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1.
Cells ; 13(13)2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38994958

ABSTRACT

The cornea is continuously exposed to injuries, ranging from minor scratches to deep traumas. An effective healing mechanism is crucial for the cornea to restore its structure and function following major and minor insults. Transforming Growth Factor-Beta (TGF-ß), a versatile signaling molecule that coordinates various cell responses, has a central role in corneal wound healing. Upon corneal injury, TGF-ß is rapidly released into the extracellular environment, triggering cell migration and proliferation, the differentiation of keratocytes into myofibroblasts, and the initiation of the repair process. TGF-ß-mediated processes are essential for wound closure; however, excessive levels of TGF-ß can lead to fibrosis and scarring, causing impaired vision. Three primary isoforms of TGF-ß exist-TGF-ß1, TGF-ß2, and TGF-ß3. Although TGF-ß isoforms share many structural and functional similarities, they present distinct roles in corneal regeneration, which adds an additional layer of complexity to understand the role of TGF-ß in corneal wound healing. Further, aberrant TGF-ß activity has been linked to various corneal pathologies, such as scarring and Peter's Anomaly. Thus, understanding the molecular and cellular mechanisms by which TGF-ß1-3 regulate corneal wound healing will enable the development of potential therapeutic interventions targeting the key molecule in this process. Herein, we summarize the multifaceted roles of TGF-ß in corneal wound healing, dissecting its mechanisms of action and interactions with other molecules, and outline its role in corneal pathogenesis.


Subject(s)
Transforming Growth Factor beta , Wound Healing , Humans , Transforming Growth Factor beta/metabolism , Animals , Corneal Diseases/metabolism , Corneal Diseases/therapy , Corneal Diseases/pathology , Corneal Diseases/drug therapy , Cornea/metabolism , Cornea/pathology , Signal Transduction
2.
bioRxiv ; 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38979305

ABSTRACT

Mechanisms of tumorigenesis in sinonasal squamous cell carcinoma (SNSCC) remain poorly described due to its rare nature. A subset of SNSCC are associated with the human papillomavirus (HPV); however, it is unknown whether HPV is a driver of HPV-associated SNSCC tumorigenesis or merely a neutral bystander. We hypothesized that performing the first large high-throughput sequencing study of SNSCC would reveal molecular mechanisms of tumorigenesis driving HPV-associated and HPV-independent SNSCC and identify targetable pathways. High-throughput sequencing was performed on 64 patients with HPV-associated and HPV-independent sinonasal carcinomas. Mutation annotation, viral integration, copy number, and pathway-based analyses were performed. Analysis of HPV-associated SNSCC revealed similar mutational patterns observed in HPV-associated cervical and head and neck squamous cell carcinoma, including lack of TP53 mutations and the presence of known hotspot mutations in PI3K and FGFR3. Further similarities included enrichment of APOBEC mutational signature, viral integration at known hotspot locations, and frequent mutations in epigenetic regulators. HPV-associated SNSCC-specific recurrent mutations were also identified including KMT2C , UBXN11 , AP3S1 , MT-ND4 , and MT-ND5 . Mutations in KMT2D and FGFR3 were associated with decreased overall survival. We developed the first known HPV-associated SNSCC cell line and combinatorial small molecule inhibition of YAP/TAZ and PI3K pathways synergistically inhibited tumor cell clonogenicity. In conclusion, HPV-associated SNSCC and HPV-independent SNSCC are driven by molecularly distinct mechanisms of tumorigenesis. Combinatorial blockade of YAP/TAZ and vertical inhibition of the PI3K pathway may be useful in targeting HPV-associated SNSCC whereas targeting MYC and horizontal inhibition of RAS/PI3K pathways for HPV-independent SNSCC. One Sentence Summary: This study solidifies HPV as a driver of HPV-associated SNSCC tumorigenesis, identifies molecular mechanisms distinguishing HPV-associated and HPV-independent SNSCC, and elucidates YAP/TAZ and PI3K blockade as key targets for HPV-associated SNSCC.

4.
Biomed Rep ; 21(2): 112, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38912171

ABSTRACT

Late-stage cancers lack effective treatment, underscoring the need for early diagnosis to improve prognosis and decrease mortality rates. Molecular markers, such as DNA methylation, offer promise in early cancer detection. The present study compared commercial kits for analyzing DNA from cervical liquid cytology samples in cancer screening. Rapid bisulfite conversion kits using silica spin-columns and magnetic beads were assessed against standard DNA extraction and bisulfite conversion methods for profiling DNA methylation using quantitative methylation-specific PCR. ß-actin amplification indicated the suitability of small sample volumes for methylation studies using either the pellet or supernatant (cell-free DNA) parts. Comparison of Bisulfite Conversion Kit-Whole Cell (Abcam), Methylamp Bisulfite Modification (Epigentek), EpiTect Fast LyseAll Bisulfite Kit (Qiagen GmbH) and EZ DNA Methylation-Direct Kit (Zymo Research Corp.) showed no significant differences in ß-actin cycle threshold values. EZ-96 DNA Methylation-Lightning MagPrep (Zymo Research Corp.), a hybrid kit in a 96-well plate format, exhibited swift turnaround time and similar amplification efficiency. Automation with magnetic bead kits increased throughput without compromising amplification efficiency in open PCR systems. Cost analysis favored direct kits over the gold standard manual protocol. This comparison aids in selecting cost-effective DNA methylation diagnostic tests. The present study confirmed comparable kit performance in methylation-based analysis, highlighting the adequacy of cytology samples and the potential of bodily fluids as alternatives for liquid biopsy.

5.
Talanta ; 276: 126189, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38718645

ABSTRACT

A film composed of agarose and graphene (G) and magnetic nanoparticles (G-MNPs) is proposed as a sorbent for the extraction and determination of medroxyprogesterone (MED), levonorgestrel (LEV), norethisterone (NOR) and progesterone (PRO) in natural water samples. Both the preparation of the film and the extraction procedure were optimized. The optimal extraction parameters were as follows: isopropyl alcohol as activation solvent, sample pH value of 3.0, extraction time of 30 min, 1.00 mL of acetonitrile as eluent, elution time of 5 min and sample volume of 100.00 mL. HPLC with photodiode array detector was used for the separation and determination. The method presented a linear range between 2.50 and 75.0 µg L-1 for all analytes, and the LODs were between 1.40 and 1.80 µg L-1. The method was applied to natural water samples, obtaining satisfactory recovery values (75-111 %). In conclusion, for the immobilization of the G-MNPs, agarose was used, which is a non-toxic, renewable and biodegradable material. The G-MNPs-agarose film was reused up to 70 times, without losing its extraction capacity significantly and presenting excellent sorbent properties, which allow the extraction and preconcentration of the progestogens under study.


Subject(s)
Progestins , Water Pollutants, Chemical , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/isolation & purification , Water Pollutants, Chemical/chemistry , Progestins/isolation & purification , Progestins/analysis , Progestins/chemistry , Adsorption , Magnetite Nanoparticles/chemistry , Solid Phase Extraction/methods , Sepharose/chemistry , Chromatography, High Pressure Liquid
6.
New Phytol ; 242(4): 1614-1629, 2024 May.
Article in English | MEDLINE | ID: mdl-38594212

ABSTRACT

Species-specific differences in nutrient acquisition strategies allow for complementary use of resources among plants in mixtures, which may be further shaped by mycorrhizal associations. However, empirical evidence of this potential role of mycorrhizae is scarce, particularly for tree communities. We investigated the impact of tree species richness and mycorrhizal types, arbuscular mycorrhizal fungi (AM) and ectomycorrhizal fungi (EM), on above- and belowground carbon (C), nitrogen (N), and phosphorus (P) dynamics. Soil and soil microbial biomass elemental dynamics showed weak responses to tree species richness and none to mycorrhizal type. However, foliar elemental concentrations, stoichiometry, and pools were significantly affected by both treatments. Tree species richness increased foliar C and P pools but not N pools. Additive partitioning analyses showed that net biodiversity effects of foliar C, N, P pools in EM tree communities were driven by selection effects, but in mixtures of both mycorrhizal types by complementarity effects. Furthermore, increased tree species richness reduced soil nitrate availability, over 2 yr. Our results indicate that positive effects of tree diversity on aboveground nutrient storage are mediated by complementary mycorrhizal strategies and highlight the importance of using mixtures composed of tree species with different types of mycorrhizae to achieve more multifunctional afforestation.


Subject(s)
Biodiversity , Carbon , Mycorrhizae , Nitrogen , Phosphorus , Plant Leaves , Soil , Trees , Mycorrhizae/physiology , Trees/microbiology , Plant Leaves/microbiology , Plant Leaves/metabolism , Phosphorus/metabolism , Soil/chemistry , Nitrogen/metabolism , Carbon/metabolism , Biomass , Soil Microbiology , Elements , Species Specificity
7.
Cell Rep ; 43(3): 113897, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38493478

ABSTRACT

Chromatin structure is regulated through posttranslational modifications of histone variants that modulate transcription. Although highly homologous, histone variants display unique amino acid sequences associated with specific functions. Abnormal incorporation of histone variants contributes to cancer initiation, therapy resistance, and metastasis. This study reports that, among its biologic functions, histone H3.1 serves as a chromatin redox sensor that is engaged by mitochondrial H2O2. In breast cancer cells, the oxidation of H3.1Cys96 promotes its eviction and replacement by H3.3 in specific promoters. We also report that this process facilitates the opening of silenced chromatin domains and transcriptional activation of epithelial-to-mesenchymal genes associated with cell plasticity. Scavenging nuclear H2O2 or amino acid substitution of H3.1(C96S) suppresses plasticity, restores sensitivity to chemotherapy, and induces remission of metastatic lesions. Hence, it appears that increased levels of H2O2 produced by mitochondria of breast cancer cells directly promote redox-regulated H3.1-dependent chromatin remodeling involved in chemoresistance and metastasis.


Subject(s)
Breast Neoplasms , Histones , Humans , Female , Histones/metabolism , Chromatin , Hydrogen Peroxide/pharmacology , Hydrogen Peroxide/metabolism , Drug Resistance, Multiple , Breast Neoplasms/genetics
8.
ISME J ; 18(1)2024 Jan 08.
Article in English | MEDLINE | ID: mdl-38366058

ABSTRACT

Ongoing global warming is expected to augment soil respiration by increasing the microbial activity, driving self-reinforcing feedback to climate change. However, the compensatory thermal adaptation of soil microorganisms and substrate depletion may weaken the effects of rising temperature on soil respiration. To test this hypothesis, we collected soils along a large-scale forest transect in eastern China spanning a natural temperature gradient, and we incubated the soils at different temperatures with or without substrate addition. We combined the exponential thermal response function and a data-driven model to study the interaction effect of thermal adaptation and substrate availability on microbial respiration and compared our results to those from two additional continental and global independent datasets. Modeled results suggested that the effect of thermal adaptation on microbial respiration was greater in areas with higher mean annual temperatures, which is consistent with the compensatory response to warming. In addition, the effect of thermal adaptation on microbial respiration was greater under substrate addition than under substrate depletion, which was also true for the independent datasets reanalyzed using our approach. Our results indicate that thermal adaptation in warmer regions could exert a more pronounced negative impact on microbial respiration when the substrate availability is abundant. These findings improve the body of knowledge on how substrate availability influences the soil microbial community-temperature interactions, which could improve estimates of projected soil carbon losses to the atmosphere through respiration.


Subject(s)
Soil Microbiology , Soil , Soil/chemistry , Global Warming , Climate Change , Temperature , Respiration , Carbon
10.
Proc Natl Acad Sci U S A ; 121(6): e2305153121, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38300860

ABSTRACT

Self-organized spatial patterns are a common feature of complex systems, ranging from microbial communities to mussel beds and drylands. While the theoretical implications of these patterns for ecosystem-level processes, such as functioning and resilience, have been extensively studied, empirical evidence remains scarce. To address this gap, we analyzed global drylands along an aridity gradient using remote sensing, field data, and modeling. We found that the spatial structure of the vegetation strengthens as aridity increases, which is associated with the maintenance of a high level of soil multifunctionality, even as aridity levels rise up to a certain threshold. The combination of these results with those of two individual-based models indicate that self-organized vegetation patterns not only form in response to stressful environmental conditions but also provide drylands with the ability to adapt to changing conditions while maintaining their functioning, an adaptive capacity which is lost in degraded ecosystems. Self-organization thereby plays a vital role in enhancing the resilience of drylands. Overall, our findings contribute to a deeper understanding of the relationship between spatial vegetation patterns and dryland resilience. They also represent a significant step forward in the development of indicators for ecosystem resilience, which are critical tools for managing and preserving these valuable ecosystems in a warmer and more arid world.


Subject(s)
Microbiota , Resilience, Psychological , Ecosystem , Soil
11.
Nat Commun ; 15(1): 327, 2024 Jan 06.
Article in English | MEDLINE | ID: mdl-38184663

ABSTRACT

Soil fungi are a key constituent of global biodiversity and play a pivotal role in agroecosystems. How arable farming affects soil fungal biogeography and whether it has a disproportional impact on rare taxa is poorly understood. Here, we used the high-resolution PacBio Sequel targeting the entire ITS region to investigate the distribution of soil fungi in 217 sites across a 3000 km gradient in Europe. We found a consistently lower diversity of fungi in arable lands than grasslands, with geographic locations significantly impacting fungal community structures. Prevalent fungal groups became even more abundant, whereas rare groups became fewer or absent in arable lands, suggesting a biotic homogenization due to arable farming. The rare fungal groups were narrowly distributed and more common in grasslands. Our findings suggest that rare soil fungi are disproportionally affected by arable farming, and sustainable farming practices should protect rare taxa and the ecosystem services they support.


Subject(s)
Ecosystem , Soil , Agriculture , Europe , Farms
12.
Proc Natl Acad Sci U S A ; 121(4): e2309881120, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38190514

ABSTRACT

Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought.


Subject(s)
Droughts , Ecosystem , Grassland , Carbon Cycle , Climate Change , Receptor Protein-Tyrosine Kinases
13.
J Ocul Pharmacol Ther ; 40(2): 111-116, 2024 03.
Article in English | MEDLINE | ID: mdl-38150537

ABSTRACT

Optic neuropathies, such as glaucoma, are some of the leading causes of irreversible blindness worldwide. There has been a lot of research for potential therapies that could attenuate and even reduce the impact of the pathological pathways that lead to the loss of retinal ganglion cells (RGCs). In recent years, vitamin B3 (nicotinamide) has gained some interest as a viable option for these neurodegenerative diseases due to its fundamental role in enhancing the mitochondria metabolism of the RGCs. This review focuses on elucidating the impact of vitamin B3 on retinal cells, especially when in a dysfunctional state like what happens in optic neuropathies, especially glaucoma. This review also summarizes the existing and future research on the clinical effects of vitamin B3 in these optic neuropathies, and determines appropriate recommendations regarding its dosing, efficacy, and eventual side effects.


Subject(s)
Glaucoma , Optic Nerve Diseases , Humans , Optic Nerve Diseases/drug therapy , Optic Nerve Diseases/etiology , Glaucoma/metabolism , Retinal Ganglion Cells/metabolism , Vitamins , Dietary Supplements
14.
Eur J Ophthalmol ; 34(3): 884-887, 2024 May.
Article in English | MEDLINE | ID: mdl-38115710

ABSTRACT

INTRODUCTION: Single-haptic iris-claw intraocular lens (IOL) dislocation is not an uncommon complication. A few different surgical techniques are available for its refixation but usually involve a more invasive approach. We aim to demonstrate an original and simple approach for refixation of single haptic retropupillary iris-claw IOL subluxations. METHODS: We present a case of an 80-year-old male with a single haptic retropupillary iris-claw IOL subluxation in a previously vitrectomized eye. We used a new surgical approach to refix this type of subluxation. RESULTS: This new technique uses only two 30-gauge needles (one of them connected to a viscosurgical device) to re-enclavate the subluxated haptic of the retropupillary iris-claw IOL. By minimising surgical manipulation, the patient's postoperative period was uneventful. CONCLUSIONS: We highlight a new, quick, safe, and unusual surgical approach to single-haptic retropupillary iris-claw IOL dislocation in vitrectomized eyes. Because of its characteristics, we named it the "fencing" IOL repositioning technique.


Subject(s)
Artificial Lens Implant Migration , Iris , Lenses, Intraocular , Humans , Male , Aged, 80 and over , Iris/surgery , Artificial Lens Implant Migration/surgery , Visual Acuity/physiology , Reoperation , Lens Implantation, Intraocular/methods , Vitrectomy/methods , Prosthesis Design
15.
Sci Adv ; 9(48): eadj8016, 2023 12.
Article in English | MEDLINE | ID: mdl-38019923

ABSTRACT

How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.


Subject(s)
Ecosystem , Soil , Humans , Fungi/genetics , Phylogeny , Soil Microbiology , Biodiversity
16.
Natl Sci Rev ; 10(11): nwad242, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37900195

ABSTRACT

Crossing certain aridity thresholds in global drylands can lead to abrupt decays of ecosystem attributes such as plant productivity, potentially causing land degradation and desertification. It is largely unknown, however, whether these thresholds can be altered by other key global change drivers known to affect the water-use efficiency and productivity of vegetation, such as elevated CO2 and nitrogen (N). Using >5000 empirical measurements of plant biomass, we showed that crossing an aridity (1-precipitation/potential evapotranspiration) threshold of ∼0.50, which marks the transition from dry sub-humid to semi-arid climates, led to abrupt declines in aboveground biomass (AGB) and progressive increases in root:shoot ratios, thus importantly affecting carbon stocks and their distribution. N addition significantly increased AGB and delayed the emergence of its aridity threshold from 0.49 to 0.55 (P < 0.05). By coupling remote sensing estimates of leaf area index with simulations from multiple models, we found that CO2 enrichment did not alter the observed aridity threshold. By 2100, and under the RCP 8.5 scenario, we forecast a 0.3% net increase in the global land area exceeding the aridity threshold detected under a scenario that includes N deposition, in comparison to a 2.9% net increase if the N effect is not considered. Our study thus indicates that N addition could mitigate to a great extent the negative impact of increasing aridity on plant biomass in drylands. These findings are critical for improving forecasts of abrupt vegetation changes in response to ongoing global environmental change.

17.
Vet Med Sci ; 9(6): 2463-2474, 2023 11.
Article in English | MEDLINE | ID: mdl-37654028

ABSTRACT

BACKGROUND: A cohort study for 2 years period analysed the prevalence, incidence and clinical-immunological features of canine Leishmania (L.) chagasi-infection in 316 mongrel dogs in a visceral leishmaniasis-endemic area in Pará State, Brazil. OBJECTIVE/METHODS: Diagnosis of infection was performed by the indirect fluorescent antibody test (IFAT-IgG), the leishmanin skin test (LST) and a parasite search (from the popliteal lymph node aspiration) at the beginning of the study and at 6, 12 and 24 months intervals. RESULTS: IFAT/LST revealed three immune profiles of infection: (I) IFAT(+) /LST(-) (81), (II) IFAT(-) /LST(+) (17) and (III) IFAT(+) /LST(+) (13). Prevalence of profiles I, II and III were 25.6, 5.4 and 4.1%, and an overall prevalence 35.1%. Incidence of profiles I, II and III were 5.4, 0.3 and 0.0%, and an overall incidence 5.7% dogs per month. Incidence at the age ranges <1 year, ≥1 year, <7 years and ≥7 years evidenced a highest rate in the age range <1 year (6.6% dogs per month). Parasitological diagnosis was positive in 19% dogs at the prevalence (85.7% profile I), and in 11% at the incidence (100% profile I). The clinical picture of 179 infected dogs showed 145 (81%) of profile I (82% subclinical); 21 (11.7%) of profile II (100% subclinical); and 13 (7.3%) of profile III (84.6% subclinical). Conversion from subclinical to sick dogs was higher (p < 0.05) in profile I (40.2%) than in profiles II (5.8%) and III (9%). Immunological conversion showed that only 3.2% of profile I dogs (prevalence) converted to LST(+) (two at the end of the first 6 months and 1 after 24 months), while 82.3% of profile II dogs converted to IFAT(+) (11 in the first 6 months, whereas three after 12 months). A 100% death rate was observed in dogs from profile I alone. CONCLUSION: These results reinforce the need of adopting preventive strategies against CVL as early as in the first semester of the dog's life.


Subject(s)
Dog Diseases , Leishmaniasis, Visceral , Humans , Dogs , Animals , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/veterinary , Brazil/epidemiology , Cohort Studies , Prevalence , Incidence , Dog Diseases/diagnosis
18.
An Acad Bras Cienc ; 95(4): e20191391, 2023.
Article in English | MEDLINE | ID: mdl-37729298

ABSTRACT

Chicken broilers digestibility and performance fed with different ME levels, with and without adjustments of digestible lysine, calcium, and available phosphorus, were evaluated. For digestibility, 210 male Cobb 500 chicken broilers were used and distributed into a 3x2+1 factorial arrangement, with three ME levels (3050; 3125 and 3200 kcal/kg) with and without nutrient adjustment, plus one control treatment (2975 kcal ME/kg), totaling seven treatments including six repetitions with five birds into each repetition. For initial performance, 1120 birds were distributed randomly with eight replications within treatments and 20 birds for each replication. For final performance, 1008 chickens were distributed with eight replications and 18 birds for each replication. The DCDM and DCCP were improved (P<0.05) according to the increase of ME and the adjustment in dietary nutrients, as well as GE digestibility. The final performance showed no interaction (P>0.05) between energy and nutrient adjustment, but the increase in energy levels improved the feed conversion ratio (FCR=1.370). Increasing energy density with nutrient adjustment improves both nutrient utilization and bird performance.


Subject(s)
Calcium , Chickens , Animals , Male , Lysine , Nutrients , Phosphorus
19.
Ocul Surf ; 30: 168-178, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37742739

ABSTRACT

PURPOSE: Lumican is a major extracellular matrix (ECM) component in the cornea that is upregulated after injury and promotes corneal wound healing. We have recently shown that peptides designed based on the 13 C-terminal amino acids of lumican (LumC13 and LumC13C-A) are able to recapitulate the effects of lumican on promoting corneal wound healing. Herein we used computational chemistry to develop peptide mimetics derived from LumC13C-A with increased stability and half-life that are biologically active and non-toxic, thereby promoting corneal wound healing with increased pharmacological potential. METHODS: Different peptides staples were rationalized using LumC13C-A sequence by computational chemistry, docked to TGFßRI and the interface binding energies compared. Lowest scoring peptides were synthesized, and the toxicity of peptides tested using CCK8-based cell viability assay. The efficacy of the stapled peptides at promoting corneal wound healing was tested using a proliferation assay, an in vitro scratch assay using human corneal epithelial cells and an in vivo murine corneal debridement wound healing model. RESULTS: Binding free energies were calculated using MMGBSA algorithm, and peptides LumC13C and LumC13S5 displayed superior binding to ALK5 compared to the non-stapled peptide LumC13C-A. The presence of the hydrocarbon staple in LumC13C enhances the stability of the α-helical conformation, thereby facilitating more optimal interactions with the ALK5 receptor. The stapled peptides do not present cytotoxic effects on human corneal epithelial cells at a 300 nM concentration. Similar to lumican and LumC13C-A, both C13C and LumC13S5 significantly promote corneal wound healing both in vitro and in vivo. CONCLUSIONS: Highly stable and non-toxic stapled peptides designed based on LumC13, significantly promote corneal wound healing. As a proof of principle, our data shows that more stable and pharmacologically relevant peptides can be designed based on endogenous peptide sequences for treating various corneal pathologies.


Subject(s)
Corneal Injuries , Epithelium, Corneal , Humans , Animals , Mice , Lumican/metabolism , Lumican/pharmacology , Cornea/pathology , Corneal Injuries/metabolism , Wound Healing , Peptides/pharmacology , Peptides/metabolism , Epithelium, Corneal/metabolism
20.
Proc Natl Acad Sci U S A ; 120(40): e2304032120, 2023 10 03.
Article in English | MEDLINE | ID: mdl-37748063

ABSTRACT

Fairy circles (FCs) are regular vegetation patterns found in drylands of Namibia and Western Australia. It is virtually unknown whether they are also present in other regions of the world and which environmental factors determine their distribution. We conducted a global systematic survey and found FC-like vegetation patterns in 263 sites from 15 countries and three continents, including the Sahel, Madagascar, and Middle-West Asia. FC-like vegetation patterns are found in environments characterized by a unique combination of soil (including low nutrient levels and high sand content) and climatic (arid regions with high temperatures and high precipitation seasonality) conditions. In addition to these factors, the presence of specific biological elements (termite nests) in certain regions also plays a role in the presence of these patterns. Furthermore, areas with FC-like vegetation patterns also showed more stable temporal productivity patterns than those of surrounding areas. Our study presents a global atlas of FCs and provides unique insights into the ecology and biogeography of these fascinating vegetation patterns.


Subject(s)
Desert Climate , Ecology , Geography , Plants , Animals
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