study, we utilized an established aged mouse model of bleomycin-induced lung fibrosis (BLM) to test our hypothesis that fibrosis may develop simultaneously in multiple organs by evaluating skin fibrosis and wound healing. Fibrosis was induced in lung in aged (18-22 month-old) C57BL/6 male mice by intratracheal BLM administration. Allogeneic adipose-derived mesenchymal stromal cells (ASCs) or saline were injected intravenously 24 hours after BLM administration. Full thickness 8-mm punch wounds were performed 7 days later to study potential systemic anti-fibrotic and wound healing effects of intravenously delivered ASCs. Mice developed lung and skin fibrosis as well as delayed wound closure. Moreover, we observed similar changes in the expression of known pro-fibrotic factors in both lung and skin wound tissue, including microRNA-199 a...

Archives of dermatological research, 2017

Cutaneous squamous cell carcinoma (cSCC) is a malignant proliferation of keratinocytes with an un... more Cutaneous squamous cell carcinoma (cSCC) is a malignant proliferation of keratinocytes with an uncertain molecular basis causing significant morbidity. MicroRNAs (miRs) are small RNA molecules that regulate gene expression on post- transcriptional level. MiRs are critical to various biological processes. To determine if miRs play a role in pathogenesis of invasive cSCC, we collected patients' specimens from in situ and invasive cSCC (n = 19) and examined miRs expression levels using qPCR. Specifically, we evaluated miR-21, miR-103a, miR-186, miR-200b, miR-203, and miR-205 expression levels due to their role in skin biology and epithelial to mesenchymal transition. MiR levels were compared between in situ and invasive cSCCs. We found statistically significant (p ≤ 0.05) upregulation of miR-21 and miR-205 in invasive cSCC compared to cSCC in situ. We concluded that miR-21 and miR-205 may have diagnostic value in determining the invasive properties of cSCCs and that each cSCC displ...

Cell and Tissue Research, 2016

C to U editing at position 32 of the anticodon loop

Surgical technology international, 2008

Keratinocytes are the major cellular component of epidermis, and they have several critical roles... more Keratinocytes are the major cellular component of epidermis, and they have several critical roles in the wound healing process. They are involved in the intricate mechanisms of initiation, maintenance, and completion of wound healing. The properties of keratinocytes vary depending upon their location and circumstances within chronic wounds. Keratinocytes at the non-healing edges of chronic wounds differ from normal, healthy keratinocytes. The cross-talk between healthy keratinocytes and other cell types participating in wound healing is critical for successful wound closure. This discovery provides the biological foundation for debridement: Removing "bad" cells from a quiescent wound edge and exposing or even replacing them with "healthy" cells with a high regenerative potential can enhance epithelialization and healing of chronic wounds. This paper will review the biological and pathological properties of keratinocytes as they relate to wound healing, and the wa...

Advances in Wound Care, 2014

Journal of Investigative Dermatology

The Journal of Immunology

Staphylococcus epidermidis (SE), nonvirulent Gram-positive (G+) bacterium, is a member of the nor... more Staphylococcus epidermidis (SE), nonvirulent Gram-positive (G+) bacterium, is a member of the normal human skin microbiota with beneficial relationship with the host. Gamma delta (GD) T cells as the major T cell population in epithelial tissues have been implicated in maintaining tissue integrity, regulating inflammation and defending against pathogens. Perforin-2 (P-2) is a recently described antimicrobial protein responsible for clearance of intracellular G+ and G− bacteria. We examine the relationship between SE and P-2 expression in the human skin. Healthy human skin tissue was used for flow cytometric and bacterial infection analyses. We analyzed P-2 expression at a single cell resolution using an amplified fluorescence in situ hybridization (FISH) technique for detection of P-2 mRNA in combination with immune-phenotyping. Methicillin resistant Staphylococcus aureus (MRSA) intracellular killing assay was performed on the skin cells that were pretreated with S. epidermidis for 2...

The Journal of Immunology

Effective and precisely timed immune response is vital for efficient wound closure. Cutaneous gam... more Effective and precisely timed immune response is vital for efficient wound closure. Cutaneous gamma delta T (GDT) cells are poised to perform skin-specific roles in inflammation and repair while factors that shape gamma delta T cell activity are still not known. GDT cell deficient mice exhibit significantly delayed wound closure compared to WT mice. We found that GDT cells constitutively express novel antimicrobial protein Perforin-2 (P-2), and we postulated that P-2 contributes to GDT cell activation and recruitment in response to wounding. We induced full thickness wounds on the dorsal skin of 2- or 10-month-old C57/BL6 WT and P-2 deficient (−/−) mice and assessed healing at day 3 and 6 post wounding. We analyzed re-epithelialization and keratinocyte activation using histomorphometry and Keratin-6 staining. We found that in 10-month old mice, wound re-epithelialization was significantly delayed at day 6 in P-2 −/− mice compared to WT. This delay was accompanied by significantly de...

Current Dermatology Reports

BackgroundMicroRNAs (miRNA) and other components contained in extracellular vesicles may reflect ... more BackgroundMicroRNAs (miRNA) and other components contained in extracellular vesicles may reflect the presence of a disease. Lung tissue, sputum and sera of individuals with idiopathic pulmonary fibrosis (IPF) show alterations in miRNA expression. We designed this study to test whether urine and/or tissue derived exosomal miRNAs from individuals with IPF carry cargo that can promote fibrosis.MethodsExosomes were isolated from urine (U-IPFexo), lung tissue myofibroblasts (MF-IPFexo), serum from individuals with IPF (n=16) and age/sex-matched controls without lung disease (n=10). We analyzed microRNA expression of isolated exosomes and their in vivo bio-distribution. We investigated the effect on ex vivo skin wound healing and in in vivo mouse lung models.ResultsU-IPFexo or MF-IPFexo expressed miR let-7d, miR-29a-5p, miR 181b-3p and miR-199a-3p consistent with previous reports of miRNA expression obtained from lung tissue/sera from patients with IPF. In vivo bio-distribution experiment...

MicroRNAs (miR) are important posttranscriptional regulators and exhibit a high potential to be u... more MicroRNAs (miR) are important posttranscriptional regulators and exhibit a high potential to be utilized in diagnosis and therapy. However, our insufficient knowledge of the miR-mediated gene regulation in human skin wound healing severely hinders the identification of clinically relevant miRs. Here, we performed paired small RNA and long RNA sequencing in human tissue samples, including matched skin and acute wounds collected at each healing stage and chronic non-healing venous ulcers (VU). With integrative small and long RNA-omics analysis, we developed a compendium (https://www.xulandenlab.com/humanwounds-mirna-mrna), which will be an open, comprehensive resource to broadly aid wound healing research. With this first clinical, wound-centric resource of miRs and mRNAs, we identified 17 pathologically relevant miRs that exhibited abnormal VU expression and displayed their targets enriched explicitly in the VU gene signature. Intermeshing regulatory networks controlled by these miRs...

Journal of Investigative Dermatology, 2021

Severe angiopathy is a major driver for diabetes associated secondary complications. Knowledge on... more Severe angiopathy is a major driver for diabetes associated secondary complications. Knowledge on underlying mechanisms essential for advanced therapies to attenuate these pathologies is limited. Injection of ABCB5+ stromal precursors (SPs) at the edge of non-healing diabetic wounds in a murine db/db model, closely mirroring human type II diabetes, profoundly accelerates wound closure. Strikingly, enhanced angiogenesis was substantially enforced by the release of the ribonuclease angiogenin from ABCB5+ SPs. This compensates for the profoundly reduced angiogenin expression in non-treated murine chronic diabetic wounds. Silencing of angiogenin in ABCB5+ SPs prior to injection significantly reduced angiogenesis and delayed wound closure in diabetic db/db mice implying an unprecedented key role for angiogenin in tissue regeneration in diabetes. These data hold significant promise for further refining SPs-based therapies of non-healing diabetic foot ulcers and other pathologies with impaired angiogenesis.

Frontiers in Immunology

Hidradenitis Suppurativa (HS) is a chronic multifactorial inflammatory skin disease with incomple... more Hidradenitis Suppurativa (HS) is a chronic multifactorial inflammatory skin disease with incompletely understood mechanisms of disease pathology. HS is characterized by aberrant activation of the innate immune system, resulting in activation of pathways that aim to protect against pathogenic microorganisms, and also contribute to failure to resolve inflammation. Imbalance in innate immunity is evident in deregulation of host antimicrobial peptides (AMPs) and the complement system associated with the microbiome dysbiosis. The pathology is further complicated by ability of pathogens associated with HS to overcome host immune response. Potential roles of major AMPs, cathelicidin, defensins, dermcidin, S100 proteins, RNAse 7 and complement proteins are discussed. Dysregulated expression pattern of innate immunity components in conjunction with bacterial component of the disease warrants consideration of novel treatment approaches targeting both host immunity and pathogenic microbiome in...

Contemporary Diabetes, 2018

Journal of Investigative Dermatology, 2021

Journal of Wound Technology, 2014

Wound Repair and Regeneration, 2019

Journal of cellular physiology, Jan 22, 2017

Fibrosis can develop in nearly any tissue leading to a wide range of chronic fibrotic diseases. H... more Fibrosis can develop in nearly any tissue leading to a wide range of chronic fibrotic diseases. However, current treatment options are limited. In this study, we utilized an established aged mouse model of bleomycin-induced lung fibrosis (BLM) to test our hypothesis that fibrosis may develop simultaneously in multiple organs by evaluating skin fibrosis and wound healing. Fibrosis was induced in lung in aged (18-22 month-old) C57BL/6 male mice by intratracheal BLM administration. Allogeneic adipose-derived mesenchymal stromal cells (ASCs) or saline were injected intravenously 24 hours after BLM administration. Full thickness 8-mm punch wounds were performed 7 days later to study potential systemic anti-fibrotic and wound healing effects of intravenously delivered ASCs. Mice developed lung and skin fibrosis as well as delayed wound closure. Moreover, we observed similar changes in the expression of known pro-fibrotic factors in both lung and skin wound tissue, including microRNA-199 a...

Archives of dermatological research, 2017

Cutaneous squamous cell carcinoma (cSCC) is a malignant proliferation of keratinocytes with an un... more Cutaneous squamous cell carcinoma (cSCC) is a malignant proliferation of keratinocytes with an uncertain molecular basis causing significant morbidity. MicroRNAs (miRs) are small RNA molecules that regulate gene expression on post- transcriptional level. MiRs are critical to various biological processes. To determine if miRs play a role in pathogenesis of invasive cSCC, we collected patients' specimens from in situ and invasive cSCC (n = 19) and examined miRs expression levels using qPCR. Specifically, we evaluated miR-21, miR-103a, miR-186, miR-200b, miR-203, and miR-205 expression levels due to their role in skin biology and epithelial to mesenchymal transition. MiR levels were compared between in situ and invasive cSCCs. We found statistically significant (p ≤ 0.05) upregulation of miR-21 and miR-205 in invasive cSCC compared to cSCC in situ. We concluded that miR-21 and miR-205 may have diagnostic value in determining the invasive properties of cSCCs and that each cSCC displ...

Cell and Tissue Research, 2016

C to U editing at position 32 of the anticodon loop

Surgical technology international, 2008

Keratinocytes are the major cellular component of epidermis, and they have several critical roles... more Keratinocytes are the major cellular component of epidermis, and they have several critical roles in the wound healing process. They are involved in the intricate mechanisms of initiation, maintenance, and completion of wound healing. The properties of keratinocytes vary depending upon their location and circumstances within chronic wounds. Keratinocytes at the non-healing edges of chronic wounds differ from normal, healthy keratinocytes. The cross-talk between healthy keratinocytes and other cell types participating in wound healing is critical for successful wound closure. This discovery provides the biological foundation for debridement: Removing "bad" cells from a quiescent wound edge and exposing or even replacing them with "healthy" cells with a high regenerative potential can enhance epithelialization and healing of chronic wounds. This paper will review the biological and pathological properties of keratinocytes as they relate to wound healing, and the wa...

Advances in Wound Care, 2014