Cinnamaldehyde, A Bioactive Compound from the Leaves of Cinnamomum osmophloeum Kaneh, Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice by Inhibiting the NLRP3 Inflammasome.

Inflammatory bowel disease (IBD) comprises a group of idiopathic intestinal disorders, including ulcerative colitis and Crohn's disease, significantly impacting the quality of life for affected individuals. The effective management of these conditions remains a persistent challenge. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a complex molecular structure, regulates the production of pro-inflammatory cytokines such as interleukin-1ß. Abnormal activation of the NLRP3 inflammasome plays a pivotal role in the development of IBD, making it a compelling target for therapeutic intervention. Our research revealed that cinnamaldehyde (CA), a major bioactive compound found in the leaves of Cinnamomum osmophloeum kaneh, demonstrated a remarkable ability to alleviate colitis induced by dextran sulfate sodium (DSS) in a mouse model. This effect was attributed to CA's ability to downregulate the activation of the NLRP3 inflammasome and reduce the expression of pro-inflammatory mediators in the colon. In the mechanism study, we observed that CA inhibited the NLRP3 inflammasome in macrophages, at least partially, by enhancing the autophagic response, without reducing mitochondrial damage. These findings collectively suggest that CA holds significant potential as a therapeutic agent for enhancing the management of IBD, offering a promising avenue for further research and development.

Improvements in identification and quantitation of alkylated PAHs and forensic ratio sourcing.

Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) are present in a number of different sources in varying proportions depending on the source material and weathering. This range of PAH sources can make it difficult to determine the origin of exposure(s). Ratios of alkylated and parent PAHs have been applied as a forensic tool to distinguish between different sources. However, few studies have examined PAH ratios comprehensively as indicators for sourcing beyond a single study area or matrix type. In this paper, we introduce an expanded analytical method based on ASTM D7363-13a which we adapted for a gas chromatography triple quadrupole mass spectrometry instrument. The modifications increase selectivity and sensitivity compared to the ASTM method. We added five alkylated series to the method. This method has then been applied to 22 independent forensic ratios. We evaluated the method and the forensic ratios with certified reference materials and known environmental samples. This analytical method and thirteen PAH ratios were found to accurately predict sources of PAHs.

Synthetic 4-Hydroxy Auxarconjugatin B, a Novel Autophagy Inducer, Attenuates Gouty Inflammation by Inhibiting the NLRP3 Inflammasome.

Gouty arthritis results from the generation of uric acid crystals within the joints. These uric acid crystals activate the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome, which is involved in chronic inflammatory diseases, including gouty arthritis. This study identified the polyenylpyrrole derivative 4-hydroxy auxarconjugatin B (4-HAB), a novel autophagy inducer, which attenuated uric acid crystals-mediated activation of the NLRP3 inflammasome in vitro and in vivo. 4-HAB dose-dependently reduced the release of interleukin (IL)-1ß, IL-18, active caspase-1 and apoptosis-associated speck-like protein (ASC) in uric acid crystals-activated macrophages. In a mechanistic study, 4-HAB was shown to inhibit uric acid crystals-induced mitochondrial damage, lysosomal rupture and ASC oligomerization. Additionally, 4-HAB inhibited the NLRP3 inflammasome through Sirt1-dependent autophagy induction. Furthermore, the anti-inflammatory properties of 4-HAB were confirmed in a mouse model of uric acid crystals-mediated peritonitis by the reduced levels of neutrophil influx, IL-1ß, active caspase-1, IL-6 and MCP-1 in lavage fluids. In conclusion, 4-HAB attenuates gouty inflammation, in part by attenuating activation of the NLRP3 inflammasome through the Sirt1/autophagy induction pathway.

Mechanistic Insight Into the Activation of the NLRP3 Inflammasome by Neisseria gonorrhoeae in Macrophages.

Gonorrhea is a type III legal communicable disease caused by Neisseria gonorrhoeae (NG), one of the most common sexually transmitted bacteria worldwide. NG infection can cause urethritis or systemic inflammation and may lead to infertility or other complications. The NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome is a protein complex composed of NLRP3, apoptosis-associated speck-like protein and caspase-1 and is an important part of the cellular machinery controlling the release of interleukin (IL)-1ß and IL-18 and the pathogenesis of numerous infectious diseases. It has been reported that NG infection activates the NLRP3 inflammasome; however, the underlying mechanism remain unclear. In this report, the signaling pathways involved in the regulation of NG-mediated NLRP3 inflammasome activation in macrophages were studied. The results indicated that viable NG, but not heat-killed or freeze/thaw-killed NG, activated the NLRP3 inflammasome in macrophages through toll-like receptor 2, but not toll-like receptor 4. NG infection provided the priming signal to the NLRP3 inflammasome that induced the expression of NLRP3 and IL-1ß precursor through the nuclear factor kappa B and mitogen-activated protein kinase pathways. In addition, NG infection provided the activation signal to the NLRP3 inflammasome that activated caspase-1 through P2X7 receptor-dependent potassium efflux, lysosomal acidification, mitochondrial dysfunction, and reactive oxygen species production pathways. Furthermore, we demonstrated that NLRP3 knockout increased phagocytosis of bacteria by macrophages and increases the bactericidal activity of macrophages against NG. These findings provide potential molecular targets for the development of anti-inflammatory drugs that could ameliorate NG-mediated inflammation.

Assessment of Robotic Console Skills (ARCS): construct validity of a novel global rating scale for technical skills in robotically assisted surgery.

BACKGROUND: Skill assessment during robotically assisted surgery remains challenging. While the popularity of the Global Evaluative Assessment of Robotics Skills (GEARS) has grown, its lack of discrimination between independent console skills limits its usefulness. The purpose of this study was to evaluate construct validity and interrater reliability of a novel assessment designed to overcome this limitation. METHODS: We created the Assessment of Robotic Console Skills (ARCS), a global rating scale with six console skill domains. Fifteen volunteers who were console surgeons for 0 ("novice"), 1-100 ("intermediate"), or >100 ("experienced") robotically assisted procedures performed three standardized tasks. Three blinded raters scored the task videos using ARCS, with a 5-point Likert scale for each skill domain. Scores were analyzed for evidence of construct validity and interrater reliability. RESULTS: Group demographics were indistinguishable except for the number of robotically assisted procedures performed (p = 0.001). The mean scores of experienced subjects exceeded those of novices in dexterity (3.8 > 1.4, p < 0.001), field of view (4.1 > 1.8, p < 0.001), instrument visualization (3.9 > 2.2, p < 0.001), manipulator workspace (3.6 > 1.9, p = 0.001), and force sensitivity (4.3 > 2.6, p < 0.001). The mean scores of intermediate subjects exceeded those of novices in dexterity (2.8 > 1.4, p = 0.002), field of view (2.8 > 1.8, p = 0.021), instrument visualization (3.2 > 2.2, p = 0.045), manipulator workspace (3.1 > 1.9, p = 0.004), and force sensitivity (3.7 > 2.6, p = 0.033). The mean scores of experienced subjects exceeded those of intermediates in dexterity (3.8 > 2.8, p = 0.003), field of view (4.1 > 2.8, p < 0.001), and instrument visualization (3.9 > 3.2, p = 0.044). Rater agreement in each domain demonstrated statistically significant concordance (p < 0.05). CONCLUSIONS: We present strong evidence for construct validity and interrater reliability of ARCS. Our study shows that learning curves for some console skills plateau faster than others. Therefore, ARCS may be more useful than GEARS to evaluate distinct console skills. Future studies will examine why some domains did not adequately differentiate between subjects and applications for intraoperative use.

Peroxyauraptenol Inhibits Inflammation and NLRP3 Inflammasome Activation by Inhibiting Reactive Oxygen Species Generation and Preserving Mitochondrial Integrity.

Peroxyauraptenol (PXT) is a peroxide-containing coumarin compound isolated from the seeds of Cnidium monnieri. PXT exerts anti-inflammatory activities, as it reduces the levels of inducible nitric oxide synthase, nitric oxide, IL-6, and NLRP3 inflammasome-derived IL-1ß in lipopolysaccharide-activated macrophages. PXT also exerts anti-inflammatory activity by reducing reactive oxygen species generation (including mitochondrial), mitogen-activated protein kinase, protein kinase C-α/δ phosphorylation, and the release of mitochondrial DNA into the cytosol. In addition, PXT suppresses the phagocytic activity of macrophages and IL-1ß secretion by Klebsiella pneumoniae-infected macrophages. The unique peroxide group is important for the anti-inflammatory activity of PXT, as this activity is reduced when the peroxide group is replaced by a hydroxyl group. These findings suggest that PXT may be a candidate for the development of anti-inflammatory agents or a healthy supplement for preventing and ameliorating inflammation-related diseases.

A review of training research and virtual reality simulators for the da Vinci surgical system.

UNLABELLED: PHENOMENON: Virtual reality simulators are the subject of several recent studies of skills training for robot-assisted surgery. Yet no consensus exists regarding what a core skill set comprises or how to measure skill performance. Defining a core skill set and relevant metrics would help surgical educators evaluate different simulators. APPROACH: This review draws from published research to propose a core technical skill set for using the da Vinci surgeon console. Publications on three commercial simulators were used to evaluate the simulators' content addressing these skills and associated metrics. FINDINGS: An analysis of published research suggests that a core technical skill set for operating the surgeon console includes bimanual wristed manipulation, camera control, master clutching to manage hand position, use of third instrument arm, activating energy sources, appropriate depth perception, and awareness of forces applied by instruments. Validity studies of three commercial virtual reality simulators for robot-assisted surgery suggest that all three have comparable content and metrics. However, none have comprehensive content and metrics for all core skills. INSIGHTS: Virtual reality simulation remains a promising tool to support skill training for robot-assisted surgery, yet existing commercial simulator content is inadequate for performing and assessing a comprehensive basic skill set. The results of this evaluation help identify opportunities and challenges that exist for future developments in virtual reality simulation for robot-assisted surgery. Specifically, the inclusion of educational experts in the development cycle alongside clinical and technological experts is recommended.

Resveratrol inhibits NLRP3 inflammasome activation by preserving mitochondrial integrity and augmenting autophagy.

The NLRP3 inflammasome is a caspase-1-containing multi-protein complex that controls the release of IL-1ß and plays important roles in the development of inflammatory disease. Here, we report that resveratrol, a polyphenolic compound naturally produced by plants, inhibits NLRP3 inflammasome-derived IL-1ß secretion and pyroptosis in macrophages. Resveratrol inhibits the activation step of the NLRP3 inflammasome by suppressing mitochondrial damage. Resveratrol also induces autophagy by activating p38, and macrophages treated with an autophagy inhibitor are resistant to the suppressive effects of resveratrol. In addition, resveratrol administration mitigates glomerular proliferation, glomerular sclerosis, and glomerular inflammation in a mouse model of progressive IgA nephropathy. These findings were associated with decreased renal mononuclear leukocyte infiltration, reduced renal superoxide anion levels, and inhibited renal NLRP3 inflammasome activation. Our data indicate that resveratrol suppresses NLRP3 inflammasome activation by preserving mitochondrial integrity and by augmenting autophagy.

Essential oil from the heartwood of Taiwan fir ameliorates LPS-induced inflammatory response by inhibiting the activation of mitogen-activated protein kinase.

The essential oil from the heartwood of Taiwan fir (EOTC) was demonstrated to exhibit anti-inflammatory activity in lipopolysaccharide (LPS)-activated mouse macrophages. EOTC reduced nitrite oxide levels and inducible nitrite oxide synthase expression in, and tumor necrosis factor-α and interleukin-6 secretion by, LPS-activated macrophages without affecting cyclooxygenase-2 expression. EOTC reduced the levels of interleukin-lß precursor induced by LPS and decreased the NLRP3 inflammasome-derived interleukin-lß secretion induced by LPS and adenosine triphosphate. In addition, the phosphorylation levels of ERKI/2, JNK1/2, and p38 in LPS-activated macrophages were reduced by EOTC. Furthermore, EOTC was composed of oxygenated sesquiterpenes (68.4%), sesquiterpene hydrocarbons (28.9%) and diterpenes (0.9%). The major compounds of the oxygenated sesquiterpenes were τ-cadinol (23.9%), α-cadinol (21.1%) and cedrol (16.9%). These findings suggest that EOTC may be a candidate for the development of anti-inflammatory agents for preventing and ameliorating inflammation-related diseases.

Bamboo vinegar decreases inflammatory mediator expression and NLRP3 inflammasome activation by inhibiting reactive oxygen species generation and protein kinase C-α/δ activation.

Bamboo vinegar (BV), a natural liquid derived from the condensation produced during bamboo charcoal production, has been used in agriculture and as a food additive, but its application to immune modulation has not been reported. Here, we demonstrated that BV has anti-inflammatory activities both in vitro and in vivo. BV reduced inducible nitric oxide synthase expression and nitric oxide levels in, and interleukin-6 secretion by, lipopolysaccharide-activated macrophages without affecting tumor necrosis factor-α secretion and cyclooxygenase-2 expression. The mechanism for the anti-inflammatory effect of BV involved decreased reactive oxygen species production and protein kinase C-α/δ activation. Furthermore, creosol (2-methoxy-4-methylphenol) was indentified as the major anti-inflammatory compound in BV. Impaired cytokine expression and NLR family, pyrin domain-containing 3 (NLRP3) inflammasome activation was seen in mice treated with creosol. These findings provide insights into how BV regulates inflammation and suggest that it may be a new source for the development of anti-inflammatory agents or a healthy supplement for preventing and ameliorating inflammation- and NLRP3 inflammasome-related diseases, including metabolic syndrome.

Polyenylpyrrole derivatives inhibit NLRP3 inflammasome activation and inflammatory mediator expression by reducing reactive oxygen species production and mitogen-activated protein kinase activation.

Two polyenylpyrroles from a soil ascomycete Gymnoascus reessii were previously identified as hit compounds in screening for cytotoxicity against lung cancer cells. These compounds and various analogs, which have been previously synthesized and tested for anti-lung cancer cell activity, were tested for anti-inflammatory activity. After preliminary screening for cytotoxicity for RAW 264.7 murine macrophage cells, the non-toxic compounds were tested for anti-inflammatory activity using lipopolysaccharide (LPS)-activated RAW 264.7 cells. Compounds 1h, 1i, and 1n reduced LPS-induced nitric oxide (NO) production, with respective ED50 values of 15 ± 2, 16 ± 2, and 17 ± 2 µM. They also reduced expression of inducible NO synthase and interleukin-6 (IL-6) without affecting cyclooxygenase-2 expression. Compound 1h also reduced secretion of IL-6 and tumor necrosis factor-α by LPS-activated J774A.1 murine macrophage cells, primary mice peritoneal macrophages, and JAWSII murine bone marrow-derived dendritic cells and reduced NLRP3 inflammasome-mediated interleukin-1ß (IL-1ß) secretion by LPS + adenosine triphosphate-activated J774A.1 and JAWSII cells. The underlying mechanisms for the anti-inflammatory activity of compound 1h were found to be a decrease in LPS-induced reactive oxygen species (ROS) production, mitogen-activated protein kinase phosphorylation, and NF-κB activation and a decrease in ATP-induced ROS production and PKC-α phosphorylation. These results provide promising insights into the anti-inflammatory activity of these conjugated polyenes and a molecular rationale for future therapeutic intervention in inflammation-related diseases. They also show how compound 1h regulates inflammation and suggest it may be a new source for the development of anti-inflammatory agents to ameliorate inflammation- and NLRP3 inflammasome-related diseases.

Generation of reactive oxygen species by polyenylpyrroles derivatives causes DNA damage leading to G2/M arrest and apoptosis in human oral squamous cell carcinoma cells.

Oral squamous cell carcinoma (OSCC) accounts for 5.8% of all malignancies in Taiwan and the incidence of OSCC is on the rise. OSCC is also a common malignancy worldwide and the five-year survival rate remains poor. Therefore, new and effective treatments are needed to control OSCC. In the present study we have investigated the efficacy and associated mechanisms of polyenylpyrroles and their analogs in both in vitro cell culture and in vivo nude mice xenografts. Auxarconjugatin B (compound 1a) resulted in cell cycle arrest in the G2/M phase and caspase-dependent apoptosis in OEC-M1 and HSC-3 cells by activating DNA damage and mitochondria dysfunction through the loss of mitochondrial membrane potential, release of cytochrome c, increase in B-cell lymphoma-2-associated X protein level, and decrease in B-cell lymphoma-2 level. Compound 1a-induced generation of intracellular reactive oxygen species through cytochrome P450 1A1 was identified as a major mechanism of its effect for DNA damage, mitochondria dysfunction and apoptosis, which was reversed by antioxidant N-acetylcysteine as well as cytochrome P450 1A1 inhibitor and specific siRNA. Furthermore, compound 1a-treated nude mice showed a reduction in the OEC-M1 xenograft tumor growth and an increase in the caspase-3 activation in xenograft tissue. These results provide promising insights as to how compound 1a mediates cytotoxicity and may prove to be a molecular rationale for its translation into a potential therapeutic against OSCC.

Use of medication by nursing home residents nearing end of life: a preliminary report.

BACKGROUND: Nursing home residents usually suffer from a variety of medical conditions and are prescribed a wider variety of medications than any other subpopulation. Polypharmacy is associated with the occurrence of adverse events. PURPOSE: The purposes of this study were to describe the medication prescription patterns of residents who died in a nursing home, to examine how this pattern changed as residents progressed toward death, and to identify correlates of increased medication prescriptions. METHODS: Thirty-one residents who had lived at one nursing home for more than 6 months before death were included in the study. Medication records for participants were obtained at four data collection points: on admission, 6 months before death, 3 months before death, and at death. RESULTS: The mean number of medications prescribed immediately before death was 7.90 (SD = 3.27), and there was an upward trend in number of prescriptions written as patients neared death. The most frequent prescription was for medication for constipation, pulmonary care, and hypertension. There was a significant correlation between residents with heart disease and increased medication use. Medication prescribed for pulmonary care and hypertension increased from admission to death, but a decreased use of medication for pain relief in the time before death in these cases was found. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: This study surveyed and described the pattern of medication use in nursing home residents from admission to the end of life. Results can be used to reinforce clinician and nursing staff awareness of prescription frequency, amounts of medication, and change over time for elderly residents under their care. In addition to safer prescribing practices for the older people, nonpharmacological strategies (e.g., lifestyle modification and physiotherapy for function training) may be used to address common symptoms and complaints during chronic care.

Muscle contributions to support and progression over a range of walking speeds.

Muscles actuate walking by providing vertical support and forward progression of the mass center. To quantify muscle contributions to vertical support and forward progression (i.e., vertical and fore-aft accelerations of the mass center) over a range of walking speeds, three-dimensional muscle-actuated simulations of gait were generated and analyzed for eight subjects walking overground at very slow, slow, free, and fast speeds. We found that gluteus maximus, gluteus medius, vasti, hamstrings, gastrocnemius, and soleus were the primary contributors to support and progression at all speeds. With the exception of gluteus medius, contributions from these muscles generally increased with walking speed. During very slow and slow walking speeds, vertical support in early stance was primarily provided by a straighter limb, such that skeletal alignment, rather than muscles, provided resistance to gravity. When walking speed increased from slow to free, contributions to support from vasti and soleus increased dramatically. Greater stance-phase knee flexion during free and fast walking speeds caused increased vasti force, which provided support but also slowed progression, while contralateral soleus simultaneously provided increased propulsion. This study provides reference data for muscle contributions to support and progression over a wide range of walking speeds and highlights the importance of walking speed when evaluating muscle function.

Myth: nephrolithiasis and medical expulsive therapy.

There is a medical myth that ureteral stones larger than 5 mm will not pass spontaneously and require urological intervention for removal. Recent findings indicate that medical expulsive therapy can facilitate spontaneous passage for stones up to 10 mm. For the management of ureteral stones, we recommend administering tamsulosin and a corticosteroid (deflazacort or prednisone) along with the standard therapy of analgesics, antibiotics and hydration.

Do the hamstrings operate at increased muscle-tendon lengths and velocities after surgical lengthening?

Children with crouch gait frequently walk with improved knee extension during the terminal swing and stance phases following hamstrings lengthening surgery; however, the mechanisms responsible for these improvements are unclear. This study tested the hypothesis that surgical lengthening enables the hamstrings of persons with cerebral palsy to operate at longer muscle-tendon lengths or lengthen at faster muscle-tendon velocities during walking. Sixty-nine subjects who had improved knee extension after surgery were retrospectively examined. The muscle-tendon lengths and velocities of the subjects' semimembranosus muscles were estimated by combining kinematic data from gait analysis with a three-dimensional computer model of the lower extremity. Log-linear analyses confirmed that the subjects who walked with abnormally short muscle-tendon lengths and/or slow muscle-tendon velocities preoperatively tended to walk with longer lengths (21 of 29 subjects, p<0.01) or faster velocities (30 of 40 subjects, p<0.01) postoperatively. In these cases, surgical lengthening may have slackened the subjects' tight hamstrings and/or diminished the hamstrings' spastic response to stretch. Other subjects walked with muscle-tendon lengths and velocities that were neither shorter nor slower than normal preoperatively (22 of 69 subjects), and the semimembranosus muscles of most of these subjects did not operate at increased lengths or velocities after surgery; in these cases, the subjects' postsurgical improvements in knee extension may have been unrelated to the hamstrings surgery. Analyses of muscle-tendon lengths and velocities may help to distinguish individuals who have "short" or "spastic" hamstrings from those who do not, and thus may augment conventional methods used to describe patients' neuromusculoskeletal impairments and gait abnormalities.

Muscles that support the body also modulate forward progression during walking.

The purpose of this study was to characterize the contributions of individual muscles to forward progression and vertical support during walking. We systematically perturbed the forces in 54 muscles during a three-dimensional simulation of walking, and computed the changes in fore-aft and vertical accelerations of the body mass center due to the altered muscle forces during the stance phase. Our results indicate that muscles that provided most of the vertical acceleration (i.e., support) also decreased the forward speed of the mass center during the first half of stance (vasti and gluteus maximus). Similarly, muscles that supported the body also propelled it forward during the second half of stance (soleus and gastrocnemius). The gluteus medius was important for generating both forward progression and support, especially during single-limb stance. These findings suggest that a relatively small group of muscles provides most of the forward progression and support needed for normal walking. The results also suggest that walking dynamics are influenced by non-sagittal muscles, such as the gluteus medius, even though walking is primarily a sagittal-plane task.

The role of estimating muscle-tendon lengths and velocities of the hamstrings in the evaluation and treatment of crouch gait.

Persons with cerebral palsy frequently walk with excessive knee flexion during terminal swing and stance. This gait abnormality is often attributed to "short" or "spastic" hamstrings that restrict knee extension, and is often treated by hamstrings lengthening surgery. At present, the outcomes of these procedures are inconsistent. This study examined whether analyses of the muscle-tendon lengths and lengthening velocities of patients' hamstrings during walking may be helpful when deciding whether a candidate is likely to benefit from hamstrings surgery. One hundred and fifty-two subjects were cross-classified in a series of multi-way contingency tables based on their pre- and postoperative gait kinematics, muscle-tendon lengths, muscle-tendon velocities, and hamstrings surgeries. The lengths and velocities of the subjects' semimembranosus muscles were estimated by combining kinematic data from gait analysis with a three-dimensional computer model of the lower extremity. Log-linear analysis revealed that the subjects who walked with abnormally "short" or "slow" hamstrings preoperatively, and whose hamstrings did not operate at longer lengths or faster velocities postoperatively, were unlikely to walk with improved knee extension after treatment (p < 0.05). Subjects who did not walk with abnormally short or slow hamstrings preoperatively, and whose hamstrings did operate at longer lengths or faster velocities postoperatively, tended to exhibit unimproved or worsened anterior pelvic tilt after treatment (p < 0.05). Examination of the muscle-tendon lengths and velocities allows individuals who walk with abnormally short or slow hamstrings to be distinguished from those who do not, and thus may help to identify patients who are at risk for unsatisfactory postsurgical changes in knee extension or anterior pelvic tilt.

Characterization of the N-deacetylase domain from the heparan sulfate N-deacetylase/N-sulfotransferase 2.

Heparin and heparan sulfate are linear sulfated polysaccharides that exert a multitude of biological functions. Heparan sulfate glucosaminyl N-deacetylase/N-sulfotransferase isoform 2 (NDST-2), a key enzyme in the biosynthesis of heparin, contains two distinct activities. This bifunctional enzyme removes the acetyl group from N-acetylated glucosamine (N-deacetylase activity) and transfers a sulfuryl group to the unsubstituted amino position (N-sulfotransferase activity). The N-sulfotransferase activity of NDST has been unambiguously localized to the C-terminal domain of NDST. Here, we report that the N-terminal domain of NDST-2 retains N-deacetylase activity. The N-terminal domain (A66-P604) of human NDST-2, designated as N-deacetylase (NDase), was cloned as a (His)(6)-fusion protein, and protein expression was carried out in Escherichia coli. Heparosan treated with NDase contains N-unsubstituted glucosamine and is highly susceptible to N-sulfation by N-sulfotransferase. Our results conclude that the N-terminal domain of NDST-2 contains functional N-deacetylase activity. This finding helps further elucidate the mechanism of action of heparan sulfate N-deacetylase/N-sulfotransferases and the biosynthesis of heparan sulfate in general.