Modulating immune responses in alopecia: therapeutic insights and potential targets of antisense oligonucleotides

Abstract

Background: Alopecia areata (AA) are hair loss disorders with distinct pathogenetic mechanisms involving immune dysregulation and microRNA modulation. AA, a T cell-mediated autoimmune disease, is characterized by sudden hair loss, with interferon-gamma (IFN-γ) playing a pivotal role in pathogenesis. The upregulation of IFN response genes, including IFN-inducible chemokines CXCL9, CXCL10, and CXCL11, in lesional skin reflects the activation of the IFN response pathway and contributes to immune cell recruitment and inflammation.

Results: Recent research highlights the role of SIRT1, a class III histone deacetylase, in modulating immune responses in AA. SIRT1 inhibition promotes the production of Th1 cytokines and chemokines, impairing inflammation, while SIRT1 activation suppresses autoreactive responses through NF-κB deacetylation and STAT3 phosphorylation. Additionally, antisense oligonucleotides (ASOs) targeting miR-485-3p show therapeutic potential in promoting hair regrowth and mitigating inflammation in murine models of androgenic alopecia (AGA) and AA.

Conclusion: Understanding chemokine dysregulation provides key insights into AA pathogenesis and highlights TAMI-M as a potential therapy for reducing inflammation and promoting hair regeneration. These findings advance the exploration of immune, microRNA, and SIRT1 pathways as targets for novel hair loss treatments.

Keywords: Alopecia areata; Antisense oligonucleotides; C3H/HeJ mice; Outer root sheath; SIRT1.

Fig. 1

Efficacy of TAMI-M weekly and monthly treatments in C3H/HeJ AA model Mice: A Schematic representation of the experimental design. Fifteen-week-old C3H/HeJ mice were injected subcutaneously with poly I: C and IFN-γ to induce AA-like symptoms. TAMI-M was administered subcutaneously at a dose of 0.8 mg/kg either weekly or monthly, while control animals received PBS (vehicle). Each treatment group consisted of 5 mice (n = 5). B Representative images of hair regrowth and alopecia severity were taken at defined intervals post-treatment on 8, 9 and 11 weeks. Images show the extent of lesional area before and after treatment in the TAMI-M weekly, monthly, and vehicle groups. C Quantitative analysis of AA lesion areas in the dorsal skin of treated and control mice was performed. Statistical significance was determined using one-way ANOVA followed by post hoc comparisons (Tukey’s test). The effects of TAMI-M treatment against AA lesion formation were significant for both dosing regimens in the presence of poly I: C and IFN-γ treatment. Statistical significance: *p < 0.05, **p < 0.01, ***p < 0.001 versus vehicle (before poly I: C induction); *p < 0.05, **p < 0.01, ***p < 0.001 versus vehicle (after poly I: C induction)

Fig. 2

Effect of TAMI-M treatment on proinflammatory chemokines, and cytokines in C3H/HeJ AA model mice: A C3H/HeJ mice were induced with AA-like symptoms using poly I: C and IFN-γ, mimicking the inflammatory milieu observed in human alopecia areata. TAMI-M was administered subcutaneously at a dose of 0.8 mg/kg weekly or monthly. B Relative expression levels of proinflammatory chemokines and cytokines were measured in dorsal skin samples via qPCR following TAMI-M treatment. Data reflect significant reductions in inflammatory markers in treated groups compared to vehicle controls. C miR-485-3p expression levels were evaluated in the skin of treated and control mice. Weekly and monthly TAMI-M dosing regimens both resulted in substantial downregulation of miR-485-3p expression compared to vehicle controls. Statistical significance was determined using one-way ANOVA followed by post hoc comparisons (Tukey’s test). Statistical significance is indicated as follows: *p < 0.05, **p < 0.01, ***p < 0.001 versus vehicle (before poly I: C induction); *p < 0.05, **p < 0.01, ***p < 0.001 versus vehicle (after poly I: C induction)

Fig. 3

Effect of TAMI-M on Poly I: C-induced production of proinflammatory chemokines, SIRT1, and Caspase-1 in HORS: A HORS cells were treated with Poly I: C for 3 h to simulate an inflammatory environment resembling alopecia areata pathology. TAMI-M was applied to evaluate its potential effects. Relative mRNA expression levels of proinflammatory chemokines were quantified using qPCR. Treatment with TAMI-M significantly reduced chemokine production compared to Poly I: C-induced controls. B TAMI-M treatment restored SIRT1 expression levels, which were downregulated following Poly I: C induction. C Caspase-1 activity, a marker of inflammasome activation, was measured by qPCR. TAMI-M treatment significantly reduced Caspase-1 activity in HORS cells compared to Poly I: C-treated controls. Statistical significance was determined using one-way ANOVA followed by post hoc comparisons (Tukey’s test). Significant differences are denoted as *p < 0.05, **p < 0.01, and ***p < 0.001 between groups

Fig. 4

Effects of TAMI-M on Polyinosinic: polycytidylic acid-induced production of proinflammatory chemokines in HORS Cells. A mRNA expression levels of CXCL9, CXCL10, and CXCL11 in human ORS cells treated with Poly I: C (10 µg/mL) and TAMI-M (100 nM) for 24 h. B mRNA expression levels of CXCL9, CXCL10, and CXCL11 in human ORS cells treated with Poly I: C, TAMI-M, and the positive control Ruxolitinib (100 nM) for 24 h. Statistical significance was determined using one-way ANOVA followed by post hoc comparisons (Tukey’s test). Significant differences are denoted as *p < 0.05, **p < 0.01, and ***p < 0.001 between groups. This figure illustrates the differential impact of TAMI-M and Ruxolitinib on the expression of chemokines associated with AA pathogenesis

Fig. 5

The counteractive effect of SIRT1 on NF-κB signaling by TAMI-M in vivo. A Immunoblotting analysis of SIRT1, AR, and CD36 expression in control, DHT-induced AGA mice, and TAMI-M treated mice (2 × 0.6 mg/kg, subcutaneously). B Expression of inflammatory markers: IL-6, P-STAT3, and P-NF-κB in the same groups. C Expression of TNF-α, HSP70, and NLRP3 in the control, DHT-induced AGA, and TAMI-M treated groups. Relative protein expression levels were quantified and normalized to β-actin. Individual data points are shown to illustrate variation within groups. Statistical significance was determined using one-way ANOVA followed by post hoc comparisons (Tukey’s test). Significant differences are indicated as *p < 0.05, **p < 0.01, and ***p < 0.001