Stem cells in psoriasis

Expert Consensus on the Application of Stem Cells in Psoriasis Research and Clinical Trials

Psoriasis is an immune-mediated, chronic, relapsing, inflammatory, systemic disease induced by individual-environmental interactions, and is often lifelong because of the difficulty of treatment. In recent years, a variety of targeted therapies, including biologics, have improved the lesions and quality of life of most psoriasis patients, but they still do not address the problem of relapse and may be associated with decreased efficacy or adverse events such as infections over time. Therefore, there is an urgent need for breakthroughs in psoriasis treatment and in relapse-delaying and non-pharmacologic strategies, and stem cell therapy for psoriasis has emerged. In recent years, research on stem cell therapy for psoriasis has received a lot of attention, however, there is no reference standard as well as consensus in this field of research. Therefore, according to the latest consensus and guidelines, combined with relevant literature reports, clinical practice experience and the results of discussions with experts, this consensus specifies the types of stem cells commonly used in the treatment of psoriasis, the methods, dosages, and routes of stem cell therapy for psoriasis, as well as the clinical evaluations (efficacy and safety) of stem cell therapy for psoriasis. In addition, this consensus also provides normative standards for the processes of collection, preparation, preservation and quality control of stem cells and their related products, as well as recommendations for the management of stem cells during infusion for the treatment of psoriasis. This consensus provides the latest specific reference standards and practice guidelines for the field of stem cell therapy for psoriasis.

The link between autophagy and psoriasis

Autophagy is a lysosome-dependent, self-renewal mechanism that degrades and recycles cellular components in eukaryotic cells to maintain the homeostasis of the intracellular environment. Psoriasis is featured by increased inflammatory response, epidermal hyperproliferation and abnormal differentiation, infiltration of immune cells and increased expression levels of both endothelial adhesion molecules and angiogenic mediators. Evidence indicates that autophagy has important roles in many different types of cells, such as lymphocytes, keratinocytes, monocytes and mesenchymal stem cells (MSCs). This paper will review the role of autophagy in the pathogenesis of psoriasis and strategies for therapeutic modulation. Key Message Autophagy regulates the functions of cutaneous cells (MSCs, KCs, T cells and endothelial cells). Since reduced autophagy contributes in part to the pathogenesis of psoriasis, enhancement of autophagy can be an alternative approach to mitigate psoriasis.

Exploring the causal relationship between inflammatory cytokines and immunoinflammatory dermatoses: a Mendelian randomization study

Objectives

Previous studies have shown that the onset and progression of several immunoinflammatory dermatoses are closely related to specific immune-inflammatory responses. To further assess the causal relationship between 41 inflammatory cytokines and immunoinflammatory dermatoses, we used a Mendelian randomization method.

Methods

Mendelian two-sample randomization utilized inflammatory cytokines from a GWAS abstract containing 8,293 healthy participants as well as psoriasis (4,510 cases and 212,242 controls), atopic dermatitis (7,024 cases and 198,740 controls), and vitiligo (131 cases and 207,482 controls). The causal relationship between exposure and outcome was explored primarily using inverse variance weighting. In addition, multiple sensitivity analyses, including MR-Egger, weighted median, simple model, weighted model, and MR-PRESSO, were simultaneously applied to enhance the final results.

Results

The results showed that in clinical practice, IL-4 and IL-1RA were suggestive indicators of atopic dermatitis risk (OR = 0.878, 95% CI = 0.78-0.99, p = 0.036; OR = 0.902, 95% CI = 0.82-1.00, p = 0.045). SCGF-b was a suggestive indicator of psoriasis risk (OR = 1.095, 95% CI = 1.01-1.18, p = 0.023). IL-4 is a suggestive indicator of vitiligo risk (OR = 2.948, 95% CI = 1.28-6.79, p = 0.011).

Conclusion

Our findings suggest that circulating inflammatory cytokines may play a crucial role in the pathogenesis of chronic skin inflammation. IL-4 and IL-1RA may have inhibitory roles in the risk of developing atopic dermatitis, while SCGF-b may have a promoting role in the risk of developing psoriasis. Furthermore, IL-4 may contribute to the risk of developing vitiligo. These results provide insights into further understanding the mechanisms of chronic skin inflammation and offer new targets and strategies for the prevention and treatment of related diseases.

Contribution of Artificial Intelligence to the Identification of Protein-Protein Interactions: A Case Study on PAR-3 and Its Partner Adapter Molecule Crk

Protein-protein interactions (PPIs) are known to be involved in most cellular functions, and a detailed knowledge of such interactions is essential for studying their role in normal and pathological conditions. Significant progress is being made in the identification of PPIs through advances in computational methods. In particular, the AlphaFold2 machine learning-based model has been shown to accelerate drug discovery process by predicting the 3D structure of protein complexes. In this chapter, a straightforward protocol for predicting interprotein interactions between PAR-3 and its protein partner adapter molecule crk is provided. Such artificial intelligence-based and publicly available approaches can provide a resource for further investigation of therapeutic drug targets.

Mesenchymal Stem Cells and Psoriasis: Systematic Review

Mesenchymal Stem Cells (MSCs) are multipotent non-hematopoietic stromal cells found in different body tissues such as bone marrow, adipose tissue, periosteum, Wharton's jelly, umbilical cord, blood, placenta, amniotic fluid, and skin. The biological behavior of MSCs depends mainly on their interaction with the microenvironment in which they are found, whose quality deeply influences the regenerative and immunomodulatory properties of these cells. Several studies confirm the interaction between MSCs and inflammatory microenvironment in the pathogenesis of psoriasis, designating MSCs as an important factor driving psoriasis development. This review aims to describe the most recent evidence on how the inflammatory microenvironment that characterizes psoriasis influences the homeostasis of MSCs and how they can be used to treat the disease.

Effects of different concentrations of human umbilical cord mesenchymal stem cells to ameliorate psoriasis-like skin lesions in BALB/c mice

Background

Psoriasis is an immune-mediated chronic, recurrent, inflammatory skin disease. In view of the research on the relationship between stem cells and the pathogenesis of psoriasis, stem cells may be a new breakthrough in the systemic treatment of psoriasis.

Methods

The BALB/c mouse psoriasis-like model induced by imiquimod was established and animals were randomly divided into a control group, model group, human umbilical cord mesenchymal stem cells (hUC-MSCs) group with different concentrations (injected separately with umbilical cord stem cells 1×10⁷/kg, 2×10⁷/kg, 4×10⁷/kg through the caudal vein) and fresh hUC-MSCs group (injected with fresh umbilical cord stem cells 2×10⁷/kg through the tail vein). The Psoriasis Area and Severity Index (PASI) score was used to observe the changes in skin lesions. The epidermal thickness, degree of keratinization and infiltration of inflammatory cells were observed by HE staining. The concentrations of TNF-α, IFN-γ, IL-17A, IL-23 and other cytokines in serum and skin of mice were measured by enzyme-linked immunosorbent assay (ELISA).

Results

Mice treated with hUC-MSCs showed a good dose-response dependence compared with the control group. As the concentration of hUC-MSCs increased, so did the spleen index. According to the PASI integral trend chart, hUC-MSCs can delay the appearance of skin lesions and accelerate the recovery of skin lesions. HE staining showed that the number of parakeratosis cells in the hUC-MSCs treatment group was significantly decreased, and the degree of dermal hyperplasia and inflammatory cell infiltration in erythrocyte extravasation was significantly lower than in the model group. The higher the concentration of hUC-MSCs, the lower the concentration of the four cytokines in serum and skin tissue.

Conclusions

hUC-MSCs had an obvious therapeutic effect on imiquimod-induced psoriasis in mice, and a high concentration of hUC-MSCs had the best therapeutic effect. This effect intensity is dose-dependent, and hUC-MSCs at high concentrations have better therapeutic effect.

Increased angiogenesis and migration of dermal microvascular endothelial cells from patients with psoriasis

Psoriasis displays both increased angiogenesis and microvascular dilation in the skin, while human dermal microvascular endothelial cells (HDMECs) are involved in angiogenesis and microvascular dilation. Whether the functions of HDMECs are altered in psoriatic skin versus healthy skin remain unknown. Here, we isolated HDMECs from the skin of 10 patients with psoriasis and 10 healthy subjects and compared angiogenesis, proliferation, migration and cell metabolism between psoriatic HDMECs and normal HDMECs. We found that the morphology of primary HDMECs was comparable between psoriatic HDMECs and normal HDMECs. After passage, psoriatic HDMECs displayed larger cell size and wider intercellular space. In addition to DiI-Ac-LDL (DiI-labelled acetylated low-density lipoprotein) uptake, expression levels of CD31, vWF (von Willebrand factor) and LYVE-1 were comparable in psoriatic HDMECs versus normal HDMECs. However, psoriatic HDMECs exhibited increased tube formation (numbers of nodes and meshes, p < 0.05) and migration (numbers of migrated cells, p < 0.001) and reductions in proliferation (growth rates, p < 0.05) and energy metabolism (oxygen consumption rate and extracellular acidification rate, p < 0.05) compared with normal HDMECs. Therefore, psoriatic HDMECs display an increased angiogenesis and migration and decreased proliferation and metabolic activity, suggesting a pathogenic role of HDMECs in psoriasis.

Psoriatic mesenchymal stem cells stimulate the angiogenesis of human umbilical vein endothelial cells in vitro

OBJECTIVE

To investigate the regulation of psoriatic dermal mesenchymal stem cells (p-DMSCs) in the expression of vascular growth factor (VEGF), and migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro.

METHODS

A co-culture model of HUVECs and dermal mesenchymal stem cells (DMSCs)was used in this study. After 7-day co-culture, changes in expression levels of VEGF mRNA and protein in HUVECs were assessed using RT-PCR and Western Blotting, respectively. Migration and tubular formation of HUVECs were also assessed following co-culture of DMSCs and HUVECs.

RESULTS

In comparison to either HUVECs alone or co-culture of n-DMSCs and HUVECs, co-culture of HUVECs and p-DMSCs significantly increased expression levels of both VEGF mRNA (p < 0.01 vs. HUVECs alone) and protein in HUVECs (p < 0.001 vs. both HUVECs alone and HUVECs co-cultured with n-DMSCs). Moreover, p-DMSCs stimulated HUVEC migration and vascular formation (p < 0.05 vs. both HUVECs alone and co-culture of n-DMSCs and HUVECs).

CONCLUSION

Psoriatic DMSCs can upregulate VEGF expression, and stimulate migration and angiogenesis of HUVECs, suggesting a pathogenic role of p-DMSCs in psoriasis.

The attentive focus on T cell-mediated autoimmune pathogenesis of psoriasis, lichen planus and vitiligo

T cell-mediated autoimmune skin diseases develop as a result of the aberrant immune response to the skin cells with T cells playing a central role. These chronic inflammatory skin diseases encompass various types including psoriasis, lichen planus and vitiligo. These diseases show similarities in their immune-pathophysiology. In the last decade, immunomodulating agents have been very successful in the management of these diseases thanks to a better understanding of the pathophysiology. In this review, we will discuss the immunopathogenic mechanisms and highlight the role of T lymphocytes in psoriasis, lichen planus and vitiligo. This study could provide new insights into a better understanding of targeted therapeutic pathways and biological therapies.

Formulation and evaluation of a topical liposomal gel containing a combination of zedoary turmeric oil and tretinoin for psoriasis activity

This study was to develop a combination of zedoary turmeric oil (ZTO) and tretinoin (TRE)-loaded liposomal gel as a topical drug delivery system. We used a combination of single-factor experiment and orthogonal experiment to systematically optimize encapsulation process of the compound liposomes. The optimized liposome vesicles were incorporated into Carbopol gel matrix and studied by continuous in vitro (skin penetration and retention) and in vivo (anti-psoriatic activity using mouse vaginal model and mouse tail model) experiments. The optimized liposomes had an entrapment efficiency (EE) of ZTO was (64.63 ± 1.00)%, EE of TRE was (90.33 ± 0.72)%, drug loading (DL) of ZTO was (9.09 ± 0.14)%, DL of TRE was (1.43 ± 0.02)%, particle size of 257.41 ± 7.58 nm, polydispersity index (PDI) of 0.10 ± 0.04 and zeta potential of -38.77 ± 0.81 mV. Transmission electron microscopy showed liposomes had a regular spherical surface. After 1-month storage at (4 ± 2)°C, the optimized liposome preparations maintained its stability. In vitro study indicated that liposome formulations could significantly prolong the penetration of drugs into the hair follicles of mice and keep more drugs in the skin compared with conventional gel formulations. In vivo study showed that liposomal gel was more effective than conventional gel in treating psoriasis and had a significant dose-dependent effect on psoriasis. In summary, liposomal gel is expected to be an ideal carrier for topical drug delivery systems of ZTO and TRE.

Stem Cells as a Target for the Delivery of Active Molecules to Skin by Topical Administration

Cutaneous stem cells, gained great attention in the field of regenerative medicine as a potential therapeutic target for the treatment of skin and hair disorders and various types of skin cancers. Cutaneous stem cells play a key role in several processes like the renovation of skin structures in the condition of homeostasis and after injuries, the hair follicle growth and the reconstruction and production of melanocytes. Thus, gaining effective access to skin stem cells for therapeutic interventions that often involve active molecules with non-favorable characteristics for skin absorption is a valuable achievement. The topical route with high patient compliance and several other benefits is gaining increasing importance in basic and applied research. However, the major obstacle for topical drug delivery is the effective barrier provided by skin against penetration of the vast majority of exogenous molecules. The research in this field is focusing more and more on new strategies to circumvent and pass this barrier effectively. In this article the existing approaches are discussed considering physical and chemical methods along with utilization of novel drug delivery systems to enhance penetration of drugs to the skin. In particular, attention has been paid to studies finalized to the delivery of molecules to cutaneous stem cells with the aim of transferring signals, modulating their metabolic program, inducing physiological modifications and stem cell gene therapy.

Mesenchymal stromal cells in cancer: a review of their immunomodulatory functions and dual effects on tumor progression

Mesenchymal stem or stromal cells (MSCs) are pluripotent cells implicated in a broad range of physiological events, including organogenesis and maintenance of tissue homeostasis as well as tissue regeneration and repair. Because their current definition is somewhat loose – based primarily on their ability to differentiate into a variety of mesenchymal tissues, adhere to plastic, and express, or lack, a handful of cell surface markers – MSCs likely encompass several subpopulations, which may have diverse properties. Their diversity may explain, at least in part, the pleiotropic functions that they display in different physiological and pathological settings. In the context of tissue injury, MSCs can respectively promote and attenuate inflammation during the early and late phases of tissue repair. They may thereby act as sensors of the inflammatory response and secrete mediators that boost or temper the response as required by the stage of the reparatory and regenerative process. MSCs are also implicated in regulating tumor development, in which they are increasingly recognized to play a complex role. Thus, MSCs can both promote and constrain tumor progression by directly affecting tumor cells via secreted mediators and cell–cell interactions and by modulating the innate and adaptive immune response. This review summarizes our current understanding of MSC involvement in tumor development and highlights the mechanistic underpinnings of their implication in tumor growth and progression. © 2020 Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Mesenchymal Stromal Cells from the Epidermis and Dermis of Psoriasis Patients: Morphology, Immunophenotype, Differentiation Patterns, and Regulation of T Cell Proliferation

Psoriasis is a skin disease characterized by hyperproliferation of keratinocytes and chronic inflammation. Mesenchymal stem/stromal cells (MSCs) exhibit an immunoregulatory function that can be altered in the skin of these patients. However, to date, the presence and functional capacity of MSCs in the dermis and epidermis of patients with psoriasis have not been fully established. In the present study, we evaluated the presence of MSCs in the skin of patients by obtaining adherent cells from the dermis and epidermis of lesional and nonlesional areas and characterizing them in a comparative manner with corresponding cells obtained from the dermis (HD-MSCs) and epidermis (HE-MSCs) of healthy donors. We determined whether the adherent cells had immunophenotypic profiles and differentiation potentials that were characteristic of MSCs. In addition, we analyzed their immunosuppression function by evaluating their capacity to decrease T cell proliferation. Our results indicate the presence of MSCs in the dermis and epidermis of healthy donors and patients with psoriasis; adherent cells from all skin sources exhibited MSC characteristics, such as expression of CD73, CD90, and CD105 markers and a lack of hematopoietic and endothelial marker expression. However, the cell populations obtained showed differences in differentiation potential toward adipogenic, osteogenic, and chondrogenic lineages. In addition, we observed a low MSC obtention frequency in nonlesional epidermal samples (NLE-MSCs), which also showed alterations in morphology and proliferation rate. Interestingly, MSCs from both the nonlesional dermis (NLD-MSCs) and lesional dermis (LD-MSCs) showed higher HLA class I antigen (HLA-I) expression than HD-MSCs. Moreover, NLD-MSCs showed a low T cell proliferation suppression capacity. In summary, this study demonstrates the presence of MSCs in the epidermis and dermis of patients with psoriasis and suggests that such cells may favor the inflammatory process and thus psoriatic lesion development through high HLA-I expression and low immunosuppression capacity.

Pathogenetic Characteristics of Mesenchymal Stem Cells in Hidradenitis Suppurativa

Importance

Hidradenitis suppurativa (HS) is a disease of the terminal hair follicle in apocrine gland-enriched skin areas, where immunobiology dysregulation of mesenchymal stem cells (MSCs) may have a key role.

Objective

To investigate the MSC profile in patients with HS and in healthy controls.

Design, Setting, and Participants

In this prospective case-control study, patients with HS were recruited from the Dermatological Clinic at the Department of Clinical and Molecular Sciences, Università Politecnica delle Marche, Ancona, Italy. Biopsy specimens were analyzed at the Histology Section of the Department of Clinical and Molecular Sciences. Participants included 11 patients with HS and 9 healthy controls, who were recruited into the study between January 20, 2015, and September 20, 2016, and underwent punch biopsy from axillary skin. None of the participants had received any antibiotics (systemic or topical therapy) within almost 12 weeks before the study.

Main Outcomes and Measures

The immunophenotypic profile of MSCs was characterized following the minimal criteria established by the International Society for Cellular Therapy for the identification of MSCs. Levels of 12 cytokines belonging to helper T-cell subtypes 1, 2, and 17 pathways were examined on the secretome of isolated cells by enzyme-linked immunoabsorbent assay.

Results

Skin MSCs were characterized in 11 patients with HS (8 women and 3 men; mean [SD] age, 35.8 [7.9] years) and 9 healthy controls (7 women and 2 men; mean [SD] age, 36.7 [6.9] years). The healthy controls were matched with patients with HS for body mass index. Mesenchymal stem cells isolated from patients with HS (HS-MSCs) and from healthy controls (C-MSCs) met the International Society for Cellular Therapy minimal criteria. Compared with C-MSCs, cytokine analyses of HS-MSCs revealed statistically significant overexpression of interleukin (IL) 6 (median [interquartile range {IQR}], 8765.00 [7659.00-9123.00] vs 2849.00 [2609.00-3001.00] pg/mL; P = .008), IL-10 (median [IQR], 29.46 [26.35-35.79] vs 21.36 [19.89-23.33] pg/mL; P = .004), IL-12 (median [IQR], 15.25 [13.27-16.25] vs 11.89 [10.73-12.33] pg/mL; P = .03), IL-17A (median [IQR], 15.24 [13.23-17.24] vs 11.24 [10.28-11.95] pg/mL; P = .008), tumor necrosis factor (median [IQR], 42.54 [42.20-43.94] vs 32.55 [31.78-33.28] pg/mL; P = .004), transforming growth factor β1 (median [IQR], 1728.00 [1535.00-1979.00] vs 500.80 [465.00-634.50] pg/mL; P = .004), and interferon γ (median [IQR], 11.49 [10.71-12.35] vs 9.45 [9.29-10.01] pg/mL; P = .005).

Conclusions and Relevance

Mesenchymal stem cells isolated from the skin of patients with HS seem to be activated toward an inflammatory status. The imbalance between proinflammatory and anti-inflammatory activities of MSCs favors the hypothesis of their pathogenic involvement in HS.

Mesenchymal stem cells for the treatment of ulcerative colitis: a systematic review and meta-analysis of experimental and clinical studies

OBJECTIVE

To explore the promising use of mesenchymal stem cells (MSCs) for ulcerative colitis (UC).

METHODS

Studies reporting MSC treatment on UC were searched on five databases. Methodological quality was assessed based on the SYRCLE's Risk of Bias (RoB) tool and MINORS tool. Data analysis was conducted using Engauge Digitizer 10.8 and Stata 14.0.

RESULTS

A total of 15 studies met the inclusion criteria including 8 animal (n = 132) and 7 human (n = 216) trials. In animal studies, mice treated with MSCs had significantly lower disease activity index (DAI) than that in the control group: the 1st day (standardized mean difference (SMD) - 0.753, p = 0.027), the 3rd day (SMD - 1.634, p = 0.000), the 5th day (SMD - 2.124, p = 0.000), the 7th day (SMD - 5.327, p = 0.000), the 9th day (SMD - 2.979, p = 0.000), and the 14th day (SMD - 5.032, p = 0.000). Lower histopathological score (HS) (SMD - 5.15, p < 0.05) and longer colon length (SMD 2.147, p = 0.001) in mice treated with MSCs were also indicated. The main outcome in clinical trials showed, compared with control group, healing rate of patients accompanied by MSC therapy elevated obviously: MSCs vs 5-aminosalicylic acids (5-ASA) (RR = 2.317, p = 0.000) and MSCs + 5-ASA vs placebo + 5-ASA (RR = 5.118). The analytical data in 4 trials conducted with single-arm studies also demonstrated increased healing rate (0.787) after MSC treatment (p = 0.000).

CONCLUSION

Our meta-analysis results supported that MSCs could be an underlying method of treating UC.

First-in-man intravenous implantation of stromal vascular fraction in psoriasis: a case study

BACKGROUND

Stromal vascular fraction (SVF) is a mixture of adipose-derived stem cells/mesenchymal stem cells, endothelial/progenitors, pericytes, fibroblasts, and other cells obtained from fat tissue. A small sample of fat or adipose tissue can be obtained under local anesthesia using a cannula. After an enzymatic digestion and centrifugation, the adipocytes (fat cells) are removed to obtain an SVF. Here, we describe the rationale and, to our knowledge, the first clinical implementation of SVF intravenously in a patient with severe psoriasis.

METHODS

Adipose tissue (60 mL) was collected under local anesthesia via a mini-lipoaspirate procedure. The SVF was separated from the adipocytes via centrifugation after an enzymatic digestion. The cells were resuspended in normal saline and injected via bolus push intravenous. The subject was monitored over a period of 12 months for safety (adverse events), medication changes, and quality of life parameters.

RESULTS

The patient did not report any safety concerns and did not experience any severe adverse events. The patient demonstrated a significant decrease in symptoms with a noticeable difference in skin quality appearance. Psoriasis area and severity index score went from 50.4 at baseline to 0.3 at 1 month follow-up.

CONCLUSION

Overall, the patient reported improved quality of life and willingness to continue treatments. This successful initial case study demonstrates that this may be a feasible treatment plan for patients suffering from psoriasis.

Stem Cells as Potential Candidates for Psoriasis Cell-Replacement Therapy

Recent years have seen considerable progress in explaining the mechanisms of the pathogenesis of psoriasis, with a significant role played in it by the hyper-reactivity of Th1 and Th17 cells, Treg function disorder, as well as complex relationships between immune cells, keratinocytes, and vascular endothelium. The effect of stem cells in the epidermis and stem cells on T cells has been identified and the dysfunction of various types of stem cells may be a prime cause of dysregulation of the inflammatory response in psoriasis. However, exploring these mechanisms in detail could provide a chance to develop new therapeutic strategies. In this paper, the authors reviewed data on the role played by stem cells in the pathogenesis of psoriasis and initial attempts at using them in treatment.