Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases. This review focuses on the participation of both MMPs (e.g., MMP-2 and MMP-9) and TIMPs (e.g., TIMP-1 and TIMP-3) in physiological processes and on how their abnormal regulation is associated with human diseases. The inclusion of current strategies and mechanisms of MMP inhibition in the development of new therapies targeting MMPs was also considered.

Background and objectives: Pytiriasis alba (PA) is a common skin disorder which affects 80% of children between six and 16 years. The etiology of PA is unclear, but hypo-pigmented patches in photo-exposed zones characterize the disease. Because the high ultraviolet exposition of the skin promotes an acute inflammatory response and an increase of oxidative stress (OS), this study aimed to evaluate the expression levels of inflammatory and OS-related genes in skin biopsies, and their association with PA. Materials and Methods: A cross-sectional study was carried out. Skin biopsies of the lesion sites and healthy skin (controls) from 16 children with PA were evaluated. The tissue expression of IL-4, IL-6, IL-17A, TNFα, INFγ, IL-1β, SOD1, and HMOX1 was analyzed by qRT-PCR, using SYBR Green and glyceraldehyde-3-phosphate dehydrogenase gene as the endogenous control. Results: There were differences in the ΔCq values of HMOX1, SOD1, IL-6, and IFNγ between tissue with lesions and healthy skin (p < 0.05). Compared with healthy skin, IL-6, IFNγ, HMOX1, and SOD1 were predominantly under-expressed in the lesion sites. However, 25% of skin biopsies with lesions showed over-expression of these four genes. Positive correlations between the expression of IL-6 and HMOX1, SOD1, and IFNγ (p < 0.05) were also observed. Conclusions: Our results suggest the presence of molecular stages of PA, defined according to the over-expression (first stage) or under-expression (second stage) of the HMOX1, SOD1, IL-6, and IFNγ genes in abnormal skin tissue. These findings may have implications for the selection of treatment for PA-related lesions.

Menkes disease (MD) is a rare and often lethal X-linked recessive syndrome, characterized by generalized alterations in copper transport and metabolism, linked to mutations in the ATPase copper transporting α (ATP7A) gene. Our objective was to identify genomic alterations and circulating proteomic profiles related to MD assessing their potential roles in the clinical features of the disease. We describe the case of a male patient of 8 months of age with silvery hair, tan skin color, hypotonia, alterations in neurodevelopment, presence of seizures, and low values of plasma ceruloplasmin. Trio-whole-exome sequencing (Trio-WES) analysis, plasma proteome screening, and blood cell migration assays were carried out. Trio-WES revealed a hemizygous change c.4190C > T (p.S1397F) in exon 22 of the ATP7A gene. Compared with his parents and with child controls, 11 plasma proteins were upregulated and 59 downregulated in the patient. According to their biological processes, 42 (71.2%) of downregulated proteins had a participation in cellular transport. The immune system process was represented by 35 (59.3%) downregulated proteins (p = 9.44 × 10⁻¹¹). Additional studies are necessary to validate these findings as hallmarks of MD.