| Theme/Process | Proposed molecular role | Key experimental evidence (study type) | Quantitative/statistical highlights | Subcellular location/context | Key citations with year and URL |
|---|---|---|---|---|---|
| MAPR family identity, heme/CYP biology | Human PGRMC2 is a MAPR-family, single-pass membrane protein with a cytochrome b5-like heme/steroid-binding domain; proposed to participate in heme handling and modulation of cytochrome P450-dependent sterol/steroid pathways, while remaining distinct from PAQR/mPR 7TM membrane progesterone receptors | Expert reviews synthesizing structural, evolutionary, and biochemical literature; family/domain comparisons and CYP/heme interaction models | PGRMC2 reported as about 247 aa; function and localization are less well characterized than for PGRMC1; mechanistic claims remain partly inferential for PGRMC2 specifically | Membrane-associated; broadly intracellular and ER-related context; sperm expression also noted in review literature | Ryu 2017 Front Pharmacol. https://doi.org/10.3389/fphar.2017.00159; Mauvais-Jarvis et al. 2022 Endocr Rev. https://doi.org/10.1210/endrev/bnab041; Barata et al. 2024 J Xenobiot. https://doi.org/10.3390/jox14020034 (pqac-00000008, pqac-00000007, pqac-00000011) |
| Maternal-fetal interface immune homeostasis | Upstream regulator of HLA-G, inflammatory restraint, and mesenchymal-epithelial balance in chorion trophoblasts; supports barrier integrity at the chorio-decidual interface | CRISPR/Cas9 PGRMC2 knockout in immortalized human chorion trophoblast cells integrated into a two-chamber microfluidic CDi-on-chip with primary decidual cells and innate immune cells; cytokine assays, transcriptomics, phenotype markers | PGRMC2 KO increased inflammatory mediators including IL-6, IL-8, TNF-alpha, and GM-CSF after LPS challenge; transcriptomics showed suppression of adherens junction and cell adhesion pathways; some cytokine changes were described as 15-fold or greater in related KO contexts | Chorion trophoblast cells at the maternal-fetal membrane interface; epithelial-mesenchymal state and immune-cell interaction context | Lintao et al. 2024 Commun Biol. https://doi.org/10.1038/s42003-024-06740-2 (pqac-00000013, pqac-00000014, pqac-00000017) |
| Postmenopausal osteoporosis and biomarker-causal inference | Candidate protective factor linked to monocyte-macrophage biology and disulfidptosis-related osteoporosis mechanisms; potential biomarker and therapeutic target | Integrated bioinformatics, single-cell and bulk transcriptomic analyses, experimental validation in ovariectomized mice using Western blot and immunohistochemistry, plus two-sample Mendelian randomization | AUC = 0.665 for discrimination; MR OR = 0.6836, p = 0.0048; decreased PGRMC2 expression validated in OVX mice | Bone tissue immune and stromal context; enriched in macrophages versus monocytes; also present in BM-MSCs, osteoblasts, and adipocytes | Wang et al. 2024 Heliyon. https://doi.org/10.1016/j.heliyon.2024.e36570 (pqac-00000016, pqac-00000018, pqac-00000026) |
| Ciliogenesis and proliferation control | Supports primary cilia formation and restrains hyperproliferative behavior; implicated in cilia-linked cell-cycle regulation | Knockdown experiments with imaging and ISH-based localization framework in a ciliary biology study | Knockdown caused significant reduction in cilia number and cilia length and produced a hyperproliferative phenotype; no exact percentages were reported in the extracted text | Primary cilium and cell body or cell-cycle context | Alanazi et al. 2024 Front Cell Dev Biol. https://doi.org/10.3389/fcell.2024.1397931 (pqac-00000019) |
| Colorectal cancer expression change | Downregulated in CRC, suggesting loss of a normal epithelial-associated function and possible biomarker relevance rather than established oncogenic driver activity | Human tissue study comparing CRC versus normal mucosa using RT-PCR, immunohistochemistry, and optical-density quantification | mRNA significantly downregulated in CRC with p less than or equal to 0.01; protein significantly decreased in CRC with p less than or equal to 0.05; cohorts reported as NM n = 10 and CRC n = 20 | Cytoplasmic staining in both normal mucosa and CRC, but lower abundance in CRC | Kaminska et al. 2023 Cancers. https://doi.org/10.3390/cancers15205074 (pqac-00000021, pqac-00000022, pqac-00000024) |
| Heme allocation to CYP3A4 and CYP2D6 negative result | Tested hypothesis that PGRMC2 mediates mitochondrial heme allocation to ER drug-metabolizing CYPs; study argues against a required role in this system | HEK293T siRNA knockdown of PGRMC2 followed by tagged CYP3A4 and CYP2D6 expression and 14C-heme incorporation assays | PGRMC2 reduced by about 80 to 85 percent, yet no detectable change in CYP protein abundance or mitochondrial 14C-heme incorporation into CYP3A4 or CYP2D6 | ER-localized CYP maturation context in human cells | Islam et al. 2024 J Biol Chem. https://doi.org/10.1016/j.jbc.2024.105633 (pqac-00000020) |
| Disease-association landscape and translational signals | Human genetic and disease-platform evidence suggests broader links to ovarian neoplasm, neurodegenerative disease, neuroendocrine neoplasm, and type 2 diabetes, but evidence is heterogeneous and not yet target-validating clinically | Open Targets integration of literature and genetic-screen evidence; no interventional clinical trials were found in the retrieved search | Example Open Targets association scores: neurodegenerative disease 0.489, ovarian neoplasm 0.324, type 2 diabetes 0.325; retrieved clinical-trial search found no PGRMC2-directed trials | Cross-disease association layer rather than direct mechanistic localization | Open Targets platform query for PGRMC2 (current retrieval) (pqac-00000027) |


*Table: This table summarizes the main experimentally supported and review-based functional themes for human PGRMC2, emphasizing recent 2023-2024 studies plus core conceptual reviews. It highlights where evidence is strong, where results are negative or preliminary, and where translational relevance is emerging.*