Neprilysin ( /ˌnɛprɪˈlaɪsɪn/ ; also known as membrane metallo-endopeptidase (MME), neutral endopeptidase (NEP), cluster of differentiation 10 (CD10) and common acute lymphoblastic leukemia antigen (CALLA)) is an enzyme that in humans is encoded by the MME gene. Neprilysin is a zinc-dependent metalloprotease that cleaves peptides at the amino side of hydrophobic residues and inactivates several peptide hormones including glucagon, enkephalins, substance P, neurotensin, oxytocin, and bradykinin. [5] It also degrades the amyloid beta peptide whose abnormal folding and aggregation in neural tissue has been implicated as a cause of Alzheimer's disease. Synthesized as a membrane-bound protein, the neprilysin ectodomain is released into the extracellular domain after it has been transported from the Golgi apparatus to the cell surface.
Neprilysin is expressed in a wide variety of tissues and is particularly abundant in kidney. It is also a common acute lymphocytic leukemia antigen that is an important cell surface marker in the diagnosis of human acute lymphocytic leukemia (ALL). This protein is present on leukemic cells of pre-B phenotype, which represent 85% of cases of ALL. [5]
Hematopoietic progenitors expressing CD10 are considered "common lymphoid progenitors", which means they can differentiate into T, B or natural killer cells. [6] CD10 is of use in hematological diagnosis since it is expressed by early B, pro-B and pre-B lymphocytes, and by lymph node germinal centers. [7] Hematologic diseases in which it is positive include ALL, angioimmunoblastic T cell lymphoma, Burkitt lymphoma, chronic myelogenous leukemia in blast crisis (90%), diffuse large B-cell lymphoma (variable), follicular center cells (70%), hairy cell leukemia (10%), and myeloma (some). It tends to be negative in acute myeloid leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, and marginal zone lymphoma. CD10 is found on non-T ALL cells, which derive from pre-B lymphocytes, and in germinal center-related non-Hodgkin lymphoma such as Burkitt lymphoma and follicular lymphoma, but not on leukemia cells or lymphomas, which originate in more mature B cells. [8]
Neprilysin-deficient knockout mice show both Alzheimer's-like behavioral impairment and amyloid-beta deposition in the brain, [9] providing strong evidence for the protein's association with the Alzheimer's disease process. Because neprilysin is thought to be the rate-limiting step in amyloid beta degradation, [10] it has been considered a potential therapeutic target; compounds such as the peptide hormone somatostatin have been identified that increase the enzyme's activity level. [11] Declining neprilysin activity with increasing age may also be explained by oxidative damage, known to be a causative factor in Alzheimer's disease; higher levels of inappropriately oxidized neprilysin have been found in Alzheimer's patients compared to cognitively normal elderly people. [12]
Neprilysin is also associated with other biochemical processes, and is particularly highly expressed in kidney and lung tissues. Inhibitors have been designed with the aim of developing analgesic and antihypertensive agents that act by preventing neprilysin's activity against signaling peptides such as enkephalins, substance P, endothelin, and atrial natriuretic peptide. [13] [14]
Associations have been observed between neprilysin expression and various types of cancer; however, the relationship between neprilysin expression and carcinogenesis remains obscure. In cancer biomarker studies, the neprilysin gene is often referred to as CD10 or CALLA. In some types of cancer, such as metastatic carcinoma and some advanced melanomas, neprilysin is overexpressed; [15] in other types, most notably lung cancers, neprilysin is downregulated, and thus unable to modulate the pro-growth autocrine signaling of cancer cells via secreted peptides such as mammalian homologs related to bombesin. [16] Some plant extracts (methanol extracts of Ceropegia rupicola, Kniphofia sumarae, Plectranthus cf barbatus, and an aqueous extract of Pavetta longiflora) were found able to inhibit the enzymatic activity of neutral endopeptidase. [17]
Inhibitors have been designed with the aim of developing analgesic and antihypertensive agents that act by preventing neprilysin's activity against signaling peptides such as enkephalins, substance P, endothelin, and atrial natriuretic peptide. [13] [14]
Some are intended to treat heart failure. [18]
Other dual inhibitors of NEP with ACE/angiotensin receptor were (in 2003) being developed by pharmaceutical companies. [19]
CD10 is used in clinical pathology for diagnostic purpose.
Thyroid neoplasm is a neoplasm or tumor of the thyroid. It can be a benign tumor such as thyroid adenoma, or it can be a malignant neoplasm, such as papillary, follicular, medullary or anaplastic thyroid cancer. Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men. The estimated number of new cases of thyroid cancer in the United States in 2023 is 43,720 compared to only 2,120 deaths. Of all thyroid nodules discovered, only about 5 percent are cancerous, and under 3 percent of those result in fatalities.
Keratin 20, often abbreviated CK20, is a protein that in humans is encoded by the KRT20 gene.
Immunohistochemistry (IHC) is a form of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells and tissue, by exploiting the principle of antibodies binding specifically to antigens in biological tissues. Albert Hewett Coons, Ernest Berliner, Norman Jones and Hugh J Creech was the first to develop immunofluorescence in 1941. This led to the later development of immunohistochemistry.
The International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by cancer registries.
Follicular lymphoma (FL) is a cancer that involves certain types of white blood cells known as lymphocytes. The cancer originates from the uncontrolled division of specific types of B-cells known as centrocytes and centroblasts. These cells normally occupy the follicles in the germinal centers of lymphoid tissues such as lymph nodes. The cancerous cells in FL typically form follicular or follicle-like structures in the tissues they invade. These structures are usually the dominant histological feature of this cancer.
Cluster of differentiation 40, CD40 is a type I transmembrane protein found on antigen-presenting cells and is required for their activation. The binding of CD154 (CD40L) on TH cells to CD40 activates antigen presenting cells and induces a variety of downstream effects.
Splenic marginal zone lymphoma (SMZL) is a type of marginal zone lymphoma, a cancer made up of B-cells that replace the normal architecture of the white pulp of the spleen. The neoplastic cells are both small lymphocytes and larger, transformed lymphoblasts, and they invade the mantle zone of splenic follicles and erode the marginal zone, ultimately invading the red pulp of the spleen. Frequently, the bone marrow and splenic hilar lymph nodes are involved along with the peripheral blood. The neoplastic cells circulating in the peripheral blood are termed villous lymphocytes due to their characteristic appearance.
Midkine, also known as neurite growth-promoting factor 2 (NEGF2), is a protein that in humans is encoded by the MDK gene.
Omapatrilat is an experimental antihypertensive agent that was never marketed. It inhibits both neprilysin and angiotensin-converting enzyme (ACE). NEP inhibition results in elevated natriuretic peptide levels, promoting natriuresis, diuresis, vasodilation, and reductions in preload and ventricular remodeling.
Forkhead box protein P1 is a protein that in humans is encoded by the FOXP1 gene. FOXP1 is necessary for the proper development of the brain, heart, and lung in mammals. It is a member of the large FOX family of transcription factors.
Bcl-6 is a protein that in humans is encoded by the BCL6 gene. BCL6 is a master transcription factor for regulation of T follicular helper cells proliferation. BCL6 has three evolutionary conserved structural domains. The interaction of these domains with corepressors allows for germinal center development and leads to B cell proliferation.
Fibroblast activation protein alpha (FAP-alpha) also known as prolyl endopeptidase FAP is an enzyme that in humans is encoded by the FAP gene.
ID4 is a protein coding gene. In humans, it encodes for the protein known as DNA-binding protein inhibitor ID-4. This protein is known to be involved in the regulation of many cellular processes during both prenatal development and tumorigenesis. This is inclusive of embryonic cellular growth, senescence, cellular differentiation, apoptosis, and as an oncogene in angiogenesis.
In medicine, desmoplasia is the growth of fibrous connective tissue. It is also called a desmoplastic reaction to emphasize that it is secondary to an insult. Desmoplasia may occur around a neoplasm, causing dense fibrosis around the tumor, or scar tissue (adhesions) within the abdomen after abdominal surgery.
Endometrial stromal sarcoma is a malignant subtype of endometrial stromal tumor arising from the stroma of the endometrium rather than the glands. There are three grades for endometrial stromal tumors, as follows. It was previously known as endolymphatic stromal myosis because of diffuse infiltration of myometrial tissue or the invasion of lymphatic channels.
In molecular biology MicroRNA-223 (miR-223) is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms. miR-223 is a hematopoietic specific microRNA with crucial functions in myeloid lineage development. It plays an essential role in promoting granulocytic differentiation while also being associated with the suppression of erythrocytic differentiation. miR-223 is commonly repressed in hepatocellular carcinoma and leukemia. Higher expression levels of miRNA-223 are associated with extranodal marginal-zone lymphoma of mucosa-associated lymphoid tissue of the stomach and recurrent ovarian cancer. In some cancers the microRNA-223 down-regulation is correlated with higher tumor burden, disease aggressiveness, and poor prognostic factors. MicroRNA-223 is also associated with rheumatoid arthritis, sepsis, type 2 diabetes, and hepatic ischemia.
Sacubitril/valsartan, sold under the brand name Entresto, is a fixed-dose combination medication for use in heart failure. It consists of the neprilysin inhibitor sacubitril and the angiotensin receptor blocker valsartan. The combination is sometimes described as an "angiotensin receptor-neprilysin inhibitor" (ARNi). In 2016, the American College of Cardiology/American Heart Association Task Force recommended it as a replacement for an ACE inhibitor or an angiotensin receptor blocker in people with heart failure with reduced ejection fraction.
Neuroendocrine differentiation is a term primarily used in relation to prostate cancers that display a significant neuroendocrine cell population on histopathological examination. These types of prostate cancer comprise true neuroendocrine cancers, such as small cell carcinoma, carcinoid and carcinoid-like tumors, as well as prostatic adenocarcinoma exhibiting focal neuroendocrine phenotype.
Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) is a cutaneous lymphoma skin disease that occurs mostly in elderly females. In this disease, B cells become malignant, accumulate in the dermis and subcutaneous tissue below the dermis to form red and violaceous skin nodules and tumors. These lesions typically occur on the lower extremities but in uncommon cases may develop on the skin at virtually any other site. In ~10% of cases, the disease presents with one or more skin lesions none of which are on the lower extremities; the disease in these cases is sometimes regarded as a variant of PCDLBL, LT termed primary cutaneous diffuse large B-cell lymphoma, other (PCDLBC-O). PCDLBCL, LT is a subtype of the diffuse large B-cell lymphomas (DLBCL) and has been thought of as a cutaneous counterpart to them. Like most variants and subtypes of the DLBCL, PCDLBCL, LT is an aggressive malignancy. It has a 5-year overall survival rate of 40–55%, although the PCDLBCL-O variant has a better prognosis than cases in which the legs are involved.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.