MES SV40 Cells Are Sensitive to Lipopolysaccharide, Peptidoglycan, and Poly I:C Expressing IL-36 Cytokines.

Mesangial cells (MC) maintain the architecture and cellular communication and indirectly join in the glomerular filtration rate for the correct functioning of the glomerulus. Consequently, these cells are activated constantly in response to changes in the intraglomerular environment due to a metabolic imbalance or infection. IL-36, a member of the IL-1 family, is a cytokine that initiates and maintains inflammation in different tissues in acute and chronic pathologies, including the skin, lungs, and intestines. In the kidney, IL-36 has been described in the development of tubulointerstitial lesions, the production of an inflammatory environment, and is associated with metabolic and mesangioproliferative disorders. The participation of IL-36 in functional dysregulation and the consequent generation of the inflammatory environment by MCs in the presence of microbial stimulation is not yet elucidated. In this work, the MES SV40 cell cultures were stimulated with classical pathogen-associated molecular patterns (PAMPs), mimicking an infection by negative and positive bacteria as well as a viral infection. Lipopolysaccharide (LPS), peptidoglycan (PGN) microbial wall components, and a viral mimic poly I:C were used, and the mRNA and protein expression of the IL-36 members were assessed. We observed a differential and dose-dependent IL-36 mRNA and protein expression under LPS, PGN, and poly I:C stimulation. IL-36ß was only found when the cells were treated with LPS, while IL-36α and IL-36γ were favored by PGN and poly I:C stimulation. We suggest that the microbial components participate in the activation of MCs, leading them to the production of IL-36, in which a specific member may participate in the origin and maintenance of inflammation in the glomerular environment that is associated with infections.

Heptapeptide HP3 acts as a potent inhibitor of experimental imiquimod­induced murine psoriasis and impedes the trans­endothelial migration of mononuclear cells.

During the progression of psoriatic lesions, abundant cellular infiltration of myeloid cells, such as macrophages and activated dendritic cells, occurs in the skin and the infiltrating cells interact with naive lymphoid cells to generate a T helper (Th)1 and Th17 environment. Therapies to treat psoriasis include phototherapy, non­steroidal and steroidal drugs, as well as antibodies to block tumor necrosis factor­α, interleukin (IL)­17­A and IL­12/IL­23, which all focus on decreasing the proinflammatory hallmark of psoriasis. The present study obtained the heptapeptide HP3 derived from phage display technology that blocks mononuclear cell adhesion to endothelial cells and inhibits trans­endothelial migration in vitro. The activity of the heptapeptide in a murine model of psoriasis was also assessed, which indicated that early administration inhibited the development of psoriatic lesions. Therefore, the results suggested that HP3 may serve as a potential therapeutic target for psoriasis.

Staphylococcus epidermidis lipoteichoic acid: exocellular release and ltaS gene expression in clinical and commensal isolates.

PURPOSE: Staphylococcus epidermidis ATCC12228 lipoteichoic acid (LTA) inhibits TNFα production from keratinocytes that are activated with poly I:C. However, this effect has not been proven in clinical or commensal isolates. METHODOLOGY: The <10 kDa fractions of S. epidermidis isolates from ocular infections (n=56), healthy skin (n=35) and healthy conjunctiva (n=32) were obtained. TNFα production was determined by elisa in HaCaT keratinocytes stimulated with poly I:C and with the <10 kDa fractions. LTA in the cytoplasmic membrane and in the <10 kDa fractions of the isolates was determined during bacterial growth by flow cytometry, Western blot and electrospray ionization mass spectrometry. The expression levels of ugtP, ltaA and ltaS were evaluated. RESULTS: Two populations of isolates were found: a population that inhibited TNFα production (TNFα-inhibitor isolates) and a population that did not inhibit it (TNFα non-inhibitor isolates). The cells from the TNFα-inhibitor isolates had less LTA in the cytoplasmic membrane compared to the cells from the TNFα non-inhibitor isolates (P<0.05). Similarly, LTA was detected in the supernatants of TNFα-inhibitor isolates, and it was absent in TNFα non-inhibitor isolates. High expression levels of the ugtP and ltaA genes in the 1850I (TNFα-inhibitor isolate) and 37HS (TNFα non-inhibitor isolate) isolates were found during bacterial growth. However, the ltaS gene had a low expression level (P<0.05) in the 37HS isolate. CONCLUSION: The TNFα-inhibitor isolates release LTA due to high expression of the LTA synthesis genes. By contrast, TNFα non-inhibitor isolates do not release LTA due to low expression level of the ltaS gene.

Low expression of IL-6 and TNF-α correlates with the presence of the nuclear regulators of NF-κB, IκBNS and BCL-3, in the uterus of mice.

The dynamic regulation of NF-κB activity in the uterus maintains a favorable environment of cytokines necessary to prepare for pregnancy throughout the estrous cycle. Recently, the mechanisms that directly regulate the NF-κB transcriptional activity in different tissues are of growing interest. IκBNS and BCL-3 are negative nuclear regulators of NF-κB activity that regulate IL-6 and TNF-α transcription, respectively. Both cytokines have been described as important factors in the remodeling of uterus for blastocyst implantation. In this work we analyzed in ICR mice the mRNA expression and protein production profile of IL-6, TNF-α, and their correspondent negative transcription regulators IκBNS or BCL-3 using real-time PCR, western blot and immunochemistry. We found that the expression of TNF-α and IL-6 was oscillatory along the estrous cycle, and its low expression coincided with the presence of BCL-3 and IκBNS, and vice versa, when the presence of the regulators was subtle, the expression of TNF-α and IL-6 was exacerbated. When we compared the production of TNF-α and IL-6 in the different estrous stages relating with diestrus we found that at estrus there is an important increase of the cytokines (p<0.05) decreasing at metestrus to reach the basal expression at diestrus. In the immunochemistry analysis we found that at diestrus BCL-3 is distributed all over the tissue with a barely detected TNF-α, but on the contrary, at estrus the expression of BCL-3 is not detected with TNF-α clearly observable along the tissue; the same phenomenon occur in the analysis of IκBNS and IL-6. With that evidence we suggest that the expression of TNF-α and IL-6 might be regulated through NF-κB nuclear regulators BCL-3 and IκBNS in the uterus of mice as has been demonstrated in other systems.

Cross Talk between Proliferative, Angiogenic, and Cellular Mechanisms Orchestred by HIF-1α in Psoriasis.

Psoriasis is a chronic inflammatory skin disease where the altered regulation in angiogenesis, inflammation, and proliferation of keratinocytes are the possible causes of the disease, and the transcription factor "hypoxia-inducible factor 1-alpha" (HIF-1α) is involved in the homeostasis of these three biological phenomena. In this review, the role of HIF-1α in the cross talk between the cytokines and cells of the immunological system involved in the pathogenesis of psoriasis is discussed.