Neurotensin (NTS) is a 13-amino acid neuropeptide originally identified in the bovine hypothalamus during the mid-1970s during substance P purification. In humans, NTS functions extend beyond the central nervous system to multiple physiological systems. Within the brain, NTS regulates luteinizing hormone (LH) and prolactin release, controls appetite, modulates pain, and influences endocrine functions . Beyond neural tissue, NTS is distributed throughout the cardiovascular system, gastrointestinal tract, endocrine system, and reproductive system .
In the endocrine system specifically, NTS regulates hormone secretion, leading to increases in adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and prolactin . Recent research has identified dramatic upregulation of NTS in human granulosa cells during the ovulatory period, with expression increasing nearly 15,000-fold between pre-hCG and late ovulatory phases, suggesting crucial roles in human reproduction .
NTS expression in human reproductive tissues is regulated through multiple converging signaling pathways. Research using cultured human granulosa-luteal cells has revealed several key regulatory mechanisms:
The cAMP/PKA pathway serves as a primary mediator of NTS induction, with the PKA inhibitor H89 significantly blocking hCG-induced NTS expression . This aligns with findings in neuronal systems where cAMP response element-binding protein (CREB) phosphorylation precedes NTS gene transcription .
The EGF receptor pathway contributes substantially, with the EGF receptor inhibitor AG1478 reducing hCG-induced NTS expression by approximately 60% in human granulosa-luteal cells . This suggests hCG signals partially through EGF receptor transactivation to induce NTS expression.
Additional signaling cascades involved include:
PKC pathway (evidenced by inhibition with GF109203x)
PI3K pathway (demonstrated using LY294002 inhibitor)
Notably, the prostaglandin synthase pathway and progesterone receptor pathway do not significantly affect hCG-induced NTS expression in human granulosa cells . This multi-pathway regulation ensures robust NTS induction during the ovulatory process, suggesting important physiological functions in human reproduction.
Investigating NTS expression in human tissues requires a comprehensive methodological approach:
1. Human tissue collection protocols: For reproductive research, granulosa-luteal cells (GLCs) are typically collected from women undergoing in vitro fertilization after controlled ovarian hyperstimulation . Following recombinant FSH administration and hCG triggering, follicles are aspirated 36 hours post-hCG. After oocyte removal, cumulus cells and GLCs are collected separately, with GLCs subjected to Percoll gradient purification to remove red blood cells .
2. In vitro culture models: GLCs are cultured for 6-7 days to create a controlled system for studying NTS expression dynamics and regulation through various treatments . This approach allows examination of temporal changes and response to pathway inhibitors.
3. Molecular expression analysis: Real-time PCR provides precise quantification of NTS mRNA expression changes, documenting dramatic upregulation (up to 15,000-fold in vivo) after hCG treatment . Cycle threshold values help determine expression levels of NTS receptors, with SORT1 identified as the most abundant receptor in human granulosa cells .
4. Signaling pathway analysis: Pharmacological inhibitors targeting specific signaling cascades are employed to investigate regulatory mechanisms:
EGF receptor inhibitor (AG1478)
Progesterone receptor antagonist (RU486)
Prostaglandin synthase inhibitors (NS398, Indomethacin)
PKA inhibitor (H89)
PKC inhibitor (GF109203x)
PI3K inhibitor (LY294002)
5. Comparative analysis: Parallel studies in human and animal models (e.g., rat granulosa cells) allow identification of species-specific and conserved regulatory mechanisms .
These methodologies collectively provide a comprehensive approach to understanding NTS expression, regulation, and potential functions in human tissues.
Comparative analysis of NTS receptor expression reveals important species-specific differences between human and rat granulosa cell models:
NTSR1 (high-affinity receptor):
Human: Expression is extremely low in both in vivo collected granulosa cells and cultured granulosa-luteal cells, with cycle threshold values above 40 cycles and no significant change with hCG treatment .
Rat: Similarly shows minimal expression with cycle threshold values above 40 cycles and no change with hCG treatment .
Comparison: Both species demonstrate negligible NTSR1 expression in granulosa cells, suggesting this receptor is not a major mediator of NTS action in ovarian tissues across species .
NTSR2 (low-affinity receptor):
Human: Expression is low but detectable. In vivo, NTSR2 mRNA decreases after hCG administration, while in cultured human granulosa-luteal cells, expression remains unchanged with hCG treatment .
Rat: Expression has high cycle threshold values (approximately 40 cycles) and does not change with hCG treatment .
Comparison: Humans show higher baseline expression and hormonal responsiveness of NTSR2 compared to rats .
SORT1 (Sortilin 1/NTSR3):
Human: In vivo, SORT1 mRNA expression decreases after hCG administration. In cultured human granulosa-luteal cells, SORT1 expression increases across time in culture, with this increase diminished by hCG administration .
Rat: Present in granulosa cells but expression does not change over time or with hCG treatment .
Comparison: SORT1 shows more dynamic regulation in human models compared to rat models .
| Receptor | Human Expression | Rat Expression | Response to hCG (Human) | Response to hCG (Rat) | 
|---|---|---|---|---|
| NTSR1 | Very low (CT>40) | Very low (CT>40) | No change | No change | 
| NTSR2 | Low but detectable | Very low (CT~40) | Decreases in vivo, unchanged in vitro | No change | 
| SORT1 | Abundant | Abundant | Decreases in vivo, moderates increase in vitro | No change | 
The magnitude of NTS induction shows remarkable differences between in vivo and in vitro human models, providing important insights into physiological versus experimental contexts:
In vivo human granulosa cells:
NTS mRNA increases approximately 15,000-fold between cells collected prior to hCG administration and those collected during the late ovulatory period . This dramatic upregulation occurs within the native ovarian environment with intact paracrine signaling networks.
In vitro cultured human granulosa-luteal cells:
NTS expression increases approximately 50-fold within 6 hours after hCG induction in the culture system . While significant, this represents only a fraction (about 0.3%) of the induction magnitude observed in vivo.
This substantial difference (300-fold higher induction in vivo) suggests several important considerations for researchers:
The in vivo ovarian environment likely provides additional amplifying factors or signaling networks absent in isolated cell cultures .
Complex intercellular communications within the follicular structure may potentiate NTS expression beyond what can be achieved in monocultured granulosa cells .
The temporal dynamics of NTS induction may differ between the systems, with potentially different peak expression timepoints .
Immunohistochemistry studies reveal that NTS protein expression patterns mimic mRNA changes but with differences in magnitude, suggesting post-transcriptional regulation that may not be fully recapitulated in vitro .
These observations highlight both the complementary nature and limitations of in vitro models in NTS research. While in vitro systems provide controlled environments for mechanistic studies, researchers should exercise caution when extrapolating quantitative findings to in vivo contexts, particularly regarding the magnitude of physiological responses.
Nontechnical Skills (NTS) in healthcare are defined as "a constellation of cognitive and social skills, exhibited by individuals and teams, needed to reduce error, and improve human performance in complex systems" . These skills complement technical medical knowledge and procedural abilities to enhance patient safety and quality of care. The core components include:
Communication: Effective verbal and non-verbal exchange of information between healthcare professionals and with patients .
Situational awareness: The ability to perceive elements in the environment, comprehend their meaning, and project their status into the near future .
Decision-making: The cognitive process of selecting appropriate courses of action using clinical reasoning and risk assessment .
Prioritization: Ranking tasks and interventions based on urgency and importance in resource-constrained settings .
Leadership: Effectively guiding teams by establishing clear roles and maintaining focus on patient care goals .
Teamwork: Collaborative functioning among professionals to achieve common goals through coordination and shared mental models .
Feedback processing: Receiving, interpreting, and incorporating constructive feedback to improve performance .
These skills are increasingly recognized as essential elements in modern healthcare delivery, with regulatory bodies like the UK General Medical Council incorporating them as key components in their Generic Professional Capabilities Framework . Research demonstrates that proficiency in these nontechnical domains significantly contributes to reducing medical errors and improving patient outcomes across all fields of medicine .
Research on Nontechnical Skills (NTS) education identifies several evidence-based teaching methodologies for undergraduate healthcare settings:
1. Simulation-based training: High-fidelity simulation provides a controlled environment for practicing NTS under realistic clinical conditions . Effectiveness increases when scenarios specifically target NTS rather than primarily technical skills, and when structured debriefing follows simulation exercises .
2. Team-based learning (TBL): This approach combines individual preparation with collaborative problem-solving in small groups, particularly effective for developing communication, teamwork, and decision-making skills . TBL works best when cases require integration of technical knowledge with NTS application and when clear team roles are established.
3. Standardized patient encounters: Trained actors simulating patients or family members provide opportunities for developing communication skills in challenging scenarios such as breaking bad news, managing conflict, or obtaining informed consent .
4. Case-based discussions: Structured analysis of real or simulated cases with explicit focus on NTS elements allows students to identify NTS components in clinical scenarios and analyze how these skills impact patient outcomes .
5. Workplace-based learning with structured feedback: Clinical placements with integrated NTS observation enable authentic practice in real healthcare environments with immediate contextual feedback from experienced clinicians .
6. Interprofessional education (IPE): Collaborative learning across healthcare disciplines enhances understanding of team dynamics and role clarity when scenarios reflect real interprofessional challenges .
Research indicates that multimodal approaches combining several methodologies throughout the curriculum yield the strongest outcomes, particularly when reinforced through deliberate practice and structured feedback . Each methodology should be selected based on specific learning objectives and appropriate developmental stage within the educational program.
Implementation of Nontechnical Skills (NTS) training in healthcare curricula faces several significant barriers that researchers and educators must address:
1. Resource constraints:
Limited availability of faculty trained in NTS concepts and teaching methods
Insufficient simulation equipment, facilities, or technology
Inadequate funding for faculty development and curriculum implementation
Crowded curricula with competing priorities for limited instructional hours
2. Knowledge and awareness barriers:
Limited understanding of NTS importance among curriculum decision-makers
Misconceptions that NTS are innate rather than teachable skills
Lack of consensus on essential NTS components and assessment methods
3. Cultural and organizational challenges:
Traditional emphasis on technical skills and knowledge acquisition
Disciplinary silos hindering interprofessional NTS education
Resistance to curriculum change from established faculty
Hierarchical medical culture conflicting with NTS principles
4. Methodological limitations:
Uncertainty about optimal teaching methods for specific NTS domains
Challenges in creating authentic assessment tools for complex skills
Difficulties measuring long-term retention and transfer to clinical practice
5. Faculty-related barriers:
Insufficient training in NTS concepts among medical educators
Limited experience with interactive teaching methodologies
Discomfort providing feedback on interpersonal and cognitive skills
6. Curricular integration challenges:
Difficulty balancing integrated versus standalone NTS teaching
Competing demands from expanding medical knowledge requirements
Fragmentation between pre-clinical and clinical education phases
Addressing these barriers requires comprehensive strategies including faculty development, institutional leadership commitment, curricular redesign approaches, and robust evaluation methodologies that demonstrate the value of NTS education for patient care outcomes .
Research has identified several key predictors of successful Nontechnical Skills (NTS) implementation in healthcare education programs:
1. Academic year integration:
In a multivariate analysis from a Hungarian cross-sectional study, teaching students in the second academic year emerged as the only independent predictor of NTS education (p = 0.012) . This suggests the importance of introducing these concepts early in professional formation while students are developing their clinical identity.
2. Institutional factors:
Strong leadership support and visible commitment
Alignment with institutional strategic priorities
Dedicated resources (financial, personnel, facilities)
3. Curriculum design characteristics:
Clear competency framework with explicit learning objectives
Strategic integration throughout the program rather than isolated modules
Progressive complexity matched to learner development stage
Multimodal teaching approaches addressing different learning styles
4. Faculty attributes:
Dedicated faculty development focused on NTS concepts and teaching
Champions with expertise driving implementation
5. Implementation process variables:
Pilot testing with iterative improvement
Phased approach allowing adaptation to local context
Regular evaluation with responsive adjustments
6. Assessment and feedback mechanisms:
Robust assessment methodology aligned with learning objectives
Formative feedback emphasizing development
7. Field of medicine context:
The Hungarian study found significant differences in NTS teaching based on medical specialty (p = 0.025), suggesting that certain clinical disciplines may be more amenable to NTS integration, particularly those emphasizing teamwork importance (p = 0.021) .
These factors collectively contribute to creating an environment conducive to successful NTS program implementation, with early integration during foundational training years being particularly important.
Effective assessment of Nontechnical Skills (NTS) in healthcare education requires carefully designed approaches that capture the complex nature of these competencies:
1. Multi-dimensional assessment framework:
Assessment should address multiple domains of NTS competence:
Knowledge component (understanding NTS principles and relevance)
Skill demonstration (observable behaviors in simulated or clinical settings)
Attitudinal aspects (valuing NTS in professional practice)
Integration capability (applying NTS alongside technical skills)
2. Validated assessment tools:
Several validated instruments designed specifically for NTS assessment can be employed:
Anaesthetists' Non-Technical Skills (ANTS) system
Non-Technical Skills for Surgeons (NOTSS) rating system
Team Emergency Assessment Measure (TEAM)
3. Observational assessment methods:
Direct observation provides the most authentic assessment approach:
Structured observation in simulation scenarios
Workplace-based assessment during clinical placements
Video analysis with standardized rating scales
4. Progressive assessment strategy:
Assessment should follow developmental progression:
Formative assessment early in the curriculum focusing on basic concepts
Increasing complexity of scenarios as learners develop
Summative assessment integrating NTS with technical skills
Longitudinal tracking of development across training program
5. Feedback mechanisms:
Effective feedback is crucial for NTS development:
Specific, descriptive feedback on observable behaviors
Balanced approach identifying strengths and development needs
Self-assessment components developing reflective capacity
6. Authentic contextual assessment:
Assessment should reflect realistic healthcare challenges:
Team-based scenarios requiring interprofessional collaboration
Variable conditions simulating clinical uncertainty
Time-pressured situations requiring prioritization
Communication challenges with simulated patients or colleagues
An effective NTS assessment program integrates these elements into a comprehensive approach that captures competence across multiple dimensions while providing actionable feedback to guide ongoing development throughout healthcare education.
Designing robust studies to investigate NTS regulation in human tissues requires careful methodological planning:
1. Sample collection and processing protocols:
Standardized timing relative to hormonal stimulation (e.g., 36 hours post-hCG in IVF patients)
Consistent cell isolation techniques (e.g., Percoll gradient for granulosa cells)
Rapid processing to preserve molecular integrity
Detailed documentation of patient demographics and treatment protocols
2. Experimental design principles:
Include appropriate time-course studies to capture dynamic expression changes
Employ paired designs when possible to reduce inter-individual variability
Include adequate biological replicates (minimum n=3-5 per condition)
Incorporate both positive and negative controls for all experiments
3. Pathway analysis approaches:
Use selective pharmacological inhibitors targeting specific signaling pathways:
Complement inhibitor studies with molecular approaches (siRNA, CRISPR)
Verify pathway activation through phosphorylation state analysis
4. Expression analysis methods:
Quantitative RT-PCR with validated reference genes
Protein confirmation via Western blot or immunohistochemistry
Receptor localization studies using immunofluorescence
5. Translational considerations:
Parallel in vitro and in vivo studies when ethically possible
Comparative analysis between human and animal models
Functional studies to determine physiological significance
6. Statistical analysis:
Select appropriate tests based on data distribution
Account for multiple comparisons in pathway analyses
Consider hierarchical or mixed models for nested data
This methodological framework provides a comprehensive approach to investigating NTS regulation, enabling robust and reproducible research findings in this complex signaling system.
NTS education research benefits from structured evaluation frameworks that capture the multidimensional nature of these skills and their development:
1. Kirkpatrick's four-level evaluation model:
This widely-adopted framework provides a comprehensive structure for NTS education assessment:
Level 1 (Reaction): Measure participant satisfaction and perceived relevance
Level 2 (Learning): Assess knowledge acquisition and skill development
Level 3 (Behavior): Evaluate transfer of learning to clinical practice
Level 4 (Results): Measure impact on patient outcomes and organizational metrics
2. Mixed-methods research design:
Combining quantitative and qualitative methodologies provides complementary insights:
Quantitative: Pre/post knowledge tests, skill performance ratings, clinical outcome metrics
Qualitative: Interviews, focus groups, reflective journals, observational field notes
Integration: Mixed analysis to identify convergence/divergence between data types
3. Longitudinal study approaches:
Measuring NTS retention and application over time:
Immediate post-training assessment
Delayed follow-up (3-6 months)
Long-term follow-up (12+ months)
Repeated measures analysis to track skill development or decay
4. Comparative effectiveness research:
Systematic comparison of different educational approaches:
Control group designs (traditional vs. NTS-enhanced education)
Comparison of different NTS teaching methodologies
Cost-effectiveness analysis including implementation resources
5. Implementation science framework:
Evaluating the process of educational intervention deployment:
Fidelity assessment (delivery as designed)
Barriers and facilitators analysis
Resource utilization measurement
6. Realist evaluation approach:
Examining what works, for whom, in what circumstances:
Context-mechanism-outcome configurations
Program theory development and testing
Stakeholder involvement in evaluation design
Effective NTS education research typically employs multiple elements from these frameworks, selecting approaches most appropriate to specific research questions while maintaining methodological rigor through attention to validity, reliability, and potential confounding factors.
The interaction between NTS signaling and other ovulatory pathways in human follicles reveals complex regulatory networks:
1. EGF-like growth factor network interactions:
hCG-induced NTS expression is partially mediated through the EGF receptor pathway, as demonstrated by the approximately 60% reduction in NTS induction when the EGF receptor inhibitor AG1478 is applied . This suggests that NTS signaling is integrated with the critical EGF-like growth factor network (including amphiregulin, epiregulin, and betacellulin) that mediates many ovulatory events.
2. PKA pathway integration:
The protein kinase A (PKA) inhibitor H89 significantly blocks hCG-induced NTS expression in human granulosa-luteal cells, positioning NTS in the classical cAMP/PKA signaling cascade that is activated by the LH surge . This aligns with findings in neuronal systems where cAMP response element-binding protein (CREB) phosphorylation precedes NTS gene transcription .
3. Independence from prostaglandin signaling:
Unlike many ovulatory genes, hCG-induced NTS expression is not affected by inhibitors of prostaglandin synthase . This distinguishes NTS from prostaglandin-dependent ovulatory pathways and suggests it may represent a parallel signaling mechanism during follicular rupture.
4. Independence from progesterone receptor signaling:
NTS induction by hCG is not altered by the progesterone receptor antagonist RU486 . This contrasts with numerous ovulatory genes that require progesterone receptor activation, again positioning NTS in a potentially distinct signaling cascade.
5. PI3K and MAPK pathway involvement:
PI3K inhibitor (LY294002) and p38 MAPK inhibitor (SB203580) partially reduce NTS expression in human granulosa-luteal cells . These pathways are known to mediate various aspects of ovulatory signaling, suggesting NTS is integrated into these broader networks.
This complex integration of NTS with multiple signaling pathways, coupled with its dramatic upregulation during the periovulatory period, suggests NTS may serve as an important coordinator or modulator of the ovulatory process in human follicles through mechanisms distinct from classical prostaglandin and progesterone pathways.
Advanced simulation approaches for NTS training are evolving rapidly to enhance realism, engagement, and learning effectiveness:
1. Hybrid simulation technologies:
Combining physical task trainers with standardized patients creates scenarios that integrate technical and nontechnical skills simultaneously . For example, a standardized patient may wear a partial task trainer while engaging in communication, allowing learners to practice procedural skills and communication concurrently.
2. In situ simulation:
Conducting simulations in actual clinical environments rather than dedicated simulation centers enhances ecological validity and identifies system-level factors affecting NTS implementation . This approach tests both individual skills and organizational readiness for complex situations requiring effective NTS deployment.
3. Virtual reality (VR) and augmented reality (AR):
Immersive technologies enable scenarios that would be difficult or impossible to recreate physically, such as mass casualty incidents or rare clinical emergencies . VR particularly excels at creating emotionally challenging situations that test decision-making and leadership under pressure.
4. Screen-based simulation:
Computer-based scenarios allowing for branching decision pathways based on learner choices provide scalable NTS training opportunities . These can be particularly effective for decision-making and situational awareness training with the advantage of standardized delivery and automated feedback.
5. Multi-patient simulation:
Advanced scenarios involving simultaneous management of multiple patients specifically target prioritization skills and resource allocation decisions . These complex simulations more accurately reflect real clinical environments where competing demands must be balanced.
6. Long-duration simulations:
Extended scenarios running several hours or across multiple days test endurance, handover communication, and the sustainability of NTS under fatigue conditions . These simulations better approximate the challenges of maintaining effective NTS during extended clinical care episodes.
7. Distributed simulation:
Technology-enabled scenarios connecting participants in different physical locations simulate the challenges of distance consultation and telemedicine communications . These approaches are increasingly relevant as healthcare delivery models incorporate more virtual care components.
These cutting-edge approaches push beyond basic simulation to create increasingly authentic learning experiences that challenge learners to integrate NTS in complex, realistic scenarios approximating the full complexity of modern healthcare environments.
Future research in NTS and human reproduction should address several critical knowledge gaps:
1. Functional significance determination:
Despite dramatic upregulation during the ovulatory period, the specific physiological functions of NTS in human reproduction remain incompletely understood . Priority investigations should include:
Targeted receptor blocking studies to determine phenotypic effects
Correlation of NTS expression levels with clinical outcomes in IVF
Investigation of NTS roles in follicular rupture mechanisms
Exploration of potential roles in oocyte maturation and quality
2. Receptor-specific signaling elucidation:
With SORT1 identified as the predominant NTS receptor in human granulosa cells, research should focus on:
SORT1-specific downstream signaling cascades
Potential interactions between SORT1 and other receptor systems
Subcellular localization and trafficking of SORT1 in response to NTS
Functional consequences of the dynamic regulation of SORT1 by hCG
3. Translation to clinical applications:
Research should explore potential clinical relevance of NTS in reproductive medicine:
NTS as a biomarker for ovulatory dysfunction
Therapeutic potential of NTS modulation in ovulatory disorders
Relationships between NTS signaling and polycystic ovary syndrome
4. Systems biology approach:
The complex regulation of NTS suggests the need for comprehensive analysis:
Transcriptomic profiling of NTS-responsive genes
Proteomic analysis of NTS-induced cellular changes
Integration of NTS into broader ovulatory signaling networks
5. Comparative physiology studies:
Building on observed species differences between human and rat models:
Expanded cross-species analysis of NTS regulation
Evolutionary perspectives on NTS signaling in reproduction
Identification of conserved versus species-specific aspects of NTS function
These research priorities would significantly advance understanding of NTS biology in human reproduction and potentially open new avenues for diagnostic and therapeutic interventions in reproductive medicine.
The landscape of NTS education in healthcare is undergoing significant evolution in response to emerging evidence, changing healthcare delivery models, and technological innovations:
1. Integration into competency-based education frameworks:
NTS are increasingly embedded within formal competency frameworks rather than treated as supplemental content . Professional regulatory bodies worldwide now explicitly include NTS domains within required graduate competencies, driving curriculum reform.
2. Earlier introduction in educational continuum:
Research indicates that introducing NTS training during early formative years (particularly second academic year) predicts successful implementation . This is shifting NTS education from primarily postgraduate to undergraduate programs, creating a developmental trajectory throughout training.
3. Interprofessional education emphasis:
Recognition that healthcare is delivered by teams rather than individuals is driving interprofessional approaches to NTS education . Programs increasingly bring together students from medicine, nursing, pharmacy, and allied health for collaborative NTS development.
4. Technology-enhanced simulation:
Advanced technologies including virtual reality, augmented reality, and artificial intelligence are expanding simulation capabilities beyond traditional approaches . These innovations enable more frequent practice opportunities and personalized feedback.
5. Workplace-based assessment integration:
NTS evaluation is moving from controlled simulation environments to authentic clinical contexts through structured workplace-based assessment tools . This shift emphasizes the application of NTS in real practice settings with actual teams.
6. Systems approach to NTS:
The focus is expanding from individual skills to team and system factors that enable or constrain effective NTS application . This broader perspective recognizes that individual competence must be supported by appropriate organizational conditions.
7. Patient involvement in NTS education:
Patients are increasingly engaged as educators and assessors in NTS training, contributing authentic perspectives on communication and shared decision-making quality . This represents a shift toward patient-centered conceptualizations of NTS.
As healthcare education continues to evolve, these trends suggest NTS will become more deeply integrated throughout health professions training, with increasingly sophisticated approaches to teaching and assessment that better reflect the complex, team-based nature of modern healthcare delivery.
Neurotensin is a tridecapeptide (13 amino acids) neuropeptide that was first isolated in 1973. It is widely distributed throughout the central nervous system (CNS) and the gastrointestinal tract. Neurotensin functions as both a neurotransmitter and a neuromodulator, playing a crucial role in various physiological processes.
Neurotensin is derived from a larger precursor protein known as pro-neurotensin/neuromedin N. The human neurotensin gene (NTS) encodes this precursor, which is subsequently cleaved to produce neurotensin and another peptide, neuromedin N . The recombinant form of human neurotensin is typically produced in E. coli or HEK293 cells, with the protein often tagged for purification purposes .
Neurotensin has a wide range of biological functions, including:
Neurotensin exerts its effects through three main receptors: NTS1, NTS2, and NTS3. These receptors are G-protein coupled receptors (GPCRs) that activate various intracellular signaling pathways. NTS1 is primarily involved in the modulation of dopamine pathways, while NTS2 and NTS3 have roles in pain modulation and neuroprotection .
Neurotensin and its receptors have been implicated in several diseases, including: