Nefropatía asociada a mutación del gen MYH9

Non-Muscle Myosin II A: Friend or Foe in Cancer?

Non-muscle myosin IIA (NM IIA) is a motor protein that belongs to the myosin II family. The myosin heavy chain 9 (MYH9) gene encodes the heavy chain of NM IIA. NM IIA is a hexamer and contains three pairs of peptides, which include the dimer of heavy chains, essential light chains, and regulatory light chains. NM IIA is a part of the actomyosin complex that generates mechanical force and tension to carry out essential cellular functions, including adhesion, cytokinesis, migration, and the maintenance of cell shape and polarity. These functions are regulated via light and heavy chain phosphorylation at different amino acid residues. Apart from physiological functions, NM IIA is also linked to the development of cancer and genetic and neurological disorders. MYH9 gene mutations result in the development of several autosomal dominant disorders, such as May-Hegglin anomaly (MHA) and Epstein syndrome (EPS). Multiple studies have reported NM IIA as a tumor suppressor in melanoma and head and neck squamous cell carcinoma; however, studies also indicate that NM IIA is a critical player in promoting tumorigenesis, chemoradiotherapy resistance, and stemness. The ROCK-NM IIA pathway regulates cellular movement and shape via the control of cytoskeletal dynamics. In addition, the ROCK-NM IIA pathway is dysregulated in various solid tumors and leukemia. Currently, there are very few compounds targeting NM IIA, and most of these compounds are still being studied in preclinical models. This review provides comprehensive evidence highlighting the dual role of NM IIA in multiple cancer types and summarizes the signaling networks involved in tumorigenesis. Furthermore, we also discuss the role of NM IIA as a potential therapeutic target with a focus on the ROCK-NM IIA pathway.

Exploring the nexus between MYH9 and tumors: novel insights and new therapeutic opportunities

The myosin heavy chain 9 (MYH9) gene, located on human chromosome 22, encodes non-muscle myosin heavy chain IIA (NM IIA). This protein is essential to various cellular events, such as generating intracellular chemomechanical force and facilitating the movement of the actin cytoskeleton. Mutations associated with thrombocytopenia in autosomal dominant diseases first highlighted the significance of the MYH9 gene. In recent years, numerous studies have demonstrated the pivotal roles of MYH9 in various cancers. However, its effects on cancer are intricate and not fully comprehended. Furthermore, the elevated expression of MYH9 in certain malignancies suggests its potential as a target for tumor therapy. Nonetheless, there is a paucity of literature summarizing MYH9's role in tumors and the therapeutic strategies centered on it, necessitating a systematic analysis. This paper comprehensively reviews and analyzes the pertinent literature in this domain, elucidating the fundamental structural characteristics, biological functions, and the nexus between MYH9 and tumors. The mechanisms through which MYH9 contributes to tumor development and its multifaceted roles in the tumorigenic process are also explored. Additionally, we discuss the relationship between MYH9-related diseases (MYH9-RD) and tumors and also summarize tumor therapeutic approaches targeting MYH9. The potential clinical applications of studying the MYH9 gene include improving early diagnosis, clinical staging, and prognosis of tumors. This paper is anticipated to provide novel insights for tumor therapy.

The Potential Impact of MYH9 (rs3752462) and ELMO1 (rs741301) Genetic Variants on the Risk of Nephrotic Syndrome Incidence

The kidney lost a lot of protein in the urine when you have nephrotic syndrome (NS). Clinical manifestations mostly common in NS include massive proteinuria, hypoalbuminemia, hyperlipidemia, and edema. Idiopathic nephrotic syndrome is currently classified into steroid-dependent (SDNS) and steroid-resistant (SRNS) based on the initial response to corticosteroid therapy at presentation. Several reports examined the association of the MYH9 gene (rs3752462, C > T) variant and ELMO1 gene (rs741301 G > A) variant as risk factors for Nephrotic Syndrome. This study aimed to determine the potential effect of the MYH9 gene (rs3752462, C > T) and ELMO1 gene (rs741301) variant on the risk of (NS) among Egyptian Children. This study included two hundred participants involving 100 nephrotic syndrome (NS) cases and 100 healthy controls free from nephrotic syndrome (NS). The MYH9 gene (rs3752462, C > T) variant and ELMO1 gene (rs G > A741301) variant were analyzed by ARMS-PCR technique. Nephrotic syndrome cases include 74% SRNS and 26% SDNS. Higher frequencies of the heterozygous carrier (CT) and homozygous variant (TT) genotypes of the MYH9 (rs3752462, C > T) variant were observed in NS patients compared to the controls with p-value < 0.001. The frequencies of the MYH9 (rs3752462, C > T variant indicated a statistically significant elevated risk of NS under various genetic models, including allelic model (OR 2.85, p < 0.001), dominant (OR 3.97, p < 0.001) models, and the recessive model OR 5.94, p < 0.001). Higher frequencies of the heterozygous carrier (GA) and homozygous variant (AA) genotypes of ELMO1gene (rs G > A741301) variant were observed in NS patients compared to the controls with p-value < 0.001. The frequencies of the ELMO1 (rs G > A741301) variant indicated a statistically significant elevated risk of NS under various genetic models, including allelic model (OR 2.15, p < 0.001), dominant models (OR 2.8, p < 0.001), and the recessive model (OR 4.17, p = 0.001). Both MYH9 and ELMO1 gene variants are significantly different in NS in comparison with the control group (p < 0.001). The MYH9 gene (rs3752462, C > T) and ELMO1gene (rs G > A741301) variants were considered independent risk factors for NS among Egyptian Children.

Non-traditional risk factors of progression of chronic kidney disease in adult population: a scoping review

Chronic kidney disease (CKD) has become a public health concern over the last several years. Nowadays developed countries spend around 3% of their annual health-care budget on patients with CKD. According to the scientific community the most remarkable risk factors for CKD are diabetes and hypertension. Unknown CKD etiology has been reported as a global phenomenon including uncommon risk factors such as: dehydration, leptospirosis, heat stress, water quality, and others. This study aims to report non-traditional risk factors for ESRD based on a scoping review methodology. The scoping review methodology described by Arksey and O'Malley was used by performing an extensive review of the information. A total of 46 manuscripts were reviewed. The non-traditional ESRD risk factors are depicted based on six categories. Gender and ethnicity have been considered as risk factors for ESRD. Erythematous systemic lupus (ESL) is reported as an important risk factor for ESRD. Pesticide use has been an significant risk factor due to its effects on human and environmental health. Some compounds commonly used in homes against insects and plants are related to ESRD. Congenital and hereditary diseases in the urinary tract have been studied as a cause of ESRD in children and young adults. End-stage renal disease is a major concern for public health on a global level. As it can be seen, non-traditional risk factors are several and have different etiologies. It is necessary to put the issue on the table and add it to the public agenda in order to find multidisciplinary solutions.

The surgical management of a patient with chronic renal failure and macrothrombocytopenia related to the MYH9 gene mutation: A case report

MYH9 disease is a rare genetic disorder in which there is a mutation in the gene for the non-muscle myosin heavy chain IIA. It initially causes macrothrombocytopenia followed by other clinical manifestations. When the patient reaches adulthood, he can develop chronic kidney failure. Thus, the risk of suffering a hemorrhage, difficulty in repairing and, infections increases in individuals with this disease. In addition, the use of drugs in these patients should be carefully evaluated. An adult patient sought dental care with a complaint associated with a tooth with advanced dental caries. He had severe thrombocytopenia (7000 platelets/mm³ ), hearing loss, and chronic kidney failure. The diagnosis of MYH9 disease was confirmed through genotyping. After clinical examination, extraction was planned. Local and systemic procedures were used to prevent hemorrhage, especially postoperatively. Although the patient had an infection at the surgical wound site and no episode of postoperative bleeding, the repair process occurred normally. The purpose of this article is to report the surgical management of a patient with MYH9 disease.

Association of MYH9-rs3752462 polymorphisms with chronic kidney disease among clinically diagnosed hypertensive patients: a case-control study in a Ghanaian population

Background

Chronic kidney disease (CKD) is a significant comorbidity among hypertensive patients. Polymorphisms in the non-muscle myosin heavy chain 9 gene (MYH9) have been demonstrated to be significantly associated with CKD, among African- and European-derived populations. We investigated the spectrum of MYH9-associated CKD among Ghanaian hypertensive patients.

Methods

The study constituted a total of 264 hypertensive patients. Hypertensive patients with glomerular filtration rate (eGFR) < 60 ml/min/1.73m² (CKD-EPI formula) or clinically diagnosed were defined as case subjects (n = 132) while those with eGFR ≥60 ml/min/1.73m² were classified as control subjects (n = 132). Demographic data were obtained with a questionnaire and anthropometric measurements were taken. Five (5) millilitres (ml) of venous blood was drawn from study subjects into gel and EDTA vacutainer tubes. Two (2) mL of EDTA anticoagulated blood was used for genomic DNA extraction while three (3) mL of blood was processed to obtain serum for biochemical measurements. Genotyping of MYH9 polymorphisms (rs3752462) was done employing Tetra primer Amplification Refractory Mutation System (T-ARMS) polymerase chain reaction (PCR). Spot urine samples were also collected for urinalysis. Hardy-Weinberg population was assessed. Logistic regression models were used to assess the associations between single nucleotide polymorphisms and CKD.

Results

The cases and control participants differed in terms of age, sex, family history, and duration of CKD (p-value < 0.001). The minor allele frequencies of rs3752462 SNP were 0.820 and 0.567 respectively among the control and case subjects. Patients with the heterozygote genotype of rs3752462 (CT) were more likely to develop CKD [aOR = 7.82 (3.81–16.04)] whereas those with homozygote recessive variant (TT) were protective [aOR = 0.12 (0.06–0.25)]. Single nucleotide polymorphism of rs3752462 (CT genotype) was associated with increased proteinuria, albuminuria, and reduced eGFR.

Conclusions

We have demonstrated that MYH9 polymorphisms exist among Ghanaian hypertensive patients and rs3752462 polymorphism of MYH9 is associated with CKD. This baseline indicates that further longitudinal and multi-institutional studies in larger cohorts in Ghana are warranted to evaluate MYH9 SNP as an independent predictor of CKD among hypertensive patients in Ghana.

The use of pan-retinal photocoagulation to treat recurrent vitreous haemorrhage with neovascularisation in the context of Epstein syndrome: an MYH9-related disorder

A female patient presented with stable chronic thrombocytopaenia with large platelets, sensorineuronal deafness and renal impairment. Her treatment was refractory to intravenous immunoglobulins (IVIG) and steroids for a putative diagnosis of immune thrombocytopaenic purpura (ITP). She underwent genetic testing which revealed a MYH9 mutation in-keeping with a diagnosis of Epstein Syndrome. Subsequently to this she developed globally constricted fields on Goldmann visual field testing. MRI pituitary was unremarkable but she was diagnosed with a pituitary microprolactinoma secondary to raised prolactin in the blood responsive to carbegoline therapy. She subsequently developed retinal haemorrhages and recurrent vitreous haemorrhages due to neovascularisation. Fluorescein angiography revealed the extent of the neovascularisation and microvascular ischaemia. She underwent pan-retinal photocoagulation (PRP) to treat the ischaemic stimulus which resulted in regression of the new vessels and cessation of vitreous haemorrhages. There are no previous reported cases of microvascular retinal disease in the literature in the context of Epstein Syndrome, and this is the first report of successful treatment with PRP.

MYH9-related disease: it does exist, may be more frequent than you think and requires specific therapy

In this issue of ckj, Tabibzadeh et al. report one of the largest series of patients with MYH9 mutations and kidney disease. The cardinal manifestation of MYH9-related disease is thrombocytopenia with giant platelets. The population frequency of pathogenic MYH9 mutations may be at least 1 in 20 000. The literature abounds in misdiagnosed cases treated for idiopathic thrombocytopenic purpura with immune suppressants and even splenectomy. Additional manifestations include neurosensorial deafness and proteinuric and hematuric progressive kidney disease (at some point, it was called Alport syndrome with macrothrombocytopenia), leucocyte inclusions, cataracts and liver enzyme abnormalities, resulting in different names for different manifestation combinations (MATINS, May-Hegglin anomaly, Fechtner, Epstein and Sebastian syndromes, and deafness AD 17). The penetrance and severity of kidney disease are very variable, which may obscure the autosomal dominant inheritance. A correct diagnosis will both preclude unnecessary and potentially dangerous therapeutic interventions and allow genetic counselling and adequate treatment. Morphological erythrocyte, granulocyte and platelet abnormalities may allow the future development of high-throughput screening techniques adapted to clinical peripheral blood flow cytometers.