当代经济研究

Stem cells: a new strategy for treatment of

 

The development of antibiotics has provided clinicians with the ability to kill major pathogens and cure infectious have saved the lives of many infected patients and provided significant control of many serious infectious , the widespread use of antibiotics has led to the induction of drug-resistant bacteria, such as methicillinresistant Staphylococcus aureus[1-2], penicillin-resistant Streptococcus pneumoniae[3-4], vancomycin-resistant Enterococci[5-6], Escherichia coli harboring mcr-1(a colistin-resistant gene)[7].There is now evidence for β-lactamases, extended-spectrum β-lactamases[8]and new delhi metallo-β-lactamase 1[9]in Klebsiella pneumoniae, Escherichia coli, and multidrug-resistant forms of Pseudomonas aeruginosa, Acinetobacter,Stenotrophomonas maltophilia[10-12], even extremely drug-resistant Mycobacterium tuberculosis[13-14]and other species[15].The evolution of multidrug-resistant bacteria has made standard anti-infection therapy more difficult[16-17].Thus, there appears to be a recrudescence of certain infectious diseases, such as tuberculosis[18-19]and malaria[20].

Antimicrobial therapy cannot cure all infectious diseases[21].The most effective treatments are for bacteria,followed by fungi and parasites, and then particular, some antiviral drugs, such as lamivudine and adefovir, can only inhibit viral spread instead of actually killing viruses[22].Furthermore, the evolution of new variants of viruses presents an additional problem[23-24].When a new viral disease breaks out, no specific drugs can cure the disease or effectively prevent an has led to increased prevalence of several serious viral diseases while severe acute respiratory syndrome(SARS), human H7N9[24], Zika virus[25], Ebola virus[26],and Middle East respiratory syndrome coronavirus(MERS-CoV)[27]are the best known new antimicrobials continue to be developed, new ideas and treatment modalities are needed to prevent and cure infectious diseases.

It was accepted that our body could get some selfrepairing from impairments including infection, which was regarded as self-organization or autopoiesis[28].Until now, few researchers can launch their understandings on the primary forces for self-organization or autopoiesis in our body.In past, our researches had hypothesized that the self-organization in our body stemmed from the interrelationships between the stem cell proliferation and differentiation (SCPD) and the energy metabolism while the SCPD are the core of autopoiesis in our , abnormality of SCPD may be a new factor for the occurrence of infection while the stem cell will become another target for the treatment of infectious diseases.

Two essential processes in the multicellular organisms

With the arrival of the 21st century, stem cell research has become an important new area of studies have examined the utilizations of stem cell transplantation for diverse clinical applications,such as leukemia[29], heart disease[30], liver disease[31],nervous system diseases[32], and other conditions[33].These applications not only provided new hopes for patients, but also implied that stem cell played an important role for the patient to get recovery from diseases.

In our novel viewpoint, the process of SCPD is one of the core physiological processes in multicellular organisms (Fig.1).Stem cells are undifferentiated cells with the capacity of infinite or long-term selfrenewal and the ability to develop into one or more types of specialized stem cells are classified as totipotent, multipotent or unipotent according to their potential for differentiation into different specialized cells.A multicellular adult is derived from a fertilized egg, which consists of totipotent stem cells that can develop into all of the different forms of somatic cells by proliferation and cells proliferate and the embryo develops into an adult, there is a gradual decrease in the differentiation capacity of cells, although a number of bone marrow stem cells remain in the mature human marrow stem cells are considered to be proliferation and differentiation, they can produce multipotent stem cells, then unipotent stem cells, and ultimately a variety of fully differentiated cells that participate in tissue self-renewal and , the stem cells in marrow are regarded as stem cell reservoir in our body.

Fig.1 Schematic diagram of human growth

Nearly all researches were concerned on the exogenous factors and/or genes which had some effects on the SCPD.It should also be pointed out that the monosaccharides, amino acids, fatty acids and so on, are the basic materials for the basic materials play two essential roles in the SCPD: fi rstly, the oxidation of these materials affords energy for the behaviors of the stem cells including cell division; secondly, these materials can be used to synthesize biomacromolecules such as glycoproteins, lipoproteins, DNA, RNA and so on for constructing the architectures of cells, and the sufficient accumulation of these biomacromolecules will advantage the stem cells to go on the way of proliferation and our body, all the basic materials for SCPD are derived from being taken, foods will be digested into monosaccharides, amino acids, fatty acids, glycerol, and other small molecules for absorption in gut; and the waste products will be removed from the , there are two basic processes in the metabolism of food after being , after absorption, small molecules (monosaccharides, amino acids, fatty acids, and glycerol) are oxidized into water,carbon dioxide, nitrogen-containing organic products,and other small water-soluble this process, the released energy will be used to drive diverse physiological functions, and these processes should also be regarded as the energy metabolisms in our , monosaccharides, amino acids, fatty acids, and glycerol should also be regarded as sources of high energy , these high energy molecules participate in stem cell proliferation, differentiation, and development of cellular structures, and play fundamental roles in changing stem cells into somatic cells that have specialized physiological completion of their physiological functions, somatic cells will go to die and then be degraded into small molecules, such as amino acids, monosaccharides, and lipids for energy the same time, stem cells begin to proliferate and differentiate into new somatic cells so as to replace the dead on these two pathways for the metabolism of food, all metabolisms in our body form a circle (Fig.2).

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