PTMA gene raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-11-05. Anything still debated is marked as such rather than presented as settled.
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.
The activity of this peptide is generally described as immunomodulatory rather than directly antimicrobial. Experimental work links it to signaling through certain Toll-like receptors on dendritic cells and to downstream maturation of antigen-presenting cells. Reported effects include expansion of T cell subsets, shifts in cytokine profiles, and increased natural killer cell activity. These observations come largely from cell culture and animal models, and the precise receptor-level events in humans remain incompletely characterized.
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。
| Property | Value | Notes |
|---|---|---|
| Residue count | 28 amino acids | Acetyl group on the first residue |
| Approximate molecular mass | 3108 daltons | Calculated from the consensus sequence |
| Origin | Cleavage product of prothymosin alpha | Not encoded as a separate gene product |
| Primary research focus | Immune modulation | Studied in viral hepatitis and as a vaccine adjuvant |
| Common synonyms | Thymalfasin, Tα1, thymosin alpha 1 | Thymalfasin is the assigned nonproprietary name |
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.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
== Genetics == In terms of the genetics of UCMD1, there are mutations in the genes COL6A1, COL6A2, and COL6A3. This sub-type of muscular dystrophy is both autosomal recessive and autosomal dominant in nature. COL6A1 plays an important part in maintaining the human body's integrity of various tissues. Alpha 1 subunit of type VI collagen is the encoded protein. In terms of the genetics of UCMD2, there are mutations in the gene COL12A1, and is autosomal recessive. Collagen VI is a principal structural component of the extracellular matrix (ECM), where it self-assembles into a distinct microfibrillar network that links the muscle fiber's basal lamina to the surrounding interstitial matrix, thereby anchoring muscle cells to the ECM. Mutations in COL6A1, COL6A2, and COL6A3 impair the proper assembly, secretion, or incorporation of collagen VI microfibrils into the ECM, disrupting its structural integrity and contributing to the muscle-fiber degeneration observed in UCMD.
While menstruation is heavily associated with human females, and they have the most pronounced menstruation, it is also typical of ape relatives and monkeys. Female macaques menstruate, with a cycle length over the course of a lifetime that is comparable to that of female humans. Estrogens and progestogens in the menstrual cycles and during premenarche and postmenopause are also similar in female humans and macaques; however, only in macaques does keratinization of the epithelium occur during the follicular phase. The vaginal pH of macaques also differs, with near-neutral to slightly alkaline median values and is widely variable, which may be due to its lack of lactobacilli in the vaginal flora. This is one reason why, although macaques are used for studying HIV transmission and testing microbicides, animal models are not often used in the study of sexually transmitted infections, such as trichomoniasis. Another is that such conditions' causes are inextricably bound to humans' genetic makeup, making results from other species difficult to apply to humans.
== Limitations == Like other staining methods, Van Gieson’s stain has limitations. It may miss very thin collagen fibrils, immature collagen can be faint or invisible with this stain. This can lead to an underestimation of collagen content. The red coloration can also fade if slides are not properly fixed or stored. The usage of the picric acid–acid fuchsin mixture tends to remove or significantly weaken majority of hematoxylin, resulting in nuclei that are faint or nearly invisible under the microscope.To overcome this, an iron-mordanted hematoxylin, such as Weigert’s hematoxylin, is typically used. Iron hematoxylins are more resistant to acid decolorization and preserve nuclear detail even after exposure to Van Gieson's solution.
As keratinocytes migrate, they move over granulation tissue but stay underneath the scab, thereby separating the scab from the underlying tissue. Epithelial cells have the ability to phagocytize debris such as dead tissue and bacterial matter that would otherwise obstruct their path. Because they must dissolve any scab that forms, keratinocyte migration is best enhanced by a moist environment, since a dry one leads to formation of a bigger, tougher scab. To make their way along the tissue, keratinocytes must dissolve the clot, debris, and parts of the ECM in order to get through. They secrete plasminogen activator, which activates plasminogen, turning it into plasmin to dissolve the scab. Cells can only migrate over living tissue, so they must excrete collagenases and proteases like matrix metalloproteinases (MMPs) to dissolve damaged parts of the ECM in their way, particularly at the front of the migrating sheet. Keratinocytes also dissolve the basement membrane, using instead the new ECM laid down by fibroblasts to crawl across. As keratinocytes continue migrating, new epithelial cells must be formed at the wound edges to replace them and to provide more cells for the advancing sheet. Proliferation behind migrating keratinocytes normally begins a few days after wounding and occurs at a rate that is 17 times higher in this stage of epithelialization than in normal tissues. Until the entire wound area is resurfaced, the only epithelial cells to proliferate are at the wound edges.
Sources: en.wikipedia.org
The Valve Index is a discontinued virtual reality headset created and manufactured by Valve. Announced on April 30, 2019, it was released on June 28 of the same year. The Index is a second-generation headset and the first to be fully manufactured by Valve. Half-Life: Alyx is bundled with the headset. In November 2025, Valve announced a successor, the Steam Frame, scheduled for launch in early 2026.
== Society and culture == In June 2009, the US Food and Drug Administration (FDA) issued a public health advisory for insulin determir after learning that 129,000 stolen vials reappeared and were being sold in the U.S. market. The FDA warned that the stolen vials "may not have been stored and handled properly and may be dangerous for patients to use." The stolen vials were identified as lots XZF0036, XZF0037, and XZF0038.
On July 13, 2024, Trump survived an assassination attempt while addressing a campaign rally near Butler, Pennsylvania. Trump was shot at by Thomas Crooks, a 20-year-old man from Bethel Park, Pennsylvania, who fired eight rounds with an AR-15–style rifle from the roof of a building located approximately 400 feet (120 meters) from the stage. According to the FBI, Trump was hit by a bullet, and injured in his upper right ear. He raised a hand to his ear before dropping down on his podium behind the lectern for cover. Secret Service agents lunged toward Trump and shielded him. After the assailant was declared "down", agents helped Trump get up. Blood was visible on his ear and face. He asked the Secret Service agents to let him get his shoes. According to Trump, the agents "hit me so hard that my shoes fell off, and my shoes are tight." As of October 12, 2024, none of the medical records pertaining to his wounds had been released. In July 2024, psychologist Simon McCarthy-Jones of Trinity College Dublin said in The Conversation that "the potential effect of the attempted assassination of Trump upon Trump's mental health – whether negligible, negative or positive – cannot be ignored". McCarthy-Jones stated that Trump being an extrovert might improve his ability to deal with the psychological impact of the event.
Sources: en.wikipedia.org
== History == Ripasudil (in the form of ripasudil hydrochloride hydrate) was approved by the PMDA of Japan on September 26, 2014. Glanatec, the trade name of the approved formulation, takes the form of an eye drop solution of 0.4% ripasudil, equivalent to 4 g of ripasudil per 1000 mL of solution. The solution is developed, marketed, and distributed by Kowa Pharmaceuticals, but the compound itself was discovered by D. Western Therapeutics Institute, a company who specializes in protein kinase inhibitory compounds. In September 2002, Kowa Company entered a licensing agreement with D. Western Therapeutics Institute, Inc. with regard to global rights of ripasudil. Under this agreement, D. Western Therapeutics Institute is eligible to receive milestone payments from Kowa. Kowa Company was issued a US patent (No. 8,193,193, entitled ‘‘Agent for prevention or treatment of glaucoma’’) on June 5, 2012 for the use of ripasudil in patients with glaucoma. As of June 25th, 2013, Glanatec is a registered U.S. federal trademark attributed to Kowa.
==== Cytosine deamination increases C-To-T mutations ==== A known result of cytosine methylation is the increase of C-to-T transition mutations through the process of deamination. Cytosine deamination can alter the genome's many regulatory functions; previously silenced transposable elements (TEs) may become transcriptionally active due to the loss of CPG sites. TEs have been proposed to accelerate the mechanism of enhancer creation by providing extra DNA that is compatible with the host transcription factors that eventually have an impact on C-to-T mutations.
Taco Bell began experimenting with fast-casual and urban concepts when it created U.S. Taco Co. and Urban Taproom in 2014 reflecting a market shift due to the popularity of Chipotle Mexican Grill. The menu consisted of tacos with American fillings, and did not sell the food sold in Taco Bell restaurants, such as burritos. It was launched in Huntington Beach, California, in August 2014. U.S. Taco Co. closed on September 15, 2015, so the company could focus on its new similar Taco Bell Cantina concept, which featured special menu items and served alcohol. It opened its first location a few days later in Chicago's Wicker Park neighborhood, followed by a location in San Francisco about a month later, located less than a block away from AT&T Park. In 2016, Taco Bell launched the Taco Bell Cantina flagship store located on the Las Vegas Strip. The 24-hour restaurant serves alcohol, unique menu items, and features a DJ. It was announced in August 2017 that the store would begin hosting weddings. Taco Bell Cantina currently has locations in San Francisco, Berkeley, Chicago (2 locations), Las Vegas, Austin, Fayetteville, Cincinnati, Cleveland, Atlanta, Newport Beach, San Diego, San Jose, Sacramento, Nashville, with them once having plans to open soon in Somerville, Massachusetts, but as of 2025, there are instead Taco Bell Cantinas in Brookline and Allston, Massachusetts. In March 2020, Taco Bell announced that it would be converting 3 of its suburban stores into Cantinas that year as part of a test run.
In 1977, Migita published further work on the coupling of allyl-tin reagents with both aryl (C) and acyl (D) halides. The greater ability of allyl groups to migrate to the palladium catalyst allowed the reactions to be performed at lower temperatures. Yields for aryl halides ranged from 4% to 100%, and for acyl halides from 27% to 86%. Reflecting the early contributions of Migita and Kosugi, the Stille reaction is sometimes called the Migita–Kosugi–Stille coupling.
Sources: en.wikipedia.org
It is usually classified as an immunomodulatory peptide rather than a classical hormone. It derives from the larger protein prothymosin alpha and acts mainly on immune cells. The thymosin label covers a group of distinct peptides, so the naming can be misleading.
The two share a family name but have different sequences, sizes, and functions. Thymosin beta-4 is a 43-residue peptide associated with actin binding and cell migration. Thymosin alpha-1 is a 28-residue peptide linked mainly to immune signaling.
Thymalfasin is the assigned international nonproprietary name for the synthetic 28-residue peptide. Thymosin alpha-1 is the descriptive research name for the same molecule. Which term appears depends on the context and the regulatory document.
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。