Transcriptome Analysis of Host Inflammatory Responses to the Ectoparasitic Mite Sarcoptes scabiei var. hominis

FLI1 Induces Plaque Psoriasis and Its Inhibition Attenuates Disease Progression

Plaque Psoriasis

Plaque psoriasis is an inflammatory skin disorder affecting nearly 2% of the world population. Despite recent advances in psoriasis treatment, there is still a need for more effective therapies. The ETS transcription factor FLI1 plays critical roles in hematopoiesis, angiogenesis, immunity, and cancer. Emerging evidence suggests that FLI1 is intricately involved in inflammatory processes underlying psoriasis pathogenesis.

Methods

RNAseq and bioinformatic analysis were used to identify the correlation between FLI1 levels and the expression of inflammatory genes associated with psoriasis. Over-expression of FLI1 in skin cells determined FLI1's role in inducing transcription of psoriasis-related inflammatory genes, including IL6, IL1A, IL1B, IL23, and TNFα. Inhibitors such as chelerythrine (CLT) were tested for their suppressive effects on these genes. Mouse models of plaque psoriasis were employed to assess the therapeutic potential of CLT and tacrolimus (TAC).

Results

Over-expression of FLI1 in skin cells upregulated 24 psoriasis-associated genes, which were identified through RNAseq. Inhibitors of FLI1, such as CLT, suppressed these inflammatory genes in skin cells. In mouse models of plaque psoriasis induced by imiquimod (IMQ) or phorbol ester (TPA), treatment with the anti-FLI1 inhibitor CLT, administered either peritoneally or topically, significantly downregulated inflammatory genes and alleviated psoriasis symptoms. Similarly, TAC, a common immunosuppressive agent, effectively attenuated IMQ-induced psoriasis by acting as a potent anti-FLI1 compound.

Conclusion

These findings demonstrate that FLI1 plays a central role in psoriasis development and highlight it as a potential therapeutic target for this skin disorder.

Sarcoptic mange in domestic rabbits: Pathogenesis, impact, and control strategies

This review article provides an in-depth examination of sarcoptic mange in domestic rabbits (Oryctolagus cuniculus), a widespread and highly contagious dermatological condition caused by Sarcoptes scabiei var. cuniculi mites. Sarcoptic mange poses significant health risks to rabbits and can lead to severe economic losses in commercial rabbit farming due to decreased productivity, inferior leather quality, and increased mortality rates. Clinical manifestations in rabbits include intense itching, skin lesions, hair loss, and secondary bacterial infections, which can be fatal if left untreated. The immune response in rabbits involves both innate and adaptive components, with keratinocytes playing a crucial role in initiating the response. The adaptive immune response is characterized by a mixed T helper cell profile, leading to inflammation and antibody production, which possibly play a key role in controlling mite infestations. Diagnosis of sarcoptic mange is typically based on clinical signs, supported by microscopic examination of skin scrapings and serological tests. The review emphasizes the risk of transmission to humans, especially those in close contact with infested rabbits, and explores the complex host-parasite immune interplay, detailing how S. scabiei evades the host's immune system through various mechanisms. The review also discusses advanced treatment approaches, focusing on the need for effective control measures to prevent the spread of mange in rabbit populations. The article underscores the importance of further research into the molecular mechanisms of the disease to develop targeted therapeutic interventions.

Genomics reveal local skin immune response key to control sarcoptic mange in Iberian ibex (Capra pyrenaica)

BACKGROUND

Sarcoptic mange is an emerging and neglected contagious skin disease caused by the mite Sarcoptes scabiei, affecting humans, domestic animals, and wildlife. Mange is the main disease and a major concern for the management and conservation of populations of Iberian ibex (Capra pyrenaica), a medium-sized mountain ungulate endemic to the Iberian Peninsula and Northern Pyrenees. Differences in host-parasite interaction and host immune response determine mange clinical outcome, but little is known about the related differences in gene expression. This study determined blood and skin gene expressions in S. scabiei-experimentally infested Iberian ibexes.

RESULTS

Infestation with S. scabiei promoted immune and inflammatory genomic responses both in skin and blood, with two different clinical outcomes: either severe infestation or recovery. Sarcoptes scabiei induced local skin immunosuppression to favour its multiplication and establishment of the infestation in the host. Skin gene expression was mostly inflammatory and inefficient to control mange in the severely infected ibexes. Conversely, the immune skin response of the recovered ibexes effectively recognised S. scabiei and activated T-cells, limiting the infestation. Consequently, inflammation-related genes were more expressed in the blood of the severely infested ibexes than in those that recovered.

CONCLUSIONS

The results demonstrate that skin local cellular immune response is key to control sarcoptic mange and prevent the systemic spread of the disease and the associated inflammatory response. These results will be useful to understand the pathogenesis and drivers of the differential outcome of mange at individual scale, and the population and ecological consequences of such variability in Iberian ibex, as well as in other wildlife species, domestic animals, and humans.

Scabies

Scabies is one of the most common and highest-burden skin diseases globally. Estimates suggest that >200 million people worldwide have scabies at any one time, with an annual prevalence of 455 million people, with children in impoverished and overcrowded settings being the most affected. Scabies infection is highly contagious and leads to considerable morbidity. Secondary bacterial infections are common and can cause severe health complications, including sepsis or necrotizing soft-tissue infection, renal damage and rheumatic heart disease. There is no vaccine or preventive treatment against scabies and, for the past 30 years, only few broad-spectrum antiparasitic drugs (mainly topical permethrin and oral ivermectin) have been widely available. Treatment failure is common because drugs have short half-lives and do not kill all developmental stages of the scabies parasite. At least two consecutive treatments are needed, which is difficult to achieve in resource-poor and itinerant populations. Another key issue is the lack of a practical, rapid, cheap and accurate diagnostic tool for the timely detection of scabies, which could prevent the cycle of exacerbation and disease persistence in communities. Scabies control will require a multifaceted approach, aided by improved diagnostics and surveillance, new treatments, and increased public awareness.

Novel Factors Regulating Proliferation, Migration, and Differentiation of Fibroblasts, Keratinocytes, and Vascular Smooth Muscle Cells during Wound Healing

Chronic diabetic foot ulcers (DFUs) are a significant complication of diabetes mellitus, often leading to amputation, increased morbidity, and a substantial financial burden. Even with the advancements in the treatment of DFU, the risk of amputation still exists, and this occurs due to the presence of gangrene and osteomyelitis. Nonhealing in a chronic DFU is due to decreased angiogenesis, granulation tissue formation, and extracellular matrix remodeling in the presence of persistent inflammation. During wound healing, the proliferation and migration of fibroblasts, smooth muscle cells, and keratinocytes play a critical role in extracellular matrix (ECM) remodeling, angiogenesis, and epithelialization. The molecular factors regulating the migration, proliferation, and differentiation of these cells are scarcely discussed in the literature. The literature review identifies the key factors influencing the proliferation, migration, and differentiation of fibroblasts, keratinocytes, and vascular smooth muscle cells (VSMCs), which are critical in wound healing. This is followed by a discussion on the various novel factors regulating the migration, proliferation, and differentiation of these cells but not in the context of wound healing; however, they may play a role. Using a network analysis, we examined the interactions between various factors, and the findings suggest that the novel factors identified may play a significant role in promoting angiogenesis, granulation tissue formation, and extracellular matrix remodeling during wound healing or DFU healing. However, these interactions warrant further investigation to establish their role alone or synergistically.

Recent Vaccines against Emerging and Tropical Infectious Diseases

Emerging diseases, re-emerging diseases and tropical diseases are a slowly progressing problem globally. This may in part be the result of shifting population, growing poverty, inadequate distribution of resources, or even complacency against personal hygiene. As a result of the low income and low standards of health in developing countries, they provide the perfect breeding grounds for the pathogens and parasites that are the root cause of Neglected Tropical diseases (NTDs). In the case of emerging diseases, most are of zoonotic origin and the recent COVID-19 pandemic is a key example. However, it is not just new diseases but re-emerging diseases such as Influenza that highlight the relentless nature of these infections. Vaccines represent the ultimate safety net against these diseases by bolstering immune systems and lowering subsequent mortality and morbidity of these conditions. In fact, against diseases with high mortalities such as AIDS, Hepatitis, and Malaria, vaccine development has markedly reduced mortality and prolonged life expectancy of those afflicted with these conditions. However, this research highlights the importance of enhancing vaccine efficacy and response. The review further underscores the necessity of research, the timing of vaccine administration, effective resource management by governments, and the perception of the population. Therefore, the review offers valuable insights for the medical community and the pharmaceutical industry in improving research and management to maximize the potential of vaccines.

A Glance into the Destiny of Transcriptomic Activity, Embodied by the HOX Genes, in Neonatal and Aging Dermal Cells

Skin is an organ having a crucial role in the protection of muscle, bone, and internal organs and undergoing continuous self-renewal and aged. The growing interest in the prevention of skin aging and rejuvenation has sparked a surge of industrial and research studies focusing on the biological and transcriptional changes that occur during skin development and aging. In this study, the aim is to identify transcriptional differences between two main types of human skin cells: the human dermal fibroblasts (HDFs) and the human epidermis keratinocytes (HEKs) isolated from 30 neonatal and 30 adults (old) skin. Through differentially expressed gene (DEG) profiling using DEseq2, 604 up-, and 769 down-regulated genes are identified in the old group. A functional analysis using Metascape Gene Ontology and Reactome pathways revealed systematic transcriptomic shifts in key skin formation and maintenance markers, alongside a distinct difference in HOX gene families crucial for embryonic development and diverse biological processes. Among the 39 human HOX gene family, ten posterior HOX genes (HOXA10, 11, 13, HOXB13, HOXC11, and HOXD9-13) are significantly downregulated, and anterior 25 genes (HOXA2-7, HOXB1-9, HOXC4-6 and 8-9, and HOXD1,3,4 and 8) are upregulated, especially in the old HDFs. The study successfully demonstrates the correlation between HOX genes and the skin aging process, providing strong evidence that HOX genes are proposed as a new marker for skin aging assessment.

Egyptian mandarin peel oil's anti-scabies potential via downregulation-of-inflammatory/immune-cross-talk: GC-MS and PPI network studies

The current study investigated the scabicidal potential of Egyptian mandarin peel oil (Citrus reticulata Blanco, F. Rutaceae) against sarcoptic mange-in-rabbits. Analysis of the oil's GC-MS identified a total of 20 compounds, accounting for 98.91% of all compounds found. Mandarin peel oil topical application improved all signs of infection, causing a scabicidal effect three days later, whereas in vitro application caused complete mite mortality one day later. In comparison to ivermectin, histopathological analysis showed that the epidermis' inflammatory-infiltration/hyperkeratosis-had disappeared. In addition to TIMP-1, the results of the mRNA gene expression analysis showed upregulation of I-CAM-1-and-KGF and downregulation of ILs-1, 6, 10, VEGF, MMP-9, and MCP-1. The scabies network was constructed and subjected to a comprehensive bioinformatic evaluation. TNF-, IL-1B, and IL-6, the top three hub protein-coding genes, have been identified as key therapeutic targets for scabies. From molecular docking data, compounds 15 and 16 acquired sufficient affinity towards the three screened proteins, particularly both possessing higher affinity towards the IL-6 receptor. Interestingly, it achieved a higher binding energy score than the ligand of the docked protein rather than displaying proper binding interactions like those of the ligand. Meanwhile, geraniol (15) showed the highest affinity towards the GST protein, suggesting its contribution to the acaricidal effect of the extract. The subsequent, MD simulations revealed that geraniol can achieve stable binding inside the binding site of both GST and IL-6. Our findings collectively revealed the scabicidal ability of mandarin peel extract for the first time, paving the way for an efficient, economical, and environmentally friendly herbal alternative for treating rabbits with Sarcoptes mange.