Effects of Bacterial Lysates and Metabolites on Collagen Homeostasis in TNF-α-Challenged Human Dermal Fibroblasts

Abstract

During skin aging, the production of extracellular matrix (ECM) proteins, such as type I collagen, decreases and the synthesis of ECM-degrading matrix metalloproteinases (MMPs) rises, leading to an imbalance in homeostasis and to wrinkle formation. In this study, we examined the effects of bacterial lysates and metabolites from three bifidobacteria and five lactobacilli on collagen homeostasis in human dermal fibroblasts during challenge with tumor necrosis factor alpha (TNF-α), modeling an inflammatory condition that damages the skin’s structure. Antiaging properties were measured, based on fibroblast cell viability and confluence, amount of type I pro-collagen, ratio of MMP-1 to type I pro-collagen, cytokines, and growth factors. The TNF-α challenge increased the MMP-1/type I pro-collagen ratio and levels of proinflammatory cytokines, as expected. With the probiotics, differences were clearly dependent on bacterial species, strain, and form. In general, the lysates elicited less pronounced responses in the biomarkers. Of all strains, the Bifidobacterium animalis ssp. lactis strains Bl-04 and B420 best maintained type I pro-collagen production and the MMP-1/collagen type I ratio under no-challenge and challenge conditions. Metabolites that were produced by bifidobacteria, but not their lysates, reduced several proinflammatory cytokines (IL-6, IL-8, and TNF-α) during the challenge, whereas those from lactobacilli did not. These results indicate that B. animalis ssp. lactis-produced metabolites, especially those of strains Bl-04 and B420, could support collagen homeostasis in the skin.

Human Probiotic Lactobacillus paracasei-Derived Extracellular Vesicles Improve Tumor Necrosis Factor-α-Induced Inflammatory Phenotypes in Human Skin

“…Epidermal thickness was quantified by measuring the epidermal area (the width per image was fixed and constant; thus, only the area was considered and automatically determined using ImageJ), and the LpEV treatment resulted in the dramatic recovery of the inflammation-induced malformed epidermal structure (Figure 4b). Contrary to TNF-α contribution in the phenotypes related to cellular senescence and inflammaging where it reduced the activity of dermal fibroblasts, i.e., proliferation and collagen synthesis [13] as proven in our experiments (Figures 2c and 3), the prolonged TNF-α presence in the epidermis results in the pathogenesis of autoimmune diseases such as psoriasis and psoriatic arthritis by activating keratinocytes and consequently promoting epidermal hyperplasia [52]. Therefore, we examined whether TNF-α treatment induced epidermal proliferation in the basal layer by performing immunostaining with the Ki-67 antibody, which is known to recognize a nuclear antigen present in proliferating cells but is absent in resting cells [53].…”

“…TNF-α, a key aging-associated proinflammatory cytokine, is upregulated in sustained hyperinflammatory states resulting from imbalanced and unresolved inflammatory responses, thereby contributing to the aging phenomenon [10][11][12]. Conversely, TNFα overexpression is also induced by age-related cellular senescence, indicating the existence of a bidirectional feedback loop between inflammation and aging [13]. In the same context, the long-term TNF-α presence increases reactive oxygen species (ROS) levels and causes premature senescence in the human dermal fibroblasts [6,7], leading to a cycle of harmful effects.…”

“…In the same context, the long-term TNF-α presence increases reactive oxygen species (ROS) levels and causes premature senescence in the human dermal fibroblasts [6,7], leading to a cycle of harmful effects. Consequently, overexpressed TNF-α reduces dermal fibroblast proliferation, interferes with dermal cell matrix formation by inhibiting collagen synthesis and accelerating collagen and elastin degradation via matrix metalloproteases (MMPs), and upregulates other proinflammatory cytokines such as IL-6 and IL-8, slowing down the healing of damaged skin and aggravating proinflammatory effects, respectively [4,13]. Given its association with skin aging, treating skin cells with TNF-α can be viewed as stimulating inflammation-associated aging processes and thus used to screen and validate the antiaging properties of biomaterials.…”