Regeneration Of Segments Research Articles

Public housing and the PINQuA in Italy

ABSTRACT After decades of disinvestment in public housing in Italy, the European Recovery and Resilience Facility (RRF) opens a window of opportunity for the regeneration of a housing segment displaying multidimensional (structural, spatial, economic, and social) criticalities. The PINQuA (Programma Innovativo Nazionale per la Qualità dell’Abitare), endowed with € 2,8 billion from the RRF, is a national programme, promoted by the Ministry of Infrastructure and Sustainable Mobility (MIMS), aimed at enhancing the quality of housing and urban spaces, with a particular focus on the requalification and increase of the social housing stock and the adoption of innovative models of management and social inclusion. After the identification of 159 projects eligible for funding, it has recently entered the implementation phase, to be concluded until 31 March 2026. As the PINQuA is currently considered the main tool for addressing severe deficiencies in the residential landscape of Italy, high hopes are associated with the programme. The objective of this paper is to understand whether these hopes are justified with respect to the regeneration needs of the Italian public housing stock, analysing (i) to which degree public housing is the object of regeneration activities in PINQuA projects; (ii) which types of regeneration activities have been admitted for funding; (iii) innovative elements that can be identified in projects; and (iv) shortcomings of the programme and related procedures. The research has been developed through document analysis and a series of semi-structured interviews with stakeholders from the public housing sector, public administrations, Federcasa (the Italian Federation of Public and Social Housing Providers) and academics.

In vitro direct and indirect regeneration of plants from nodal and petiole explants in Pelargonium odoratissimum (L.) Herit.

Nodal and petiole explants were employed to study the direct and indirect regeneration from Pelargonium odoratissimum in vitro. Direct shoots regeneration of nodal segments was tried in MS medium containing 1 and 2 mg l-1 BAP and 0.5 mg l-1 IBA. The highest mean shoots number and the greatest shoots per explant number were obtained in the medium containing 2 mg l-1 BAP. Nodal segments were the source of petiole explants and the resulting petioles were cultured in ½ MS medium supplemented by 1, 1.5, 2 and 4.5 mg l-1 BAP enriched with 0.1, 1 and 1.5 mg l-1 NAA. With the petiole explants, the lowest browning percentage, the highest callus induction and also, the top number of shoots per explant were recorded in 2 mg l-1 BAP + 0.1 mg l-1 NAA medium. The medium supplemented with 0.2 mg l-1 NAA exhibited the desired effect on rooting percentage and mean root number and length. The rooted young plants were transferred to the pots containing peat-moss and perlite (1:1) and the acclimatization was successful since, more than 90 % of plants adapted-well in the greenhouse conditions. This in-vitro propagation methodology would be advisable to the plant production systems and to whom wish to produce the clonal homogenous plants for the commercial ideas and for the detailed molecular studies.

Gene Therapy in Opn1mw-/-/Opn1sw-/- Mice and Implications for Blue Cone Monochromacy Patients with Deletion Mutations.

Blue cone monochromacy (BCM) is a congenital vision disorder affecting both middle-wavelength (M) and long-wavelength (L) cone photoreceptors of the human retina. BCM results from abolished expression of green and red light-sensitive visual pigments expressed in M- and L-cones, respectively. Previously, we showed that gene augmentation therapy to deliver either human L- or M-opsin rescues dorsal M-opsin dominant cone photoreceptors structurally and functionally in treated M-opsin knockout (Opn1mw-/-) mice. Although Opn1mw-/- mice represent a disease model for BCM patients with deletion mutations, at the cellular level, dorsal cones of Opn1mw-/- mice still express low levels of S-opsin, which are different from L- and M-cones of BCM patients carrying a congenital opsin deletion. To determine whether BCM cones lacking complete opsin expression from birth would benefit from AAV-mediated gene therapy, we evaluated the outcome of gene therapy, and determined the therapeutic window and longevity of rescue in a mouse model lacking both M- and S-opsin (Opn1mw-/-/Opn1sw-/-). Our data show that cones of Opn1mw-/-/Opn1sw-/- mice are viable at younger ages but undergo rapid degeneration. AAV-mediated expression of human L-opsin promoted cone outer segment regeneration and rescued cone-mediated function when mice were injected subretinally at 2 months of age or younger. Cone-mediated function and visually guided behavior were maintained for at least 8 months post-treatment. However, when mice were treated at 5 and 7 months of age, the chance and effectiveness of rescue was significantly reduced, although cones were still present in the retina. Crossing Opn1mw-/-/Opn1sw-/- mice with proteasomal activity reporter mice (UbG76V-GFP) did not reveal GFP accumulation in Opn1mw-/-/Opn1sw-/- cones eliminating impaired degradation of ubiquitinated proteins as stress factor contributing to cone loss. Our results demonstrate that AAV-mediated gene augmentation therapy can rescue cone structure and function in a mouse model with a congenital opsin deletion, but also emphasize the importance that early intervention is crucial for successful therapy.

How the discovery of oligochaete regeneration during the Enlightenment was pivotal to the advancement of annelid research

Abstract Within a few months of the year 1741, Lyonet and Trembley in Holland, Bonnet in Geneva and Réaumur in Paris all experimented industriously with the regeneration of various invertebrates, including the still unknown microdrile oligochaetes. Some of these worms were prone to spontaneous fragmentation as a natural mode of asexual multiplication, preceded (paratomy) or followed (architomy) by regenerative processes. Bonnet and Réaumur raised the stakes and began to study regeneration in earthworms, a challenge that, especially in Italy, inspired scholars and educated people among the clergy and aristocracy. Spallanzani conducted the most rigorous experiments and was the first to obtain consecutive regenerations of the head in one and the same megadrile. He saw detached mid-body sections becoming complete with a new head and a new tail, and he determined the points of the body where regeneration does not take place and how much length to leave for each section so that it could reintegrate. Above all, Spallanzani obtained regeneration of the gonadic segments, both in terrestrial and in freshwater megadriles, the latter today identified as Criodrilus lacuum. This and other important anatomical and physiological findings by Spallanzani, largely unpublished during his lifetime and for a long time after, preceded the discoveries of later authors by almost 50 years.

The Role of Stem Cells and Their Derived Extracellular Vesicles in Restoring Female and Male Fertility.

Infertility is a globally recognized issue caused by different reproductive disorders. To date, various therapeutic approaches to restore fertility have been attempted including etiology-specific medication, hormonal therapies, surgical excisions, and assisted reproductive technologies. Although these approaches produce results, however, fertility restoration is not achieved in all cases. Advances in using stem cell (SC) therapy hold a great promise for treating infertile patients due to their abilities to self-renew, differentiate, and produce different paracrine factors to regenerate the damaged or injured cells and replenish the affected germ cells. Furthermore, SCs secrete extracellular vesicles (EVs) containing biologically active molecules including nucleic acids, lipids, and proteins. EVs are involved in various physiological and pathological processes and show promising non-cellular therapeutic uses to combat infertility. Several studies have indicated that SCs and/or their derived EVs transplantation plays a crucial role in the regeneration of different segments of the reproductive system, oocyte production, and initiation of sperm production. However, available evidence triggers the need to testify the efficacy of SC transplantation or EVs injection in resolving the infertility issues of the human population. In this review, we highlight the recent literature covering the issues of infertility in females and males, with a special focus on the possible treatments by stem cells or their derived EVs.

Structural and Functional Characterization of the FGF Signaling Pathway in Regeneration of the Polychaete Worm Alitta virens (Annelida, Errantia).

Epimorphic regeneration of lost body segments is a widespread phenomenon across annelids. However, the molecular inducers of the cell sources for this reparative morphogenesis have not been identified. In this study, we focused on the role of fibroblast growth factor (FGF) signaling in the posterior regeneration of Alitta virens. For the first time, we showed an early activation of FGF ligands and receptor expression in an annelid regenerating after amputation. The expression patterns indicate that the entire regenerative bud is competent to FGFs, whose activity precedes the initiation of cell proliferation. The critical requirement of FGF signaling, especially at early stages, is also supported by inhibitor treatments followed by proliferation assay, demonstrating that induction of blastemal cells depends on FGFs. Our results show that FGF signaling pathway is a key player in regenerative response, while the FGF-positive wound epithelium, ventral nerve cord and some mesodermal cells around the gut could be the inducing tissues. This mechanism resembles reparative regeneration of vertebrate appendages suggesting such a response to the injury may be ancestral for all bilaterians.

Small Intestinalization of Colon Using Ileum Organoids.

Given the mismatch in size and morphology of intestinal organoids with native intestine, their application in intestinal segment regeneration has yet to be achieved. By engrafting ileal organoids in epithelium-removed colon, Sugimoto et al. recently constructed transplantable colonic segments with functional ileal epithelium and a subepithelial lymphovascular system, providing hope for the treatment of short bowel syndrome.

Injury-Induced Innate Immune Response During Segment Regeneration of the Earthworm, Eisenia andrei.

Regeneration of body parts and their interaction with the immune response is a poorly understood aspect of earthworm biology. Consequently, we aimed to study the mechanisms of innate immunity during regeneration in Eisenia andrei earthworms. In the course of anterior and posterior regeneration, we documented the kinetical aspects of segment restoration by histochemistry. Cell proliferation peaked at two weeks and remitted by four weeks in regenerating earthworms. Apoptotic cells were present throughout the cell renewal period. Distinct immune cell (e.g., coelomocyte) subsets were accumulated in the newly-formed blastema in the close proximity of the apoptotic area. Regenerating earthworms have decreased pattern recognition receptors (PRRs) (e.g., TLR, except for scavenger receptor) and antimicrobial peptides (AMPs) (e.g., lysenin) mRNA patterns compared to intact earthworms. In contrast, at the protein level, mirroring regulation of lysenins became evident. Experimental coelomocyte depletion caused significantly impaired cell divisions and blastema formation during anterior and posterior regeneration. These obtained novel data allow us to gain insight into the intricate interactions of regeneration and invertebrate innate immunity.

Analysis of Polysaccharide Fraction from Yerba Mate (Ilex paraguariensis St. Hil.) on Regeneration of Planarian (Girardia tigrina)

AbstractThe present study evaluates the regenerative activity of a polysaccharide fraction from yerba mate (Ilex paraguariensis St. Hil.) using planarian (Girardia tigrina) as a model. At 10 mg L–1, the polysaccharide fraction improves the regeneration of the head, pharynx, and tail of G. tigrina. At the end of experiment, at 10 mg L–1, the planarians obtained are 22–72% higher than the control group. The planarian fragments exposed to the highest concentration used, i.e., (60 mg mL–1), show signs of toxicity, producing death of some organisms. Thus, the polysaccharide fraction presents a great potential for improving the regeneration of planarian segments, suggesting its potential use in tissue regeneration.

Wnt5a expression in the regeneration of the inferior segment of rat hair follicle at embryonic and postnatal stages

Wnt5a expression in the regeneration of the inferior segment of rat hair follicle at embryonic and postnatal stages

Treatment of Infected Tibial Non-Unions with Ilizarov Technique: A Case Series.

Background: The Ilizarov external fixation technique has been widely used for the treatment of long-bone infected non-unions. After surgical infected bone resection, to allow filling of the remaining bone gap, biomaterials with antibacterial properties could be used. The aim of this study was to report outcomes of infected tibial non-unions treated using the Ilizarov technique and antibacterial bioactive glass. Methods: Between April 2009 and December 2014, 26 patients with infected tibial non-unions were treated with the Ilizarov technique and possible use of the bioactive glass, S53P4. The Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria, a clinical and radiographic evaluating tool, was used for assessing the sample. Results: The average age at the start of treatment was 51 years. The mean follow-up time was 113 weeks. According to the ASAMI Functional Scoring System, 10 excellent (38.5%) cases and 12 good (46.1%) values were recorded. According to the ASAMI Radiological System, they were excellent in 16 (61.5%) cases and good in nine (34.6%). Conclusions: Treatment of infected tibial non-unions using the Ilizarov technique was effective in bone segment regeneration. To fill the remaining bone gap, additional bioactive glass S53P4 could be used, allowing a decrease in re-interventions and minimizing complications.

Neev, a novel long non-coding RNA, is expressed in chaetoblasts during regeneration of Eisenia fetida

Eisenia fetida, the common vermicomposting earthworm, shows robust regeneration of posterior segments removed by amputation. During the period of regeneration, the newly formed tissue initially contains only undifferentiated cells but subsequently differentiates into a variety of cell types including muscle, nerve and vasculature. Transcriptomics analysis, reported previously, provided a number of candidate non-coding RNAs that were induced during regeneration. We found that one such long non-coding RNA (lncRNA) is expressed in the skin, only at the base of newly formed chaetae. The spatial organization and precise arrangement of the regenerating chaetae and the cells expressing the lncRNA on the ventral side clearly support a model wherein the regenerating tissue contains a zone of growth and cell division at the tip and a zone of differentiation at the site of amputation. The temporal expression pattern of the lncRNA, named Neev, closely resembled the pattern of chitin synthase genes, implicated in chaetae formation. We found that the lncRNA has 49 sites for binding a set of four microRNAs (miRNAs) while the chitin synthase 8 mRNA has 478 sites. The over-representation of shared miRNA sites suggests that lncRNA Neev may act as a miRNA sponge to transiently de-repress chitin synthase 8 during formation of new chaetae in the regenerating segments of Eisenia fetida.

Optimization of Hormonal Combinations for In Vitro Regeneration of Lesser Periwinkle (Vinca minor L.) and Assessment of Genetic Homogeneity

Lesser Periwinkle (Vinca minor L.) is an important source of valuable secondary metabolites. To survey the effect of different combinations of plant growth regulators on the direct regeneration of Lesser Periwinkle, axillary and lateral bud segments of V. minor were used as explants. First, for shoot multiplication, Murashige and Skoog (MS) medium were fortified with four concentrations (0, 0.5, 1, and 1.5 mg l−1) of benzylaminopurine (BAP) in combination with three concentrations (0, 0.25, and 0.5 mg l−1) of indol-3-butyric acid (IBA). Then, root induction was assessed in full- and half-strength MS medium supplemented with three concentrations of IBA (0, 0.25, and 0.5). Finally, the genetic homogeneity of the regenerated plant was subsequently assessed using 10 Inter Simple Sequence Repeat (ISSR) Markers. Higher shoot number per explant (6.50) and shoot length were obtained in MS medium containing the 1.5 mg l−1 BAP with 0.5 mg l−1 IBA and 0.5 mg l−1 BAP with 0.5 mg l−1 IBA, respectively. Moreover, the best root induction rate was observed on half-strength MS containing 1 mg l−1 IBA. PCR profiles with nine ISSR primers on the regenerated and donor plants also verified the genetic homogeneity of the regenerated plantlets. The present study introduced an efficient protocol for future large-scale propagation and production of secondary metabolites in Lesser Periwinkle.

In vitro shoot regeneration of mint (Mentha sp. L.) Using different types of explants and levels of benzylaminopurine

An experiment was conducted in the Tissue Culture Laboratory of the Department of Horticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur-1706 from March 2013 to February 2014 for in vitro shoot regeneration of mint using different explants and levels of benzylaminopurine (BAP) in full strength MS media. Three different types of explants viz. nodal segment, shoot tip and leaf were evaluated using three levels of BAP (1.0, 2.0 and 3.0 mg/l) along with control for shoot regeneration. Results revealed that shoot tip and nodal segments performed better than leaf as explants in almost all the characters studied. Shoot tip and nodal segments initiated shoot within the shortest time of 9.6 and 10.6 days, respectively with 1.0 mg/l of BAP. Regarding number of shoot per explant and number of node/shoot, shoot tip and nodal segments along with 1.0 mg/l of BAP performed superior at almost all days after inoculation. In case of interaction of explants and BAP, better performance was recorded in most of the studied parameters from shoot tip and nodal segments alongwith 1.0 mg/l BAP. Therefore, for in vitro shoot regeneration of mint, shoot tip or nodal segment may be used with 1.0 mg/l of BAP.Bangladesh J. Agril. Res. 43(4): 703-716, December 2018

Is the adipofascial flap the key to regenerative surgery?

Objectives“Form and function restoration” is the ultimate goal of reconstructive surgery, which is oriented toward regeneration rather than reparation. Recently, research in reconstructive surgery has focused on the regenerative potential of the adipose tissue. The aim of the study is to illustrate the surgical methods and show the functional and aesthetic results achieved by the reconstruction of finger soft-tissue defects using homodigital dorsal adipofascial reverse flap (HDARF). Materials and methodsA total of 63 cases (45 acute and 18 elective) were included between September 2010 and August 2016. In each case, we preliminarily performed surgical debridement and then harvested an adipofascial flap from the back of the finger. Nine injured thumbs that were repaired with the flap as emergency cases were also included. The average age of the patients was 46 (range: 4–69) years. ResultsAll flaps survived without any complications during the 24-month follow-up. Good nail regrowth through the flap and full regeneration were observed in approximately all cases. Sensitivity tests and histological analysis of biopsy samples of the regenerated fingers confirmed full regeneration of the epidermis, dermis, cutaneous adnexa, and nerves. All the patients were satisfied with the hand functionality and aesthetic appearance. ConclusionThe HDARF represents a very useful alternative for the reconstruction of nailbed crushes, achieving regeneration of injured segments in deformities caused by trauma or infection.

Effect of Portal Vein Ligation Plus Venous Congestion on Liver Regeneration in Rats

Introduction and aim. We developed a rat model of portal vein ligation (PVL) with venous congestion (PVL+C) to investigate beneficial effect PVL plus congestion for regeneration of intact liver segments. Materials and methods. In the PVL group, portal vein branches were ligated except the caudate lobe (CL). In the PVL + C group, the left lateral hepatic vein was ligated in addition to PVL. Chronological changes in the following variables were compared among the groups: CL weight to body weight ratio (CL/BW), embolized liver weight to body weight ratio (EL/BW), histological findings of the embolized/non-embolized liver, and expression of several mediators that affect liver regeneration in the non-embolized liver. Results. Weight regeneration of CL continued up to postoperative day (POD)7 in PVL + C, but terminated at POD2 in PVL. CL/BW at POD7 was significantly higher in PVL + C than in PVL (2.41 ± 0.33% vs. 1.22 ± 0.18%, P < 0.01). In contrast, EL/BW continued to decrease up to POD7 in PVL + C but reached nadir at POD2 in PVL. Furthermore, EL/BW at POD7 was significantly smaller in PVL + C than in PVL (0.35 ± 0.03% vs. 0.67 ± 0.08%, P < 0.01). Histologically-proven injury in the embolized liver was more severe in PVL + C than in PVL. Expression of Ki-67, IL-6, TNF-α, and HGF were greater and/or more prolonged in PVL + C than in PVL. Conclusions. Our rat model of PVL + C was considered useful for investigating the beneficial effect of congestion in addition to PVC. PVL + C caused increased devastation of the embolized liver, and higher and more prolonged expression of factors promoting liver regeneration in the non-embolized liver tan in PVL.

A novel role in skeletal segment regeneration of extracellular vesicles released from periodontal-ligament stem cells.

PurposeThe combination of oral derived stem cells and 3-D scaffolds is considered advantageous in bone repair. In particular, collagen membranes possess ideal biological properties and can support infiltration and proliferation of osteoblasts, promoting bone regeneration. Our study aimed to develop a new biocompatible osteogenic construct composed of a commercially available collagen membrane (Evolution [Evo]), human periodontal-ligament stem cells (hPDLSCs) enriched with extracellular vesicles (EVs), or polyethylenimine (PEI)-engineered EVs (PEI-EVs).MethodsOsteogenic ability and expression of osteogenic genes were evaluated in vitro in hPDLSCs cultured with or without Evo, with Evo and EVs, or PEI-EVs. In addition, the bone-regeneration capacity of Evo, Evo enriched with hPDLSCs, Evo enriched with hPDLSCs and EVs/PEI-EVs was investigated in rats subjected to calvarial defects.ResultsOur results showed that Evo enriched with EVs and PEI-EVs showed high biocompatibility and osteogenic properties in vitro and in vivo. In addition, quantitative reverse-transcription polymerase chain reaction demonstrated the upregulation of osteogenic genes, such as TGFB1, MMP8, TUFT1, TFIP11, BMP2, and BMP4, in the presence of PEI-EVs. Upregulation of BMP2/4 was confirmed for Evo enriched with PEI-EVs and hPDLSCs both in vitro by Western blot and in vivo by immunofluorescence.ConclusionOur results indicated that Evo enriched with hPDLSCs and PEI-EVs is able to promote a bone-regeneration process for the treatment of calvarium and ossification defects caused by accidental or surgery trauma. In particular, PEI-EVs had a significant role in activation of the osteogenic process.

Toxic responses of Sox2 gene in the regeneration of the earthworm Eisenia foetida exposed to Retnoic acid

Exogenous retinoic acid delays and disturbs the regeneration of Eisenia foetida. The stem cell pluripotency factor, Sox2, can play a crucial role in cell reprogramming and dedifferentiation. In this study, we compared the regeneration of Eisenia foetida in different segments after amputation and the effects of retinoic acid on the regeneration of different segments. The results showed that the regeneration speed of the head and tail was slightly faster than the middle part, and retinoic acid disrupted and delayed the regeneration of the earthworm. The qRT-PCR and Western blot analysis showed that the expression of the Sox2 gene and Sox2 protein was highest on the seventh day in different segments (p<0.05). After treatment with retinoic acid, the expression level of the Sox2 gene and Sox2 protein was significantly reduced (p<0.05). The results indicated that the regeneration of earthworms and the formation of blastema are related to the expression of the Sox2 gene and protein. Retinoic acid delays and interferes with the regeneration of the earthworm by affecting the expression levels of the Sox2 gene and protein.

Microplastics reduced posterior segment regeneration rate of the polychaete Perinereis aibuhitensis

Microplastics are found in abundance in and on coastal sediments, and yet, whether exposure to this emerging pollutant negatively impact whole organism function is unknown. Focusing on a commercially important polychaete, Perinereis aibuhitensis, we demonstrated that presence of microplastics increased mortality and reduced the rate of posterior segment regeneration. The impact of the micro-polystyrene beads was size-dependent with smaller beads (8–12μm in diameter) being more detrimental than those bigger in size (32–38μm). This observed difference suggests microplastic impact could be affected by physical properties, e.g., sinking speed, surface area available for sorption of chemicals and bacteria, and selective feeding behaviors of the target organism.

Protective role of metallothionein during regeneration in Eisenia andrei exposed to cadmium

Lumbricid earthworms are often exposed to simultaneous action of various environmental stressors like soil contamination, temperature fluctuation or predators' attacks, which may induce extrusion of coelomocyte-containing coelomic fluid or loss of tail segments. If the injuries are not lethal, renewal of the immune-competent cells and soluble components of coelomic fluid and/or the regeneration of tail segments occurs. The aim of our investigations was to test the hypothesis that exposure of adult earthworms Eisenia andrei to cadmium-polluted soil at room temperature (RT) and/or low temperature (6°C) have adverse effects on restoration of experimentally depleted coelomocytes or on regeneration of amputated posterior segments. Intact control earthworms and their experimental counterparts subjected to electrostimulation-induced coelomocyte depletion or surgical amputation of posterior segments were maintained either in control soil or in soil spiked with cadmium chloride (500mg/kg air-dried soil) at RT or 6°C. Four weeks after the beginning of experiments, cadmium accumulation in earthworm bodies was significantly lower at 6°C than at room temperature. The numbers of restored cells and fluorophore contents were hardly affected by temperature or cadmium. However, cocoon production was reduced by cadmium and completely abolished at 6°C and regeneration of amputated posterior segments was inhibited in cold but was enhanced by cadmium exposure at RT. Independently on the temperature, the 4-week cadmium exposure of adult earthworms was connected with significantly upregulated expression of Cd-metallothionein (but not of catalase, lysenin and phytochelatin) in coelomocytes.