Destruction of Bone Tissue and Loss of its Vascularization.
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Osteomyelitis is an infectious process that occurs in bone tissue and leads to its destruction. The penetration of the pathogen into the bone tissue and the further development of the inflammatory process can be carried out both by the hematogenous route and as a result of trauma or surgical intervention. When the pathogen reaches the bone surface, it causes a strong inflammatory response, followed by destruction of bone tissue and loss of its vascularization. Under physiological conditions, bone is constantly undergoing remodelling, a complex process that includes both bone formation and bone resorption. These processes are finely controlled by the combined action of osteoblasts and osteoclasts, which are sequentially responsible for the synthesis of new bone and the resorption of old bone. Bone formation follows a cascade of complex events that include the proliferation of primitive stem cells, their differentiation into osteoblasts, matrix formation, and final mineralization. Bone resorption is carried out by activated multinuclear osteoclasts. NDMâ€1 sequence is similar to other MBLs, with the active form including dimer and monomer conformations. The monomer structure belongs to the B1 MBL group, while hydrophobic and van der Waals interactions form the dimer. The dimer form of NDMâ€1 can exist in both membraneâ€bound and purified states, which has been hypothesized to contribute to the unique resistance mechanisms. Regarding the NDMâ€1 inhibitors, namely dâ€captopril and thiorphan, this study reveals that some mutants have docking scores increase while others witness a decrease in docking scores compared to the complex with NDMâ€1 wildâ€type protein. Regarding the activity on hydrolysis of NDMâ€1 protein toward antibiotics, most of the complexes between imipenem and meropenem with the NDMâ€1 mutants have higher docking scores than the wild type. There are two mutants with docking scores of imipenem increasing by more than 50%, namely D124G and H122Q. During the MD process, the two mutant complexes and the wildâ€type complex fluctuate stably, which can be seen in RMSD and RMSF values within the regulatory threshold. Moreover, the number of Hâ€bonds in the mutant complexes is lower than in the wild type, with unstable Hâ€bond frequency during the simulation. However, the two mutant proteins gain a higher frequency of Hâ€bonds formation with imipenem at interacting residues.