High Regenerative Capacity Research Articles

Identification and functional analysis of LpNAC37 associated with somatic embryogenesis in Lilium pumilum DC. Fisch. based on transcriptome analysis

Somatic embryogenesis (SE) is important for Lilium bulb propagation, germplasm conservation, and genetic transformation. The transition of somatic cells to embryonic cells is a critical step in SE, but the associated regulatory mechanisms have not been fully elucidated. Lilium pumilum DC. Fisch has a high regenerative capacity, and this study clarifies the critical timing of embryonic cell appearance in Lilium SE. Transcriptome sequencing using RNA-seq technology was performed on 5 representative samples from the early stage of Lilium SE. The 15 established cDNA libraries yielded 91.47 GB of valid data, and a total of 11,155 genes were consistently differentially expressed in the early stages of Lilium SE. GO annotation and KEGG pathway analysis of differentially expressed genes (DEGs) suggested that transcriptional regulation, hormone signaling, and stress response pathways play essential roles in the early stages of Lilium SE. WOX8, WOX11, SHR2, NAC37, AHP2, ANT, PIN1C, LAX2, LBD4, ACS12, YUC4, NFYB3, WRKY28, SAUR50, PYL9, and WRKY39 may be candidate genes for regulating early SE in Lilium. We further cloned LpNAC37, one of the key DEGs obtained from WGCNA and screening. LpNAC37 encodes a protein of 303 amino acids with a conserved NAM structural domain. The protein is a nuclear transcription factor with the highest homology to carrot DcNAC37. Overexpression of LpNAC37 suggested that LpNAC37 promotes embryonic callus formation in Arabidopsis. These results will help reveal the molecular mechanisms of the early stages of Lilium SE and advance the application of SE in Lilium propagation and genetic transformation.

Adult Mesenchymal Stem Cells from Oral Cavity and Surrounding Areas: Types and Biomedical Applications.

Adult mesenchymal stem cells are those obtained from the conformation of dental structures (DMSC), such as deciduous and permanent teeth and other surrounding tissues. Background: The self-renewal and differentiation capacities of these adult stem cells allow for great clinical potential. Because DMSC are cells of ectomesenchymal origin, they reveal a high capacity for complete regeneration of dental pulp, periodontal tissue, and other biomedical applications; their differentiation into other types of cells promotes repair in muscle tissue, cardiac, pancreatic, nervous, bone, cartilage, skin, and corneal tissues, among others, with a high predictability of success. Therefore, stem and progenitor cells, with their exosomes of dental origin and surrounding areas in the oral cavity due to their plasticity, are considered a fundamental pillar in medicine and regenerative dentistry. Tissue engineering (MSCs, scaffolds, and bioactive molecules) sustains and induces its multipotent and immunomodulatory effects. It is of vital importance to guarantee the safety and efficacy of the procedures designed for patients, and for this purpose, more clinical trials are needed to increase the efficacy of several pathologies. Conclusion: From a bioethical and transcendental anthropological point of view, the human person as a unique being facilitates better clinical and personalized therapy, given the higher prevalence of dental and chronic systemic diseases.

Glycidyl methacrylate-phytic acid crosslinked maleic anhydride-β-cyclodextrin hydrogel as an efficient cationic dye adsorbent

To address the problem of cationic organic dye pollution in wastewater, a hydrogel of glycidyl methacrylate-phytic acid crosslinked maleic anhydride-β-cyclodextrin (PAG-β-CDM) was synthesized through free radical polymerization. The structure of PAG-β-CDM was characterized by FT-IR, XPS, elemental analysis, ICP, SEM, XRD, inverse and photometric titrations. The adsorption capabilities of PAG-β-CDM for cationic dyes were studied as well. The results revealed that PAG-β-CDM has a porous structure with abundant functional groups that can effectively adsorb cationic dyes through host-guest interactions, hydrogen bonding, and electrostatic interactions. The maximum adsorption capacities for malachite green, crystal violet, methylene blue and astrazon pink FG were 3655.47, 3183.2, 1336.33, and 2987 mg/g, respectively. Over 90% of the dyes were adsorbed within the first 15 min, indicating that the adsorption rate of dyes on PAG-β-CDM is fast. The results from the adsorption kinetics and isotherms data are consistent with predictions from both Langmuir isotherm model and pseudo-second-order kinetic model. Thermodynamic results indicated that the adsorption of cationic dyes on PAG-β-CDM is spontaneous and exothermic. Additionally, PAG-β-CDM demonstrated high stability and good regenerative capacity over five regeneration cycles.

Zebrafish pancreatic β cell clusters undergo stepwise regeneration using Neurod1-expressing cells from different cell lineages.

Pancreatic β cell clusters produce insulin and play a central role in glucose homeostasis. The regenerative capacity of mammalian β cells is limited and the loss of β cells causes diabetes. In contrast, zebrafish β cell clusters have a high regenerative capacity, making them an attractive model to study β cell cluster regeneration. How zebrafish β cell clusters regenerate, when the regeneration process is complete, and the identification of the cellular source of regeneration are fundamental questions that require investigation. Here, using larval and adult zebrafish, we demonstrate that pancreatic β cell clusters undergo a two-step regeneration process, regenerating functionality and then β cell numbers. Additionally, we found that all regenerating pancreatic β cells arose from Neurod1-expressing cells and that cells from different lineages contribute to both functional and β cell number recovery throughout their life. Furthermore, we found that during development and neogenesis, as well as regeneration, all β cells undergo Neurod1expression in zebrafish. Together, these results shed light on the fundamental cellular mechanisms underlying β cell cluster development, neogenesis, and regeneration.

Peculiarities of formation of yield of green mass by crops of synthetic crop ×Trititrigia

The article presents the results of studying the features of the growth and development of new lines of ×Trititrigia in comparison with the traditional fodder crop of winter rye under conditions of soddy-podzolic heavy loamy soils with a low supply of humus in 2018-2019. By the phase of milky ripeness, the height of plants of the trititrigia lines reached an average of 109–124 cm, in the winter rye variety Snegirevskaya 152 cm. t/ha When measuring the amount of dry matter in green fodder, 24.4-26.8 t/ha was obtained on trititrigia lines, and 26.8 t/ha on Snegirevskaya. A feature of trititrigia is its high regenerative capacity, due to which it is able to form an ear every time after mowing and throughout the entire growing season. This allows you to use the green mass in the autumn as a complete feed for animals.

A short dasatinib and quercetin treatment is sufficient to reinstate potent adult neuroregenesis in the aged killifish

The young African turquoise killifish has a high regenerative capacity, but loses it with advancing age, adopting several aspects of the limited form of mammalian regeneration. We deployed a proteomic strategy to identify pathways that underpin the loss of regenerative power caused by aging. Cellular senescence stood out as a potential brake on successful neurorepair. We applied the senolytic cocktail Dasatinib and Quercetin (D + Q) to test clearance of chronic senescent cells from the aged killifish central nervous system (CNS) as well as rebooting the neurogenic output. Our results show that the entire aged killifish telencephalon holds a very high senescent cell burden, including the parenchyma and the neurogenic niches, which could be diminished by a short-term, late-onset D + Q treatment. Reactive proliferation of non-glial progenitors increased substantially and lead to restorative neurogenesis after traumatic brain injury. Our results provide a cellular mechanism for age-related regeneration resilience and a proof-of-concept of a potential therapy to revive the neurogenic potential in an already aged or diseased CNS.

Green Synthesis of MOF-801(Zr/Ce/Hf) for CO2/N2 and CO2/CH4 Separation.

The purification of natural gas and the removal of carbon dioxide from flue gases are crucial to economize precious resources and effectively relieve a series of environmental problems caused by global warming. Metal-organic framework (MOF) materials have demonstrated remarkable performance and benefits in the area of gas separation; however, obtaining materials with high gas capacity and selectivity simultaneously remains difficult. In addition, harsh synthesis conditions and solvent toxicity have been restricted in large-scale production and industrial application. Therefore, MOF-801(Zr/Ce/Hf) was created based on the green synthesis of the MOF-801 construction unit by altering the kinds of metal salts, and the impact of three metal nodes on the performance of gas adsorption and separation was demonstrated by contrasting the three MOFs. The results showed that MOF-801(Ce) has the best CO2 adsorption capacity (3.3 mmol/g at 298 K), which also was demonstrated with in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results, CO2/CH4 (ideal adsorbed solution theory (IAST) = 13.28 at 298 K, 1 bar, CO2/CH4 = 1:1, v/v), and the separation performance of CO2/N2 (IAST = 57.46 at 298 K, 1 bar, CO2/N2 = 1:1, v/v) among the group. Green synthesis of MOF-801(Zr/Ce/Hf) is an ideal candidate for flue gas separation and methane purification because of its high regeneration capacity and strong cyclic stability.

2023 TERMIS – AMERICAS Conference & Exhibition Boston Marriott Copley Place April 11–14, 2023

2023 TERMIS – AMERICAS Conference & Exhibition Boston Marriott Copley Place April 11–14, 2023

The new directions in genetics, breeding and biotechnology of ornamental and berry crops in the N.I. Vavilov Institute of Plant Genetic Resources (VIR)

The use of modern breeding methods, biotechnology, and molecular genetics makes it possible to identify promising accessions with specified economically important traits at early pre-breeding stages. The success of creating new varieties depends on the availability of unique collections of plant genetic resources, information about genomes, possibility of in vitro cultivation with high regenerative capacity, and practical skills and competencies in this area. One of the advanced methods for accelerating the breeding process is genome editing using the CRISPR/Cas system. This method allows the effective modification of genes in order to obtain varieties with desired traits. In 2022, a new youth laboratory of genetics, breeding, biotechnology of ornamental and berry crops was set up at VIR as part of the National Project "Science and Universities". It is noteworthy that this event coincided with the 135th anniversary of the birth of N.I. Vavilov. The work of the laboratory is aimed at obtaining lines with desired properties for the further breeding process; identifying target genes of economically important traits for obtaining new varieties, lines, and hybrids; as well as creating protocols for the accelerated reproduction of virus-free material of commercially demanded varieties oriented towards import substitution. This review discusses current trends in breeding of ornamental and berry crops: e.g., flower color change in snapdragon and peony; flower aroma improvement in rose; architectonics change in actinidia; and increase of resistance to stress factors in blackberries, strawberries, and grapes.

Research progress of platelet-rich plasma in treatment of discogenic low back pain

To summarize the research progress of platelet-rich plasma (PRP) for the treatment of discogenic low back pain (DLBP). The literature on the treatment of DLBP with PRP was extensively reviewed, and the classification, treatment mechanism, in vitro and in vivo experiments and clinical trial progress of PRP were summarized. According to the PRP composition, preparation methods, and physicochemical properties, there are five commonly used PRP classification systems at present. PRP is involved in delaying or reversing the progress of disc degeneration and pain control by promoting the regeneration of nucleus pulposus cells, increasing the synthesis of extracellular matrix, and regulating the internal microenvironment of degenerative intervertebral disc. Although several in vitro and in vivo studies have confirmed that PRP can promote disc regeneration and repair, significantly relieve pain, and even improve the mobility of DLBP patients. But the contrary conclusion has been reached in a few studies, and there are limitations to the application of PRP. Current studies have confirmed the effectiveness and safety of PRP in the treatment of DLBP and intervertebral disc degeneration, as well as the advantages of PRP in terms of ease of extraction and preparation, low immunological rejection, high regenerative and repair capacity, and the ability to compensate for the shortcomings of traditional treatment modalities. However, relevant studies are still needed to further optimize PRP preparation methods, unify systematic classification guidelines, and clarify its long-term effectiveness.

Ectopic Expression of PgF3′5′H in Commercial Gypsophila paniculata Cultivar through Optimized Agrobacterium-Mediated Transformation

Gypsophila paniculata is one of the most popular cut flowers in the world whose major cultivars are blooming white. As is well known, blue flowers could be generated via the overexpression of the gene encoding flavonoid 3′5′-hydroxylase (F3′5′H) in species that naturally lack it. In this study, we established the regeneration and a genetic transformation system for the commercial cultivar ‘YX4’ of G. paniculata and introduced the F3′5′H of Platycodon grandiflorus (PgF3′5′H) successfully into ‘YX4’ using the established protocol. A total of 281 hygromycin (Hyg)-resistant plantlets were obtained, and 38 of them were polymerase chain reaction (PCR) positive, indicating a 13.5% transformation efficiency. Shoot apex without meristem was more suitable for explant due to its high regeneration capacity, and the supplement of thidiazuron (TDZ) provided the most efficient promotion of adventitious bud induction, whereas the supplement of 6-Benzyladenine (6-BA) and 1-naphthaleneacetic acid (NAA) did not affect much. Additionally, the combination of 1 day (d) pre-culture, 5 d co-culture, 10 min infection, 30 mg·L−1 additional acetosyringone (AS) supplement, and 10 mg·L−1 Hyg selection formed the optimized system for ‘YX4’ transformation. This reliable and efficient agrobacterium-mediated transformation of the valuable commercial cultivar ‘YX4’ will contribute not only to the creation and improvement of G. paniculata cultivars, but also to the function research of genes associated with important ornamental traits.

The Impact of Prolonged and Intermittent Fasting on PGC-1α, Oct-4, and CK-19 Liver Gene Expression.

Liver stemness refers to the high regenerative capacity of the organ. This intrinsic regeneration capacity allows the restoration of post-resection liver function in up to 50% of liver donors. Liver cirrhosis is one of the terminal liver diseases with a defect in the intrinsic regeneration capacity. Several attempts to restore intrinsic regeneration capacity by conducting in vivo studies on stem cells in various organs have shown the positive impact of fasting on stemness. An increased capacity for stem cell proliferation and regeneration was reported due to fasting. Prolonged fasting (PF) has been reported to maintain the long-term proliferative ability of hematopoietic stem cells. However, clinical trials on intermittent fasting (IF) have not conclusively given positive results for fasting individuals. This research aims to investigate the effect of fasting on liver stemness by comparing the expression of octamer-binding transcription factor 4 (Oct-4), cytokeratin 19 (CK-19), and peroxisome proliferator-activated receptor γ co-activator α (PGC-1α) in liver cells of fasted rabbits with rabbits fed ad libitum. This study compares two types of fasting, which are intermittent (16 hours) and prolonged (40 hours) fasting, for liver stemness and intrinsic regenerative capacity. A total of 18 rabbits were conditioned into 3 different groups. The first group was subjected to an ad libitum diet, the second to intermittent fasting (16-hour fasting), and the third to prolonged fasting (40-hour fasting). Afterward, the RNA was extracted from the liver tissues of each rabbit and analyzed via real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Relative expression was calculated using the Livak method. Compared to the ad libitum diet, a greater increase was reported in PGC-1α, upregulated Oct4, and steady CK-19 gene expressions in the livers of intermittent fasting rabbits. Prolonged fasting increased PGC1α, reduced liver stemness, and a statistically insignificant decrease in intrinsic liver regenerative capacity. Intermittent fasting indicates preferable molecular alterations in liver stemness and intrinsic regenerative capacity compared to prolonged fasting.

Studying the adaptability of promising breeding forms of tea to static environmental factors

The article presents the results of a long-term assessment of the adaptive potential of breeding forms of tea plants cultivated in the natural and climatic conditions of the North-Western Caucasus (the Republic of Adygea) in order to select the most promising samples from the existing gene pool and use them to breed local highly adaptive varieties. In the course of studying adaptability, generally accepted methods have been used, including the «Program and Methodology for the Study of Fruit, Berry and Nut Crops», 1999 and «Determining the Resistance of Fruit and Berry Crops to Cold Season Stressors in Field and Controlled Conditions», 2002. Meteorological and climatic features of the tea growing area have been analyzed, weather conditions compared with the biorhythms of introduced plants, their influence on the state and productivity of tea noted. Correlation relationships between the temperature factor and the onset of the development phase of tea plants have been characterized. As a result, data have been obtained on the winter hardiness of the studied forms for various components, resistance to excess and lack of heat, and the characteristics of the growth and development of tea plants in various weather conditions and against the background of various regeneration processes have been analyzed. To accelerate the determination of the viability of the conducting system, the authors carried out the growth of damaged shoots at room temperature and presented in the article the results of observations that made it possible to see hidden local tissue damage and characterize their types. The most adaptive forms are AF-3 and AF-5, which show the best resistance to damaging environmental factors, have a high regenerative capacity and can provide a good harvest of green tea leaves for the sustainable development of tea growing in Adygea.

Understanding the adsorption of iron oxide nanomaterials in magnetite and bimetallic form for the removal of arsenic from water

Arsenic decontamination is a major worldwide concern as prolonged exposure to arsenic (>10 µg L-1) through drinking water causes serious health hazards in human beings. The selection of significant, cost-effective, and affordable processes for arsenic removal is the need of the hour. For the last decades, iron-oxide nanomaterials (either in the magnetite or bimetallic form) based adsorptive process gained attention owing to their high arsenic removal efficiency and high regenerative capacity as well as low yield of harmful by-products. In the current state-of-the-art, a comprehensive literature review was conducted focused on the applicability of iron-based nanomaterials for arsenic removal by considering three main factors: (a) compilation of arsenic removal efficiency, (b) identifying factors that are majorly affecting the process of arsenic adsorption and needs further investigation, and (c) regeneration capacity of adsorbents without affecting the removal process. The results revealed that magnetite and bimetallic nanomaterials are more effective for removing Arsenic (III) and Arsenic (V). Further, magnetite-based nanomaterials could be used up to five to six reuse cycles, whereas this value varied from three to six reuse cycles for bimetallic ones. However, most of the literature was based on laboratory findings using decided protocols and sophisticated instruments. It cannot be replicated under natural aquatic settings in the occurrence of organic contents, fluctuating pH and temperature, and interfering compounds. The primary rationale behind this study is to provide a comparative picture of arsenic removal through different iron-oxide nanomaterials (last twelve yearsof published literature) and insights into future research directions.

A rice–chicory rotation pattern ensures safe grain production and phytoremediation of cadmium-contaminated paddy fields: A four-year field experiment in southern China

Cadmium (Cd) contamination in paddy systems is a serious problem, and a strategy must be devised that ensures safe grain production and rapid remediation of soil Cd contamination. To investigate the remediation potential of crop rotation and its effect on Cd accumulation in rice, a four-year (seven-season) rice–chicory rotation field trial was conducted on a moderately acidic Cd-contaminated paddy soil. Rice was planted in summers, followed by straw removal, and chicory, a Cd-enrichment plant, was planted during winter fallows. Rotation effects were compared with those with rice only (control). Rice yields between the rotation and control were not significantly different, whereas Cd concentrations in rice tissues decreased in the rotation. Cd concentration in brown rice of the low-Cd variety decreased to less than 0.2 mg/kg (national food safety standard) from the third season onward, whereas in the high-Cd variety, it decreased from 0.43 mg/kg in the first season to 0.24 mg/kg in the fourth season. The highest Cd concentration in chicory aboveground parts was 24.47 mg/kg, with an enrichment factor of 27.81. Chicory had high regenerative capacity and was repeatedly harvested for biomass in multiple mowings, with average aboveground biomass over 2000 kg/ha in a single mowing. Theoretical phytoextraction efficiency (TPE) of one rice season with straw removal was 0.84%–2.44%, whereas the highest TPE of one chicory season reached 8.07%. The seven seasons of rice–chicory rotation extracted up to 407 g/ha Cd from soil with a TPE exceeding 20%. Therefore, rice–chicory rotation and straw removal can effectively reduce Cd accumulation in subsequent rice crops, without interrupting production and simultaneously rapidly remediating Cd-contaminated soil. Thus, the production potential of light to moderately Cd-contaminated paddy fields can be realized with crop rotation.

Expression of Stem Cell Niche-Related Biomarkers at the Base of the Human Tricuspid Valve.

Stem cell niches have been thoroughly investigated in tissue with high regenerative capacity but not in tissues where cell turnover is slow, such as the human heart. The left AtrioVentricular junction (AVj), the base of the mitral valve, has previously been proposed as a niche region for cardiac progenitors in the adult human heart. In the present study, we explore the right side of the human heart, the base of the tricuspid valve, to investigate the potential of this region as a progenitor niche. Paired biopsies from explanted human hearts were collected from multi-organ donors (N = 12). The lateral side of the AVj, right atria (RA), and right ventricle (RV) were compared for the expression of stem cell niche-related biomarkers using RNA sequencing. Gene expression data indicated upregulation of genes related to embryonic development and extracellular matrix (ECM) composition in the proposed niche region, that is, the AVj. In addition, immunohistochemistry showed high expression of the fetal cardiac markers MDR1, SSEA4, and WT1 within the same region. Nuclear expression of HIF1α was detected suggesting hypoxia. Rare cells were found with the co-staining of the proliferation marker PCNA and Ki67 with cardiomyocyte nuclei marker PCM1 and cardiac Troponin T (cTnT), indicating proliferation of small cardiomyocytes. WT1+/cTnT+ and SSEA4+/cTnT+ cells were also found, suggesting cardiomyocyte-specific progenitors. The expression of the stem cell markers gradually decreased with distance from the tricuspid valve. No expression of these markers was observed in the RV tissue. In summary, the base of the tricuspid valve is an ECM-rich region containing cells with expression of several stem cell niche-associated markers. Co-expression of stem cell markers with cTnT indicates cardiomyocyte-specific progenitors. We previously reported similar data from the base of the mitral valve and thus propose that human adult cardiomyocyte progenitors reside around both atrioventricular valves.

Solanum carolinense L.

<i>Solanum carolinense</i> L.

Polyoxometalate supported on a magnetic Fe3O4/MIL-88A rod-like nanocomposite as an adsorbent for the removal of ciprofloxacin, tetracycline and cationic organic dyes from aqueous solutions.

In this work, a magnetic H3PW12O40/Fe3O4/MIL-88A (Fe) rod-like nanocomposite as a stable and effective ternary adsorbent was fabricated by the hydrothermal method and utilized for the removal of ciprofloxacin (CIP), tetracycline (TC) and organic dyes from aqueous solution. Characterization of the magnetic nanocomposite was accomplished by FT-IR, XRD, Raman spectroscopy, SEM, EDX, TEM, VSM, BET specific surface area and zeta potential analyses. The influencing factors on the adsorption potency of the H3PW12O40/Fe3O4/MIL-88A (Fe) rod-like nanocomposite including initial dye concentration, temperature and adsorbent dose were studied. The maximum adsorption capacities of H3PW12O40/Fe3O4/MIL-88A (Fe) for TC and CIP were 370.37 mg g-1 and 333.33 mg g-1 at 25 °C, respectively. In addition, the H3PW12O40/Fe3O4/MIL-88A (Fe) adsorbent had high regeneration and reusability capacity after four cycles. In addition, the adsorbent was recovered through magnetic decantation and reused for three consecutive cycles without a considerable reduction in its performance. The adsorption mechanism was mainly ascribed to electrostatic and π-π interactions. According to these results, H3PW12O40/Fe3O4/MIL-88A (Fe) can act as a reusable effective adsorbent for the fast elimination of tetracycline (TC), ciprofloxacin (CIP) and cationic dyes from aqueous solutions.

Morphofunctional characteristics of proliferation and apoptosis of germinal epithelium: pathogenesis of temporary azoospermia after local electron irradiation.

At present, the violation of male reproductive function caused by electron irradiation, leading to a decrease in the proliferative activity of germ cells, as well as the development of methods for its correction are relevant. The effect of leukocyte-poor platelet-rich plasma (LP-PRP) growth factors, which have a high regenerative capacity for the restoration of spermatogenesis, remains poorly understood. Objective of the study: immunohistochemical (IHC) assessment of the proliferation of germinal epithelium after electron irradiation with a dose of 2 Gy. Wistar rats (n=60) were divided into groups (conventional names): (I) control (n=30), which were injected with saline; (II) single local irradiation of the testes with electrons at a dose of 2 Gy (n=30). Animals were gradually withdrawn from the experiment over 11 weeks: 5 animals one week after irradiation, and then 5 animals once every 2 weeks. The testes were studied by histological and IHC methods using antibodies to Ki-67, Bcl-2, and p53. Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) method was used to study DNA fragmentation in germ cells, which were stained with TdT solution (Thermo Fisher, USA) and incubated for 60 minutes. The nuclei were counterstained with 4',6-diamidino-2-phenylindole (DAPI) (blue spectrum) (Thermo Fisher), and the luminescence intensity was controlled in a fluorescent microscope with a set of fluorescein isothiocyanate (FITC) filters (green spectrum). IHC analysis of testes after irradiation showed a shift in the proliferative-apoptotic balance towards apoptosis of germ cells: a decrease in the expression levels of Ki-67 (16.3%±1.1%, P<0.05) and Bcl-2 (9.1%±1.1%, P<0.05), an increase in p53-positive cells (74.8%±1.2%, P<0.05) by the end of the experiment. In the experimental model, local irradiation of the testes with electrons at a dose of 2 Gy causes the development of focal hypospermatogenesis, affecting up to 1/8 of the sections of the tubules (in the first week) with a subsequent increase to 1/4 (in the second month), with a tendency to recovery in the third month (temporary azoospermia). The basis of focal hypospermatogenesis is the irradiation-induced proliferative-apoptotic imbalance towards the dominance of apoptosis, which is most pronounced in the pool of spermatogonia.

Distinct fibroblast progenitor subpopulation expedites regenerative mucosal healing by immunomodulation.

Injuries that heal by fibrosis can compromise organ function and increase patient morbidity. The oral mucosal barrier has a high regenerative capacity with minimal scarring, but the cellular mechanisms remain elusive. Here, we identify distinct postnatal paired-related homeobox-1+ (Prx1+) cells as a critical fibroblast subpopulation that expedites mucosal healing by facilitating early immune response. Using transplantation and genetic ablation model in mice, we show that oral mucosa enriched with Prx1+ cells heals faster than those that lack Prx1+ cells. Lineage tracing and scRNA-seq reveal that Prx1+ fibroblasts exhibit progenitor signatures in physiologic and injured conditions. Mechanistically, Prx1+ progenitors accelerate wound healing by differentiating into immunomodulatory SCA1+ fibroblasts, which prime macrophage recruitment through CCL2 as a key part of pro-wound healing response. Furthermore, human Prx1+ fibroblasts share similar gene and spatial profiles compared to their murine counterpart. Thus, our data suggest that Prx1+ fibroblasts may provide a valuable source in regenerative procedures for the treatment of corneal wounds and enteropathic fibrosis.