This is a working overview of prothymosin alpha, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-05-15. Anything still debated is marked as such rather than presented as settled.
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
| Property | Value | Notes |
|---|---|---|
| 主要靶细胞 | T细胞、树突状细胞 | 也影响NK细胞 |
| 信号通路 | TLR/MyD88/NF-κB | 部分实验模型 |
| 细胞因子偏向 | Th1型 | 增加IL-2、IFN-γ |
| 给药途径 | 皮下注射 | 临床常用 |
| 半衰期 | 约2小时 | 血浆中较短 |
The name itself causes confusion, because several unrelated thymic peptides share the thymosin label. Thymosin beta-4, for example, is a different molecule with different functions. Naming conventions in the literature also mix descriptive research terms with assigned nonproprietary names, so a reader should confirm which entity a given paper addresses. Clarifying that point is usually the first step in interpreting any claim about this peptide.
Thymosin alpha-1 is a short peptide of 28 amino acid residues first described in the 1970s as a component of thymic extracts. Its N-terminal residue carries an acetyl group, and the sequence is highly conserved across mammalian species. The peptide is not encoded as a standalone gene product; it is released by proteolytic cleavage from the N-terminus of prothymosin alpha, a larger acidic nuclear protein. That precursor relationship places it within a broader family of thymic and immune-associated peptides that have been studied for decades.
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
Lyophilized thymosin alpha 1 is typically stored refrigerated at 2 to 8 degrees Celsius and kept away from light. Reconstituted solutions are less stable and are usually used promptly after preparation. Repeated freeze-thaw cycles are avoided because they can promote aggregation and loss of activity. The peptide adsorbs to some plastic and glass surfaces, so a carrier protein is often added to dilute working solutions. Manufacturer instructions and published protocols both govern handling.
Identity and purity testing for thymosin alpha 1 relies mainly on reversed-phase high-performance liquid chromatography and mass spectrometry. Chromatography separates the parent peptide from truncated or modified variants, while mass spectrometry confirms the expected molecular mass. Amino acid analysis and peptide mapping provide additional sequence confirmation. Counterion content, water content, and residual solvents are measured separately as part of specification testing. No single method captures every attribute, so laboratories combine several techniques.
The peptide lacks cysteine, methionine, and tryptophan, so disulfide scrambling and sulfur oxidation are not major degradation routes. Instead, aspartate residues can undergo isomerization or cyclization to succinimide intermediates, generating isoaspartate variants. Hydrolysis of peptide bonds also occurs slowly in solution. These changes may reduce biological activity even when the main peak remains detectable. Stability studies therefore track both potency and the appearance of related substances.
== Sources == Isotope masses from: National Nuclear Data Center. "NuDat 3.0 database". Brookhaven National Laboratory. Half-life, spin, and isomer data selected from the following sources. National Nuclear Data Center. "NuDat 3.0 database". Brookhaven National Laboratory. IAEA - Nuclear Data Section. Live Chart of Nuclides. Vienna International Centre. Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
In 1987, Yates purchased Temple Gym on Temple Street in Birmingham. In 2006, he franchised four additional Temple Gym locations, three of which are in the UK. As of 2020, only the original Birmingham gym is still in operation; it later relocated from Temple Street to the city's Jewellery Quarter. In 1994, Yates and bodybuilding brothers Mike and Ray Mentzer formed the California-based company Heavy Duty Inc., which marketed athletic apparel and bodybuilding books. In 1998, he partnered with Kerry Kayes to form the bodybuilding supplement company CNP Professional, which marketed a "Dorian Yates Approved" product line in the U.S. He left the company in 2006 to form his own company, Dorian Yates Ultimate Formulas, which offers a line of protein and weight-gain supplements. Yates started a second company in 2010 called EU Peptides, which sells peptide hormones and other pro-hormone supplements. He left this company in 2012, having founded a third company called DY Nutrition in 2011; it specializes in pre-workout formulas, has released several training DVDs, and offers a line of workout related supplements endorsed by Yates.
and an honorary citizen of the cities of Frankfurt am Main and Göttingen in 1959, and of Berlin (1968). Hahn was made an Officer of the Ordre National de la Légion d'Honneur of France (1959), and was awarded the Grand Cross First Class of the Order of Merit of the Federal Republic of Germany (1959). In 1966, US President Lyndon B. Johnson and the United States Atomic Energy Commission (AEC) awarded Hahn, Lise Meitner and Fritz Strassmann the Enrico Fermi Award. The diploma for Hahn bore the words: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies culminating in the discovery of fission." He received honorary doctorates from the University of Gottingen, the Technische Universität Darmstadt, the Goethe University Frankfurt in 1949, and the University of Cambridge in 1957. Objects named after Hahn include:
=== Skin healing === HA plays an important role in the normal epidermis. HA also has crucial functions in the re-epithelialization process due to several of its properties. These include being an integral part of the extracellular matrix of basal keratinocytes, which are major constituents of the epidermis; its free-radical scavenging function, and its role in keratinocyte proliferation and migration. In normal skin, HA is found in relatively high concentrations in the basal layer of the epidermis where proliferating keratinocytes are found. CD44 is collocated with HA in the basal layer of epidermis where additionally it has been shown to be preferentially expressed on plasma membrane facing the HA-rich matrix pouches. Maintaining the extracellular space and providing an open, as well as hydrated, structure for the passage of nutrients are the main functions of HA in epidermis. A report found HA content increases in the presence of retinoic acid (vitamin A). The proposed effects of retinoic acid against skin photo-damage and photoaging may be correlated, at least in part, with an increase of skin HA content, giving rise to increased tissue hydration. It has been suggested that the free-radical scavenging property of HA contributes to protection against solar radiation, supporting the role of CD44 acting as a HA receptor in the epidermis. Epidermal HA also functions as a manipulator in the process of keratinocyte proliferation, which is essential in normal epidermal function, as well as during reepithelization in tissue repair.
Sources: en.wikipedia.org
=== Reconstitution === Perhaps the most extreme of treatments is "reconstitution", wherein fragments of fine turquoise material, too small to be used individually, are powdered and then bonded with resin to form a solid mass. Very often the material sold as "reconstituted turquoise" is artificial, with little or no natural stone, made entirely from resins and dyes. In the trade reconstituted turquoise is often called "block turquoise" or simply "block".
== Origin of eukaryotes == The great oxygenation event began with the biologically induced appearance of oxygen in the Earth's atmosphere about 2.45 billion years ago. The rise of oxygen levels due to cyanobacterial photosynthesis in ancient microenvironments was probably highly toxic to the surrounding biota. Under these conditions, the selective pressure of oxidative stress is thought to have driven the evolutionary transformation of an archaeal lineage into the first eukaryotes. Oxidative stress might have acted in synergy with other environmental stresses (such as ultraviolet radiation and/or desiccation) to drive this selection. Selective pressure for efficient repair of oxidative DNA damages may have promoted the evolution of eukaryotic sex involving such features as cell-cell fusions, cytoskeleton-mediated chromosome movements and emergence of the nuclear membrane. Thus, the evolution of meiotic sex and eukaryogenesis may have been inseparable processes that evolved in large part to facilitate repair of oxidative DNA damages.
=== United States === In the United States, semaglutide is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes, and to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes and established cardiovascular disease. In combination with a reduced-calorie diet and increased physical activity, semaglutide (as Wegovy) is indicated to reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) in adults with established cardiovascular disease and who are either obese or overweight; to reduce excess body weight and maintain weight reduction long term in obese individuals twelve years of age or older, or for overweight adults with at least one weight-related comorbid condition. In August 2025, the Food and Drug Administration (FDA) expanded the indication for semaglutide (as Wegovy) to include the treatment of noncirrhotic metabolic-associated steatohepatitis (MASH), formerly known as nonalcoholic steatohepatitis (NASH), with moderate to advanced liver fibrosis (consistent with stages F2 to F3 fibrosis) in adults. In October 2025, the FDA further expanded the indication for semaglutide (as Rybelsus) to reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) in adults with type 2 diabetes who are at high risk for these events.
Sources: en.wikipedia.org
16 April – A review suggests that global prevalence of long COVID conditions after infection could be as high as 43%, with the most common symptoms being fatigue and memory problems. 19 April – NASA publishes its Planetary Science Decadal Survey for 2023-2032. The future mission recommendations include a Uranus orbiter (the first visit to the planet since 1986) and the Enceladus Orbilander (landing in the early 2050s). 20 April Micronovae, a previously unknown class of thermonuclear explosions on the surface of white dwarfs, are described for the first time. A study shows that common single-use plastic products – such as paper coffee cups that are lined with a thin plastic film inside – release trillions of microplastics-nanoparticles per liter into water during normal use. 21 April – Researchers discover that humans are interrupting a 66-million-years-old feature of ecosystems, the relationship between diet and body mass, by driving the largest vertebrate animals towards extinction, which they suggest could have unpredictable consequences. 22 April The Large Hadron Collider recommences full operations, three years after being shut down for upgrades. Scientists suggest in a study that space governance of satellites/space debris should regulate the current free externalization of true costs and risks, with orbital space around the Earth being an "additional ecosystem" which should be subject to regulations as e.g. oceans on Earth.
Human cells require iron in order to obtain energy as ATP from a multi-step process known as cellular respiration, more specifically from oxidative phosphorylation at the mitochondrial cristae. Iron is present in the iron–sulfur cluster and heme groups of the electron transport chain proteins that generate a proton gradient that allows ATP synthase to synthesize ATP (chemiosmosis). Heme groups are part of hemoglobin, a protein found in red blood cells that serves to transport oxygen from the lungs to other tissues. Heme groups are also present in myoglobin to store and diffuse oxygen in muscle cells.
Office for National Statistics data for the year up to June 2023 shows fewer UK births than deaths over a 12-month period for the first time since the 1970s, with 16,300 fewer births occurring, while net migration increased the population by 662,400 to an estimated 68,265,200. Housing and planning minister, Matthew Pennycook, is referred to the parliamentary commissioner for standards for not revealing his close relationship with the author of the Institute for Fiscal Studies paper which Labour ministers have used as evidence to support their introduction of 20% value-added tax (VAT) on private school fees. 9 October – The All England Club announces it will adopt electronic line calling from 2025, meaning line judges will disappear from the Wimbledon Championships. 10 October A new King Charles III heraldic Coat of Arms, alongside the new Lesser Arms, used by the UK government, both by artist Timothy Noad are officially unveiled. A further 65 women are reported to have contacted the BBC regarding sexual abuse by the late former Harrods owner Mohamed Al-Fayed. The Prince and Princess of Wales visit Southport, where they meet the families of the three children killed in the July stabbing. It is the Princess's first public engagement since her cancer treatment. A technical fault with the BBC Weather website and app leads to incorrect forecasts of hurricane winds in the UK and internationally, with one forecast predicting winds of 13,508 mph in London.
The rectus abdominis, (Latin: straight abdominal) also known as the "abdominal muscle" or simply better known as the "abs", and sometimes informally referred to as the "six-pack", is a pair of segmented skeletal muscle on the ventral aspect of a person's abdomen. The paired muscle is separated at the midline by a band of dense connective tissue called the linea alba, and the connective tissue defining each lateral margin of the rectus abdominus is the linea semilunaris. The muscle extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of the 5th–7th ribs superiorly. The rectus abdominis muscle is contained in the rectus sheath, which consists of the aponeuroses of the lateral abdominal muscles. Each rectus abdominus is traversed by bands of connective tissue called the tendinous intersections, which interrupt it into distinct muscle bellies.
Sources: en.wikipedia.org
它促进未成熟T细胞分化并增强成熟T细胞的增殖与细胞因子分泌。这些作用有助于放大抗原特异性免疫应答。
目前认为它可能通过Toll样受体等模式识别受体传递信号，但精确的受体身份和结合机制尚未完全阐明。
不同试验在患者选择、给药方案、联合治疗和终点定义上差异很大。这些异质性使得跨研究比较困难，结论难以统一。
It corresponds to a fragment of the larger protein prothymosin alpha, which is present in many tissues. The isolated 28-amino-acid peptide was originally obtained from thymus preparations, and the pharmaceutical product is synthesized rather than extracted. The term therefore describes both a natural fragment and a manufactured drug substance.