TINAGL1 Human

What is TINAGL1 and what are its primary functions in human biology?

TINAGL1 (Tubulointerstitial Nephritis Antigen Like 1) is a secreted glycoprotein that functions as an extracellular matrix protein involved in cell adhesion, proliferation, migration, and differentiation . It shares sequence similarity with tubulointerstitial nephritis antigen, which is recognized by antibodies in certain immune-related tubulointerstitial nephritis cases .

From a functional perspective, TINAGL1 demonstrates cysteine-type peptidase activity and scavenger receptor activity, though it is classified as a non-catalytic peptidase C1 family protein . Research indicates it may be implicated in adrenocortical zonation and mechanisms for repressing CYP11B1 gene expression in adrenocortical cells . The protein has been identified as having involvement in multiple physiological systems, with particularly notable roles emerging in reproductive biology and potential implications in several pathological conditions.

How is TINAGL1 expressed across different human tissues and what regulates its expression?

TINAGL1 expression patterns vary significantly across tissue types, with emerging research highlighting its presence in human granulosa cells of the ovary . Expression regulation appears to be tissue-specific and potentially hormone-responsive, as evidenced by research in mouse models showing TINAGL1 functions as a serum biomarker that fluctuates throughout the estrous cycle, with peak expression during the estrous phase .

The gene is associated with multiple transcript variants encoding different isoforms, with at least three identified variants according to current research . These different isoforms may contribute to tissue-specific functions and regulatory mechanisms. The molecular weight of the protein is approximately 52 kDa with 467 amino acids, consistent with observations in immunoblotting experiments .

Gene regulation may involve microRNA-mediated mechanisms, as TINAGL1 has been identified as a potential target for multiple microRNAs, suggesting complex post-transcriptional regulatory networks .

What are the most reliable methods for detecting TINAGL1 in human tissue samples?

For reliable TINAGL1 detection in human tissue samples, immunological techniques have demonstrated significant efficacy. Specifically:

Immunofluorescence (IF): Validated antibodies such as the Rabbit Polyclonal TINAGL1 antibody (CL647-12077) have shown excellent reactivity with human samples in immunofluorescence applications. For optimal results, recommended dilution ranges are 1:50-1:500 for immunofluorescence on paraffin-embedded tissues (IF-P) .

Enzyme-linked Immunosorbent Assay (ELISA): Commercial ELISA kits have been successfully employed to quantify TINAGL1 protein levels in human follicular fluid, as demonstrated in research studying its relationship to ovarian reserve .

Quantitative Real-time PCR (qPCR): For gene expression analysis, qPCR following RNA extraction and cDNA amplification has proven effective for quantifying TINAGL1 mRNA expression in human cells, such as granulosa cells recovered from follicular fluid .

The choice of method should be tailored to the specific research question, with consideration of whether protein localization, quantification, or gene expression data is most relevant to the investigation.

What antibodies are currently available for TINAGL1 research and what are their validated applications?

This antibody has been specifically validated for immunofluorescence on paraffin-embedded tissues (IF-P) with a recommended dilution range of 1:50-1:500. It recognizes the full TINAGL1 protein (52 kDa) and has demonstrated specific staining in human liver cancer tissue .

When selecting antibodies for TINAGL1 research, considerations should include:

• Target application (Western blot, immunohistochemistry, immunofluorescence, etc.)

• Species cross-reactivity requirements

• Conjugation needs (fluorescent tags vs. unconjugated primary antibodies)

• Mono vs. polyclonal properties depending on specificity requirements

Researchers should validate antibodies in their specific experimental conditions, as performance can vary based on tissue type, fixation methods, and detection systems .

What is the significance of TINAGL1 in human ovarian biology and fertility research?

Recent research has identified TINAGL1 as a potentially critical factor in human reproductive biology, particularly in ovarian function. A 2024 study (the first to demonstrate TINAGL1 expression in human granulosa cells) found that TINAGL1 concentration was significantly lower in the follicular fluid of patients with diminished ovarian reserve (DOR) compared to control patients without infertility or those with polycystic ovarian syndrome (PCOS) .

The protein's importance in reproduction is further supported by evidence from animal models. TINAGL1 knockout mice have been documented to be infertile, suggesting a fundamental role in normal reproductive function . Additionally, TINAGL1 functions as a serum biomarker that fluctuates throughout the mouse estrous cycle, with peak expression during the estrous phase, indicating hormone-responsive regulation .

These findings collectively suggest that TINAGL1 may serve as a novel biomarker for ovarian reserve assessment and potentially play a mechanistic role in female fertility. The correlation between decreased TINAGL1 levels and diminished ovarian reserve could provide new insights into the molecular basis of certain forms of female infertility.

How should researchers design experiments to study TINAGL1's role in human granulosa cells?

Based on recent methodological approaches in TINAGL1 ovarian research, investigators should consider the following experimental design elements:

Sample Collection Protocol:

• Collect follicular fluid during oocyte retrieval procedures from well-defined patient populations (e.g., DOR patients, PCOS patients, and controls undergoing fertility preservation or with partners with male factor infertility only)

• Isolate granulosa cells from follicular fluid using standardized separation techniques

• Ensure proper demographic and clinical data collection for meaningful stratification and analysis

Protein Expression Analysis:

• Quantify TINAGL1 protein levels in follicular fluid using validated commercial ELISA kits

• Consider analyzing TINAGL1 in matched serum samples to determine if circulating levels correlate with follicular fluid concentrations

Gene Expression Analysis:

• Extract RNA from isolated granulosa cells using standardized protocols

• Perform cDNA synthesis and qPCR with validated TINAGL1-specific primers

• Include appropriate housekeeping genes as internal controls

Functional Studies:

• Consider in vitro modulation of TINAGL1 expression in cultured granulosa cells (knockdown or overexpression)

• Assess impact on cell proliferation, steroidogenesis, and response to gonadotropins

• Evaluate interactions with extracellular matrix components and potential receptor-mediated signaling

A comprehensive approach combining these methods would provide insights into both the potential utility of TINAGL1 as a biomarker and its functional significance in ovarian physiology and pathology .

What is known about TINAGL1's role in cancer biology, particularly colorectal adenocarcinoma?

TINAGL1 has emerging significance in cancer biology with notable associations to colorectal adenocarcinoma. According to GeneCards data, colorectal adenocarcinoma is among the diseases associated with TINAGL1 gene dysregulation . While the search results don't provide extensive details about the specific mechanisms in colorectal cancer, research in other cancer models offers relevant insights.

In breast cancer research, TINAGL1 has been studied in the context of tumor microenvironment interactions. Studies have indicated that TINAGL1 can bind to EGFR and integrins on tumor cells, which in the 4T1 murine breast cancer model resulted in downregulation of cancer proliferation and metastasis pathways . This suggests that TINAGL1 may function as a matricellular protein that influences cancer cell signaling and potentially tumor progression.

For researchers investigating TINAGL1 in colorectal cancer, examination of:

• Expression patterns in tumor versus normal mucosa

• Correlation with disease stage and progression

• Potential interactions with known colorectal cancer signaling pathways (such as Wnt/β-catenin)

• Its utility as a prognostic or predictive biomarker

would be valuable approaches to better understand its role in this specific cancer type.

What methodological approaches are recommended for studying TINAGL1 in pathological contexts?

When investigating TINAGL1 in disease states, researchers should consider implementing the following methodological approaches:

Tissue Expression Analysis:

• Immunohistochemistry/immunofluorescence to evaluate TINAGL1 expression patterns in diseased versus normal tissues

• Tissue microarrays for high-throughput screening across multiple patient samples

• Laser capture microdissection to isolate specific cell populations for more precise expression analysis

Functional Studies:

• Gene knockdown or overexpression in relevant cell lines to assess phenotypic effects

• Co-immunoprecipitation to identify protein-protein interactions relevant to disease mechanisms

• Receptor binding assays to characterize interactions with EGFR, integrins, or other potential binding partners

Clinical Correlation:

• Analysis of TINAGL1 levels in patient biospecimens (tissue, serum, or other biological fluids)

• Correlation with clinicopathological parameters and patient outcomes

• Multivariate analysis to assess independent prognostic value

Animal Models:

• Development or utilization of conditional tissue-specific knockout models to assess TINAGL1 function in relevant disease contexts

• Xenograft studies with TINAGL1-manipulated cells to evaluate effects on tumor growth and metastasis

These approaches should be tailored to the specific disease context and research question. Researchers should be mindful that TINAGL1's matricellular nature suggests both structural roles and signaling functions that may be tissue-specific and context-dependent .

How does TINAGL1 interact with other proteins and signaling pathways in human cellular systems?

TINAGL1 demonstrates complex interactions with various proteins and signaling pathways that are beginning to be elucidated. Based on current research:

TINAGL1 has been shown to interact with cell surface receptors, notably EGFR (epidermal growth factor receptor) and integrins in cancer models. These interactions appear to influence downstream signaling, potentially affecting proliferation and metastasis pathways . This suggests TINAGL1 may function as a ligand or co-factor in receptor-mediated signaling.

The protein's extracellular matrix (ECM) association indicates interactions with other ECM components that may modulate cell adhesion, migration, and tissue organization. Its structure suggests potential interactions with elements of the basement membrane, which would be consistent with its role in cell-matrix communication .

In adrenocortical cells, TINAGL1 has been implicated in mechanisms repressing CYP11B1 gene expression, suggesting involvement in transcriptional regulation pathways, though the exact signaling intermediates remain to be fully characterized .

For advanced investigation of TINAGL1 interaction networks, researchers should consider:

• Proteomics approaches to identify binding partners

• Phosphoproteomic analysis to determine effects on signaling cascades

• Transcriptomic profiling following TINAGL1 modulation to identify downstream effects

• Chromatin immunoprecipitation studies if nuclear interactions are suspected

What are the technical challenges in developing effective TINAGL1 knockout or knockdown models?

Creating effective TINAGL1 knockout or knockdown models presents several technical challenges that researchers should consider when designing experiments:

Complete Knockout Challenges:

• Embryonic lethality or severe developmental defects may complicate generation of viable knockout models, as suggested by TINAGL1's importance in embryonic development including heart and adrenal glands

• Infertility in knockout mice makes breeding and maintaining knockout lines difficult, potentially requiring heterozygous breeding schemes

Tissue-Specific and Inducible Systems:

• Development of conditional knockout systems (Cre-loxP) is recommended to circumvent embryonic lethality

• Temporal control using inducible systems (e.g., tetracycline-controlled transcriptional activation) allows study of TINAGL1 function at specific developmental stages or in adult tissues

RNAi and CRISPR Approaches:

• siRNA or shRNA approaches may achieve incomplete knockdown, necessitating validation of knockdown efficiency at both mRNA and protein levels

• CRISPR-Cas9 editing requires careful gRNA design to minimize off-target effects

• Verification of knockout by sequencing and functional assays is essential

Compensatory Mechanisms:

• Related proteins (particularly paralog TINAG) may compensate for TINAGL1 loss, potentially masking phenotypes

• Analysis of compensatory changes in gene expression should be incorporated into experimental design

Delivery Methods:

• For in vivo manipulation, determining appropriate delivery vectors (viral vectors, nanoparticles) for tissue-specific targeting

• Cell type-specific promoters may be necessary for targeted manipulation in complex tissues

Researchers should incorporate appropriate controls and validation steps to ensure the specificity and efficacy of their TINAGL1 manipulation strategy.

What are the most promising translational applications of TINAGL1 research in clinical medicine?

Several promising translational applications of TINAGL1 research are emerging in clinical medicine:

Biomarker for Ovarian Reserve Assessment:
The discovery that TINAGL1 levels are decreased in the follicular fluid of patients with diminished ovarian reserve (DOR) suggests significant potential as a novel biomarker for fertility assessment . This could provide an additional tool for clinicians evaluating patients with fertility concerns, potentially offering earlier or more accurate detection of DOR than current methods.

Cancer Diagnostics and Therapeutics:
TINAGL1's association with colorectal adenocarcinoma and its demonstrated ability to bind EGFR and integrins, influencing cancer proliferation and metastasis pathways , indicates potential applications in:

• Diagnostic or prognostic stratification of cancer patients

• Therapeutic targeting of TINAGL1-mediated pathways

• Development of TINAGL1-based compounds that could disrupt tumor progression

Reproductive Medicine Interventions:
The critical role of TINAGL1 in fertility, supported by evidence that TINAGL1 knockout mice are infertile , suggests potential therapeutic approaches for certain forms of infertility through:

• Modulation of TINAGL1 expression or activity

• Development of recombinant TINAGL1 supplementation strategies

• Screening for TINAGL1 genetic variants in unexplained infertility cases

Extracellular Matrix-Related Disorders:
As an extracellular matrix protein involved in cell adhesion, proliferation, migration, and differentiation , TINAGL1 may have relevance to conditions involving ECM dysfunction, potentially including fibrotic diseases or certain developmental disorders.

Future translational research should focus on validating these potential applications through larger clinical studies and deeper mechanistic investigations.

What methodological advances would accelerate understanding of TINAGL1's physiological functions?

Several methodological advances would significantly accelerate our understanding of TINAGL1's physiological functions:

Advanced Imaging Techniques:

• Implementation of super-resolution microscopy for precise localization of TINAGL1 within tissues and subcellular compartments

• Live-cell imaging with fluorescently tagged TINAGL1 to track dynamics in real-time

• Correlative light and electron microscopy to connect TINAGL1 localization with ultrastructural context

Single-Cell Analysis:

• Single-cell RNA sequencing to identify cell populations expressing TINAGL1 and characterize heterogeneity in expression patterns

• Single-cell proteomics to detect TINAGL1 protein levels and post-translational modifications at the individual cell level

• Spatial transcriptomics to map TINAGL1 expression within the architectural context of tissues

Structural Biology Approaches:

• Cryo-electron microscopy or X-ray crystallography of TINAGL1 to determine precise three-dimensional structure

• Structural studies of TINAGL1 in complex with binding partners to elucidate interaction mechanisms

• Molecular dynamics simulations to predict functional domains and binding interfaces

High-Throughput Functional Screening:

• CRISPR activation/inhibition screens to identify genes that modify TINAGL1 function

• Protein-protein interaction screens to map the complete TINAGL1 interactome

• Small molecule screening to identify compounds that modulate TINAGL1 expression or activity

Integrative Multi-Omics:

• Combined analysis of transcriptomics, proteomics, and metabolomics data following TINAGL1 modulation

• Integration of epigenetic profiling to understand TINAGL1 regulation

• Systems biology approaches to position TINAGL1 within broader biological networks

These methodological advances would provide a more comprehensive understanding of TINAGL1's diverse functions across different physiological contexts and potentially reveal new applications in both basic science and clinical medicine.