Epidermal Tissue Research Articles

Response of hibiscus mealybug (Hemiptera: Pseudococcidae) to citrus volatiles induced by mechanical injury.

Hibiscus mealybug, Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae), is a recent invasive pest of citrus and many other crops in Florida. Nipaecoccus viridis attacks all above ground parts of citrus trees and heavy infestation can cause leaf drop and premature abortion of developing fruits. We quantified greater captures of N. viridis in cardboard band traps on areas of citrus trees that were intentionally injured by mechanical rasping of epidermal tissues as compared with similar but uninjured citrus branches. Direct field collection of headspace volatiles from mechanically injured or intact citrus branches revealed both qualitative and quantitative differences. Certain volatiles (γ-terpinene, citronellal, citronellyl acetate, β-E-farnesene, α-humulene, and α-E-E-farnesene) were only present in samples from damaged citrus branches. Behavioral assays using a laboratory Y-tube olfactometer revealed attraction of N. viridis to volatiles associated with mechanical damage of citrus including synthetic β-ocimene, γ-terpinene, sabinene, isomers of farnesene, and citronellal when loaded into lures at either of 2 concentrations (0.01 or 0.1 µg/µl). Subsequent field trapping experiments confirmed increased captures of various life stages of N. viridis in cardboard band traps baited with a 10.0 µg/µl concentration of farnesene:ocimene:sabinene blend (in 7:13:17 ratio), as well as those releasing either farnesene or ocimene alone at this same concentration, as compared with the mineral oil (diluent) negative control. Our results indicate that common plant related terpenes released by citrus following mechanical damage may be useful for development of an effective monitoring trap for N. viridis.

Chronic stress-mediated dysregulations in inflammatory, immune and oxidative circuitry impairs the therapeutic response of methotrexate in experimental autoimmune disease models.

Chronic stress is significantly implicated in the worsening of autoimmune disorders, contributing to elevated inflammation and diminished therapeutic efficacy. Here, in this study, we investigated the detrimental impact of an 8-week chronic unpredictable stress (CUS) protocol on the progression of arthritis and psoriasis using collagen-induced arthritis (CIA) and imiquimod (IMQ)-induced psoriasis rat models, respectively. Our objective was to elucidate how prolonged stress exacerbates disease severity and impairs the effectiveness of treatment drug. Following the induction of CIA and IMQ, rats were subjected to an 8-week CUS paradigm designed to simulate chronic stress conditions. Moreover, after 5 weeks of CUS, methotrexate (MTX; 2 mg/kg, administered once weekly for 3 weeks, intraperitoneally) was introduced as a therapeutic intervention. The severity of CUS-induced effects and the therapeutic impairment of MTX in arthritis and psoriasis rats were assessed through pathological examination of joint and epidermal tissues, respectively. Additionally, we measured various pro-inflammatory cytokine levels, including NF-κB (nuclear factor kappa B), IFN-γ (interferon-gamma), TNF-α (tumour necrosis factor alpha), IL (interleukin)-1β, IL-6, IL-17 and IL-23 using enzyme-linked immunosorbent assay (ELISA), analysed immune cells through complete haematological profiling and evaluated oxidative stress markers. Our findings revealed that CUS significantly aggravated the pathological features of both arthritis and psoriasis. Prolonged stress exposure led to heightened inflammatory responses, increased oxidative stress and more severe tissue damage. Moreover, the therapeutic efficacy of MTX was notably reduced in stressed rats compared to non-stressed, underscoring the detrimental effects of chronic stress on treatment outcomes. Taken together, our results emphasize the importance of considering chronic stress as a critical factor in the management of autoimmune diseases.

Single and combined applications of dopamine and 24-epibrassinolide in soybean seedlings under water deficiency: tolerance mechanisms essential to inhibit deleterious effects

Water limitations often cause plants’ physiological, biochemical and morphological disorders, restricting their growth and performance and negatively impacting agricultural yield and global food security. Dopamine (DOP) is an essential water-soluble antioxidant, representing an exciting alternative for use in agriculture, as it maximises plant tolerance under adverse stress conditions. The 24-epibrassionolide (EBR) has the most bioactive function on plant metabolomics, being biodegradable and environmentally friendly. EBR can promote plant tolerance under stress conditions, including water deficiency. Therefore, this study aimed to verify the possible contributions of pre-treatment with DOP and EBR in soybean seedlings subjected to water deficiency, evaluating the responses linked to root anatomy, germination, antioxidant system and biomass accumulation. The single and combined use of growth regulators (DOP and EBR) mitigated the harmful effects caused by water deficiency in seedlings. However, the single use of DOP under the conditions of this research had better results. DOP and EBR positively affected root anatomy, modulating plastic changes in the epidermis tissues, metaxylem and vascular cylinder tissues. Increments in biomass and growth of seedlings exposed to drought and treated with growth regulators can be explained by the intense activities of antioxidant enzymes, maximising redox metabolism and protecting root tissues from oxidative damage.

Immune Responses of Club Cells in Fish: A Review

The primary line of defense against pathogens from the environment is often fish epidermis tissue. Nevertheless, little is understood about the physiological mechanisms that underlie the non-specific and/or specific protection that these cells can offer. The exact nature of the relationship between the evolution of ostariophysan fish club cells and chemical warning signals is still unknown and controversial. Fish epidermis layer cells comprise mucus cells, lymphocytes, macrophage cells, cuboidal and squamous epithelial cells, and cells specific to certain fish species. Club cells, also called "alarm cells," are chemical alarms that sound in the event of a potentially hazardous scenario. These cells will burst in the presence of a predator, releasing pheromones that, if the skin is physically damaged, trigger an avoidance and terror reaction. In sturgeon larvae, mucus cells were visible in week 1, but club cells did not appear until week 4. Due to their later development during ontogenesis and after wounding, club cells may not have as much of a protective effect during wound healing as filament or mucus cells. Club cells are mostly found in the epidermis of the skin, and it is thought that when they work in tandem with mucus and goblet cells to fight infections, they serve as the body's first line of defense.

Heterozygous DSP in-frame deletion in a poodle with syndromic ichthyosis involving additional hair and tooth abnormalities.

Ichthyoses comprise a large heterogeneous group of skin disorders, characterized by generalized scaly and hyperkeratotic skin. We investigated a miniature poodle with early onset generalized scaling, dry and irregularly thickened skin, paw pad hyperkeratosis and abnormalities in hair and teeth. The clinical signs of ichthyosis were confirmed by histopathological examination, which revealed mild epidermal hyperplasia and lamellar orthokeratotic hyperkeratosis. A hereditary condition was suspected and a genetic investigation was initiated. We sequenced the whole genome of the affected dog and searched for potentially causative variants in functional candidate genes for the observed phenotype. The analysis revealed a heterozygous in-frame deletion in DSP, NC_049256.1:g.8804542_8804544del resulting from a de novo mutation event as evidenced by genotyping leukocyte DNA from both parents. The 3 bp deletion is predicted to remove one aspartic acid without disrupting the open reading frame (XM_038584124.1:c.1821_1823del, XP_038440052.1:p.(Asp608del)). The DSP gene encodes desmoplakin, a desmosomal plaque protein, responsible for cell-cell adhesion to provide resistance to mechanical stress in epidermal and cardiac tissues. We hypothesize that the deletion of one amino acid in the N-terminal globular head domain acts in a dominant negative manner and thus impairs the proper connection with other proteins. Several variants in DSP in humans and cattle have been described to result in different phenotypes associated with hair and skin abnormalities, sometimes in combination with variable cardiac and/or dental manifestations. In conclusion, we characterized a new syndromic ichthyosis phenotype in a dog and identified a de novo 3 bp deletion in the DSP gene as causal variant.

Unraveling developmental patterns and differentiation trajectories in a single developing internode of Moso Bamboo (Phyllostachys edulis)

Bamboo, a significant carbon sink and eco-friendly resource, possesses substantial economic value and ecological benefits. A single internode represents the fundamental unit of bamboo culm, yet research focusing on the pivotal cellular destinies and molecular mechanisms underpinning the growth and development of a single internode remains comparatively scarce. In the study, we pioneered the establishment of a high-resolution single-cell transcriptomic atlas for a single internode of Moso bamboo. Utilizing known marker genes, we identified six major cell clusters (meristem, epidermis, phloem, xylem, pre-xylem/phloem, and vascular bundle sheath) and found many potential marker genes in the internode of Moso bamboo. Subsequently, we reconstructed the developmental trajectories of the epidermis and vascular tissues and further unveiled the key regulatory factors determining cell fates. Moreover, ectopic expression of PheIAA15 in Arabidopsis thaliana resulted in a marked reduction in the number of vascular bundles within the stems, as well as a significant decrease in their cross-sectional areas, diverging from existing research in Arabidopsis. The interaction between PheIAA15 and PheWOX4c suggested a potential novel auxin response mechanism in Moso bamboo. We subsequently elucidated that PheIAA15 bound to the promoter region of PheCLE25, thereby down-regulating the expression of PheCLE25, whereas PheWOX4c can activate the transcription of PheCLE25, which suggested that these two factors regulated the expression of PheCLE25 through an antagonistic mechanism. This finding highlighted the critical role of the complex regulatory network established among these elements in the differentiation of vascular tissues in the internodes of Moso bamboo. Overall, the study fills a critical research void concerning internodal development in bamboo plants at the single-cell level, laying a foundation for future studies to unravel the origin and differentiation of vascular bundle cells during internode development in perennial Gramineous plants.

Connecting high-resolution 3D chromatin maps with cell division and cell differentiation at the root apical meristem

Key messageWe used marker-free technologies to study chromatin at cellular resolution. Our results show asymmetric chromatin distribution, explore chromatin dynamics during mitosis, and reveal structural differences between trichoblast and atrichoblast cell.The shapes, sizes, and structural organizations of plant nuclei vary considerably among cell types, tissues, and species. This diversity is dependent on various factors, including cellular function, developmental stage, and environmental or physiological conditions. The differences in nuclear structure reflect the state of chromatin, which, in turn, controls gene expression and regulates cell fate. To examine the interrelationship between nuclear structure, cell morphology, and tissue-specific cell proliferation and differentiation processes, we conducted multiple visualizations of H3K4me1, H3K9me2, 4′,6-diamidino-2-phenylindole, 5-ethynyl 2′-deoxyuridine, and SCRI Renaissance 2200, followed by subsequent quantitative analysis of individual cells and nuclei. By assigning cylindrical coordinates to the nuclei in the iRoCS toolbox, we were able to construct in situ digital three-dimensional chromatin maps for all the tissue layers of individual roots. A detailed analysis of the nuclei features of H3K4me1 and H3K9me2 in the mitotic and the elongation zones in trichoblast and atrichoblast cells at the root apical meristem revealed cell type-specific chromatin dynamics with asymmetric distribution of euchromatin and heterochromatin marks that may be associated with cell cycle and cell differentiation characteristics of specific cells. Furthermore, the spatial distribution of nuclei stained with 5-ethynyl 2′-deoxyuridine in the epidermis and cortex tissues suggests short-range coordination of cell division and nuclear migration in a linear sequence through an unknown regulatory mechanism.

Deseeded sunflower fractions and their anatomy and cell morphology

Deseeded sunflower is a heterogeneous lignocellulosic biomass that has not been well utilized due to the incomplete understanding of its biological structure. In this study, deseeded sunflower was fractioned into the stalk rind, stalk pith, receptacle, bract, bractlet, leaf blade, and petiole, and their anatomy, cell morphology, and fiber dimension were studied using light microscope, environmental scanning electron microscope, and fiber quality analyzer. The results showed that the major fractions were the stalk rind and receptacle (49.4 wt% and 28.1 wt%, respectively) and each of the other fractions was less than 10 wt% of the total biomass. The pith was only composed of parenchyma tissue, and the other fractions were composed of epidermal, parenchyma, and vascular tissues. The arrangement and number of vascular tissues were different among fractions. The fiber length in the stalk rind was 0.823 mm, the width was 21.3 μm, and the aspect ratio was 38.6. The content of fiber fines in other fractions was higher than 50%, and these fractions should be developed for other uses. Fractionation was judged to be an effective way to achieve high value utilization of deseeded sunflower.

Pathology of tissue loss in three key gorgonian species in the Mediterranean Sea

The Mediterranean is known for its marine biodiversity, especially gorgonian forests. Unfortunately, these are experiencing rapid declines due to climate change, manifested by repeated marine heat waves resulting in mass mortality events since the early 1990 s. To better understand why gorgonians are declining, more systematic approaches to investigate the exact causes are needed, and pathology may aid in this goal.We described gross and microscopic pathology of tissue loss in three key gorgonian species in the Mediterranean region, Paramuricea clavata, Eunicella cavolini, and Leptogorgia sarmentosa, that were all experiencing various degrees of acute to subacute tissue loss characterized by exposed axial skeleton sometimes partly colonized by epibionts and thinning of adjacent tissues. The most significant variety of lesions was seen in P. clavata followed by L. sarmentosa and E. cavolini. For all species, dissociation of gastrodermal cells was the dominant microscopic lesion followed by necrosis of the gastrodermis. Ciliates invading gastrodermis and associated with necrosis of polyps were seen only in E. cavolini. Epidermal tissue loss was seen only in L. sarmentosa, while P. clavata was distinguished by a prominent inflammatory response and unidentified dark round structures within the tentacle epidermis and gastrodermis with no host response. Further work to understand the cause of death in gorgonians is needed, particularly to elucidate the role of ciliates and environmental co-factors or infectious agents not visible on light microscopy, as well as applications of additional tools such as cytology.

Adelola Adeyole (1935-2021): Early descriptor of congenital dermoid or epidermoid inclusion cyst over the anterior fontanelle and below the galea aponeurotica.

The author wished to detail the life and contributions of Dr. Adelola Adeloye, MBBS, MS, FWCS, FRCS, FACS, FRCP, in hope to pay homage to this giant in Global Neurosurgery. Dr. Adelola Adeloye was born on July 18, 1935 in Illesa, Osun State, present-day South-West Nigeria. The Adeloye-Odeku disease is an eponym for a congenital dermoid or epidermoid inclusion cyst (CDIC/CEDIC) over the anterior fontanelle and below the galea aponeurotica. In 1971, Adeloye and Odeku first described these cysts in 18 Nigerian patients. While overall rare and predominantly noted in children, the Adeloye-Odeku disease has been found to impact adults too. In terms of rarity, CDICs make up 0.1-0.5% of cranial tumors and 0.2% of inclusion cysts. CDICs can be distinguished from CEDICs through histopathology as dermoid cysts may contain hair follicles, sweat, sebaceous glands, and teeth, whereas CEDICs usually are only composed of keratinized debris and epidermal tissue. Assumed first to be an African cyst, cases of the Adeloye-Odeku disease were subsequently reported in other ethnic populations: Turkish, Czechs, Slovaks, Chinese, Japanese, Canadians, Saudi Arabians, Indians, Caucasians, Bangladeshis, Spaniards, and Brazilians.

Diagnosis and Surgical Removal of a Corneal Dermoid in a Red-eyed Tree Frog, Agalychnis callidryas (Anura, Hylidae), From the Tenorio Volcano, Costa Rica

Abstract A male, red-eyed frog (Agalychnis callidryas) was collected from the Tenorio Volcano region in Costa Rica due to the presence of a unilateral ocular abnormality affecting its left eye. Approximately 70% of the cornea was replaced by a well demarcated, 5.0 mm in diameter, opaque, bright green and roughened tissue compatible with skin. The affected eye was enucleated under established ophthalmic surgical procedures. A dermoid was confirmed by histopathology based on the finding of amphibian cutaneous (epidermal and dermal) tissue replacing the cornea and characterized by the presence of keratinized epidermis, spongy dermis, and integumentary glands. After a successful post-operative recovery period the frog was released back to the wild, demonstrating the viability of medical intervention and surgery in wild amphibians. Dermoids are congenital lesions that result from a failure in the differentiation of the superficial ectoderm to generate normal corneal epithelium and the subsequent development of epidermis and dermal tissues in the area. Corneal dermoids have been reported in horses, cattle, sheep, wildebeest, pigs, rats, dogs, cats, birds, and humans, this being the first case reported in amphibians. In the locality where the frog was found, several other ophthalmic abnormalities have been documented in other amphibians. Active monitoring of wild amphibians is ongoing, and possible causes of ophthalmic abnormalities in the area are being investigated.

Preying on cyprinid snout warts (pearl organs) as a novel and peculiar habit in the Lake Malawi cichlid Docimodus evelynae

Cichlid fishes in the African Great Lakes have undergone explosive speciation, acquiring markedly varying ecologies and diets. There are multiple lineages of scale-eating cichlids, and their natural history and evolutionary ecology is only partially understood. We examined the feeding habit of Docimodus evelynae, a known scale eater, in Lake Malawi. The stomach contents of young individuals mainly consisted of unknown 1 mm hard, white warts (> 30%). To clarify the origin of these warts, we conducted an X-ray fluorometer analysis, and found they were rich in sulphur but low in silicon and calcium, suggesting they were epidermal tissues. Histological and morphological analyses revealed they were multicellular and cup-shaped. These characteristics matched only those of the pearl organs of the coexisting cyprinid Labeo cylindricus. DNA was extracted from the warts found in the stomach of five D. evelynae individuals, followed by PCR using primers targeting the partial COI gene of L. cylindricus. The resulting sequences exhibited 98% similarity to those of L. cylindricus. Pearl organs, never reported as a primary food for fish, could offer a substantial nutritional source based on calorific calculations. Understanding how this peculiar diet is foraged is essential for full comprehension of the food-web structure in this lake.

Skin Absorbed Dose Coefficients for Human Legs from Beta Radiation as a Function of Height

External exposure to skin from beta-emitter radionuclides following severe reactor accidents or nuclear testing can result in beta burning and other health complications. The skin absorbed dose coefficient (SADC) measures the energy deposition into the skin during such accidents. The U.S. Environmental Protection Agency has published several reports to measure the possible energy deposition into the skin in such accidents. However, the most recent SADC published by Federal Guidance Report (FGR) 12 was computed only at one meter above the contaminated surface. Therefore, it was necessary to develop a model to estimate the absorbed dose coefficients for skin at different heights. In this manuscript, Geant4, a Monte Carlo simulator toolkit, was used to estimate the absorbed dose coefficients from electron sources located on the soil surface with energies ranging from 0.1 to 4 MeV. The energy deposited from primary electrons, secondary electrons, and photons in a 50 µm thick layer of epidermis tissue (Basal Cells Layer) located at a depth of 50 µm from the skin surface was estimated at several discrete heights of human leg phantom. More than 40% of the total energy deposited comes from secondary electrons and photons in energy sources of 0.1 and 0.2 MeV on average, but for higher energies, this percentage is less than 1%, which indicates primary electrons are the main source of the deposited energy in the skin. Furthermore, the results showed the energy deposited into skin closer to the ground was 50–100% higher than the previously estimated doses for 1 m above the ground. The results from Geant4 showed a great correlation (R2 = 0.972) with the FGR 12 data at one meter height, and they were aligned with the published values from FGR 12, which validated the simulation results. Therefore, the calculated dose coefficients for different energy sources and different heights could be used in radiation protection measurements.

The structural organization of the outer tissues in the gametophytic stem of the umbrella moss Hypnodendron menziesii optimizes load bearing.

The ultrastructural design and biochemical organization of the significantly thickened outer tissues of the gametophytic stem of Hypnodendron menziesii optimizes load bearing of the stem. Hypnodendron menziesii is a bryoid umbrella moss growing in high humid conditions on the forest floors of New Zealand. The erect gametophyte bears up to eight whorls of branches in succession, spreading across the stem that bears the heavy weight of branches with highly hydrated leaves. Our investigation using a combination of light microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and TEM-immunolabeling techniques provided novel information on the structural design and biochemical organization of greatly thickened cell walls of epidermal, hypodermal, and outermost cortical tissues, comparing underlying thin-walled cortical tissues in the gametophytic stem. Probing into the ultrastructure of the cell wall architecture of these target tissues by TEM and SEM revealed the cell walls to display a multilamellar organization, in addition to demonstrating the presence of an electron-dense substance in the cell wall, presumably flavonoids. The pattern of distribution and concentration of rhamnogalacturonan, homogalacturonan, and heteromannan, as determined by immunogold labeling, suggests that it is the combination of structural and molecular design of the cell wall that may optimize the mechanical function of the epidermal, hypodermal, and outer cortical tissues. Statistical relationships between the overall thickness of epidermal, hypodermal, and outer cortical cell walls, the lumen area of cells and the percentage area of cell wall occupied in these tissues at different heights of the stem, and thickness of secondary cell wall layers (L1-L4/5) were explored. The results of these analyses unequivocally support the contribution of outer tissues to the mechanical strength of the resilient stem.

GelMA loaded with platelet lysate promotes skin regeneration and angiogenesis in pressure ulcers by activating STAT3

Pressure ulcers (PU) are caused by persistent long-term pressure, which compromises the integrity of the epidermis, dermis, and subcutaneous adipose tissue layer by layer, making it difficult to heal. Platelet products such as platelet lysate (PL) can promote tissue regeneration by secreting numerous growth factors based on clinical studies on skin wound healing. However, the components of PL are difficult to retain in wounds. Gelatin methacrylate (GelMA) is a photopolymerizable hydrogel that has lately emerged as a promising material for tissue engineering and regenerative medicine. The PL liquid was extracted, flow cytometrically detected for CD41a markers, and evenly dispersed in the GelMA hydrogel to produce a surplus growth factor hydrogel system (PL@GM). The microstructure of the hydrogel system was observed under a scanning electron microscope, and its sustained release efficiency and biological safety were tested in vitro. Cell viability and migration of human dermal fibroblasts, and tube formation assays of human umbilical vein endothelial cells were applied to evaluate the ability of PL to promote wound healing and regeneration in vitro. Real-time polymerase chain reaction (PCR) and western blot analyses were performed to elucidate the skin regeneration mechanism of PL. We verified PL’s therapeutic effectiveness and histological analysis on the PU model. PL promoted cell viability, migration, wound healing and angiogenesis in vitro. Real-time PCR and western blot indicated PL suppressed inflammation and promoted collagen I synthesis by activating STAT3. PL@GM hydrogel system demonstrated optimal biocompatibility and favorable effects on essential cells for wound healing. PL@GM also significantly stimulated PU healing, skin regeneration, and the formation of subcutaneous collagen and blood vessels. PL@GM could accelerate PU healing by promoting fibroblasts to migrate and secrete collagen and endothelial cells to vascularize. PL@GM promises to be an effective and convenient treatment modality for PU, like chronic wound treatment.

Enhanced skin regeneration and therapeutic delivery using novel diamond-augmented zinc oxide.

Recent advancements in dermatological therapeutics have highlighted the need for treatments that enhance skin regeneration and healing. Diamond-Augmented Zinc Oxide (ND-ZnO) technology combines zinc oxide with diamond particles in a unique core-shell structure, offering a multifaceted approach to overall skin health. This study evaluates the efficacy of ND-ZnO in promoting human dermal fibroblast migration and growth, enhancing total collagen synthesis, and improving transdermal delivery of active ingredients as a daily comprehensive skin regeneration topical therapy. In vitro assays assessed wound healing, collagen production, and skin absorption. Human Dermal Fibroblasts (HDFs) were used in scratch wound assays. Collagen synthesis was quantified using enzyme-linked immunosorbent assays (ELISA). Permeation tests were performed on reconstructed human epidermal tissues to evaluate niacinamide absorption. Clinical case studies validated ND-ZnO efficacy in post-CO₂ laser treatments and Actinic Keratosis removal recovery. ND-ZnO increased HDF migration by 198% compared to controls. Collagen synthesis assays showed a 71.3% restoration of collagen production in aged HDFs. Skin permeation studies revealed a 203% increase in niacinamide skin absorption with ND-ZnO. Clinical case studies demonstrated faster and more effective healing post-ablative CO₂ laser and significant improvements in Actinic Keratosis recovery. ND-ZnO technology enhances wound healing, collagen synthesis, and active ingredient delivery, offering substantial benefits for daily skin regeneration and other dermatological applications. This innovative approach holds promise for advancing dermatological therapeutics, providing comprehensive skin care solutions that address both protective and regenerative needs.

A Highly Standardized Pre-Clinical Porcine Wound Healing Model Powered by Semi-Automated Histological Analysis.

The wound-healing process is a physiological response that begins after a disruption to the integrity of tissues present in the skin. To understand the intricacies involved in this process, many groups have tried to develop different in vitro models; however, the lack of a systemic response has, until this day, been the major barrier to the establishment of these models as the main study platform. Therefore, in vivo models are still the most common system for studying healing responses following different treatments, especially porcine models, which share several morphological similarities to the human skin. In this work, we developed a porcine excisional wound model and used semi-automated software as a strategy to generate quantitative morphometric results of healing responses by specific tissues and compartments. Our aim was to extract the most information from the model while producing reliable, reproducible, and standardized results. In order to achieve this, we established a 7-day treatment using a bacterial cellulose dressing as our standard for all the analyzed wounds. The thickness of the residual dermis under the wound (DUtW) bed was shown to influence the healing outcome, especially for the regeneration of epidermal tissue, including the wound closure rate. The analysis of the DUtW throughout the entire dorsal region of the animals opened up the possibility of establishing a map that will facilitate the experimental design of future works, increasing their standardization and reproducibility and ultimately reducing the number of animals needed. Thus, the developed model, together with the automated morphometric analysis approach used, offers the possibility to generate robust quantitative results with a rapid turnaround time while allowing the study of multiple extra morphometric parameters, creating a more holistic analysis.

Decellularized Antler Cancellous Bone Matrix Material Can Serve as Potential Bone Tissue Scaffold.

Due to the limited supply of autologous bone grafts, there is a need to develop more bone matrix materials to repair bone defects. Xenograft bone is expected to be used for clinical treatment due to its exact structural similarity to natural bone and its high biocompatibility. In this study, decellularized antler cancellous bone matrix (DACB) was first prepared, and then the extent of decellularization of DACB was verified by histological staining, which demonstrated that it retained the extracellular matrix (ECM). The bioactivity of DACB was assessed using C3H10T1/2 cells, revealing that DACB enhanced cell proliferation and facilitated cell adhesion and osteogenic differentiation. When evaluated by implanting DACB into nude mice, there were no signs of necrosis or inflammation in the epidermal tissues. The bone repair effect of DACB was verified in vivo using sika deer during the antler growth period as an animal model, and the molecular mechanisms of bone repair were further evaluated by transcriptomic analysis of the regenerated tissues. Our findings suggest that the low immunogenicity of DACB enhances the production of bone extracellular matrix components, leading to effective osseointegration between bone and DACB. This study provides a new reference for solving bone defects.

RABR-1, an atypical Rab-related GTPase, cell-nonautonomously restricts somatosensory dendrite branching.

Neurons are highly polarized cells with dendrites and axons. Dendrites, which receive sensory information or input from other neurons, often display elaborately branched morphologies. While mechanisms that promote dendrite branching have been widely studied, less is known about the mechanisms that restrict branching. Using the nematode Caenorhabditis elegans, we identify rabr-1 (for Rab-related gene 1) as a factor that restricts branching of the elaborately branched dendritic trees of PVD and FLP somatosensory neurons. Animals mutant for rabr-1 show excessively branched dendrites throughout development and into adulthood in areas where the dendrites overlay epidermal tissues. Phylogenetic analyses show that RABR-1 displays similarity to small GTPases of the Rab-type, although based on sequence alone, no clear vertebrate ortholog of RABR-1 can be identified. We find that rabr-1 is expressed and can function in epidermal tissues, suggesting that rabr-1 restricts dendritic branching cell-nonautonomously. Genetic experiments further indicate that for the formation of ectopic branches rabr-1 mutants require the genes of the Menorin pathway, which have been previously shown to mediate dendrite morphogenesis of somatosensory neurons. A translational reporter for RABR-1 reveals a subcellular localization to punctate, perinuclear structures, which correlates with endosomal and autophagosomal markers, but anticorrelates with lysosomal markers suggesting an amphisomal character. Point mutations in rabr-1 analogous to key residues of small GTPases suggest that rabr-1 functions in a GTP-bound form independently of GTPase activity. Taken together, rabr-1 encodes for an atypical small GTPase of the Rab-type that cell-nonautonomously restricts dendritic branching of somatosensory neurons, likely independently of GTPase activity.

Multifunctional Glycopeptide-Based Hydrogel via Dual-Modulation for the Prevention and Repair of Radiation-Induced Skin Injury.

The radiation-induced skin injury (RISI) remains a great challenge for clinical wound management and care after radiotherapy, as patients will suffer from the acute radiation injury and long-term chronic inflammatory damage during the treatment. The excessive ROS in the early acute stage and prolonged inflammatory response in the late healing process always hinder therapeutic efficiency. Herein, we developed an extracellular matrix (ECM)-mimetic multifunctional glycopeptide hydrogel (oCP@As) to promote and accelerate RISI repair via a dual-modulation strategy in different healing stages. The oCP@As hydrogel not only can form an ECM-like nanofiber structure through the Schiff base reaction but also exhibits ROS scavenging and DNA double-strand break repair abilities, which can effectively reduce the acute radiation damage. Meanwhile, the introduction of oxidized chondroitin sulfate, which is the ECM polysaccharide-like component, enables regulation of the inflammatory response by adsorption of inflammatory factors, accelerating the repair of chronic inflammatory injury. The animal experiments demonstrated that oCP@As can significantly weaken RISI symptoms, promote epidermal tissue regeneration and angiogenesis, and reduce pro-inflammatory cytokine expression. Therefore, this multifunctional glycopeptide hydrogel dressing can effectively attenuate RISI symptoms and promote RISI healing, showing great potential for clinical applications in radiotherapy protection and repair.