The process of freezing cells or tissues and depositing them in liquid nitrogen at –196 °C is called cryopreservation. Sub-zero temperature is not a physiological condition for cells and water ice crystals represent the main problem since they induce cell death, principally in large cells like oocytes, which have a meiotic spindle that degenerates during this process. Significantly, cryopreservation represents an option for fertility preservation in patients who develop gonadal failure for any condition and those who want to freeze their germ cells for later use. The possibility of freezing sperm, oocytes, and embryos has been available for a long time, and in 1983 the first birth with thawed oocytes was achieved. From the mid-2000s forward, the use of egg vitrification through intracytoplasmic sperm injection has improved pregnancy rates. Births using assisted reproductive technologies (ART) have some adverse conditions and events. These risks could be associated with ART procedures or related to infertility. Cryopreservation generates changes in the epigenome of gametes and embryos, given that ART occurs when the epigenome is most vulnerable. Furthermore, cryoprotective agents induce alterations in the integrity of germ cells and embryos. Notably, cryopreservation extensively affects cell viability, generates proteomic profile changes, compromises crucial cellular functions, and alters sperm motility. This technique has been widely employed since the 1980s and there is a lack of knowledge about molecular changes. The emerging view is that molecular changes are associated with cryopreservation, affecting metabolism, cytoarchitecture, calcium homeostasis, epigenetic state, and cell survival, which compromise the fertilization in ART.

FAM20C is a gene coding for a protein kinase that targets S-X-E/pS motifs on different phosphoproteins belonging to diverse tissues. Pathogenic variants of FAM20C are responsible for Raine syndrome (RS), initially described as a lethal and congenital osteosclerotic dysplasia characterized by generalized atherosclerosis with periosteal bone formation, characteristic facial dysmorphisms and intracerebral calcifications. The aim of this review is to give an overview of targets and variants of FAM20C as well as RS aspects. We performed a wide phenotypic review focusing on clinical aspects and differences between all lethal (LRS) and non-lethal (NLRS) reported cases, besides the FAM20C pathogenic variant description for each. As new targets of FAM20C kinase have been identified, we reviewed FAM20C targets and their functions in bone and other tissues, with emphasis on novel targets not previously considered. We found the classic lethal and milder non-lethal phenotypes. The milder phenotype is defined by a large spectrum ranging from osteonecrosis to osteosclerosis with additional congenital defects or intellectual disability in some cases. We discuss our current understanding of FAM20C deficiency, its mechanism in RS through classic FAM20C targets in bone tissue and its potential biological relevance through novel targets in non-bone tissues.

FBN1 (15q21.1) encodes fibrillin-1, a large glycoprotein which is a major component of microfibrils that are widely distributed in structural elements of elastic and non-elastic tissues. FBN1 variants are responsible for the related connective tissue disorders, grouped under the generic term of type-1 fibrillinopathies, which include Marfan syndrome (MFS), MASS syndrome (Mitral valve prolapse, Aortic enlargement, Skin and Skeletal findings, Acromicric dysplasia, Familial ectopia lentis, Geleophysic dysplasia 2, Stiff skin syndrome, and dominant Weill-Marchesani syndrome. Two siblings presented with isolated skeletal manifestations of MFS, including severe pectus excavatum, elongated face, scoliosis in one case, and absence of other clinical features according to Ghent criteria diagnosis, were screened for detection of variants in whole FBN1 gene (65 exons). Both individuals were heterozygous for the R2726W variant. This variant has been previously reported in association with some skeletal features of Marfan syndrome in the absence of both tall stature and non-skeletal features. These features are consistent with the presentation of the siblings reported here. The presented cases confirm that the R2726W FBN1 variant is associated with skeletal features of MFS in the absence of cardiac or ocular findings. These findings confirm that FBN1 variants are associated with a broad phenotypic spectrum and the value of sequencing in atypical cases.

Two siblings from a Mexican family who carried lethal Raine syndrome are presented. A newborn term male (case 1) and his 21 gestational week brother (case 2), with a similar osteosclerotic pattern: generalized osteosclerosis, which is more evident in facial bones and cranial base. Prenatal findings at 21 weeks and histopathological features for case 2 are described. A novel combination of biallelic FAM20C pathogenic variants were detected, a maternal cytosine duplication at position 456 and a paternal deletion of a cytosine in position 474 in exon 1, which change the reading frame with a premature termination at codon 207 and 185 respectively. These changes are in concordance with a negative detection of the protein in liver and kidney as shown in case 2. Necropsy showed absence of pancreatic Langerhans Islets, which are reported here for the first time. Corpus callosum absence is added to the few reported cases of brain defects in Raine syndrome. This report shows two new FAM20C variants not described previously, and negative protein detection in the liver and the kidney. We highlight that lethal Raine syndrome is well defined as early as 21 weeks, including mineralization defects and craniofacial features. Pancreas and brain defects found here in FAM20C deficiency extend the functional spectrum of this protein to previously unknown organs.

The interaction between advanced glycation end products (AGEs) and their RAGE receptor (AGEs/RAGE axis) triggers several signaling pathways that lead to the development of diabetic nephropathy (DN). One of the most studied AGEs is Nε-(1-Carboxymethyl)-L-lysine (CML). Spinacia oleracea is an edible plant with beneficial health properties, but its effect on the AGE/RAGE axis in kidney damage is unknown. Objective: We aimed to investigate the functional role of spinach methanolic extract (SME) on kidney damage in diabetic rats associated with the CML/RAGE axis. Methods: Forty adult male Wistar rats were used in this study and divided into four groups: control rats (CTRL), SME-administered CTRL (400 mg/kg; SME), streptozotocin-induced diabetic nephropathy rats (STZ), and SME-treated STZ (STZ-SME); treatments were administered daily. After 12 weeks, serum AGEs, creatinine in urine, and lipid peroxidation in kidneys were measured. The distribution and expression levels of inflammatory and fibrotic mediators and RAGE signaling were evaluated through immunohistochemistry (NOX4, CML, RAGE, nuclear NF-κB, TNF-α, IL-1β, TGF-β1, SMAD2/3, CTGF, and a-SMA) and immunolocalization of CML/RAGE. Results: Glycoside flavonoid derivatives, such as patuletin and spinacetin, were primarily identified in the extract. Kidneys from the STZ group showed altered morphology, dead cells in the proximal tubules, and increased oxidative stress markers; notably, these effects were improved by SME treatment (STZ-SME). The STZ-SME group showed a lower staining intensity for CML and RAGE, which was associated with a decrease in the expression of inflammatory and fibrotic factors compared with the STZ group. In all groups, the distribution of these markers varied among proximal tubule, glomerular, and interstitial cells. Conclusions: SME treatment may help to prevent or delay kidney damage in diabetic rats by regulating inflammatory and fibrotic processes associated with the AGEs/RAGE pathway, a mechanism involved in the development of nephropathy.

Tuberculosis (TB) is a global public health issue requiring early and accurate diagnosis. The loop-mediated isothermal amplification (LAMP) assay is a promising alternative recommended by the WHO for the initial diagnosis of pulmonary TB, particularly in resource-limited settings. This study evaluated the sensitivity and specificity of a commercial LAMP assay for TB detection using 198 samples from different countries including Mexico. The LAMP assay results were compared to the results of standard tests: AFB smear microscopy, cell culture, and Xpert PCR. Across all samples, LAMP showed a sensitivity of 96.20% and a specificity of 84.61%. When compared specifically to “true positives” and “true negatives” (defined by the consistency across the standard tests), LAMP demonstrated 100% sensitivity and 92.30% specificity. For context, the sensitivity of AFB smear microscopy against the culture and Xpert tests was 79.04%. A significant finding was that the LAMP test detected a high percentage (92.5%) of samples found positive by the culture and Xpert tests but negative by the AFB smear, highlighting its ability to identify cases missed by traditional microscopy. This study concluded that the LAMP assay is a sensitive and specific tool for TB diagnosis with potential for rapid and accurate diagnosis, especially in resource-limited areas.