An Overview of Molecular Nutrition
Nicole M. Farmer, Andres Victor Ardisson Korat in Cooking for Health and Disease Prevention, 2022
Regeneration is the process by which the body grows vital new cells. Stem cells are special cells that are able to divide and turn into different types of tissue, depending on what the body needs. The body is constantly maintaining, repairing, and regenerating itself using its stem cells. Like angiogenesis, regeneration must be kept in balance, especially because otherwise cells would grow without control, like tumors. Certain foods can boost the regenerative capacity of normal stem cells, while other foods can suppress or even destroy cell growing out of control such as cancer cells.
Biological Perspectives of Cytokine and Hormone Networks
Andrzej Mackiewicz, Irving Kushner, Heinz Baumann in Acute Phase Proteins, 2020
Liver regeneration is a highly complex process triggered by hepatocyte growth factors (HGFs) which also appear to be potent mitogens for some epidermal and epithelial cells, but which inhibit proliferation of hepatomas (for references, see References 100 and 101). We observed that human recombinant HGF stimulates the synthesis of α2-macroglobulin in primary cultures of rat hepatocytes.102 Its effects on the synthesis of AP proteins are broader in Hep G2 cells, where HGF inhibits the synthesis of albumin, but increases the basal production of fibrinogen, α1-antichymotrypsin, and α1-proteinase inhibitor (Figure 3). However, in cells stimulated by high concentrations of IL-6, HGF decreases the maximum response of haptoglobin, fibrinogen, and α1-antichymotrypsin. A similar phenomenon was observed with insulin (Figure 3). On the other hand, TGFβ increased the production of α1 antichymotrypsin and al-proteinase inhibitor in Hep G2 cells, even at high concentrations of IL-6. These results emphasize again the existence of intricate networks of cytokines and cellular growth factors in the regulation of the liver AP response.
The liver, gallbladder and pancreas
C. Simon Herrington in Muir's Textbook of Pathology, 2020
Within the parenchyma of the liver there is a complex network of cells. Although the predominant cell type is the hepatocyte, a significant number of other cells, both resident and transitory, are important. Hepatocytes are arranged in plates, lining the blood-filled sinusoids. Sinusoidal endothelial cells are fenestrated, allowing direct access of hepatocytes to constituents of the blood. On the sinusoidal endothelial wall lie phagocytic Kupffer cells and within the perisinusoidal space of Disse are the hepatic stellate cells; these are myofibroblast precursors important in liver fibrosis (Figure 11.3). Liver-specific natural killer (NK) cells are located within the space of Disse and play an important role in the innate immune system response to viral infections. When liver cells are injured, regeneration is rapid and may be complete. Proliferation of hepatocytes can occur anywhere in the acinus, although experimental studies suggest that there is a reserve of hepatic progenitor cells close to the portal tract, within the canal of Hering, the ductular compartment connecting the bile canaliculi to the bile ductules at the limiting plate. The hepatic progenitor cells are capable of differentiating into hepatocytes and/or bile duct cells (cholangiocytes) when toxic injury or extensive hepatic necrosis precludes regeneration of mature hepatocytes.
The sweet side of wound healing: galectins as promising therapeutic targets in hemostasis, inflammation, proliferation, and maturation/remodeling
Published in Expert Opinion on Therapeutic Targets, 2023
Matúš Čoma, Joachim C Manning, Herbert Kaltner, Peter Gál
In a well-healing wound, healing may enter the proliferation phase after the inflammation subsides approximately 2–4 days after injury [96]. The proliferation phase involves critical processes for the regeneration and repair of damaged skin. Fibroblasts repair the injured dermis by producing a loose ECM and collagens that provide a temporary provisional scaffold for proliferating cells [97]. Myofibroblasts contain stress fibers, fibronectin, and α-smooth muscle actin, allowing contraction forces to develop for wound closure [98,99]. Keratinocytes restore the injured epidermis by migrating from the wound edge and skin adnexa to the surface and rebuild the protective barrier, by a process called re-epithelization [100]. In parallel, angiogenesis (formation of new vessels from pre-existing vessels) led to the formation of new blood vessels that provide nutrients and oxygen to satisfy the cravings of rapidly proliferating cells [101]. The interaction of cells involved in the abovementioned processes, an epithelial-mesenchymal cross-talk between fibroblasts, endothelial cells, and keratinocytes, has significant implications for wound healing. Faulty interactions can lead to excessive accumulation of fibrotic tissue, including hypertrophic/keloid scarring. The effect of galectins on each of the critical processes of the proliferation phase is discussed in the following chapters separately.
Cell homing strategy as a promising approach to the vitality of pulp-dentin complexes in endodontic therapy: focus on potential biomaterials
Published in Expert Opinion on Biological Therapy, 2022
Elaheh Dalir Abdolahinia, Zahra Safari, Sayed Soroush Sadat Kachouei, Ramin Zabeti Jahromi, Nastaran Atashkar, Amirreza Karbalaeihasanesfahani, Mahdieh Alipour, Nastaran Hashemzadeh, Simin Sharifi, Solmaz Maleki Dizaj
As previously mentioned, dental pulp tissue engineering regenerates pulp-like tissue with the help of biomaterials to treat inflamed pulp or necrosis. In this strategy, stem cells play a crucial role in tissue regeneration. To date, various studies have been performed on the regeneration of pulp and dentin tissue with the help of dental stem cells transplanted into damaged tooth tissue of large and small animals [2,52]. However, the results of studies have shown that cell-based therapy has many problems in clinical translation and goes through complex steps from cell isolation to pulp tissue preparation. Also, allograft transplantation has the problem of cell survival, high cost, rejection of the cell by the recipient tissue, pathogen transmission, and tumorigenesis. In this case, this technique cannot be an excellent alternative to dental implants and routine dental tissue treatments [53,54]. The cell homing approach solves the problems of cell-to-tooth transplantation. It regenerates dentin or pulp by invoking endogenous host stem cells into damaged tooth tissue with the help of biological signaling molecules [55,56]. This approach is clinically easier than cell transplantation because it does not require isolating and preparing stem cells in vitro [17,57,58]. The cell homing strategy involves bioactive scaffolds with signaling molecules injected into the root canal to recruit endogenous stem cells around the root, including PDLSCs, SCAP, and bone marrow stem cells (BMSCs) into an anatomic compartment of the root canal [6,59].
Assessments of regenerative potential of silymarin nanoparticles loaded into chitosan conduit on peripheral nerve regeneration: a transected sciatic nerve model in rat
Published in Neurological Research, 2021
Pouria Ebrahimi-Zadehlou, Alireza Najafpour, Rahim Mohammadi
This study was the first to demonstrate that silymarin nanoparticles when loaded into chitosan conduit bear neuroprotective effects on peripheral nerve injury in rats. Restoration of normal neurological function of transected peripheral nerve remains a great challenge in regenerative medicine and surgery. Entubulation neurorrhaphy is an excellent alternative to short interposition nerve grafts. Selection of an appropriate method to evaluate functional recovery of nerve regeneration is extremely influential. Walking is a coordinated activity involving sensory input, motor response and cortical integration [11]. Therefore, walking track analysis (sciatic function index) is a comprehensive test. The results of the present study showed that chitosan when loaded with silymarin nanoparticles ended up a faster and significant improvement of functional recovery of the sciatic nerve throughout the study period.
Related Knowledge Centers
- Bacteria
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- Cell
- Species
- Regulation of Gene Expression