Small-molecule-induced epigenetic rejuvenation promotes SREBP condensation and overcomes barriers to CNS myelin regeneration.

Remyelination failure in diseases like multiple sclerosis (MS) was thought to involve suppressed maturation of oligodendrocyte precursors; however, oligodendrocytes are present in MS lesions yet lack myelin production. We found that oligodendrocytes in the lesions are epigenetically silenced. Developing a transgenic reporter labeling differentiated oligodendrocytes for phenotypic screening, we identified a small-molecule epigenetic-silencing-inhibitor (ESI1) that enhances myelin production and ensheathment. ESI1 promotes remyelination in animal models of demyelination and enables de novo myelinogenesis on regenerated CNS axons. ESI1 treatment lengthened myelin sheaths in human iPSC-derived organoids and augmented (re)myelination in aged mice while reversing age-related cognitive decline. Multi-omics revealed that ESI1 induces an active chromatin landscape that activates myelinogenic pathways and reprograms metabolism. Notably, ESI1 triggered nuclear condensate formation of master lipid-metabolic regulators SREBP1/2, concentrating transcriptional co-activators to drive lipid/cholesterol biosynthesis. Our study highlights the potential of targeting epigenetic silencing to enable CNS myelin regeneration in demyelinating diseases and aging.

Photodynamic Skincare: A Prospective Single-Center Study.

BACKGROUND: Peer-reviewed, clinical studies measuring the efficacy and usability of skin care products enhance their integrity and may guide experts in the field in providing recommendations. A single-blind, prospective clinical study was designed to assess the subject satisfaction, clinical benefit, and safety of three photodynamic topical formulations referred to as MMSRepose (MMSRep), MMSRevive (MMSRev), and MMSBalance (MMSB).  Methods: Thirteen male and female patients (mean age 49 +/- 17.8 years) applied one of the three topical serums twice daily over a period of 12 weeks. Subjects returned for photography, and blinded investigator evaluation of rhytides (fine lines) and dyspigmentation were measured on a 6- and 4-point scale, respectively. Patient-perceived efficacy of multiple clinical outcomes was measured on a 5-point scale.  Results: 100% of subjects reported at least a 1-grade improvement in global aesthetic at the conclusion of the study. Investigator assessment revealed an overall 53.3% decrease in rhytides, correlating to a mean point reduction from 1.65 +/- 0.77 to 0.77 +/- 0.53 (P<0.001) from baseline to week 12. Investigator assessment of dyspigmentation revealed a 62.7% decrease, correlating to a mean point reduction of 1.85 +/- 0.68 from week 1 to 0.69 +/- 0.48 at week 12 (P<0.001). CONCLUSION: Photodynamic serums demonstrate clinical efficacy in skin rejuvenation and high user satisfaction. There were no serious adverse events. This study is limited by the inability to randomize to placebo due to the small sample size, as subject retention was heavily impacted by the SARS-CoV-2 pandemic. Future studies may be indicated to undergo comparison with a larger cohort.  J Drugs Dermatol. 2024;23(5):332-337. doi:10.36849/JDD.7167.

Enhancement of skin rejuvenation and hair growth through novel near-infrared light emitting diode (nNIR) lighting: in vitro and in vivo study.

The study aimed to explore the impact of a novel near-infrared LED (nNIR) with an extended spectrum on skin enhancement and hair growth. Various LED sources, including White and nNIRs, were compared across multiple parameters: cytotoxicity, adenosine triphosphate (ATP) synthesis, reactive oxygen species (ROS) reduction, skin thickness, collagen synthesis, collagenase expression, and hair follicle growth. Experiments were conducted on human skin cells and animal models. Cytotoxicity, ATP synthesis, and ROS reduction were evaluated in human skin cells exposed to nNIRs and Whites. LED irradiation effects were also studied on a UV-induced photoaging mouse model, analyzing skin thickness, collagen synthesis, and collagenase expression. Hair growth promotion was examined as well. Results revealed both White and nNIR were non-cytotoxic to human skin cells. nNIR enhanced ATP and collagen synthesis while reducing ROS levels, outperforming the commonly used 2chip LEDs. In the UV-induced photoaging mouse model, nNIR irradiation led to reduced skin thickness, increased collagen synthesis, and lowered collagenase expression. Additionally, nNIR irradiation stimulated hair growth, augmented skin thickness, and increased hair follicle count. In conclusion, the study highlighted positive effects of White and nNIR irradiation on skin and hair growth. However, nNIR exhibited superior outcomes compared to White. Its advancements in ATP content, collagen synthesis, collagenase inhibition, and hair growth promotion imply increased ATP synthesis activity. These findings underscore nNIR therapy's potential as an innovative and effective approach for enhancing skin and promoting hair growth.

Use of platelet rich plasma for skin rejuvenation.

OBJECTIVE: Platelet-rich plasma (PRP) is recognized as a safe and effective therapy for regenerative skin healing and rejuvenation, utilizing autologous blood enriched with various growth factors. This review aims to assess the efficacy of PRP treatments for skin rejuvenation. METHODS: Keywords such as "platelet-rich plasma," "rejuvenation," "skin aging," and "wrinkles" were queried on Ovid, PubMed, and MEDLINE to identify pertinent studies on PRP treatment for skin rejuvenation. RESULTS: Analysis revealed that PRP treatment led to significant enhancements in multiple facial parameters after one to three sessions. Improvements were noted in skin pore size, texture, wrinkle reduction, pigmented spots, collagen density, hyaluronic acid levels, and protection against ultraviolet damage. Combining PRP with hyaluronic acid demonstrated a synergistic effect, particularly enhancing skin elasticity in patients with lower body mass index and firmness in individuals aged 50s and 60s. Incorporating both physical and biometric data for assessment proved superior to relying solely on physical observations for evaluating subtle skin quality and structural changes. CONCLUSION: This study underscores the efficacy of PRP monotherapy for skin rejuvenation and emphasizes the necessity of standardizing PRP preparation protocols in future investigations. Heightened awareness and advancements in technology have contributed to the emergence of higher-quality, less biased studies supporting PRP as a reliable and safe therapeutic option for skin rejuvenation.

Use of a fractional 1570-nm diode laser scanner for non-ablative face and neck rejuvenation.

BACKGROUND: The use of non-ablative fractionated lasers for skin rejuvenation has been proven to be effective in improving skin texture, and has become popular due to minimal wounding, significantly shorter recovery times and decreased adverse effects. OBJECTIVE: To retrospectively analyze improvement in skin texture in healthy women aged over 18 years with Fitzpatrick skin types II-IV. METHODS: Participants received three facial and/or neck treatments with the 1570-nm fractional scanning diode laser at 1-month intervals. Three months after the last treatment session two blinded evaluators assessed skin improvement using before and after photos. Pain and patient satisfaction were recorded. RESULTS: Sixteen women with a mean age of 45.4 ± 4.1 years (range 35-50 years) and skin type II-IV were included in the analysis. All 16 participants received facial treatments and seven (43.8%) also received neck treatments. Three months follow-up evaluation showed that the majority of participants had a visible change in the treated areas. Mean pain score was low and decreased with each treatment session. CONCLUSION: Skin treatment using fractional scanning 1570-nm diode laser improves skin laxity in women with skin types II-IV. Larger studies are warranted to further clarify the efficacy and safety of this modality.

Basic concepts in facial and neck thread lifting procedures.

In this review article, our objective is to elucidate fundamental principles and offer practical illustrations concerning the procedures involved in facial and neck thread lifting. Moreover, we aim to explore associated concepts such as the fixing point, hanging point, and anchoring point terminologies, along with the elucidation of vectors. Additionally, we will provide anatomically oriented explanations of the lifting process required for each facial region using thread lifting methods like V, U, and I techniques using floating type threads (Secrete line, Hyundai Meditech., Inc., Wonjusi, Republic of Korea). Furthermore, our intention is to delve deeply into the concepts of tensile strength, anchoring strength, and holding strength, contextualizing their practical applications within this specific field.

A highly biocompatible CE-crosslinked collagen implant with exceptional anti-calcification and collagen regeneration capabilities for aging skin rejuvenation.

Skin aging, a complex and inevitable biological process, results in wrinkles, dermal laxity, and skin cancer, profoundly influencing appearance and overall health. Collagen serves as the fundamental element of the dermal matrix; nevertheless, collagen is susceptible to enzymatic degradation within the body. Crosslinking is employed to enhance the physicochemical properties of collagen. However, conventional crosslinking agents may harbor potential issues such as cytotoxicity and calcification risks, constraining their application in the biomedical field. Therefore, we have for the first time developed a highly biocompatible CE-crosslinked collagen implant with exceptional anti-calcification and collagen regeneration capabilities for aging skin rejuvenation. A novel collagen crosslinking agent (CE) was synthesized through a reaction involving chitosan quaternary ammonium salt with 1,4-butanediol diglycidyl ether. Compared to collagen crosslinked with glutaraldehyde (GA), the CE-crosslinked collagen implant exhibited notable stability and durability. The implant demonstrated excellent injectability and viscosity, resisting displacement after implantation. Additionally, the CE-crosslinked collagen implant displayed superior biocompatibility, effectively promoting the proliferation and adhesion of HFF-1 cells compared with the GA-crosslinked collagen. The CE-crosslinked collagen represented a safer and more biologically active implant material. In vivo experiments further substantiated that the implant significantly facilitated collagen regeneration without inducing calcification. The innovative collagen implant has made substantial strides in enhancing aesthetics and reducing wrinkles, presenting the potential for revolutionary progress in the fields of skin rejuvenation and collagen regeneration.

A highly bioactive THPC-crosslinked recombinant collagen hydrogel implant for aging skin rejuvenation.

Skin aging, a complex physiological progression marked by collagen degradation, poses substantial challenges in dermatology. Recombinant collagen emerges as a potential option for skin revitalization, yet its application is constrained by difficulties in forming hydrogels. We have for the first time developed a highly bioactive Tetrakis(hydroxymethyl) phosphonium chloride (THPC)-crosslinked recombinant collagen hydrogel implant for aging skin rejuvenation. THPC demonstrated superior crosslinking efficiency compared to traditional agents such as EDC/NHS and BDDE, achieving complete recombinant collagen crosslinking at minimal concentrations and effectively inducing hydrogel formation. THPC's four reactive hydroxymethyl groups facilitate robust crosslinking with triple helical recombinant collagen, producing hydrogels with enhanced mechanical strength, excellent injectability, increased stability, and greater durability. Moreover, the hydrogel exhibited remarkable biocompatibility and bioactivity, significantly promoting the proliferation, adhesion, and migration of human foreskin fibroblast-1. In photoaged mice skin models, the THPC-crosslinked collagen hydrogel implant notably improved dermal density, skin elasticity, and reduced transepidermal water loss, creating a conducive environment for fibroblast activity and healthy collagen regeneration. Additionally, it elevated superoxide dismutase (SOD) activity and displayed substantial anti-calcification properties. The THPC-crosslinked recombinant collagen hydrogel implant presents an innovative methodology in combating skin aging, offering significant promise in dermatology and tissue engineering.

Multi-omics characterization of partial chemical reprogramming reveals evidence of cell rejuvenation.

Partial reprogramming by cyclic short-term expression of Yamanaka factors holds promise for shifting cells to younger states and consequently delaying the onset of many diseases of aging. However, the delivery of transgenes and potential risk of teratoma formation present challenges for in vivo applications. Recent advances include the use of cocktails of compounds to reprogram somatic cells, but the characteristics and mechanisms of partial cellular reprogramming by chemicals remain unclear. Here, we report a multi-omics characterization of partial chemical reprogramming in fibroblasts from young and aged mice. We measured the effects of partial chemical reprogramming on the epigenome, transcriptome, proteome, phosphoproteome, and metabolome. At the transcriptome, proteome, and phosphoproteome levels, we saw widescale changes induced by this treatment, with the most notable signature being an upregulation of mitochondrial oxidative phosphorylation. Furthermore, at the metabolome level, we observed a reduction in the accumulation of aging-related metabolites. Using both transcriptomic and epigenetic clock-based analyses, we show that partial chemical reprogramming reduces the biological age of mouse fibroblasts. We demonstrate that these changes have functional impacts, as evidenced by changes in cellular respiration and mitochondrial membrane potential. Taken together, these results illuminate the potential for chemical reprogramming reagents to rejuvenate aged biological systems and warrant further investigation into adapting these approaches for in vivo age reversal.

The Rejuvenation and Functional Restoration of Aged Adipose Stem Cells by DUXAP10 Knockdown via the Regulation of the miR-214-3p/RASSF5 Axis.

Adipose stem cell (ASC)-based therapies provide an encouraging option for tissue repair and regeneration. However, the function of these cells declines with aging, which limits their clinical transformation. Recent studies have outlined the involvement of long non-coding RNAs in stem cell aging. Here, we reanalyzed our published RNA sequencing (RNA-seq) data profiling differences between ASCs from young and old donors and identified a lncRNA named double homeobox A pseudogene 10 (DUXAP10) as significantly accumulated in aged ASCs. Knocking down DUXAP10 promoted stem cell proliferation and migration and halted cell senescence and the secretion of proinflammatory cytokines. In addition, DUXAP10 was located in the cytoplasm and functioned as a decoy for miR-214-3p. miR-214-3p was downregulated in aged ASCs, and its overexpression rejuvenated aged ASCs and reversed the harm caused by DUXAP10. Furthermore, Ras Association Domain Family Member 5 (RASSF5) was the target of miR-214-3p and was upregulated in aged ASCs. Overexpressing DUXAP10 and inhibiting miR-214-3p both enhanced RASSF5 content in ASCs, while DUXAP10 knockdown promoted the therapeutic ability of aged ASCs for skin wound healing. Overall, this study offers new insights into the mechanism of age-related ASC dysfunction and names DUXAP10 and miR-214-3p as potential targets for energizing aged stem cells.

Advanced Facial Rejuvenation: Synergistic Effects of Lower Blepharoplasty and Ultrasound Guided Mid-Face Lift Using Polydioxanone (PDO) Threads.

BACKGROUND: Traditional facial aging surgeries have risks and extended recovery times, leading to a demand for minimally invasive alternatives. PDO (polydioxanone) threads, which are absorbable sutures that stimulate collagen production and tissue contraction, offer improved aesthetic outcomes. This paper evaluates the combined use of PDO thread mid-cheek lift and lower blepharoplasty for facial rejuvenation. METHODS: This retrospective study compared outcomes in patients undergoing lower blepharoplasty combined with a mid-face lift using PDO threads versus those undergoing only lower blepharoplasty. Focused on individuals with baggy lower eyelids and pronounced nasolabial folds, outcome measures included the Modified Fitzpatrick wrinkle scale, Allergan® midface volume deficit scale, Width of inter zygomatic distance, Patient and Observer Scar Assessment Scale, and patient satisfaction questionnaires, assessed at baseline, 3 months, and 1 year postoperatively. RESULTS: The combined procedure demonstrated superior aesthetic outcomes and higher patient satisfaction compared to lower blepharoplasty alone. Improvements were more significant in wrinkle reduction, midface volume, and inter-zygomatic distance in the combined procedure group. Although the combined procedure had a longer mean operation time, scar assessment scores were similar between both groups, with no complications reported. CONCLUSION: The combination of lower blepharoplasty and mid-face lift using PDO threads is a comprehensive and effective approach for facial rejuvenation. It significantly enhances wrinkle reduction, mid-face lifting, and patient satisfaction. Ultrasound-guided thread lifting, a method of assessing and performing mid-face lifting, proves to be safe and efficient. This approach holds promise as a future option in cosmetic anti-aging surgery, presenting a minimally invasive alternative with natural-looking results and reduced downtime. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://link.springer.com/journal/00266 .

Combining Liposuction and Thread-Lifting for Middle-Lower Facial Rejuvenation.

BACKGROUND: Thread-lifting (TL) is a minimally-invasive technique for facial rejuvenation, whereas liposuction is commonly used for facial contouring. This retrospective cohort study aims to introduce and evaluate a novel technique that combines liposuction and thread-lifting for mid-lower facial rejuvenation. METHODS: Consecutive patients who underwent TL for mid-lower facial rejuvenation from May 2016 to May 2021 were divided into thread-lifting group (TL group) or thread-lifting plus liposuction group (TLL group) according to whether liposuction was performed adjunctively. The co-primary outcomes were the changes between the preoperative and 6-month postoperative Wrinkle Severity Rating Scale (WSRS) and Facial Aging Evaluation Scale (FAES). RESULTS: A total of 185 patients (184 females) with an average age of 34.5±5.5 years were included. There were no significant differences in patients' age, number of threads, and preoperative WSRS and FAES between the two groups. The TLL group (n = 128) had significantly lower postoperative WSRS (1.5±0.6 vs. 1.8±0.8, p<0.001) and FAES (2.5±1.4 vs. 3.8±2.1, p<0.001) than the TL group (n = 57). The decrease in WSRS (0.8±0.6 vs. 0.2±0.7, p<0.001) and FAES (2.7±1.3 vs. 1.6±1.6, p<0.001) were greater in the TLL group. Only 3.8% patients experienced slight side effects and totally recovered. CONCLUSIONS: The combination of TL and liposuction is an effective and safe technique for simultaneous contour improvement and facial rejuvenation in middle-aged East Asian females. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

Skin boosters: Definitions and varied classifications.

BACKGROUND: The concept of "skin boosters" has evolved, marking a shift from traditional uses of hyaluronic acid (HA) fillers primarily for augmenting skin volume to a more diverse application aimed at improving dermal conditions. Restylane Vital and other HA fillers have been repurposed to combat skin aging and wrinkles by delivering HA directly to the dermis. OBJECTIVES: This review aims to define the term "skin booster" and to discuss the various components that constitute skin boosters. It seeks to provide a comprehensive overview of the different ingredients used in skin boosters, their roles, and their impact on enhancing dermal conditions. METHODS: A comprehensive review was conducted, focusing on representative skin booster ingredients. The approach involved analyzing the different elements used in skin boosters and their specific roles in enhancing dermal improvement. RESULTS: The findings indicate that skin boosters, encompassing a range of ingredients, are effective in improving the condition of the skin's dermis. The review identifies key ingredients in skin boosters and their specific benefits, including hydration, elasticity improvement, and wrinkle reduction. CONCLUSIONS: Skin boosters represent a significant development in dermatological treatments, offering diverse benefits beyond traditional HA fillers. This review provides valuable insights into the constituents of skin boosters and their effectiveness, aiding readers in making informed decisions about these treatments. The potential of skin boosters in dermatological practice is considerable, warranting further research and application.

What are filling (volumizing) threads?

Facial aging prompts a shift in the demands for lifting procedures, transitioning from targeted improvements in younger individuals to overall facial contour enhancements as skin elasticity declines in later years. This paper examines the evolution of PDO volumizing threads, delineating their development from initial limitations to contemporary innovations aimed at addressing tissue deformation and maintaining thread integrity post-insertion. Categorizing these threads based on elasticity, shape, and functionality underscores their versatility and application nuances, catering to specific wrinkle correction, contour sculpting, and facial volume restoration. The discussion emphasizes the pivotal role of thread characteristics in achieving optimal outcomes while minimizing potential complications. By delving into historical contexts, mechanisms, effectiveness, and thread classification, this paper equips practitioners with a comprehensive understanding to make informed decisions in selecting threads for volumizing thread procedures. Recommendations for future research directions, including long-term safety assessments and patient-specific outcomes, seek to enhance the clinical utility and applicability of this analysis.

Role of folate receptor α in the partial rejuvenation of dentate gyrus cells: Improvement of cognitive function in 21-month-old aged mice.

Neuronal aging may be, in part, related to a change in DNA methylation. Thus, methyl donors, like folate and methionine, may play a role in cognitive changes associated to neuronal aging. To test the role of these metabolites, we performed stereotaxic microinjection of these molecules into the dentate gyrus (DG) of aged mice (an average age of 21 month). Folate, but not S-Adenosyl-Methionine (SAM), enhances cognition in aged mice. In the presence of folate, we observed partial rejuvenation of DG cells, characterized by the expression of juvenile genes or reorganization of extracellular matrix. Here, we have also tried to identify the mechanism independent of DNA methylation, that involve folate effects on cognition. Our analyses indicated that folate binds to folate receptor α (FRα) and, upon folate binding, FRα is transported to cell nucleus, where it is acting as transcription factor for expressing genes like SOX2 or GluN2B. In this work, we report that a FRα binding peptide also replicates the folate effect on cognition, in aged mice. Our data suggest that such effect is not sex-dependent. Thus, we propose the use of this peptide to improve cognition since it lacks of folate-mediated side effects. The use of synthetic FRα binding peptides emerge as a future strategy for the study of brain rejuvenation.

Application of PLLA (Poly-L-Lactic acid) for rejuvenation and reproduction of facial cutaneous tissue in aesthetics: A review.

Poly-L-lactin acid (PLLA) has been widely used in the field of bio-medicine. In 2004, as an injectable material, PLLA was approved by the FDA to treat AIDS-related facial atrophy. Since then, several injectable stuffs containing PLLA have been approved for marketing in various countries and regions. Recently, PLLA has often been used to treat facial rejuvenation problems like cutaneous depressions and static wrinkles which always induce unsatisfactory facial expression. This review introduces the physicochemical properties, regeneration stimulating mechanism, applications in aesthetics and injectable comorbidity of PLLA.

Combined microfocused ultrasound and delicate pulsed light for facial rejuvenation: A prospective, randomized, and split-face study.

OBJECTIVES: Public's interest in noninvasive skin rejuvenation treatments continues to grow. The advantage of combination therapy lies in that it can target different aspects of skin rejuvenation. This study aimed to assess the efficacy and safety of microfocused ultrasound (MFU) combined with delicate pulsed light (DPL) for facial rejuvenation. METHODS: Twenty-one patients with facial relaxation were enrolled. All patients received whole-face MFU treatment, and one side of the face was randomly assigned to receive DPL. MFU treatment was performed at Months 0 and 3, while DPL treatment was performed at Months 1, 2, 4, and 5. The length and angle of the nasolabial fold and perioral wrinkles, melanin index (MI), erythema index (EI), transepidermal water loss (TEWL), and follow-up time were recorded at Months 0, 3, and 6. Side effects were recorded during treatment and each follow-up visit. RESULTS: Twenty patients successfully completed the study. At the sixth month, the average length of perioral wrinkles and nasolabial folds on the combined side decreased by 11.5% (pwithin < 0.001) and 6.5% (pwithin = 0.011), while 8.3% (pwithin = 0.012) and 3.8% (pwithin = 0.02) on the MFU side. Compared with MFU treatment alone, the combined treatment also showed significant improvements in nasolabial fold angle (from 28.8 ± 3.4° to 32.7 ± 5.0°) and perioral wrinkle angle (from 39.3 ± 5.0° to 43.7 ± 5.1°). In addition, the combined side had greater benefits than the MFU side in improving MI, EI, TEWL, and skin elasticity (pbetween < 0.05). Except for one patient who withdrew due to increased skin sensitivity after MFU treatment, other subjects did not experience permanent or serious side effects. CONCLUSIONS: The combination of MFU and DPL for facial rejuvenation treatment is safe and effective. The combined treatment has better efficacy in skin firmness, and improving skin tone.

Depleting myeloid-biased haematopoietic stem cells rejuvenates aged immunity.

Ageing of the immune system is characterized by decreased lymphopoiesis and adaptive immunity, and increased inflammation and myeloid pathologies1,2. Age-related changes in populations of self-renewing haematopoietic stem cells (HSCs) are thought to underlie these phenomena3. During youth, HSCs with balanced output of lymphoid and myeloid cells (bal-HSCs) predominate over HSCs with myeloid-biased output (my-HSCs), thereby promoting the lymphopoiesis required for initiating adaptive immune responses, while limiting the production of myeloid cells, which can be pro-inflammatory4. Ageing is associated with increased proportions of my-HSCs, resulting in decreased lymphopoiesis and increased myelopoiesis3,5,6. Transfer of bal-HSCs results in abundant lymphoid and myeloid cells, a stable phenotype that is retained after secondary transfer; my-HSCs also retain their patterns of production after secondary transfer5. The origin and potential interconversion of these two subsets is still unclear. If they are separate subsets postnatally, it might be possible to reverse the ageing phenotype by eliminating my-HSCs in aged mice. Here we demonstrate that antibody-mediated depletion of my-HSCs in aged mice restores characteristic features of a more youthful immune system, including increasing common lymphocyte progenitors, naive T cells and B cells, while decreasing age-related markers of immune decline. Depletion of my-HSCs in aged mice improves primary and secondary adaptive immune responses to viral infection. These findings may have relevance to the understanding and intervention of diseases exacerbated or caused by dominance of the haematopoietic system by my-HSCs.