PAQR7 Antibody

What is PAQR7 and what are its alternative nomenclatures in the scientific literature?

PAQR7, or Progestin and adipoQ receptor family member 7, is a membrane-bound progesterone receptor that mediates non-genomic progesterone signaling. In the scientific literature, PAQR7 is also known by several alternative names including MPRA, PGLP, mSR, membrane progestin receptor alpha, and 2310021M12Rik (in mice). The protein has a molecular weight of approximately 39.7 kilodaltons and plays crucial roles in reproductive physiology, particularly in ovarian function and granulosa cell apoptosis regulation. PAQR7 is part of the larger progestin and adipoQ receptor family that features seven transmembrane domains, though its structure differs from G protein-coupled receptors. Understanding these nomenclature variations is essential when searching literature and databases for PAQR7-related research .

What are the primary experimental applications for PAQR7 antibodies in reproductive biology research?

PAQR7 antibodies have multiple critical applications in reproductive biology research, with the most common techniques being Western blotting, immunofluorescence (IF), immunocytochemistry (ICC), and enzyme-linked immunosorbent assay (ELISA). In reproductive physiology studies, these antibodies are particularly valuable for investigating progesterone's non-genomic actions in granulosa cells, oocytes, and follicular development. Western blotting with PAQR7 antibodies enables quantification of expression levels across different reproductive tissues or under various hormonal treatments. Immunofluorescence and immunocytochemistry applications allow visualization of subcellular localization, especially important when studying membrane-associated progesterone signaling. For high-throughput screening, ELISA-based detection using PAQR7 antibodies provides quantitative analysis of expression levels across numerous samples. Additionally, these antibodies are instrumental in chromatin immunoprecipitation (ChIP) assays when investigating transcriptional regulation mechanisms associated with PAQR7 signaling pathways .

What species reactivity is available for commercially produced PAQR7 antibodies?

Commercial PAQR7 antibodies exhibit varied species reactivity profiles, which researchers must carefully consider when designing experiments. The majority of available antibodies show reactivity to human PAQR7, making them suitable for studies using human cell lines like KGN granulosa cells. Many antibodies also demonstrate cross-reactivity with mouse and rat orthologs, facilitating comparative studies across species. Some specialized antibodies provide expanded reactivity to include guinea pig, horse, and other mammals. When selecting PAQR7 antibodies for cross-species studies, it's essential to verify the specific epitope conservation across target species. The table below summarizes typical reactivity patterns found among commercial PAQR7 antibodies:

When designing studies involving less common research models, researchers should conduct preliminary validation experiments to confirm antibody specificity and performance .

What are the recommended protocols for validating the specificity of PAQR7 antibodies?

Validating PAQR7 antibody specificity is critical for ensuring experimental reliability, particularly given its membrane localization and multiple isoforms. A comprehensive validation approach should include multiple complementary techniques. Begin with western blotting using both positive control tissues (ovaries, granulosa cells) and negative controls (tissues with minimal PAQR7 expression or PAQR7 knockout samples). A specific PAQR7 antibody should detect a band at approximately 39.7 kDa. Perform peptide competition assays by pre-incubating the antibody with the immunizing peptide, which should eliminate specific binding. For genetic validation, compare staining patterns between wild-type samples and those with PAQR7 knockdown (siRNA) or knockout. This genetic approach is particularly valuable as demonstrated in recent studies where PAQR7 deficiency significantly affected KGN cell apoptosis patterns. Immunoprecipitation followed by mass spectrometry can provide additional confirmation of antibody specificity. Finally, correlate protein detection with mRNA expression through parallel qRT-PCR analysis. Document all validation steps meticulously, including images of western blots showing full molecular weight ranges, to provide complete transparency regarding antibody performance and specificity .

How should researchers design knockout/knockdown experiments to study PAQR7 function in reproductive contexts?

When designing knockout/knockdown experiments to study PAQR7 function in reproductive contexts, researchers should employ a multi-faceted approach combining both in vitro and in vivo models. For in vitro knockdown, siRNA transfection in human granulosa cell lines (such as KGN cells) has proven effective, with optimal transfection typically achieved at 60-70% cell confluence in 6-well plates using 2×10^5 cells. To eliminate confounding effects from endogenous progesterone, researchers should culture cells with charcoal/dextran-treated serum and consider adding aminoglutethimide (AG, 0.2 μM) to inhibit endogenous progesterone secretion. For rescue experiments, supplement with exogenous progesterone (1 μM) after PAQR7 knockdown to determine pathway specificity. For in vivo studies, PAQR7 knockout mouse models provide valuable insights into reproductive phenotypes. When analyzing these models, comprehensive assessment should include estrous cycle length monitoring, follicular development analysis, spontaneous ovulation quantification, and reproductive hormone profiling (particularly E2 and AMH). Histological examination of ovarian tissues should quantify primordial, primary, secondary, and antral follicles, as well as atretic follicles. Additionally, measure fertility parameters including litter frequency and size. For mechanistic insights, examine apoptosis markers in granulosa cells, particularly focusing on the BCL-2/BAX/CASPASE-3 pathway components that have been implicated in PAQR7-mediated anti-apoptotic effects .

What controls are essential when using PAQR7 antibodies for immunohistochemistry in reproductive tissues?

When conducting immunohistochemistry (IHC) with PAQR7 antibodies in reproductive tissues, implementing comprehensive controls is crucial for result interpretation and validation. Primary controls should include positive tissue controls—ovarian tissues are ideal as they express significant levels of PAQR7, particularly in granulosa cells of developing follicles. Negative tissue controls should use tissues known to have minimal PAQR7 expression or PAQR7 knockout tissues when available. Technical negative controls, omitting the primary antibody while maintaining all other staining steps, help distinguish between specific staining and background. Additionally, implement peptide competition controls by pre-incubating the antibody with excess immunizing peptide to confirm binding specificity. For reproductive tissues specifically, include different follicular stages in ovarian sections to demonstrate the expected differential expression pattern of PAQR7 across follicular development. When studying pathological conditions like decreased ovarian reserve (DOR), include age-matched normal ovarian tissues as comparative controls. For dual immunofluorescence studies, single-staining controls help identify potential spectral overlap. Finally, quantification controls using standardized positive controls should be included in each experimental batch to normalize for staining intensity variations between experiments. These robust controls ensure reliable interpretation of PAQR7 expression patterns in reproductive tissues and minimize the risk of artifacts or misinterpretation .

How can PAQR7 antibodies be used to investigate the BCL-2/BAX/CASPASE-3 signaling pathway in granulosa cell apoptosis?

PAQR7 antibodies can be strategically employed to elucidate the relationship between progesterone signaling and the BCL-2/BAX/CASPASE-3 apoptotic pathway in granulosa cells through several sophisticated approaches. Begin with co-immunoprecipitation experiments using PAQR7 antibodies to pull down protein complexes, followed by immunoblotting for BCL-2, BAX, and other pathway components to identify direct protein-protein interactions. Implement dual immunofluorescence staining with PAQR7 antibodies combined with antibodies against BCL-2, BAX, or cleaved CASPASE-3 to visualize co-localization patterns and potential translocation events during apoptotic signaling. For functional studies, combine PAQR7 knockdown/knockout approaches with Western blot analysis of BCL-2/BAX ratio and cleaved CASPASE-3 levels under varying progesterone concentrations. Recent research has demonstrated that PAQR7 deficiency significantly increases granulosa cell apoptosis, an effect that can be reversed with progesterone supplementation, suggesting PAQR7 mediates progesterone's anti-apoptotic effects. Time-course experiments are particularly valuable—treat cells with progesterone and collect samples at multiple time points (0, 15, 30, 60, 120 minutes) to track the temporal dynamics of PAQR7 activation and subsequent changes in BCL-2/BAX ratios. For pathway validation, use specific inhibitors of intermediate signaling molecules while monitoring PAQR7 and apoptotic marker expression. Additionally, chromatin immunoprecipitation (ChIP) assays using PAQR7 antibodies can identify potential genomic targets that influence BCL-2 and BAX expression. These comprehensive approaches can establish the precise mechanistic relationship between PAQR7-mediated progesterone signaling and granulosa cell survival .

What methodologies are most effective for studying PAQR7's role in ovarian aging and decreased ovarian reserve?

To effectively study PAQR7's role in ovarian aging and decreased ovarian reserve (DOR), researchers should implement a multi-dimensional approach combining clinical samples, animal models, and molecular techniques. For clinical studies, collect granulosa cells from follicular fluid obtained during IVF procedures from both DOR patients and age-matched controls with normal ovarian reserve. Quantify PAQR7 expression using Western blotting, immunofluorescence, and qRT-PCR to establish expression patterns across different patient populations, correlating with clinical parameters like follicle count, AMH levels, and reproductive outcomes. For animal models, utilize both naturally aged mice and chemically-induced DOR models (cyclophosphamide treatment) to compare PAQR7 expression patterns. PAQR7 knockout mice provide a valuable tool for studying accelerated follicular depletion and potential DOR phenotypes. Histological assessment should quantify follicle numbers at different developmental stages and measure markers of follicular atresia. Mechanistically, investigate the relationship between PAQR7 expression levels and markers of cellular senescence (p16, p21) and DNA damage (γH2AX) in granulosa cells. Single-cell RNA sequencing of ovarian cells from young versus aged subjects can reveal PAQR7-associated transcriptional networks that change during aging. Functionally, ex vivo culture of ovarian tissue fragments with PAQR7 modulators can assess effects on follicular survival and development. Recent research has demonstrated reduced PAQR7 expression in granulosa cells from DOR patients and DOR-like mouse models, suggesting PAQR7 downregulation may contribute to premature follicular atresia via increased apoptosis. These comprehensive approaches can elucidate PAQR7's potential as both a biomarker and therapeutic target in ovarian aging contexts .

How can researchers differentiate between genomic and non-genomic progesterone actions using PAQR7 antibodies?

Differentiating between genomic and non-genomic progesterone actions requires sophisticated experimental approaches centered around temporal dynamics, subcellular localization, and pathway specificity. To study non-genomic rapid signaling, perform time-course experiments using progesterone treatment with very short time intervals (30 seconds, 1, 2, 5, 10, 30 minutes) and use PAQR7 antibodies for immunoprecipitation followed by phosphorylation state analysis of downstream effectors like MAPK or PI3K. This approach captures rapid signaling events that occur too quickly to involve transcriptional changes. For subcellular fractionation studies, separate membrane, cytoplasmic, and nuclear fractions, then use PAQR7 antibodies in Western blots to track receptor localization and potential translocation following progesterone stimulation. Implement pharmacological approaches using membrane-impermeable progesterone conjugates (P4-BSA) that specifically activate membrane receptors like PAQR7 without entering cells to trigger genomic effects. Conversely, use selective nuclear progesterone receptor modulators to isolate genomic effects. For definitive differentiation, combine PAQR7 knockout/knockdown with gene expression profiling at both early (15-30 minutes) and late (4-24 hours) timepoints after progesterone treatment. Non-genomic effects will persist in the early timeframe despite transcriptional inhibition with actinomycin D, while genomic effects will be abolished. Additionally, proximity ligation assays using PAQR7 antibodies paired with antibodies against signal transduction proteins can visualize immediate protein-protein interactions triggered by progesterone. For comprehensive pathway analysis, use phospho-specific antibody arrays to simultaneously detect multiple signaling events following progesterone treatment in the presence or absence of PAQR7, helping distinguish between membrane-initiated and nuclear receptor-mediated signaling cascades .

Why might Western blots using PAQR7 antibodies show multiple bands, and how should these results be interpreted?

Multiple bands in Western blots using PAQR7 antibodies can arise from several biological and technical factors that require careful interpretation. Biologically, PAQR7 can undergo post-translational modifications including phosphorylation, glycosylation, and ubiquitination, resulting in bands of varying molecular weights. Additionally, alternative splicing of PAQR7 mRNA can generate different isoforms with distinct molecular weights. The primary band for PAQR7 should appear at approximately 39.7 kDa, with potential additional bands representing modified forms. Technically, incomplete protein denaturation can lead to dimers or oligomers presenting as higher molecular weight bands. Protein degradation during sample preparation may generate lower molecular weight fragments, while non-specific antibody binding can produce irrelevant bands. To differentiate between specific and non-specific bands, implement peptide competition assays and compare results with PAQR7 knockout/knockdown controls. When working with recombinant tagged PAQR7, additional bands may represent the tag alone or incomplete translation products. For proper interpretation, document the entire blot including molecular weight markers, and consider batch-to-batch antibody variations. Reference the antibody manufacturer's data sheet for expected banding patterns, as multiple bands may be normal for certain antibodies. If studying tissue-specific expression, remember that PAQR7 may exhibit different processing or modification patterns across tissues, particularly between reproductive and non-reproductive tissues. In cases where multiple bands persist despite optimization, consider using alternative PAQR7 antibodies targeting different epitopes to confirm band identity .

What approaches can resolve inconsistent staining patterns when using PAQR7 antibodies in immunohistochemistry?

Inconsistent staining patterns with PAQR7 antibodies in immunohistochemistry can be resolved through systematic troubleshooting addressing sample preparation, antibody conditions, and detection parameters. Optimize fixation protocols first, as PAQR7 is a membrane protein that may require specialized fixation to preserve epitope accessibility—compare results using different fixatives (4% paraformaldehyde, methanol, or acetone) and fixation durations. Implement antigen retrieval optimization by testing multiple methods (heat-induced epitope retrieval with citrate buffer pH 6.0 versus EDTA buffer pH 9.0, or enzymatic retrieval). For blocking conditions, test different blocking agents (5-10% normal serum, BSA, or commercial blocking reagents) to reduce background while preserving specific signal. Antibody dilution optimization should involve a titration series (typically 1:100 to 1:1000) to identify the optimal concentration that maximizes signal-to-noise ratio. If membrane staining is particularly challenging, consider membrane permeabilization methods using detergents like 0.1-0.3% Triton X-100 or 0.1% Tween-20, adjusting concentration and duration to enhance antibody access to membrane proteins without creating artifacts. For detection systems, compare different secondary antibodies and visualization methods (fluorescent vs. enzymatic), ensuring appropriate controls for each method. Verify staining specificity using peptide competition controls and PAQR7 knockout tissues. When working with ovarian tissues specifically, account for potential expression variations across different follicular stages and corpus luteum. For multiplex staining, sequential antibody application with intermediate blocking steps may help reduce cross-reactivity. Finally, standardize all protocol steps, including incubation times, temperatures, and washing procedures, and maintain detailed records of conditions that produce optimal and consistent results .

How should researchers interpret conflicting results between PAQR7 protein detection and mRNA expression analyses?

Discrepancies between PAQR7 protein and mRNA expression levels require careful scientific interpretation considering multiple biological and technical factors. Post-transcriptional regulation mechanisms, including microRNA-mediated repression and RNA-binding protein interactions, can significantly impact translation efficiency without affecting mRNA levels. Protein stability differences may also contribute—PAQR7 protein might undergo rapid turnover under certain physiological conditions despite robust mRNA expression. Conversely, the protein might exhibit extended half-life in some contexts, persisting even as mRNA levels decline. Methodologically, validate both protein and mRNA detection techniques independently. For protein detection, confirm antibody specificity through knockout/knockdown controls and appropriate positive controls. For mRNA analysis, verify primer specificity and efficiency through melt curve analysis and standard curves. Consider the timing of sample collection, as temporal delays between transcription and translation can create apparent discrepancies in rapidly changing physiological states like follicular development. Subcellular localization changes might affect protein detection without impacting mRNA measurements—PAQR7 may redistribute between membrane and intracellular compartments under different hormonal conditions. Additionally, examine tissue heterogeneity within samples; bulk tissue analysis might mask cell type-specific expression patterns. When studying PAQR7 in reproductive tissues specifically, account for cycle-dependent expression patterns and potential regulation by steroid hormones. For comprehensive analysis, complement traditional methods with in situ approaches like RNAscope (for mRNA) and immunohistochemistry (for protein) on sequential sections to visualize expression patterns at the cellular level. These combined approaches can help reconcile apparent discrepancies and provide insight into the complex regulation of PAQR7 expression in reproductive physiology .

How can PAQR7 antibodies be utilized to investigate potential crosstalk between progesterone and adiponectin signaling pathways?

PAQR7 antibodies can be strategically employed to investigate the intriguing crosstalk between progesterone and adiponectin signaling pathways through several sophisticated experimental approaches. Begin with co-immunoprecipitation studies using PAQR7 antibodies to pull down protein complexes, followed by immunoblotting for adiponectin receptors (AdipoR1/AdipoR2) and shared downstream effectors to identify physical interactions or complexes. Implement proximity ligation assays (PLA) using paired antibodies against PAQR7 and adiponectin receptors to visualize and quantify protein interactions at the single-molecule level within intact cells. For signaling pathway investigation, stimulate cells with progesterone or adiponectin independently and in combination, then use phospho-specific antibodies against common downstream targets (AMPK, mTOR, PI3K) alongside PAQR7 immunoprecipitation to track pathway activation dynamics. Perform siRNA-mediated knockdown of PAQR7 followed by adiponectin stimulation to assess whether PAQR7 influences adiponectin signaling efficiency. Conversely, manipulate adiponectin receptor expression and evaluate effects on progesterone-induced PAQR7 signaling. For transcriptional regulation analysis, use ChIP-seq with PAQR7 antibodies after progesterone and/or adiponectin treatment to identify genomic binding sites and potential convergent gene regulation. In reproductive tissues specifically, implement dual immunofluorescence for PAQR7 and adiponectin receptors across different stages of follicular development and corpus luteum formation to map expression pattern overlap. For functional assessment, measure metabolic parameters (glucose uptake, fatty acid oxidation) and apoptotic markers in response to progesterone and adiponectin in wild-type versus PAQR7-deficient cells. These multifaceted approaches can reveal whether PAQR7 represents a molecular integration point between reproductive hormone signaling and metabolic regulation, potentially explaining clinical associations between metabolic disorders and reproductive dysfunction .

What methods are recommended for investigating PAQR7's role in non-reproductive tissues and pathologies?

Investigating PAQR7's role in non-reproductive tissues and pathologies requires tailored methodological approaches that account for tissue-specific expression patterns and potential functions beyond reproductive physiology. Begin with comprehensive tissue expression profiling using validated PAQR7 antibodies across multiple human and animal tissues through Western blotting, immunohistochemistry, and qRT-PCR to establish baseline expression patterns beyond the reproductive system. Focus particularly on tissues with potential progesterone responsiveness, including the nervous system, immune cells, and adipose tissue. For functional studies, generate tissue-specific PAQR7 knockout models using Cre-loxP systems targeting non-reproductive tissues of interest, allowing assessment of tissue-specific phenotypes without reproductive system confounders. In cancer research contexts, analyze PAQR7 expression across tumor types and correlate with prognostic markers and patient outcomes using tissue microarrays with PAQR7 antibodies. For mechanistic studies, perform phosphoproteomic analysis after progesterone stimulation in non-reproductive cell types expressing PAQR7 to identify tissue-specific signaling pathways. Implement single-cell RNA sequencing of tissues with heterogeneous cell populations (such as brain or immune tissues) to identify specific cell types expressing PAQR7 and correlate with functional cell markers. For translational applications, develop cell-based screening assays using PAQR7 antibodies to identify tissue-specific modulators of PAQR7 activity. In inflammatory conditions, evaluate PAQR7 expression in relation to inflammatory markers and assess progesterone's anti-inflammatory effects in wild-type versus PAQR7-deficient models. Additionally, investigate potential metabolic functions by analyzing PAQR7 expression in metabolic disorders and assessing parameters like insulin sensitivity and lipid metabolism in tissue-specific PAQR7 knockout models. These systematic approaches can uncover novel roles for PAQR7 beyond reproduction and potentially identify new therapeutic targets for non-reproductive pathologies .

What are the most promising future research directions for PAQR7 antibody applications in reproductive medicine?

The future of PAQR7 antibody applications in reproductive medicine shows exceptional promise across several innovative research directions. Single-cell proteomics represents a frontier technology where PAQR7 antibodies could enable precise mapping of expression patterns at the individual cell level throughout follicular development, potentially revealing previously unrecognized heterogeneity in granulosa cell populations with distinct progesterone responsiveness. Therapeutic antibody development targeting PAQR7's extracellular domains may provide novel approaches for modulating non-genomic progesterone signaling in conditions like decreased ovarian reserve, where PAQR7 expression appears diminished. In clinical diagnostics, developing standardized immunoassays for PAQR7 detection in follicular fluid or granulosa cells could establish new biomarkers for ovarian reserve assessment and IVF outcome prediction. For precision medicine applications, correlating PAQR7 expression patterns with patient-specific responses to fertility treatments may enable personalized therapeutic approaches. Advanced tissue engineering approaches incorporating PAQR7-positive cells within artificial ovarian constructs could potentially advance fertility preservation strategies. In the emerging field of extracellular vesicle research, PAQR7 antibodies could help characterize vesicle cargo from follicular fluid, potentially identifying novel intercellular communication mechanisms during folliculogenesis. Multiplexed imaging technologies combining PAQR7 antibodies with spatial transcriptomics could create comprehensive maps of receptor distribution and associated gene expression patterns across intact ovarian tissues. Additionally, investigating PAQR7's role in oocyte-somatic cell communication through selective inhibition in different follicular compartments represents an exciting research direction. These innovative approaches have potential to transform our understanding of reproductive physiology and develop novel interventions for conditions ranging from infertility to premature ovarian insufficiency .